Proceedings of the IEEK Conference (대한전자공학회:학술대회논문집)
The Institute of Electronics and Information Engineers (IEIE)
- 기타
2006.06a
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Fast IP address lookup in routers is essential to achieve packet forwarding in wire-speed. The longest prefix matching for IP address lookup is more complex than exact matching because of its dual dimensions, length and value. By thoroughly studying the current proposals for IP address lookup, we find out that the binary search could be a low-cost solution while providing high performance. Most of the existing binary search algorithms based on trie have simple data structures which can be easily implemented, but they have some problems because of empty internal nodes. The proposed algorithm is based on trie structure, but empty internal nodes are replaced by priority prefixes. The best-matching-prefix search in the proposed algorithm is more efficiently performed since search can be finished earlier when input is matched with a priority prefix. The performance evaluation results show that the constructed priority-trie has very good performance in the lookup speed and the scalability.
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iSCSI is a block-oriented storage access protocol that enables a user to recognize a remote storage as their own local block device through general TCP/IP networks. This paper presents an alternative approach to overcome the limited storage space of mobile devices based on the iSCSI initiator driver in IPv6 environment, which was originally designed for wired networks.
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F-HMIPv6 is protocol that supports fast handovers for Hierarchical Mobile IPv6. Unlike HMIPv6 (Hierarchical Mobile IPv6), it sends FBU(Fast Binding Update) by predicted Router's Information for a potential handover. But, The current version of this protocol doesn't ensure impeccably between mobile node and router. To make up for the weak points of the security, we propose the architecture for F-HMIPv6 protocol to structurally reinforce the security and improve weak security of among mobile node, MAP(Mobility Anchor Point), and routers for binding update when mobile node conducts handovers.
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This paper proposes a linking protocol which supports the data transmission among PANs. Proposed protocol supports backward compatibility and scalability, while does not affect the topology and address of the linked PANs.
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An algorithm to improve the efficiency of the hierarchical routing in ZigBee Networks is proposed. By forwarding the data to the nearest neighbor in the hierarchy, more efficient path can be achieved without any control and memory overhead. Simulation results shows the proposed algorithm provides about 20% shorter path.
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In this paper, an efficient butterfly structure for Radix-4 FFT algorithm using DA(Distributed Arithmetic) is proposed. It is shown that DA can be efficiently used in twiddle factor calculation of the Radix-4 FFT algorithm. The Verilog-HDL coding results for the proposed DA butterfly structure show 61.02% cell area reduction comparison with those of the conventional multiplier butterfly structure. Furthermore, the 64-point Radix-4 pipeline structure using the proposed butterfly and delay commutators is compared with other conventional structures. Implementation coding results show 46.1% cell area reduction.
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In this paper, we propose an adaptive SLM scheme based on peak observation for PAPR reduction of OFDM signals. The proposed scheme is composed of three steps: peak scaling, sequence selection, and SLM procedures. In the first step, the peak signal samples in the IFFT outputs of the original input sequence are scaled down. In the second step, the sub-carrier positions where power difference between the original input sequence and the FFT outputs of the scaled signal is large, are identified. Then, the phase sequences which have the maximum number of phase-reversed sequence words only for these positions, are selected. Finally, only using the selected phase sequences, the generic SLM procedure is performed for the original input sequence. Simulation results reveal that the proposed adaptive SLM remarkably reduces the complexity in terms of IFFT and PAPR calculations than the conventional SLM, while maintaining the PAPR reduction performance.
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In this paper, we propose a robust detection scheme of OSTBCs with channel estimation errors over time-selective fading channels. Channel estimation errors are inevitable over time-selective fading channels and even small channel estimation errors dramatically degrade the performance of space-time block coding schemes. Therefore, it is desired to investigate the effect of channel estimation errors on the performance of the proposed detection scheme compared with the existing detection scheme. The proposed detection scheme minimizes noise enhancement and impact of channel estimation errors which occur in an existing detection scheme. It is shown by simulations that the proposed detection scheme performs better than the existing detection scheme over time-selective fading channels.
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In this paper, to reduce uplink feedback information for the beam weight and simultaneously maintaining the performance, we propose a MIMO-OFDM (Multi Input Multi Output-Orthogonal Frequency Division Multiplexing) system based on beamforming with antenna selection. In the proposed system, to perform the beamforming with more useful transmit antennas, the optimal combination of transmit antennas with maximum MRT (Maximum Ratio Transmission) beamforming gain is selected. Simulation results reveal that the proposed MIMO-OFDM system adopting the beamforming with antenna selection can reduce the feedback information for the beam weights as compared to the system using all the transmit antennas without serious degradation of system performance.
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In this paper, to improve OFDM PAPR reduction performance of the conventional SLM method, we propose an effective SLM-PRSC hybrid scheme based on the repeated utilization of identical PRSC sequences in time domain. In the proposed scheme, after performing the SLM for the frequency domain OFDM symbol excluding the pre-determined PRSC positions, the final SLM-PRSC hybrid sequence with the lowest PAPR, which is generated by adding the time domain PRSC sequence to the results of the SLM is selected as the transmitted OFDM symbol. In particular, since the identical PRSC sequences generated a priori are repeatedly used for every OFDM symbol, excessive IFFT calculations are avoided. Moreover, the selected PRSC symbols in the frequency domain may be utilized as an overhead information for the SLM. Simulation results reveal that the proposed SLM-PRSC hybrid scheme can remarkably improve the PAPR reduction performance of the conventional SLM, while avoiding excessive increase of IFFT and PAPR calculations and the overhead for the SLM.
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Choi, Yoon-Ho;Park, Jong-Ho;Kim, Sang-Kon;Seo, Seung-U;Kang, Yu;Choi, Jin-Gi;Moon, Ho-Gun;Lee, Myung-Su 33
Computer Forensics is a research area which finds the malicious users by collecting and analyzing the intrusion or infringement evidence of the computer crime. Many research about Computer Forensics has been done. But those research have focussed on how to collect the evidence after receiving the damage reports from computer users or network administrators. This paper describes about collecting the evidence of good quality at the time of infringement occurrence by the malicious user. By calculating Infringement severity of observable and protective hosts and referring to this value, we collect the evidence at the time of infringement occurrence to minimize the information modification of the evidence. We can reduce also the amount of logs that we use to analyze the infringement and can minimize the loss of the evidence. -
This paper presents an effective multiplier in GF(
$2^m$ ) based on programmable cellular automata (PCA) and uses a normal basis. The proposed architecture has the advantage of high regularity and a reduced latency. The proposed architecture can be used in the effectual hardware design of exponentiation, division, inversion architectures. -
In this paper, we describe a security problem of IPsec. And we propose a solution for this problem. The problem is a fragility of IPsec Gateway which is used in tunnel mode. The role of IPsec Gateway is encrypting or decrypting IPsec packets. Because of the role of IPsec Gateway, IPsec Gateway suffers overhead for decrypting numerous packets. Adversaries can easily attack IPsec Gateway using a DDoS attack. To solve this problem, we propose the "Priority based Random Packet Drop" method. In this method, the white list which is a list of normal users is created. After that, according to the frequency of uses, the method marks priorities of random drops to the white list. If anomalous traffic appeared, this method will drop many packets which consist of anomalous traffic. In simple experiment, we show our solution is proper to defend IPsec Gateway. For this experiment, we use empirical backbone traffic which includes DoS attacks.
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This paper modeled UWB system transmission channel in indoor environment. For channel modeling, we extracted transmission channel parameter, and then measured from 10MHz to 16.01GHz by using method of CIR(Channel Impulse Response) and CTF(Channel Transfer Function) in small room(
$5.5{\times}5.5m^2$ ) environment. -
In this paper, we propose a rapid asynchronous UWB (Ultra Wide Band) position location scheme based on double RTTs (Round-Trip Transmissions). In the proposed scheme, to avoid performance degradation of the position location in harsh multipath channel environments where LoS (Line-of-Sight) components are not always guaranteed, the remaining RTT information is solved from realistic double RTTs. Simulation results in IEEE 802.15.4a UWB channel models reveal that the proposed scheme can achieve closely comparable position location accuracy of the conventional ToA (Time of Arrival) method based on triple RTTs, while reducing the processing delay required for the calculation of the position locations.
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In this paper modeled UWB system transmission channel in apartment environment while furniture and household electric appliance etc. existed. We measured from 10MHz to 16.01GHz by using method of CIR and CTF in both LOS and NLOS environment. Also we design channel model simulator by MATLAB. The Result of Simulation shows BER characteristics by SNR.
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An ultrawide bandpass filter with sharp rejection and wider stopband is designed and implemented using multilayer ceramic configuration. The proposed filter is composed of a broadside coupled structure and a ring type filter with an embedded stripline stub. The measured results show that the fractional bandwidth and upper stopband of the proposed filter are 106 % and better than -30 dB, respectively. The insertion loss is less than 1 dB, and group delay is less than 0.3 ns in the passband. In addition, ring and broadside coupled gap structures are characterized and compared to the proposed structure.
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In this paper, we analyze the impact of superframe order on the performance of the IEEE 802.15.4 slotted CSMA/CA. A new analytic model to evaluate the saturation throughput is proposed. The new model describes slot time behaviors of the IEEE 802.15.4 slotted CSMA/CA. The proposed model is validated via the comparison with ns-2 simulation results.
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Digital satellite systems are usually integrated with terrestrial systems to provide various services, and in these cases they should satisfy the performance objectives defined by the terrestrial systems. Recommendation ITU-R S.1062 specifies the performance of digital satellite systems. The performance objectives were given in terms of bit error probability divided by the average number of errors per burst versus percentage of time. This paper presents theoretical method to estimate performance measure of digital satellite systems defined in Recommendation ITU-R S.1062. We show performance estimation results of duo-binary Turbo codes, and verify them by comparing to the simulation results.
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In this paper, we propose an efficient video streaming method to improve quality of service (QoS) over wireless 3G network. In the proposed method, the video stream is adopted in various available bandwidth (AB) using dynamic frame skipping (DFS). In addition, error concealment (EC)compensates the video degradation by transmitting the MVs of the skipped frame. Experimental results indicate that the proposed method provides better QoS for video stream than the conventional methods.
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In this paper, we analytically evaluate packet delay and energy consumption of S-MAC protocol with a modified Markov chain model. Although some models, based on IEEE 802.11 MAC protocol, to analyze the S-MAC protocol in wireless sensor network (WSN) have been proposed, they fail to consider the differences in architecture between the S-MAC and the 802.11 MAC. Therefore, by reflecting the significant features in the S-MAC function, we model the operation of S-MAC protocol, and derive its packet delay and energy consumption in single-hop WSN. Numerical results show the delay and the dissipated energy at various duty cycle values according to offered load, where a practical mote is used.
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Directional antennas are used to improve spatial reuse, but have the problem of deafness. The DUDMAC protocol uses the ORTS, OCTS, DDATA, and DACK mechanisms and a blocking algorithm for directional transmissions. In this paper, we propose a tone dual-channel directional MAC (Tone DUDMAC) protocol to improve spatial reuse. The Tone DUDMAC protocol uses the ORTS, DCTS, DDATA, and DACK mechanisms including the DDATA_tone and OCTS_tone. We use ORTS as that in DUDMAC because of location unawareness of neighbor's nodes. The DDATA_tone and OCTS_tone reduce a blocking area and improve spatial reuse. We confirm the throughput performance of the proposed MAC protocol by computer simulations using Qualnet ver.3.8 simulator.
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Ad hoc MAC protocols using directional antennas can be used to improve the network capacity by improving spatial reuse. But, the directional MAC protocols have the problem of deafness and have a poor throughput performance. The dual-channel DMAC protocol has been proposed to mitigate deafness and improve spatial reuse. In this paper, we propose a dual-channel DMAC protocol using the omnidirectional antenna for an out-of-band tone and directional antennas for control/data channels. In the proposed MAC protocol, an omnidirectional out-of-band tone mitigates deafness and directional antennas used in control/data channels improve spatial reuse and reduce interference packets. The throughput performance of the proposed MAC protocol is confirmed by computer simulations using Qualnet ver. 3.8 simulator.
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TCP applied to the wireless-wired integrated network is the one that was applied to the existing wired network. In the wireless-wired integrated network, both wireless and congestion loss can occur. When wireless packet losses occur, the congestion control of TCP causes performance degradation by reducing its transmission rate. In this paper, we propose the algorithm to distinguish the wireless packet loss from congestion packet loss using MIB of the 802.11 MAC which has been generally used recently in wireless links.
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In this paper, using Bianchi's model with channel idle probability we analyze performance of power management scheme of IEEE 802.11 DCF according to ATIM window size and number of nodes for wireless ad hoc networks. The analytical results show that, when the number of nodes is given, the selected ATIM window size limits the performance.
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In this paper, the open loop antenna using a strip-conductor for an RFID reader at dual-band frequency(910MHz, 2.45GHz) is proposed. The impedance is matched by varying the antenna parameters such as the length of strip-conductor and the gap of between two strip-conductors. Return loss and gain of designed antenna are -11.919dB, 2.5dBi at 910MHz, and -15.766dB, 5.65dBi at 2.45GHz, respectively.
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In this paper, we designed and fabricated a broadband antenna for EMI site validation above 1 GHz. To develop the antenna which is satisfied omni-directional radiation pattern and broadband characteristics required by CISPR, we designed biconical type with cylindrical load. The developed antenna has good characteristics of the radiation patterns and VSWR<2 the frequency range from 1 GHz to 18 GHz.
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A suspended microstrip line structure over mushroom-like SMPs is designed and is applied to a dual-frequency and dual-polarization microstrip patch antenna. This structure has a distinctive and sharp rejection band and provides near 0 dB insertion loss outside the rejection band. Applying the structure to the conventional DFDP antenna enhanced the isolation between the two ports more than 20 dB. The structure is expected to have a wide range of applications in antennas and filters due to its compactness and integrability in circuits.
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Air-guided single-mode propagation of THz radiation in a photonic crystal waveguide (PCW) has been experimentally demonstrated for the first time. The PCW has been fabricated by introducing an air defect at the center of an air/Si 1D photonic crystal. By using a THz time-domain spectroscopic technique, we have experimentally shown that the guiding mechanism of the air-guiding PCW is the photonic bandgap effect.
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In this paper, we designed and fabricated the Doherty power amplifier which operates at 2140 MHz by using MRF 21125 RF Power FET (Motorola Co.) and Teflon substrate (
${\varepsilon}_r$ =2.55, H=0.76 mm, t=$70{\mu}m$ ,$tan{\delta}$ =0.001). As a result, we obtained th improved efficiency and linearity in comparison with the conventional balanced amplifier. -
In this paper, we designed, constructed and evaluated the system for the FTTH suited to a residence and apartment using CWDM-PON techniques. These systems have capacity to service at 100Mbps rate to 384 users in the same breath. Also, the services include the internet, CATV, IPTV and wireless LAN. In the case of wire network, the data could be transmitted by UTP cable and optical fiber and case of wireless one, the data transmitted using WLAN. The distance between the cental office and the user is 20km and the data rate is 100Mbps maximum. Of course, the optical network used just one fiber optical core. For the basic material, we obtained the characteristics of optical transceiver module, Mux/Demux and transmission qualities depends on the environment.
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A new broadcasting standard for Digital Multimedia Broadcasting(DMB) has been announced in Korea to provide audio, video, and data broadcasting services. There exist two types of DMB; terrestrial DMB and satellite DMB. And in order to service DMB on the single system, the integration of RF module is required. In this paper, we describe an integrated RF tuner module that can receive T-DMB and S-DMB at the same time, which includes an L-band down-converter, a Band III tuner, and a S-DMB tuner.
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This paper presents a signal quality estimation technique for QAM modulation systems. By making a LUT(Look-up table) putting the number of N enough, we can derive estimated SNR from LUT even though N is small. That is so called MOTM algorithm. In 16-QAM, the distance
$d_a$ , between adjacent symbols is always invariable, so absolute value of R(the amplitude of signal) minus$d_a$ has a always same signal distribution value. This value does not form a Gaussian shape but, by making a little bit correction, we can make this symmetrical. So, from the received symbol value, by using LUT we can easily derive the estimated SNR. By considering this, we introduce a signal quality estimation technique for QAM schemes. This proposed method can be applicable to high order modulation schemes and wide range of signal to noise ratio. -
In this paper, we compare two different anti-jamming schemes, Subspace projection and SCORE algorithm. For multipath cancelation, nulling technique is applied to both anti-jamming schemes. It is noted that SCORE algorithm is more robust to the multipath interference. It is also noted that Subspace projection scheme requires nulling technique for multipath mitigation.
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Most work on cooperative diversity has assumed that the cooperating group (source and partners) and the associated average channel conditions between terminals (source, partners, and destination) are predetermined. In practical situations, however, it is important to develop the efficient algorithms for assigning the terminals with good inter-user channels for cooperating groups. In this paper, we propose the partner assignment algorithm for cooperative diversity in mobile communication systems. The proposed partner assignment algorithm is investigated by using the path loss model for mobile communication systems. Numerical results show that the proposed partner assignment algorithm provides the comparable probability of cooperative transmission to the partner assignment algorithm using exhaustive search. The probability of cooperative transmission increases with the number of users, which gives potential benefits of practical implementation to user cooperation in mobile communication systems.
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In this paper, we introduce the AF cooperative diversity with multiple relays using phase feedback. Simulation results show that the proposed schemes obtain the diversity gain according to the number of the cooperating terminals. The performance of proposed scheme using tolerable quantized feedback is close to that of proposed scheme using full feedback.
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In this paper, we propose an adaptive turbo system for a varying channel between being frequency-flat and frequency-selective. The proposed system unites a turbo code and a turbo equalization and selects one of two algorithms adaptively to the channel variation with the feedback information from the receiver. The performance of the proposed system in varying channel is evaluated by computer simulation when the feedback delay exists. It is shown that when the feedback delay is moderate, the proposed system outperforms both the conventional turbo code system and turbo equalization system without increasing the complexity.
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In this paper, we propose a new selective scanning scheme based on hand-off path information, which can provide an efficient reducing of delay time. This scheme eliminates almost of the scanning delay time by using Selective Scan based on Experience Path Table(SSEPT) algorithm and also completed hand-off within few milliseconds by using the next candidate channel indexing mechanism. Our scheme reduces the total number of scanning channels as well as the delay time on each channel. From the simulation result, we show that the proposed scheme is advantageous over the legacy schemes in terms of the scanning channels and the total delay time.
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In this paper, the performances of the IEEE 802.15.4 under the IEEE 802.11b interference are compared under two kinds of channel sensing mechanisms: carrier sense (CS) and energy detection (ED). For each channel sensing mechanism, the average transmission delay, and the throughput are used as performance measures.
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In this paper, we propose a technical standard that applies to the MNP between 2G and 3G. We define network function, system function and information flow for MNP. We designed call processing mechanism for MNP by QoR. We also define the processing method of SMS according to the MNP.
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A variety of systems have been attempted for effective urban management. In this paper, we introduce integrated urban management system (IUMS), which mainly consists of optical line terminal (OLT), optical network terminal (ONTs) and wireless access points (APs), by combining passive optical network (PON) and radio over fiber (RoF) technologies so as to take advantages of both two systems. Further, several IUMS services including disaster detection and prevention system (DDPS), bus information system (BIS) and real time location system (RTLS) are demonstrated in order to employ IUMS for the realization of future ubiquitous city (U-city).
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Fusion of decisions from multiple distributed sensor nodes is studied in this work. Based on the canonical parallel fusion model, we derive the optimal likelihood ratio based fusion rule with the assumptions of the generalized Gaussian noise model and the arbitrary fading channel. This optimal fusion rule, however, requires the complete knowledge of the channels and the detection performance of local sensor nodes. To mitigate these requirements and to provide near optimum performance, we derive suboptimum fusion rules by using high and low signal-to-noise ratio (SNR) approximations to the optimal fusion rule. Performance evaluation is conducted through simulations.
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One of the fundamental problems in sensor networks is the deployment of sensor nodes. The Fuzzy C-Means(FCM) clustering algorithm is proposed to determine the optimum location and minimum number of sensor nodes for the specific application space. We performed a simulation using two dimensional L shape model. The actual length of the L shape model is about 100m each. We found the minimum number of 15 nodes are sufficient for the complete coverage of modeled area. We also found the optimum location of each nodes. The real deploy experiment using 15 sensor nodes shows the 95.7%. error free communication rate.
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Similar to Orthogonal Frequency Division Multiplexing (OFDM), a Single Carrier with Frequency Domain Equalization (SC-FDE) system is computationally efficient since equalization is performed on a block of data in the frequency domain. In coherent QAM schemes, the mean phase rotation error caused by the residual carrier frequency offset may lead to serious degradation. When the frequency equalizer is combined with the mean phase error tracking algorithm, its performance can be enhanced noticeably.
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In this paper, we analyze the UAV datalink design with calculating link budget of long-distance (200 km) Ku-band LOS wireless link. We calculate C/N of the real system and compare it with the required C/N, using the CCIR reports. In the rainy day of summer on the Korean peninsula, to maintain percent reliability 90% and BER 10^(-5) together, link budget of uplink of the system has a lot of margin at 200 km, link budget of downlink using the block turbo code is enough for distance 200 km.
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It is important to identify the exact target optical cable that a worker look for when he executes a cable construction work. Until now, An Optical cable identification work has been done by a manual pulling of an optical cable or by the method of using RF signals. But these methods not only consume much time and labor costs but also have a distance limit of the optical cable to identify. In this paper, we propose a method that uses the phase change signal of the optical interferometer to identify an optical cable. With the proposed method the field worker can have an efficient tool to prevent miscutting the optical cable and can also save operating costs.
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In order to meet the customers'emerging demands for more bandwidth and diverse IP multimedia applications including high definition(HD) video streaming service, KT presents innovative FTTP solution using WDM-PON system. FTTP comprises an OLT inside the central office, a fiber optic distribution network including a passive remote node in the outside plant, and ONU installed on the pole or wall of customers premise. The passive remote node is located in a manhole near the subscribers and does not require any electrical power supply. And finally, UTP cable is connected from ONU to subscribers'IP appliances like PC or HGW or IP-STB. KT finished its FTTP trial service in 2004 and commercial deployment has begun since 2005. With this FTTP solution, each subscriber can enjoy high-speed internet service with speeds of up to symmetric 100 Mbit/s and various IP media applications including HD quality IP video streaming service and high quality video phone service.
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We propose a data rate increasing technique for T-DMB (terrestrial digital multimedia broadcasting) system. With the application of hierarchical modulation, it is possible to increase data rate and improve services. We conducted the performance analysis of the proposed hierarchical modulation in AWGN channel and showed the BER analysis. The simulation results show that the proposed method shows possibilities to increase the data rate with a moderate degradation of the existing system.
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In this paper, dual-gate mixer has been designed and optimized to have variable conversion gain for WiBro and WLAN applications and to save power. With the LO power of 0dBm and RF power of -50dBm, the mixer shows 15dB conversion gain. When RF power increases from -50dBm to -20dBm, the conversion gain decreases to -2dB with bias change. The variable conversion gain can reduce the high dynamic range requirement of AGC burden at IF stage. Also, it can save the dc power dissipation of mixer up to 90%.
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UWB 시스템은 실내 LBS 에 가장 유망한 기술로 각광받고 있다. 그러나 실내건물을 이루는 손실성 매질로 인해서 신호에 지연이 발생, 거리오차가 발생하게 된다. 본 문제를 해결하기 위해서 공기중의 채널과 매질의 채널정보를 통해서, 신호의 지연을 추정하려고 하였다. 신호의 스팩트럼의 주파수에 관한 손실기울기는 투과한 매질의 두께에 비례하여, 깊어진다는 것을 사용하여, 매질 투과로 인한 신호의 지연시간을 추정하는 기술과 손실기울기를 측정하기 위한 RAKE 수신기를 소개한다.
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Recently, the fusion of communication and broadcasting surfaces streaming service such as IPTV with killer application of BcN. In this paper, Premium IP multicast is called as transport service technology that transfer streaming service such as IPTV through integrated, controllable, maintainable network in order to guarantee end-to-end QoS to predefined person. It capacitates billing of multicast service instead of network operator guarantees high quality QoS to subscriber. So, network operators are able to create benefits and find benefit models. The other side, subscribers can use various high quality streaming services.
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In this paper, we suggest postal RFID adaptation model, tag data structure and code which can be used for real time trace and track of parcel processing and pallet management. This paper also shows postal RFID application system architecture and testbed based on the proposed tag data structure and code, and shows recognition performance of tag on parcel and pallet by speed and mounting tag material such as can, water, and paper using implemented postal RFID system for postal logistics. The contribution of this paper is to stimulate deployment of RFID technology for postal logistics service and SCM (Supply Chain Management).
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In this paper, a zigbee system is based on IEEE 802.15.4 is a technology. It is a wireless communication and Ubiquitous Sensor Network which we have been concern about. It attempts to provide a low data rate, low power, low cost and short sensor wireless networking on the device-level communication. These devices are likely to operate in offices and factories. In this paper, we introduce some receiver schemes and show a BER performance.
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This paper investigates an efficient pre-equalization technique that can be applied on the up-link of a time division duplex (TDD) orthogonal frequency division multiplexing (OFDM) systems. This technique provides the spectral efficiency by omitting the usage of training sequences on the up-link. In this paper, the performance of a variety of pre-equalization techniques is analyzed and simulations are performed by applying power efficient pre-equalization algorithms with phase and amplitude & phase pre-equalization in the Rayleigh fading channel.
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본 논문에서는 주파수 오차가 큰 IEEE 802.15.4 시스템에서의 프레임 동기 및 주파수 추정기법을 제안한다. 주파수 오차의 영향을 제거하기 위해 coherent 방식이 아닌 non-coherent 방식의 프레임 동기가 요구된다. 차등 신호와 절대값을 이용하여 주파수 옵셋의 영향을 완벽히 제거한 프레임 동기를 제안하였다. 그리고 주파수 옵셋 추정의 분산을 줄이기 위한 over-sampling 주기의 주파수 옵셋 검출 기법을 제안하였다.
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In this paper, we propose a novel signaling method using chirp signals in UWB radio with satisfaction of FCC regulation. Chirp signals have been used in many ranging systems such as radar because of its good correlation properties. Because it is important to use broader signal bandwidth in order to get higher precision of the ranging, according to the Cramer-Rao Lower Bound, UWB radio is extremely good as the ranging systems. But, it is very difficult to apply existing chirp signals to UWB, because FCC regulates that the systems operating in UWB radio must occupy signal bandwidth more than 500MHz on the condition of stopping the frequency sweeping. So, we propose multiple chirp signals which can satisfy the regulation of FCC while maintaining chirp signal's properties. The multiple chirp signals which are composed of the sub-chirps modulated by sub-carriers can expand the signal bandwidth with the same principle of OFDM systems. The simulation results show that the BER performance of the proposed multiple chirp signals is identical to that of conventional OFDM when it is applied to data communication, and that the correlation properties of the proposed signals are almost the same with properties as those of single chirp signals whose sweeping bandwidth is the same value with the proposed one.
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As the research of wireless personal area network (WPAN) is more activated, various communication systems operating on 2.4Ghz are being developed. Systems such as Bluetooth, 802.11b, Zigbee and DBO-CSS are operating on 2.4Ghz. In addition to these communication systems, microwave oven resides in 2.4Ghz, so co-existance between each of these communication systems and microwave Oven is considered important factor of system performance. The effect of microwave oven on these communication systems is so critical that these systems are recommended to avoid the impact of microwave oven by allocation of different channel. In this paper, based on the DBO-CSS operating on 2.4Ghz, we propose a new algorithm of reducing the effect of microwave oven to develop robust communication system against microwave oven.
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XML Web Services are a distributed computing component which enables users to use services existing in remote places by using a standardized language called XML. Web Services were developed as the cooperation and business scales between companies as businesses had been widened due to the improvement of internet services. For this reason, enterprise sized Web Services are mainly used at present. But as the number of Internet users has been increased, they became in need of more diverse services, and providing individual Web Services are also being more emphasized. Therefore, an Embedded Web Server for personal Web Services for embedded systems such as cell phones had been implemented in this paper. This paper shows the possibility of building up a small, personal sized Web Services Server not the enterprise sized one by doing real implementation.
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In this paper the platform system for IEEE 802.15.4 Low Rate WPAN is designed and fabricated. IEEE 802.15.4 Low Rate WPAN system serves the functions and realization of home-area network. According to the IEEE 802.15.4 standard, there are two modes, One is BPSK modulation in 868/915MHz frequency band. The other is O-QPSK modulation in 2.45GHz frequency band. In this paper we implemented the platform system mounted in one PCB board in 868/915MHz frequency band of IEEE 802.15.4 Low Rate WPAN system. We measured that the platform system which consists of digital part and RF part has good performance. Also RF part is realized by design and fabrication of the RF transceiver IC. The key issue is to make the platform system which provides the function of Low Rate WPAN system to meet the requirement of IEEE 802.15.4 standards.
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There are a numerous number of mobile platforms so that content developers have difficulties of developing many versions of the same content by platforms. At present, each country becomes realizing the need of standardization, however, the progress of standardization is very slow because of the service providers and market flows. This paper investigates about the present state and standardization trend of mobile platform technologies so that it would help to lead the standardization process in the future.
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NEMO(Network MObility) is a complex model of mobile network which refers to a forming of Nested Mobile Network by a moving transportation like vessel, bus, or a train which then moves a Mobile Node, or by a movement of a PAN(Personal Area Network). In a Nested NEMO, pinball routing is the primary obstacle as exemplified by the IPv6 environment. This paper will focus on improving such models as RRH, RBU+ and MANET Approach, that attempted to solve pinball routing by route optimization.
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This paper presents an adaptive OFDM system with multistep predictor to effectively compensate multiple feedback delays. The proposed scheme adaptively changes the modulation order per subcarrier based on the predicted CSI to improve data capacity and system performance.
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In this paper, when concurrent transmission and diversity reception at each relay are assumed to increase bandwidth efficiency in linear multihop system, we analyze interference due to concurrent transmission and verify it. In the interference-free environment, more diversity sources at each relay result in better performance [1][2]. However, interference degrades BER performance because accumulated and propagated interference power surpasses original data power. Therefore, if we use the result of this paper, we can make bandwidth efficiency increase as well as BER performance good in linear multihop system by considering concurrent transmission with reuse factor and developing the algorithm which determines the number of diversity source.
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Describe about CAN-LIN integrated network in this treatise. Describe an search their advantage about CAN communication and LIN communication protocol. Introduce CAN-LIN integrated network system and decide.
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In this paper, design, simulation, fabrication method, and measured results of a digital frequency discriminator(DFD) operating in E, F, and G band are introduced. We describe the direct conversion scheme(DCS) with microwave integrated-circuit(MIC) developed for the small-area and high-speed system. When the input signal is the pulse with a pulse width of 100 ns, accuracy of frequencies measured by the DFD has 1.335 MHz RMS at no noise and 2.64 MHz RMS at signal-to-noise(S/N) ratio within 3 dB in E, F, and G band, which nearly satisfy the specification of 2.5 MHz RMS.
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Multi-hop system has advantage of low power consumption, improved cell capacity, and enlarged service coverage. Most of previous researches show that multi-hop relaying beyond dual-hop relaying does not improve system performance significantly. This leads most researches are focused on dual-hop relaying system. In this paper, we propose an optimal boundary condition to support maximal data rate for fluctuation of traffic load in single cell dual-hop relay system.
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We propose the dynamic channel allocation (DCA) algorithm for multi-cell OFDMA systems to avoid co-channel interference (CCI). The proposed algorithm is utilized not in a centralized, but in a distributed manner which reduces complexity. The simulation results confirm that the number of overlapping allocated subcarriers is reduced and the average SINR of a sub-carrier is increased by this algorithm.
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일반적으로 사용자가 인터넷 서비스를 제공받기 위해서는 자신의 정보를 먼저 등록해야 한다. 그러나 인터넷 서비스의 활용이 많아질수록 이와 같이 선 등록되어야 하는 정보의 양도 많아지며 또한 이들 정보가 불일치하는 문제가 발생한다. 본 논문은 이와 같은 문제를 해결하기 위해 사용자 Identity 정보를 웹 상에서 공유하는 기술인 Liberty Alliance 의 ID-WSF(Identity Web Service Framework)에 대하여 기술한다.
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무선 센서 네트워크에서 각 센서 노드는 에너지의 한계를 가지기 때문에, 에너지 소비문제는 매우 중요한 이슈이다. 조밀한 환경의 센서 네트워크에서 모든 노드들이 센싱에 참여한다면, 센싱영역의 중복영역이 커지게 되고, 이로 인해 불필요한 에너지를 소비하게 된다. 본 논문에서는 WSN 에서 connectivity 와 coverage 를 보장할 수 있는 효율적인 활성화 노드를 선택하는 기법을 제안하여, 불필요한 센서노드들의 에너지소비를 막고 전체적인 네트워크의 lifetime 을 연장시키고자 한다
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We present a multiuser synchronization scheme for OFDMA uplink systems. First a new preamble structure is proposed by which timing and frequency offsets estimation is developed. Based on proposed structure a new joint synchronization scheme is presented and the simulation results show that the performance of this scheme don't suffer from the number of users.
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동기식 전송망에서 발생되는 장애는 장비의 구성정보에 따라 다양한 알람정보를 발생시킨다. 전송망에서 발생되는 알람은 장애 원인으로 추정되는 근원알람과 장애로 인해 파생되는 파생알람으로 분류할 수 있다. 본 고는 이러한 분류체계를 기반으로 알람 상관관계 기법을 적용한 네트워크 장애관리시스템 구현 사례를 제시한다. 적용된 상관관계 방법은 Rule 기반의 접근방법 및 Codebook 기반의 접근방법을 접목한 hybrid 상관관계 방법을 적용하였고, 복잡성을 최소화 하기 위해 회선 기반의 grouping 기법을 사용하였다.
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실생활에서 나타나는 Social Network 을 웹에서 실현하기 위해서 Social Web 이 등장하고 그 전 단계로 Identity Web 이 현재 연구되고 있다. 그리고 웹의 확장으로 도메인간의 자유로운 데이터를 공유하기 위해서는 XML, XRI, XDI 가 제공되고 있다.. 본 논문은 Identity Web 을 실현하기 위한 기반 기술에 대하여 조사한 내용을 기술하고 이러한 인프라에서 자유로운 데이터의 공유를 하기 위해서는 어떠한 보안 요구사항들이 필요한지 고려하여 본다.
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By using a ceramic material with dielectric constant 37, the miniature waveguide ceramic bandpass filter was implemented. The proposed waveguide ceramic bandpass filte was based on the mode matching method and simulation process. For overcoming high power, We used the connector at in/output of waveguide ceramic bandpass filte. The result of power test satisfied the 30W. The product will used as a parts of repeater for wibroband.
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Mobile Ad Hoc Networks (MANETs) has the characteristics such as dynamic network topology, constrained power capacity, constrained wireless bandwidth and quality, etc. For MANETs AODV (Ad-Hoc On-Demand Distance Vector) routing protocol has been proposed. However AODV routing protocol has some inefficiency related to re-routing path establishment corresponding to node's failure. In this paper, we propose a Self-Healing Routing Technique for MANETs that uses the one-hop nodes from the failed node to set up the routing path efficiently. We also include simulation results to show the performance of our method.
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A band pass filter for the V-band application with unique circuit and structure was designed and implemented using 2-metals, 3-BCB layers. In the mean while the effective electrical conductivity of metal layer was extracted and its value was
$4{\times}10^7S/m$ . The insertion loss of band pass filter at 60 GHz was 3.0 dB and group delay was below 0.1 ns. -
In first-order moving-average Cauchy noise, the maximum likelihood (ML) and suboptimum ML (S-ML) detectors are analyzed in terms of the bit-error-rate in impulsive environment. Despite reduced complexity and simpler structure, the S-ML detector exhibits practically the same performance as the ML detector.
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High power amplifier (HPA), which is used in transmitter of wireless communication systems, usually works in near saturation point in order to achieve maximum efficiency. In this region, HPA can introduce undesirable nonlinear effects. In this paper, we present a polynomial modeling method for efficient techniques to compensate for nonlinear distortion introduced by nonlinear HPA. Proposed polynomial predistorter inverses actual amplifier. Namely, we derive polynomials of amplifiers from analytical method and the electrical parameters in the data sheet of an actual amplifier and then can derive polynomial predistorter by inversing them. It is an effective and a simple method to compensate nonlinear distortion. SSPA(Solid-state power amplifier) is considered. We also analyze the effects of predistortion on the SER performance of communication system with 16-QAM modulation format. The results have shown the efficiency of this model.
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본 논문은 IMS 개발-에 있어서 컨버전스 서비스를 지향하는 망 진화 방향을 제안한다. 4 세대 라고 언급하고 있는 4G 네트워크의 핵심인 IMS 는 3GPP 에서 표준화를 진행하며, ITU-T, MSF, TISPAN 과 같은 표준화 단체에서도 유사한 망구조로 제안하고 있다. 그러나 IMS망을 통하여 생성되는 컨버전스 서비스로의 발전에는 고려해야 할 사항들이 많이 있다. 본 논문에서는 망구조를 통하여 단말의 입장과 서비스의 진화방향을 제안한다.
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The real-time tracking system is an essential factor for the development of low cost sensor networks for use in pervasive computing and ubiquitous networking. In this paper, we address the interference problems of the sensor network platform with ultrasonic for location tracking system. Ubiquitous indoor environments often contain substantial amounts of metal and other such reflective materials that affect the propagation of radio frequency signals in non-trivial ways, causing severe multi-path effects, dead-spots, noise, and interference. Especially we present a novel reducing interference location system that is particularly well suited to support context-aware computing. The system called Pharos, aims to combine the advantages of real-time tracking systems that implement distributed environment with regardless of infrastructure or infrastructure-less wireless sensor networks.
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Photoconductive three-wire folded dipole antennas for terahertz photomixers have been developed. The folded antennas are characterized by a free space time-domain measurement technique, and the measured data are in good agreement with the simulation results. The folded dipole antennas have much higher antenna resistance than other resonant dipole antennas, implying that they can be used for higher output power of THz photomixers.
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The simulation on the mechanism of terahertz NSOM(near-field scanning optical microscopy) have been investigated. Based on experimental results, we have demonstrated the antenna effects on the coupling between a metal tip and substrate for an emission-type terahertz NSOM. It has been found that the lateral resolution can be estimated by a simplified model using an infinitesimal dipole in the substrate.
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Guided-wave propagation of sub-ps terahertz (THz) pulses in a highly birefringent plastic photonic crystal fiber has been experimentally demonstrated. The fabricated fibers have exhibited an extremely high birefringence of
${\sim}0.021$ at 0.3 THz. -
In CDMA based mobile communication network, signaling messages are routed through Signaling Transfer Point(STP) which is responsible for MTP layer 3 switching. As WCDMA based UMTS network is considered as next generation technology allowing global roaming services, all nodes in networks have their own identity number called Global Title(GT). Therefore, it is essential to introduce Signaling Gateway(SG) responsible for SCCP layer switching to solve the problem each node has all GT tables including even all overseas nodes. In this paper, we propose the signaling network architecture in UMTS networks using SG and we show that we can reduce CAPEX and OPEX in each node. To show the validity of the proposed method some simulations are given in which the results can be expected by intuitive observation.
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본 논문에서는 유비쿼터스 사회로의 출발점인 '홈네트워크'를 구축하는데 있어서 가장 기본이 되는 홈서버와 센서간의 인증을 구현하는데 목적을 두었다. 홈 서버와 센서간에 통신을 할 때 해쉬함수 중 MD5를 통해 그룹키를 생성하고 그룹키를 조도센서에 적용하여 서버와 센서간의 인증이 이뤄지는 것을 확인하였다.
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An orthogonal antenna is presented for reader applications of radio frequency identification (RFID) at 433 MHz. The antenna is composed of two
$1{\times}2$ sub-arrays orthogonally placed on a ground plane. Two different feeding networks are introduced to control horizontal and vertical radiation current flows for each sub-array, respectively. An inverted-F structure is used as a radiation element with vertical and horizontal currents flowing on the radiator, thereby obtaining two linear polarizations. Antenna gains are 3.71 and 3.43 dBi and isolation between the two input ports is less than 25dB. -
In this paper, the SPINS, a sensor network security mechanism, was researched to design a system to be applied to home network structure and check the security of which degree was ensured by a virtual network of home networking middleware. Sensor Network security mechanism SPINS provides data confidentiality and authentication by SNEP, and provides authenticated broadcast by
${\mu}TESLA$ . We designed the system that applied SPINS to home networking middleware basic structure. -
Frame synchronization is an critical factor for an effective operation of OFDM (orthogonal frequency division multiplexing) based communication systems. In this paper, we present and analyze an efficient frame synchronization method based on m-sequence for OFDM-based mobile multimedia communication systems. The cyclic extension preceding OFDM frames is of decisive importance for this method. The m-sequence is added directly to cyclic extension signal in the time domain. By utilizing the autocorrelation characteristics of m-sequence, efficient frame synchronization can be achieved. And we also consider frequency offset estimation simultaneously. The proposed frame synchronization method can be applied to the OFDM-based mobile multimedia communication systems.
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본 논문에서는 센서 네트워크에 SPINS 보안 프로토콜을 적용하여 그 성능을 판별하려 하였다. 센서 네트워크의 보안을 유지하기 위해 SPINS에서는 SNEP과
${\mu}TESLA$ 로 세분화 되어 데이터 인증, 보안과 키 관리를 각각 담당하게 된다. 본 논문에서는 그 중 SNEP을 nesC를 이용하여 TinyOS기반 센서에 적용하였다. -
In this paper, we deal with suggestion of effective traffic information transfer methods using voice broadcasting when traffic information are transferred by Digital Multimedia Broadcasting TPEG service. We apply TPEG service, which is used for collecting real-time traffic information, also we implement the GPS for identifying the drivers spot. We suggested traffic information selection method by distance and a weighted traffic information with their testing algorithm.
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In this paper, we achieved software and hardware implementation of SHA-1 hash function for sensor network. We implemented the software to be compatible with TinySec. In hardware design, we optimized operation logics for small area of hardware and minimized data transitions of register memory for low power design. Designed the software and hardware is verified on commercial sensor motes and our secure motes respectively.
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We present and demonstrate a novel method of alternate-phase return-to-zero (RZ) signal generation and pulse-amplitude equalization simultaneously in a rational harmonic mode-locked fiber ring laser, using a dual-drive Mach-Zehnder (MZ) modulator. By adjusting the voltages applied to both arms of the modulator, the rational harmonic mode-locked pulse trains are equalized in their amplitudes. In addition to that, the amplitude-equalized pulse trains multiplying the repetition rate at
${\sim}10\;GHz$ have alternate$\pi$ phase difference between adjacent pulses. The alternate-phase RZ signal generated by the proposed method enhances transmission performance through the single-mode fiber (SMF) links without dispersion compensation. -
In this paper, we have proposed an ad-hoc routing protocol named "RRMR (Reliable and Resilient Multipath Routing)" that is expanded from AODV to acquire multiple path at one time. This protocol needs less overhead to configure data routing paths and the paths are maintained to transmit data stably. To get these advantages, RRMR protocol is constructed by expanding from multipath acquiring and maintaining method based on distance vector method and hop-by-hop routing of AODV.
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Intrusion detection technology is highlighted in order to establish a safe information-oriented environment. Intrusion detection system can be categorized into anomaly detection and misuse detection according to intrusion detection pattern. In this paper, we propose an architecture to make up for the defect of conventional anomaly intrusion detection. This architecture reduces additional resource consumption and cost by placing the agent in the strategic location in Internet.
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Hierachical Mobile IPv6 (HMIPv6) solves Micro-mobility protocol problem about Handover. Mobility Anchor Point(MAP) helps reducing the handover, but this makes a load on the MAP. Besides the MAP operates this work everytime, and every Nodes. In this paper, we propose the algorithm that reduces the amount of Map working.
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This paper represents a Doherty amplifier with analog predistorter to improve the linearity of the Doherty amplifier while preserving the high efficiency. A
$3^{rd}$ -order predistorter cancels$5^{th}$ -order intermodulation (IM5) as well as$3^{rd}$ -order intermodulation (IM3) components by their same phase difference in the predistorter and Doherty amplifier. This is accomplished by independently controlling their phase by using the phase-controlled error generator in the predistorter. For experimental verification, a$3^{rd}$ -order predistorter has been implemented and tested in a 180-W Doherty amplifier at the wide-band code division multiple access (WCDMA) band. The measured results show good performance with the predistortion Doherty amplifier. -
To reduce the feedback overhead of predicted CSI (channel status information) of adaptive OFDM (orthogonal frequency division multiplexing), we use partial data of CSI and employ linear interpolation. Simulation results show estimated CSI and its MSE.
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In this paper, the antenna the with linear active phased array of
$1{\times}16$ operated in DBS band was designed. The antenna was composed of sixteen radiating elements, sixteen active channels and five Wilkinson power combiners with 4-channel inputs, a digital control board and a stabilizing DC bias board. The radiating element of the array has the structure of a microstrip stack patch with a left-hand circular polarization. And, each active channel consists of a low noise ampilifier, a 3-bit digital phase shifter and a variable analog attenuator. The breadboard of linear active phased array antenna was also fabricated to test the electrical performances. The radiation patterns of the antenna were measured after correcting initial phases of each active channel in aechoic chamber. And also, the beam scanning chracteristcs of$10^{\circ}$ ,$20^{\circ}$ ,$30^{\circ}$ were measured. -
We propose a method for improving the performance of the Amplitude Shift Keying (ASK) system using a fuzzy logic system for automatically tuning the bandwidth of low pass filter. Instead of a fixed bandwidth of a low pass filter of receiver, the fuzzy logic system is used to automatically adjust the bandwidth. The inputs to the fuzzy logic system are the error and change of error, and output is a bandwidth. Simulation results showed that the proposed system improves considerably on the performance of the fixed bandwidth.
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In this paper, we designed and implemented the Dual Band Dipole Antenna with Tapered Microstrip Balun for WLAN Access Point. Two dipole antennas with different resonant frequency and the antenna structure combined additional line were implemented for dual band performance. In order to feed the balun current, the tapered microstrip balun was used. Produced the Dual Band Antenna shows a special quality. The quality is that all VSWR is less than 1.5 in the 2.4GHz and 5GHz frequency bands in 802.11 standards, and it profits not less than 1.7dBi having typical Dipole Antenna pattern the very "a form of 8"pattern and Omni-directional pattern.
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Today, Web Services is very well-known as a middle-ware that can inter-communicate between many different program languages. This paper test web services by implementing two different web services platforms which are MS .NET based server and Apache AXIS based client. Those platforms have different data structure/process, and they could not give the developer seamless data compatibility through web services. However we confirmed that handling data, by some data transforming rules, web services can successfully inter-communicate between MS .NET based server and Apache AXIS based client.
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A service level agreement (SLA) is a formal contract between a service provider and a subscriber that contains detailed technical specifications called service level specifications (SLSs). In this paper, we propose SLA data analysis system which provides an effective decision-making information to network service provider. The SLA data analysis system executes trend analysis and statistics analysis using SLA violation and refund information. The analysis results are presented in many ways such as tables, graphs.
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In this paper, we introduce the design and fabrication of 60 GHz low noise amplifier MMIC for IEEE802.15.3c WPAN system. The 60 GHz LNA was designed using ETRI's
$0.12{\mu}m$ PHEMT process. The PHEMT shows a peak transconductance ($G_{m,peak}$ ) of 500 mS/mm, a threshold voltage of -1.2 V, and a drain saturation current of 49 mA for 2 fingers and$100{\mu}m$ total gate width (2f100) at$V_{ds}$ =2 V. The RF characteristics of the PHEMT show a cutoff frequency,$f_T$ , of 97 GHz, and a maximum oscillation frequency,$f_{max}$ , of 166 GHz. The performances of the fabricated 60 GHz LNA MMIC are operating frequency of$60.5{\sim}62.0\;GHz$ , small signal gain ($S_{21}$ ) of$17.4{\sim}18.1\;dB$ , gain flatness of 0.7 dB, an input reflection coefficient ($S_{11}$ ) of$-14{\sim}-3\;dB$ , output reflection coefficient ($S_{22}$ ) of$-11{\sim}-5\;dB$ and noise figure (NF) of 4.5 dB at 60.75 GHz. The chip size of the amplifier MMIC was$3.8{\times}1.4\;mm^2$ . -
In this thesis, we analyze performance related to reduction scheme of inter-cell interference causing serious problems in portable internet system. Frequency reusing factor(FUF) is 1 in portable internet system, and it means that a adjacent cell uses same frequency band. This channel environment raises inter-cell interference problem, which provokes serious problems related to system performance and channel capacity. Consequently, it affects deterioration in system performance as a whole. We analyze inter-cell interference when appling a various schemes such as (DCA)Dynamic Channel Allocation, CS(Channel Segregation), IDMA(Interleave Division Multiple Access), FH-OFDM, CRSA(Conceptual Random Subcarrier Allocation), and HDD
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In this paper, we developed a simulator for the DVB-T which can predict the performance of the system. In the simulator, the transmitter and receiver are implemented based on the European standard of the DVB-T. The BER performance is measured for various QAM levels and coding rates in Rician channels with several mobile speeds.
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In this paper, we propose a novel PAPR reduction scheme, which requires no change of a receiver structure or no additional information transmission. The approach we employed is clipping in the time and frequency domains within EVM, which is a suboptimal method with lower computational complexity compared to the optimal method. The simulation results demonstrated that the proposed method is more effective at lower modulation levels with larger constellation errors.
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IEEE 802.16 networks support mobile stations (MSs) to access broadband wireless networks while moving at a vehicular speed. However, IEEE 802.16 networks do not provide link layer native multicast capability because of point-to-multipoint connection characteristic. Due to this feature, it is not easy to adopt protocols or applications which need native link layer multicast capability. In order to solve the multicast support problem, we use the built-in LAN emulation feature of IEEE 802.16 which is based on Convergence Sublayer (CS). Our proposed operational procedures support not only the delivery of link local scope multicast packets, but also the delivery of non-link local scope multicast packets such as site local or global scope multicast packets. We also present the method of forming multicast Connection Identifier (CID) which is used to transport IP packets over IEEE 802.16 networks.
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In this study, we examined all peaks of confocal Raman spectra as peaks are the most important features for discrimination between basal cell carcinoma (BCC) and normal tissue (NOR). 14 peaks were extracted from these peaks using decision tree. For dimension reduction, frequently selected 4 peaks were chosen. They are located at 1014, 1095, 1439,
$1523cm^{-1}$ . These peaks were used as an input feature of the multilayer perceptron networks (MLP). According to the experimental results, MLP gave classification error rate of about 6.5%. -
MPEG Surround is an audio coding technology that represents multi-channel audio signal with downmixed audio signal(s) and very low bitrate side information based on Binaural Cue Coding. The side information consists of Inter-Channel Level Difference, Inter-Channel Correlation, and payloads. These two parameters are correspondent to the well-known spatial parameters in psycho-acoustics, Inter-aural Level Difference (ILD) and Inter-Aural Cross Correlation (IACC). Though ICLD is to provide perceptually equivalent ILD to the listener, however, the ILD of the original multi-channel audio signal and that of the MPEG Surround encoded signal was different. The difference between two ILD values is defined as ILD Distortion (ILDD). This paper provides how ILDD can be applied to enhance sound quality in MPEG Surround and how much ILDD is decreased.
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In this study, we propose a speech/music discrimination method using spectral peak track analysis. The proposed method uses the spectral peak track's duration at the same frequency channel for feature parameter. And use the duration threshold to discriminate the speech/music. Experiment result, correct discrimination ratio varies according to threshold, but achieved a performance comparable to another method and has a computational efficient for discrimination.
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In this paper, we proposed using MFCC coefficients(Mel-Scaled Cepstral Coefficients) and a simple but efficient classifying method. Many other features: IAV, zero crossing, LPCC,
$\ldot$ and their derivatives are also tested and compared with MFCC coefficients in order to find the best combination. GMM and HMM (Discrete and Continuous Hidden Markov Model), are studied as well in the hope that the use of continuous distribution and the temporal evolution of this set of features will improve the quality of emotion recognition. -
In this paper, we propose a new sound localization algorithm for an active perception system. In an active perception system, an acquired sound is mixed with the sound of motors. So a sound localization algorithm for an active perception system requires a robustness for the noise and a computational efficiency. The proposed localization algorithm can achieve robustness and efficiency to use only sub-band channels that are contained harmonic structure of the target speech.
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Nowadays adaptive technique allows arrays of any geometry to be used with fast direction-of-arrival (DOA) estimators designed for linear arrays. So the interpolation of data from a given antenna array onto the output of a virtual array is needed before the direction finding technique is applied to the outputs of a uniform linear virtual array (ULVA). In this paper some superresoluntion methods are used to estimate DOA by best-fit transformation matrix T under different nonuniformly spaced array.
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In this paper, we presented an extension of the broadband DOA estimation method using frequency-domain frequency-invariant beamforming (FDFIB). The technique uses FDFIB instead of conventional frequency invariant beamforming (FIB) methods. And different narrowband DOA estimation methods, MUSIC, ESPRIT, and MPM, are used respectively. A comparison is made to demonstrate that the FDFIB-MPM not only offers a better resolution than the FDFIB-MUSIC, FDFIB-ESPRIT, but also it is computationally very efficient.
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In this paper, we design and implement an active perception system. The proposed active perception system consists of four parts : an active robot, an aural active perception part, a visual perception part and an association part.
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Raman spectroscopy has strong potential for providing noninvasive dermatological diagnosis of skin cancer. In this study, we investigated two classification methods with maximum a posteriori (MAP) probability and multi-layer perceptron (MLP) classification. The classification framework consists of preprocessing of Raman spectra, feature extraction, and classification. In the preprocessing step, a simple windowing method is proposed to obtain robust features. Classification results with MLP involving 216 spectra preprocessed with the proposed method gave 97.3% sensitivity, which is very promising results for automatic Basal Cell Carcinoma (BCC) detection.
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In this paper, we address several issues in the real time implementation of MPEG-1 Layer II decoder on a fixed-point digital signal processor (DSP), especially TMS320C6416. There is a trade-off between processing speed and the size of program/data memory for the optimal implementation. In a view of the speed optimization, we first convert the floating point operations into fixed point ones with little degradation in audio quality, and then the look-up tables used for the inverse quantization of the audio codec are forced to be located into the internal memory of the DSP. And then, window functions and filter coefficients in the decoder are precalculated and stored as constant, which makes the decoder faster even larger memory size is required. It is shown from the real-time experiments that the fixed-point implementation enables us to make the decoder with a sampling rate of 48 kHz operate with 3 times faster than real-time on TMS320C6416 at a clock rate of 600 MHz.
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Since audio speech recognition is affected by noise in real environment, visual speech recognition is used to support speech recognition. For the visual speech recognition, this paper suggests the extraction of lip-feature using two types of image segmentation and reduced ASM. Input images are transformed to YCbCr based images and lips are segmented using the contrast of Y/Cb/Cr between lip and face. Subsequently, lip-shape model trained by PCA is placed on segmented lip region and then lip features are extracted using ASM.
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According to the previous work, various well known methods including maximum a posteriori probability classifier (MAP) and multi layer perceptron networks classifier (MLP) showed competitive results. Since even the small errors often leads to a fatal result, we investigated the method that reduces classification error perfectly by screening out some ambiguous patterns. Those ambiguous patterns can be examined by routine biopsy. We incorporated an ambiguous category in MAP and MLP. Classification results involving 216 spectra gave 100% sensitivity for the case of MLP.
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In this paper, an efficient and fast algorithm to reduce calculation amount of FIR(Finite Impulse Responses) filtering is proposed. Proposed algorithm enables arbitrary size of parallel processing, and their structures are also easily derived. Furthermore, it is shown that the number of multiplication/sample is reduced, and number of instructions using MAC(Multiplication and Accumulation) processor are also reduced. For theoretical improvement, numbers of sub filters are compared with those of conventional algorithm. In addition to the theoretical improvement, it is shown that number of element for hardwired implementation are reduced comparison to those of the conventional algorithm.
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In this paper, we propose an efficient rate control scheme based on the received power level to overcome a quality degradation of video under time varying channel condition caused by the movement of mobile devices. First, we statistically obtain the relation between the PLR and the received power level. With this information and the sequences of received power level, we calculate the transition probability for the Markov Channel Model. Then, with using Markov chain rule, we obtain the probability where the channel condition remains in a good state and finally find the efficient target bit rate by multiplying it by the offered bandwidth when the network access has begun. We use TMN8 to adjust the bit rate to our proposed outcome. Experimental results show that the proposed method can efficiently enhance the video quality and provide better PSNR performance than with only using TMN8 rate control method.
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Advanced TV makes the life more convenient for the viewers and it is based on the recognition technology. In this paper, we propose the implementation of face tracking system for efficient face recognition in intelligent digital TV. To recognize the face, face detection should be performed earlier. We use the motion information to track the face. Continuous face tracking is possible by using continuous detected face region and motion information. Thus the computational complexity of the recognition module in the whole system can be reduced.
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내용 기반 영상검색을 위한 효과적 특징 추출 방법에 대한 관심이 집중되고 있다. 본 논문에서는 물체의 크기에 강인한 영상검색을 위한 색상 특징정보와 상관관계를 이용한 RGB 칼라 검색 기법을 제안하였다. R, G, B 영상을 각 칼라 R, G, B 크기 순으로 배열한 후 칼라 R, G, B 간의 분산 차이를 특징 벡터로 사용하였다. 그리고 각 계산된 분산차를 3개의 구역으로 표본화여 재배열하였다. 제안된 알고리즘은 실험을 통하여 기존의 칼라 히스토그램, CCV, 칼라 코렐로그램 보다 검색 성능이 더 향상됨을 보였다.
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칼라기반 영상 검색에서 칼라의 색상 정보를 이용하는 기법에 많은 연구가 진행되고 있다. 본 논문에서는 칼라의 색상 정보와 명암 정보인 Gray-level의 특징자를 이용해서 영상을 검색하는 시스템을 제안한다. 칼라영상의 RGB 각각의 픽셀 값들을 R값, G값, B값의 크기순으로 배열하고 칼라 그레이-레벨을 구한 뒤 양자화 한다. 이러한 칼라의 특징 정보를 사용함으로써 이미지의 확대, 축소, 회전에도 강인한 검색을 할 수 있음을 실험을 통하여 성능의 우수함을 보였다.
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본 논문에서는 내용기반 영상검색을 보다 효과적인 알고리즘 설계를 위해 칼라 RGB 특징정보 추출에 median 필터링을 이용한 영상검색의 성능을 분석하였다. 칼라영상에서 각각의 R,G,B칼라영상으로 나눈 후 일정크기의 블록으로 분할하여 R,G,B 각각의 중간값을 추출하고 크기순과 레벨의 특징자를 이용한 영상검색 기법을 제안한다.
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Recently, as development of technique about super highway network and multimedia, the technique which effectively transfers, manages, stores and retrieves multimedia data is influenced. In this paper, by using HMMD color model and edge Histogram for segmentation of movie, efficient video segmentation is implemented than existing technologies.
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This paper describes a method for reconstructing 3D feet in a real time vision based marker free motion capture system. The proposed method is developed based on the visual hull and model fitting. For a real time computing, a special lookup table is employed in this paper. This method is implemented and tested using three CCD cameras and preliminary results are presented in this paper.
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This paper proposed a method of the camera calibration for noncontact measure of badly illumination. The method with a semi-automation camera calibration, The user designates minimum 4 points in calibration pattern. The Perspective transformation predicts the remaining point calibration pattern. It uses at input value of the Tsai and it searches a better point, When being smaller allowable error than until, it repeats and it puts out a good calibration result.
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In this paper, we propose a novel segmentation and classification method using texture features for the document image. First, we extract the local entropy and then segment the document image to separate the background and the foreground using the Otsu's method. Finally, we classify the segmented regions into each component using PCA(principle component analysis) algorithm based on the texture features that are extracted from the co-occurrence matrix for the entropy image. The entropy-based segmentation is robust to not only noise and the change of light, but also skew and rotation. Texture features are not restricted from any form of the document image and have a superior discrimination for each component. In addition, PCA algorithm used for the classifier can classify the components more robustly than neural network.
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H.264 provide good coding efficiency compared with existing video coding standards as H.263, MPEG-4, etc. However, H.264 require the increase of encoder complexity. In this paper, fast mode decision algorithm by skipping variable block size motion estimation and spatial-predictive coding, which occupies most encoder complexity, is proposed. Experimental results show that the proposed approach can save encoding time to 55% compared with the H.264 standard.
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CG and Photo-realistic image composition in the ocean scenes is frequently used in movies and TV advertisement. But it is very difficult task because it's impossible to use calibration tool in outdoor environment or to use auto-calibration algorithm using natural features like KLT(Kanade Lucas Tomasi feature tracker) from the ocean scene. We propose a simple, effective method for solving camera motion using previous knowledge about background structure. We applied our method to the production of a commercial movie, 'Hanbando' and the result was satisfactory.
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With increasing the volume of digital multimedia market, the security and multimedia content protection issues are arising. Interest in H.264/AVC is emerging and special features in H.264/AVC element stream must be considered. We developed a new algorithm which scrambles and descrambles H.264/AVC element stream in compressed domain using manipulating CABAC initialization table and DCT coefficients. Extensive experimental results indicate that the proposed algorithm is effective and promising.
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This paper presents rate-distortion optimization that is considered sequence statistics(complexity) to choose the best macroblock mode decision in H.264. In previous work, Lagrange multiplier is derived by the function of constant value 0.85 and QP so that is not the proper Lagrange multilplier for any image sequence. The proposed algorithm solves the problem by changing constant value 0.85 into adaptive value which is influenced by image complexity, and by reducing the encoder complexity to estimate the image statistics with the multiplication of transformed, quantized rate and distortion. Proposed algorithm is achieved the bit-rate saving up to 5% better than previous method.
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Interscale dependency and Liptschitz regularity of the wavelet coefficients imply the existence of functional mapping between scales. In this paper, the neural networks are exploited to learn an intercale mapping. We apply a phase-shifting filter for effective learning of the neural networks.
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This paper implements a method that tracking the moving objects that detected by the motion detection function of the digital CCTV system. We simply implement the motion detection function of the digital CCTV system that use frame difference and thresholding. When motion is detected, the motion detection function generates two outputs. One output is the event that the motion is arised in input image frame. The other output is coordinate that motion is exists. Then, do the block matching algorithm[2] using coordinate, that motion is exists, as initial coordinate of the block matching algorithm. The best matched coordinate is new initial coordinate of the block matching algorithm for the next image frame. We simply use the block matching algorithm that implements tracking the moving objects. It is simple, but useful the actual digital CCTV system.
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In this paper, we propose a real-time surveillance system for security of important area such as military bases, prisons, and strategic infra structures. The proposed system recognizes the movement of objects in dark environments. First, the Multi-scale retinex (MSR) is processed to enhance the contrast of image captured in dark environments. Then, the enhanced input image is subtracted with the background image. Finally, each bounding box enclosing each objects are tracked. The center point of each bounding box obtained by the proposed algorithm provides more accurate tracking information. Experimental results show that the proposed system provides good performance even though an object moves very fast and the background is quite dark.
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In this paper, we propose a segmentation algorithm which combines the ideas from local watershed transforms and the region merging algorithm based hierarchical queue. Only the process of watershed and region merging algorithm can be restricted area. A fast region merging approach is proposed to extract the video object from the regions of watershed segmentation. Results show the effectiveness and convenience of the approach.
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Load effect which occurs due to the electrode structure for PDP(plasma display panel) can seriously reduce the image quality of PDP. In this paper, we propose the method of reducing load effect in presentation images, which have the possibility of load effect, by using LUT(look-up table). The proposed method enhances the image quality of PDP by correcting load effect region of the still image.
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This paper proposes detection method of vehicles using camera for auto-vehicle-system. Detection method is based on shadow detection and symmetric feature of vehicle. This method consists of three part. First is lane detection. By lane detection, we can reduce the area for vehicle detection. Second part is shadow detection. Shadow has information of vehicle width and position. Third part is symmetry. This feature is helpful for confirming the vehicle.
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To avoid the large scale of damage when fire occurs in the tunnel, it is necessary to have a system to minimize the damage, and early discovery of the problem. In this paper, we have proposed algorithm using the image processing, which is the high-speed detection for the occurrence of fire or smoke in the tunnel. The fire detection is different to the forest fire detection as there are elements such as car and tunnel lightings and other variety of elements different from the forest environment. Therefore, an indigenous algorithm should be developed.The two algorithms proposed in this paper, are able to complement with each other and also they can detect the exact position, at the earlier stay of detection. In addition, by comparing properties of each algorithm throughout this experiment, we have proved the propriety of algorithm.
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In recent, displays have very good properties at high luminance, fast response, and size. Also They have good quality in terms of color according to the development of the gamut extension and color reproduction. However, despite these merits, there is a characteristic that at a high luminance display, observer perceive the different color from the originally re-producted color due to the change of perceived luminance in human visual system. In this paper, we propose a model that is the hue shift phenomenon between a normal display and a high luminance display, and then an algorithm which compensate the color between two devices, so that observer can perceive the same color.
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This paper presents an enhanced algorithm for compensating the visual quality in backlight image. Current cameras do not represent all details of scene into human's eye. Saturation and underexposure are common problems in backlight image. Retinex algorithm, derived from Land's theory on human visual perception is known to be effective in enhancing the contrast. However, its weaknesses are long processing time and low contrast of bright area in backlight scene because of compensating the details of dark area. In this paper, K-Retinex algorithm is proposed to reduce the processing time and enhance the contrast in both dark and bright area. To show the superiority of proposed algorithm, we compare the processing time and local variance of each area above.
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In this paper, a real-time stereoscopic image conversion method using a single frame from a 2-D image is proposed. If original image is too much dark, it is difficult to create correct luminance value. So stereoscopic image is generated after applied image enhancement algorithm to original image. The Stereoscopic image is generated by creating depth map using vertical position information and parallax processing.
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Obtained disparity map from the stereo camera by using the several stereo matching algorithms carries lots of noise because of various causes. In our approach, mode filtering and noise elimination technique using the histogram and projection-based region merging methods are adopted for improving the quality of disparity map and image segmentation. The proposed algorithms are implemented in VHDL and the real-time experimentation shows the accurately divided objects.
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As different media formats converge into one digital content, we need to put time information in the content to synchronize those media. In this paper, we propose more efficient methods to represent time information aimed at Karaoke application. We utilize the linguistic and musical characteristic of Karaoke. Especially we make a novel codeword rule for the beat of music. In our experiment, our proposed methods turn out to drastically reduce time information.
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There are lot of noises and errors in depth map image which is gotten by using a stereo camera. These errors are caused by mismatching of the corresponding points which occur in texture-less region of input images of stereo camera or occlusions. In this paper, we use a method which is able to get rid of the noises through post processing and reduce the errors of disparity values which are caused by the mismatching in the texture-less region of input images through the correlation between the depth map images and the input images. Then we propose a novel method which segments the object by using the improved disparity map images and projections.
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In this paper, we propose a vision based system employing two cameras to provide effective touch screen function. The two main processes - determining touch (or no-touch) and contact location of screen plane - are essential for enabling touch screen function. First region of interest is found by using color characteristic and histogram for determining the contact mode. Second, if the hand touches the mirror, the fingertip point in image is found using the correlation coefficient based on the mirror attribute. Subsequently, the fingertip coordinate in image is transformed to the location in mirror plane by using four predefined points (termed as four-point method) and bilinear transform. Representative experimental results show that the proposed system is suited to touch screen.
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In this paper, we propose a method that extracts invariant iris codes from user's iris pattern in order to apply these codes to a new cryptographic construct called fuzzy vault. The fuzzy vault, proposed by Juels and Sudan, has been used to manage cryptographic key safely by merging with biometrics. Generally, iris data has intra-variation of iris pattern according to sensed environmental changes, but cryptography requires correctness. Therefore, to combine iris data and fuzzy vault, we have to extract an invariant iris feature from iris pattern. In this paper, we obtain invariant iris codes by clustering iris features extracted by independent component analysis(ICA) transform. From experimental results, we proved that the iris codes extracted by our method are invariant to sensed environmental changes and can be used in fuzzy vault.
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This study proposes an effective algorithm that can simulate a lighting environment, especially an LED backlight unit, using the photon mapping method. For higher reliable simulation, we modeled spectral and optical characteristics of LEDs, light sources, and optical sheets. From rendered images, we confirmed that the proposed algorithm can effectively simulate the lighting distribution of LED backlight unit.
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This paper proposes a new frame interpolation algorithm mainly designed for intra-mode blocks. In order to improve the accuracy of pixel interpolation, the new algorithm exploits two different interpolation modes for inter-mode blocks and intra-mode blocks, respectively. The use of the two modes reduces ghost artifacts but increases blocking artifacts between the blocks interpolated by different modes. To reduce blocking artifacts, this paper proposes an interpolation algorithm that attempts to isolate a fast moving object and interpolates such objects as the intra-mode while the remaining blocks are interpolated as the inter-mode. Simulation results show that the proposed algorithm improves subjective and objective quality of pictures by reducing ghost artifacts.
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This paper proposes a method for rejecting false matches in automobile rear view camera image sequences. Our method consists of two submethods which utilize the motion characteristics of an automobile. One is for a straight motion and the other is for a curve motion. First, we classify an image sequence into a straight motion or a curve motion and then apply an appropriate submethod. Our method works in cases where the percentage of true matches is as low as 30%.
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This paper presents a recovery technique for images with block-based corruption by transmission losses. Conventional methods that do not consider edge directions can cause blocked blurring artifacts. In this paper, we present a block recovery scheme using Haar wavelet features. The adaptive selection of neighboring blocks is performed based on the energy ratio f wavelet subbands. The lost blocks are recovered by linear interpolation in the spatial domain using selected block pairs. The proposed directional recovery method is effective for the strong edge because it exploits the varying neighboring blocks adaptively according to the edges and the directional information in the image. The proposed method outperforms the previous methods that used only a predefined set of neighboring blocks.
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To enhance security and privacy in biometrics, changeable (or cancelable) biometrics have recently been introduced. The idea is to transform a biometric signal or feature into a new one for enrollment and matching. In this paper, we proposed changeable biometrics for face recognition using on PCA based approach. PCA coefficient vector extracted from an input face image. The vector is scrambled randomly and removed. When a transformed template is compromised, it is replaced by a new scrambling rule. In our experiment, we compared the performance between when PCA coefficient vectors are used for verification and when the transformed coefficient vectors are used for verification.
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In this study, information compression based on the wavelet technique is described. The principle of signal or image compression is performed by optimization of quantization, that is the bit allocation taking advantage of their energy concentration in low frequency components. The wavelet transform is one of frequency decomposition, such as the discrete cosine transform or sub-band filtering, and it is also implemented as a filter bank. Wavelet transform with use of spatially localized basis function can reduce several drawbacks in conventional methods. The benifit of wavelet based compression method is described as comparing the transform method to another ones.
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In this paper, we propose an active shape image segmentation method for three-dimensional(3-D) medical images using a generation method of the 3-D shape model. The proposed method generates the shape model using a distance transform and a tetrahedron method for landmarking. After generating the 3-D model, we extend the training and segmentation processes of 2-D active shape model(ASM) and improve the searching process. The proposed method provides comparative results to 2-D ASM, region-based or contour-based methods. Experimental results demonstrate that this algorithm is effective for a semi-automatic segmentation method of 3-D medical images.
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In this paper, a low-power deblocking filter structure for H.264 video coding algorithm is proposed. By sharing addition hardware for common filter coefficients, we have designed an efficient deblocking filter structure. Proposed deblocking filter utilizes MUX and DEMUX circuits for input data sharing and shows 44.2% reduction for add operation. In the HDL coding simulation and FPGA implementation, we achieved 19.5% and 19.4% gate count reduction, respectively, comparison with the conventional deblocking filter structure.
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The direction of arrival of the sound signal can be derived from the time differences at the microphone array and the motor controls the camera to point at the direction of the sound signal. You can get through to the homepage and confirm the camera image on a client computer which connects to the server computer through Internet.
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In this paper, the biomedical signal compression method with multi-stage vector quantization is proposed. It utilizes characteristic of wavelet coefficients in which the energy is concentrated on approximation coefficients. The transmitted codebook index consists code vectors obtained by wavelet coefficients of ECG and Error signals from the 1024 block length, respectively. The proposed compression method showed 2.1298% in average PRD and 1.8 kbits/sec in CDR.
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In this paper, we propose the noise suppressor with the psychoacoustic model and wavelet packet transform. The objective of the scheme is to enhance speech corrupted by colored or non-stationary noise. If corrupted noise is colored, subband approach would be more efficient than whole band one. To avoid serious residual noise and speech distortion, we must adjust the Wavelet Coefficient threshold. In this paper, the subband is designed matching with the critical band. And WCT is adapted by noise masking threshold(NMT) and segmental signal to noise ratio(seg_SNR). Consequently this work improve the PESQ-MOS about 0.23 in the case of coded speech.
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This paper presents very low bit rate speech coder, ZFE-CELP(ZINC Function Excitation-Code Excited Linear Prediction). The ZFE-CELP speech codec is based on a ZINC function and CELP modeling of the excitation signal respectively according to the frame characteristic such as a voiced speech and an unvoiced speech. And this paper suggest strategies to improve the speech quality of the very low bit rate speech coder.
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The objective criterion is necessary to decide the signal for vehicle audio. In this time, the signals have decided by golden ear or some simple parameters. In this paper, we propose the system for sound quality assessment in the vehicle audio signals. The vehicle audio signals were recorded in many vehicles by same condition. From these signals, objective and subjective parameters were extracted and using these signals listening test was done. The function was estimated between three results by simple neural network system. The score of arbitrary signal can be estimated using the function made by three results. In this way, Sound signal quality is assessed objectively.
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This paper suggests the packet loss recovery method to communicate in real-time in the Internet. To reduce the effects of packet loss, Forward Error Correction(FEC) that adds redundant information to voice packets can be used. The major cause for speech quality degradation in IP-networks is packet loss. So, We recovered single lossy packet by using FEC method and concealed continued errors. The proposed scheme is evaluated in the Gilbert Internet channel model. The high quality of audio maintained up to 30% packet loss.
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MPEG-4 ER-BSAC decoder employes a full search method for maximum significance search and arithmetic decoding position search in spectral data decoding procedure. Then the search procedure have the most complexity. This paper proposes the new search method, the maximum significance tree structure, for the optimized implementation of BSAC decoder.
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We propose the robust PBFLMS in noises, which is the enhanced acoustic echo canceller using ACPBF-LMS(Alternative Constrained Partitioned Block Frequency domain Least Mean Square) algorithm. The defect of the block structure filtering is the deterioration of convergence efficiency from noise and interference. To improve the performance of convergence efficiency, noise effect should be reduced. The new method of reducing noise effect is proposed, which apply the estimated background noise to adaptive filter step size. By experiments, the proposed acoustic echo canceller has TCL of 50dB, and always provides faster convergence speed and lower complexity than the full-tap NLMS. We also carried out an implementation of PBFLMS using ARM9EJ-S.
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Magnetic Flux Leakage (MFL) methods are widely employed for the non-destructive testing of gas pipelines. In the application of MFL pipeline inspection technology, corrosion anomalies are detected and identified via their leakage filed due to changes in wall thickness. This paper presents discrete cosine transform (DCT) based MFL signal analysis for defect feature extraction of natural gas pipelines. The original MFL signals are transformed into new ones based on the analysis. The usefulness of the approach has been shown by the experimental results.
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Magnetic Flux Leakage (MFL) inspection is a general non-destructive testing (NDT) method to detect the corrosion of natural gas pipelines. Currently, it is subjectively analyzed by trained analysts. In spite of investing much time and human resources, the inspection results may be different according to the analysts' expertise. So, many gas suppliers are keenly interested in the automation of the interpretation process. This paper presents a Gaussian variance filtering method of MFL signals, which is taken from MFL pigging of underground pipelines. In the proposed algorithm the original MFL signals are filtered by multiple Gaussians with different variance. Experimental results show that this approach does not need to align bias and to use explicit noise reduction algorithm.
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The direction of arrival of the sound signal can be derived from the time differences at the microphone array and the motor controls the camera to point at the direction of the sound signal. You can get through to the homepage and confirm the camera image on a client computer which connects to the server computer through Internet.
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This paper describes a pre-processing methodology which can apply to remote speech recognition system of service robot in noisy environment. By combining beamforming and blind source separation, we can overcome the weakness of beamforming (reverberation) and blind source separation (distributed noise, permutation ambiguity). As this method is designed to be implemented with hardware, we can achieve real-time execution with FPGA by using systolic array architecture.
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This paper presents an analytic derivation of phase measurement error. The analysis derives the measurement error caused by the finite-bit quantization of both input signals and twiddle factors used in the recursive implementation of the phasor measurement algorithm. The derivation is based on the statistical exploration of the error dynamic equations. The effect of frequency deviation and the number of DFT points are also included in the study. The analysis results are verified with the data obtained from the computer simulation by widely varying the values of error causing factors.
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This paper presents a new method for Huffman decoding specially designed for the MPEG-2 AAC audio. The method significantly enhances the processing efficiency of the conventional Huffman decoding realized with the ordinary binary tree search method. A data structure is newly designed based on the numerical interpretation of the incoming bit stream and its utilization for the offset oriented nodes allocation. The experimental results show the average performance enhancement of 54% and 665%, compared to those of the conventional binary tree search method and the sequential search method, respectively.
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In this paper, we propose a method that measures quality of digital correlator. Quality of digital correlator in field of image composition of radio astronomy have as important position for acquisition of radio wave image with high precision. Digital correlator should have wide bandwidth and high precision to study on deep space. Digital correlator, therefore, should be designed to have high speed processing and high precision. But, real time measurement of quality of digital correlator using acquisition data is difficult to compare accuracy of result because digital correlator should process a large quantity of data with high speed. Measurement method of quality, also, has intricate implementation of experiment equipment. this paper present methods that compose experiment equipment without external installation easily and verify quality of digital correlator perfectly.
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JPEG2000 achieves a target bit rate by selecting the bitstream for adequate coding passes after encoding full passes in Tier-1 coder. Tier-1 encoding is complicated and time-consuming process. In this paper, we propose a new rate control technique that chooses the necessary passes without the full passes coding of Tier-1 by using previous image information for volumetric image. The simulation result shows that the proposed technique reduces encoding time of coding passes up to 81.5%.
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In this paper, we propose a wavelet-based audio watermarking algorithm to be robust against capturing attack. Commercial capturing tools enable us to obtain audio contents without noticeable degradation in audio quality, and it is possible to be a source of illegal distribution. By adjusting mean values of the lowest subband in audio, the proposed method can survive after capturing attack including sampling rate conversion, random cropping and compression. By applying a simple human auditory model, the inaudibility of the watermark is achieved, and detection probability is improved based on the difference information. This is confirmed by experimental results.
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The proposed method measures the correlation maps of SVD that are used to interpret data relations and structures between the original image and the distorted image. It seems that the SVD results can be used to assist us in gaining information about covariance structure of two images. This method is able to work in the complete absence of any digital watermark or signature. The effectiveness of this method is seen through testing the robustness against JPEG compression.
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As a result of growth sensor-enabled mobile devices such as PDA, cellular phone and other computing devices, in recent years, users can utilize the diverse digital contents everywhere and anytime. However, the interfaces of mobile applications are often unnatural due to limited resources and miniaturized input/output. Especially, users may feel this problem in some applications such as the mobile game. Therefore, Novel interaction forms have been developed in order to complement the poor user interface of the mobile device and to increase the interest for the mobile game. In this paper, we describe the demonstration of the gesture and posture input supported by an accelerometer. The application example we created are AM-Fishing game on the mobile device that employs the accelerometer as the main interaction modality. The demos show the usability for the gesture and posture interaction.
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In this paper, we present an efficient architecture for connected speech recognition that can be efficiently implemented with FPGA. The architecture consists of newly derived two-level dynamic programming (TLDP) that use only bit addition and shift operations. The advantages of this architecture are the spatial efficiency to accommodate more words with limited space and the computational speed from avoiding propagation delays in multiplications. The architecture is highly regular, consisting of identical and simple processing elements with only nearest-neighbor communication, and external communication occurs with the end processing elements.
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The P-ECLMS algorithm adapted the existing Post-Processing method occurs the distortion of the near-end signal at the double-talk situationt. To solve this problem, we propose the SP-ECLMS(Selective Post-Processing ECLMS) algorithm which makes the Post-Processing coefficient differently at the case of the single-talk and the double-talk. When the correlation level is not output less than 30%, the proposed algorithm output the original signal to prevent the signal's distortion.
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온라인 가상강의는 전형적인 오프라인 강좌에 비해 많은 장점을 가지고 있는 반면에 교수자의 학습감독권과 교수자가 학습자의 상태를 파악하여 능동적으로 강의내용을 변경할 수 있는 기능을 갖지 못하기 때문에 학습자의 결연한 학습의지가 전제되지 않으면 기대하는 학습효율을 얻을 수 없다는 문제점들이 교육공학적인 측면에서 거론되고 있다. 따라서, 본 연구에서는 온라인 가상강좌에서 해결되지 않은 학습감독원을 부여하기 위해서 눈꺼플 움직임과 머리의 상하움직임만으로 학습자의 학습태도를 평가하고, 이에 따라 능동적으로 강좌가 진행될 수 있는 교수-학습모델을 제안한다.
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In this paper, we propose an efficient algorithm based on PCA and LDA combining K-means clustering method, which has better accuracy of face recognition than Eigenface and Fisherface. In this algorithm, PCA is firstly used to reduce the dimensionality of original face image. Secondly, a truncated face image data are sub-clustered by K-means clustering method based on Euclidean distances, and all small subclusters are labeled in sequence. Then LDA method project data into low dimension feature space and group data easier to classify. Finally we use nearest neighborhood method to determine the label of test data. To show the recognition accuracy of the proposed algorithm, we performed several simulations using the Yale and ORL (Olivetti Research Laboratory) database. Simulation results show that proposed method achieves better performance in recognition accuracy.
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The goal of this paper is automation of a remocon inspection process using machine vision system. This system prevents error that is occurred by physical and spirit condition of human. Also this system has been developed to raise the reliability of remocon inspection. This system has been developed only using PC, CCD Camera and Visual C++ for universal workplaces. The performance of this system is an accuracy improvement of
$2{\sim}3[%]$ and a processing time reduction of about 100[ms] against existing pattern matching method. -
In x-ray imaging system, twokinds of noises are involved. First, the charge generated from the radiation interaction with the detector during exposure is modeled by Poisson process. Second, the signal is then added by readout electronics noise, which is modeled by Gaussian distribution. In this paper, we applied Wiener filter and Wavelet to remove noise from medical X-ray image, the result shows that wavelet yield better segmentation results than the wiener filter.
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This paper lists various error resilience tools and analyzes performance in IP Datacast over DVB-H systems and schemes are proposed. Experiments shows that, in DVB-H environment, encoding with macroblock line intra update can achieve the best error correction ability, because this tool can make full use of spatial correlation for intra prediction and reduce the requirement of bit rate.
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본 논문에서는 얼굴 인식의 성능을 효율적으로 향상시키기 위하여 Discrete Cosine Transform (DCT)와 Principal Component Analysis(PCA)에 기반한 새로운 특징 추출 방법을 제안한다. 얼굴 영상의 공간 영역은 DCT를 이용하여 주파수 영역으로 변환되며, DCT 도메인에서 얼굴 영상이 갖는 고유한 주파수 특성을 최적화 하는 주파수 밴드 영역을 추출한다. 차원이 축소된 데이터는 PCA 를 이용하여 데이터의 변별력에 가장 적합한 얼굴의 특징을 추출하고 Nearest Neighbor Classification 을 통해 본인여부를 확인 한다. 실험 결과 제안된 방법은 데이터의 차원을 효과적으로 축소하면서 기존의 얼굴 인식 방법에 비해 높은 인식률 향상을 보였다.
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본 논문에서는 이미지 검색을 위해 가장 기본적인 요소인 이미지 색상에 따른 칼라 분포정보를 이용하고 다양한 요소에 따라 가중치를 부여한 칼라기반의 검색 기술자를 제안하였고 실험적 평가를 통하여 제안 기술자의 성능을 평가하였다. 칼라 히스토그램을 통한 이미지 검색 기술자를 설계하는데 있어 칼라모델은 HSV, 웨이블릿 변환 필터는 D9/7, 웨이블릿 분해는 2 레벨을 적용하였을 때 가장 좋은 검색효율성을 보였다.
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음성인식, 합성 및 분석과 같은 음성신호처리 분야에 있어서 기본주파수 즉, 피치를 정확히 검출하는 것은 중요하다. 그러나 포만트의 영향과 천이진폭의 영향 때문에 음성신호에서 피치를 정확히 구하는 것은 매우 어렵다. 더구나 노이즈가 포함된 신호에서는 더 더욱 어려워진다. 따라서 본 논문에서는 켑스트럼영역에서 포만트의 영향 을 제거하고 밴드 필터링 한 후 기본 피치 정보를 강조 보상하여 피치주기를 검출하는 방법을 새로이 제안한다.
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In this paper, we proposed muli-dimensional feature vector matching method combined with disparity smoothness constraint. The smoothness constraint was calculated using the difference between disparity of center pixel and those of 4-neighbor pixels. By applying proposed algorithm to IKONOS satellite stereo imagery, we obtained robust stereo matching result in urban areas.
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This paper proposes the new algorithm for the extraction of the corresponding points. Our algorithm is based on RANSAC(Random Sample Consensus) with EM(Expectation-Maximization). In the procedure of RANSAC, N-points are selected by the result of EM instead of the random selection. EM+SAC algorithm is applied to the correspondence for the mosaicing.
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In this paper, we propose a new reversible image authentication technique based on watermarking where if the image is authentic, the distortion due to embedding can be completely removed from the watermarked image after the hidden data has been extracted. This technique utilizes histogram characteristics of the difference image and modifies pixel values slightly to embed more data than other reversible data hiding algorithm. The proposed scheme is quite simple and the execution time is rather short. Experimental results demonstrate that the proposed scheme can detect any modifications of the watermarked image.
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We propose a surface modeling method using multi-laser lining. We can acquire 3D surface by analyzing projected laser lines on object. The laser lines reflect the surface curvature. In this paper, we show two novel approaches to reconstruct 3D shape of moving object. One is used for robust laser line extraction, and the other for registration between 3D shapes.
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In this paper, we proposed a fast algorithm for inter prediction included the most complexity in H.264/AVC. It decide search range according to direction of predicted motion vector, and then perform adaptive candidate spiral search. Simultaneously, it perform motion estimation of variable loop with threshold for variable block size. Conclusively, it is implemented in JM FME with high complexity applying to rate-distortion optimization. Experimental results show that significant complexity reduction is achieved while the degradation in video quality is negligible.
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In this paper, we propose an efficient coding method of digital hologram (or fringe pattern) using multi-view prediction technique based on video and image coding standard such as MPEG. The proposed algorithm illustrates that it has better properties for reconstruction and higher compression rate than the previous researches.
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In this paper, we proposed a new coding technique of digital hologram video using 3D scanning method and video compression technique. The proposed coding consists of capturing a digital hologram to separate into RGB color space components, localization by segmenting the fringe pattern, frequency transform using
$M{\tiems}N$ (segment size) 2D DCT (2 Dimensional Discrete Cosine Transform) for extracting redundancy, 3D scan of segment to form a video sequence, motion compensated temporal filtering (MCTF) and modified video coding which uses H.264/AVC. -
In this paper, we propose a new fast algorithm which reduces search range by checking reliability of predicted vector in multi-view video coding (MVC). Block position matching algorithm is implemented to improve the proposed algorithm. The processing time is decreased by from 40 to 60% in each frame in the proposed algorithm.
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In the new video coding standard H.264/AVC, motion estimation (ME) is allowed to search multiple reference frames for improve the rate-distortion performance. The complexity of multi-frame motion estimation increases linearly with the number of used reference frame. However, the distortion gain given by each reference frame varies with the video sequence, and it is not efficient to search through all the candidate frames. In this paper, we propose a fast mult-frame selection method using all zero coefficient block (AZCB) prediction and sum of difference (SAD) of neighbor block. Simulation results show that the speed of the proposed algorithm is up to two times faster than exhaustive search of multiple reference frames with similar quality and bit-rate.
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Using the still image through the camera reports which the moving object tracking system. Moving object direction detected to compare the two difference images. And base block set at moving object. Matching area set current difference image. The edge image of prior frame and current frame implement the moving object tracking system to block matching.
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This paper describes a 3D face recognition using different devices for 3D faces and input faces which include several different pose. Before the recognition stage, through the EC-SVD, all data have to be preprocessed and normalized. At recognition stage, we propose the multi-point signature method for measuring facial surface information. And we use the root mean square error for matching. From the experiment results, we have 92.5% recognition rate.
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Overdriving schemes are used to improve the response time of liquid crystal display. Typically they are implemented by using LUTs (look-up table) within an image processor. However, the size of LUT is limited by the physical memory size and system cost. In this paper, we present an improved method for LUT implementation using linear interpolation and piecewise least-square polynomial regression. Using the proposed method, the performance of LUT can be improved and memory size of that can be reduced.
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This paper presents an image fingerprinting scheme for the print-to-capture model performed by a photo printer and digital camera. When capturing an image by a digital camera, various kinds of distortions such as noise, geometrical distortions, and lens distortions are applied. slightly and simultaneously. In this paper, we consider several steps to extract fingerprints from the distorted image in print-and capture scenario. To embed ID into an image as a fingerprint, multi-bits embedding is applied. We embed 64 bits information as a fingerprint into spatial domain of color images. In order to restore a captured image from distortions a noise reduction filter is performed and a rectilinear tiling pattern is used as a template. To make the template, a multi-bits fingerprint is embedded repeatedly like a tiling pattern. We show that the extracting is successful from the image captured by a digital camera through the experiment.
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In this paper, we describe the architecture of interactive data broadcasting server that can transmit the various data-service contents of the Terrestrial DMB(digital multimedia broadcasting). In the broadcasting environment of the Terrestrial DMB, we enjoys the PADS(program associated data service), or the PIDS(program independent data service) to be executed on various T-DMB terminals as well as the basic video or audio services. This server provides the function such as the data contests management, data channel management, service information configure, return channel connection. Etc. Particularly, this system provides the method to create and transfer the application signaling information for the T- DMB middle application based the java language.
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A new disparity estimation method in hierarchical frameworks is proposed. The two main ideas for improving accuracy are to obtain an object boundary map for distinction of homogeneous/object boundary region and to choose adaptive window size/shapes. Moreover, for the reduction of computational complexity, we change reference regions in hierarchical framework. The experimental results show that the proposed method can acquire good results which are robust to homogeneous and object boundary regions.
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When working with multi-view images, imbalances between multi-view images occur a serious problem in multi-view video coding because they decrease the performance of disparity estimation. To overcome this problem, we propose inter-view balanced disparity estimation for multi-view video coding. In general, the imbalance problem can be solved by a preprocessing step that transforms reference images linearly. However, there are some problems in pre-processing such as the transformation of the original images. In order to obtain a balancing effect among the views, we perform block-based disparity estimation, which includes several balancing parameters.
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Virtual view synthesis is essential for 3DTV systems, which utilizes the motion parallax cue. In this paper, we propose a multi-step view synthesis algorithm to efficiently reconstruct an arbitrary view from limited number of known views of a 3D scene. We describe an efficient image rectification procedure which guarantees that an interpolation process produce valid views. This rectification method can deal with all possible camera motions. The idea consists of using a polar parameterization of the image around the epipole. Then, to generate intermediate views, we use an efficient dense disparity estimation algorithm considering features of stereo image pairs. Main concepts of the algorithm are based on the region dividing bidirectional pixel matching. The estimated disparities are used to synthesize intermediate view of stereo images. We use computer simulation to show the result of the proposed algorithm.
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This paper presents precise measurement system for the lifetime of OLED. The proposed system collects the data for using voltage drop across the OLED Panels, and then the computer program makes an analysis of the data. In this process of measurement, the current across OLED material must be amplified because the current is very small. However, amplifying the current causes the amplification of noise. Therefore, the proposed system measures the current using an algorithm which minimizes the noise.
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In this paper, a spatial-based perceptual watermarking considering human visual system (HVS) that is proposed for small-size images such as internet shopping-mall image. In our method, a multi-bit data can be embedded in luminance component of color images still keeping the perceptual quality of image. Experimental results demonstrated that watermarks can be strongly embedded while preserving a good fidelity.
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This paper is concerned with a substantial speed up of image processing methods and less power consumption on 2D images making use of modern FPGA (Field Programmable Gate Array) technology. We implemented 2D FFT and edge detection algorithms based on FPGA and examined processing time and power consumption compared with C/C++ and Alti-Vec technologies.
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In this paper, we propose tracking algorithm using multi resolution in wavelet transform domain. This algorithm consists of two steps. The first step is feature extraction that is select feature-points using 1-level wavelet transform in ROI (Region of Interest). The other step is feature tracking. Based on multi resolution of wavelet transform, we estimate a displacement between current frame and next frame on the basis of selected feature-points. Experimental results show that the proposed algorithm confirmed a better performance than a centroid tracking and correlation tracking.
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This paper describes an adaptive hybrid fingerprint matching method using minutiae, filterbank, and the quality of fingerprint. We estimate the quality of each block in the fingerprint image and extract the probability expectation about the quality of each block. By using this expectation, we could achieve the robust matching rate despite of noise distortion. The matching rate of the proposed method is higher than that of other methods. However, the matching speed is similar with that of others as shown in the results.
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In this paper, we present a 3D reconstruction method using multi-camera. This method is very compact algorithm so that can be implemented easily on small hardware architecture. By using multi-camera, it gives exacter result than existing method and we propose accurate index for each matching nodes to use multi-camera.
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In this paper, we propose an invertible biometric image watermarking algorithm which can detect block-wise malicious manipulations. The proposed method embeds two types of watermark. The first type can completely remove distortion due to authentication if the data is deemed authentic. The second type can detect block-wise malicious manipulation by applying the parity bits concept to biometric image blocks.
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This paper presents an automatic pose-normalized 3D face data acquisition method using 2D and 3D information. We propose an automatic pose-normalized 3D face acquisition method that accomplishes 3D face modeling and 3D face pose-normalization at once. The proposed method uses 2D information with AAM (Active Appearance Model) and 3D information with 3D normal vector. The 3D face modeling system consists of 2 cameras and 1 projector. In order to verify proposed pose-normalized 3D modeling method, we made an experiment for 2.5D face recognition. The experimental result shows that proposed method is robust against pose variation.
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This paper propose design and implementation methods of ensemble multiplexer which is the purpose of Terrestrial DMB Conditional Access Service. Also transmit ensemble stream which is scrambled through the proposed ensemble multiplexer, by descrambling or decoding received stream as the scramble mode which is applicated through receiving verfication platform and by desplaying it, verificate the performance of ensemble multiplexer.
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In this paper we introduce the implementation of PC-based receiver platform to verify T-DMB middleware APIs. Recently, generic APIs in T-DMB middleware (called DMB MATE API) have been designed to enable inter-operable applications to be downloaded from both the broadcast and telecommunication networks in advance and to be executed on T-DMB receivers from any manufacturers. We also verify the designed MATE API through execution of several applications at the PC-based receiver. In future, the T-DMB middleware verified in PC can be implemented at various receivers such as T-DMB phone and portable T-DMB receiver.
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In this paper, novel analog duty cycle corrector (DCC) with a digital duty error detector is proposed. The digital duty error detector measures the duty error of the clock and converts it into a digital code. This digital code is then used to accurately correct the duty ratio by adaptively steering the charge-pump current. The proposed duty cycle corrector was implemented using an 80nm DRAM process with 1.8V supply voltage. The simulation result shows that the proposed duty cycle corrector improves the settling time up to
$70{\sim}80%$ at 500MHz clock frequency for the same duty correction accuracy as the conventional analog DCC. -
To perform the comparative study, we experimented on two differential epitaxial structures, the conventional Metamorphic High Electron Mobility Transistor (MHEMT) using the InAlAs/InGaAs structure and the InP-composite channel MHEMT adopting the InAlAs/InGaAs/InP/n-InP structure. Compared to the conventional MHEMT, the InP-composite channel MHEMT shows improved breakdown performance; over about 3.5 V. This increased breakdown voltage can be explained by the lower impact ionization coefficient of the InP-composite channel MHEMT than that of the conventional MHEMT.
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Surface Acoustic Wave(SAW) devices can be used to as wireless sensor elements, called SAW transponders, for measuring shysical quantities such as temperature that do not need any power supply and may be accessed wirelessly. SAW devices were fabricated on Y-Z
$LiNbO_3$ piezoelectric substrate with a good temperature coefficient property. The signal response of SAW sensor on the temperature change were compared. To measure the change of SAW velocity. Temperature changed form$20^{\circ}C$ to$400^{\circ}C$ was linearly changed, the SAW sensor is application to the temperature sensor. -
Baek, Yong-Hyun;Oh, Jung-Hun;Han, Min;Choi, Seok-Gyu;Lee, Bok-Hyung;Lee, Seong-Dae;Lee, Jin-Koo 471
The passivation technology is very important, because this technology can protect a device against the influence of ambient environment, and prevent the performance reduction. In this paper, we fabricated the$0.1{\mu}m\;{\Gamma}$ -gate InAlAs/InGaAs metamorphic high electron mobility transistors (MHEMTs) on GaAs substrates using the low-k benzocyclobutene (BCB) and$Si_3N_4$ as a passivation and we performed the comparisons of characteristics of the MHEMTs. After passivation, the DC and RF measurement results were decreased either the conventional Si3N4 or BCB layers. The decrement of the BCB passivation was smaller than the$Si_3N_4$ passivation. -
Boron Phosphide films were deposited on (111) Si substrate at
$650^{\circ}C$ , by the reaction of B2H6 with PH3 using APCVD. N2 was carried out as carrier gas. The optimal gas rates were$20\;m{\ell}/min$ for B2H6,$60\;m{\ell}/min$ for PH3 and$1\;{\ell}/min$ for N2. After as grown the films were insitu annealed for 1hour in N2 ambient at$550^{\circ}C$ and measured. The measurement of AFM shows that the RMS is$29.626{\AA}$ for the reaction temperature at$650^{\circ}C$ . The measurement of XRD shows that the films have the orientation of (101). Also, the measurement of AES is shown that the films have B13P2 stoichiometry. -
Cho, Seong-Jae;Yun, Jang-Gn;Park, Il-Han;Lee, Jung-Hoon;Kim, Doo-Hyun;Lee, Gil-Seong;Lee, Jong-Duk;Park, Byung-Gook 475
Recently, the demand for high density MOSFET arrays are increasing. In implementing 3-D devices to this end, it is inevitable to ion-implant vertically in order to avoid screening effects caused by high silicon fins. In this study, the dependency of drain current characteristics on doping profiles is investigated by 3-D numerical analysis. The position of concentration peak (PCP) and the doping gradient are varied to look into the effects on primary current characteristics. Through these analyses, criteria of ion-implantation for 3-D devices are established. -
In this paper, we could improve the mobility with OTS treatment on PVP gate, and also reduce the off-state current, which was usually large after OTS treatment, by using cosolvent. Also we treated Hexamethyl-disilazane (HMDS) and Ozone on PVP. It gives large off-state currents and on-currents.
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We fabricated pentacene organic thin film transistor with good uniformity. And we extracted contact resistance in organic thin film transistors from the plot of the inverse of drain current versus channel length by extrapolating the curve to a channel length of zero, and multiplying by drain-source voltage. Extracted contact resistance is about
$70K{\Omega}$ at gate-drain voltage of -20 V -
In this paper, we fabricated the organic bi-stable devices under the different condition from the other groups and analyzed the electrical characteristics. Then we investigated the effects of the device structure such as organic layer thickness, middle metal layer thickness and middle metal layer deposition rate on the memory characteristics.
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This paper proposes a novel low-cost CMOS temperature sensor for controlling the self-refresh period of a mobile DRAM. In this temperature sensor, ring oscillators composed of cascaded inverter stages are used to obtain the temperature of the chip. This method is highly area-efficient, simple and easy for IC implementation as compared to traditional temperature sensors based on analog bandgap reference circuits. The proposed CMOS temperature sensor was fabricated with 80 nm 3-metal DRAM process. It occupies a silicon area of only about less than
$0.02\;mm^2$ at$10^{\circ}C$ resolution with under 5uW power consumption at 1 sample/s processing rate. This area is about 33% of conventional temperature sensor in mobile DRAM. -
In this paper, we analyzed the FBGA packages operating in high speeds and high frequency rates for DRAM. Using 3D simulations, we could extract s-parameters of packages. We realize that the proposed FBGA package does not operate properly at 3Gbps bacause the FBGA package have delta-I noise(
$V_{{\Delta}I-peak}$ ) of 132.0mV and crosstalk of 300mV, which is 25% of the operating clock level. -
This paper presents a switch type 2.4/5.8 GHz dual band low-noise amplifier, designed with
$0.13{\mu}m$ RF CMOS technology. Using MOS switch allows the LNA to have two different input transconductance and output capacitance modes. Given supply voltage of 1.2 V, the simulation exhibits gains of 8.1 dB and 17.1 dB, noise figures of 3.1 dB and 2.57 dB and power consumptions of 13.0 mW and 10.2 mW at 2.4 GHz and 5.8 GHz, respectively. -
Lee, Sang-Jin;Ahn, Dan;Lee, Mun-Kyo;Kwon, Hyuk-Ja;Baek, Tae-Jong;Jun, Byoung-Chul;Park, Hyun-Chang;Rhee, Jin-Koo 491
The MMIC (Microwave Monolithic Integrated Circuit) self oscillating double conversion mixer was designed and fabricated for the V-band transmitter applications. The MMIC self oscillating double conversion mixer which dose not need external local oscillator was designed using GaAs PHEMT technology. The first self oscillating mixer use PHEMT technology. The first self oscillating mixer use PHEMT for$f_{LO}$ signal generation and$f_{IF}$ signal is applied at gate port and$f_{RF1}$ signal is generated at a drain port of first stage. The second gate mixer use PHEMT for$f_{LO}$ signal and$f_{RF1}$ signal is applied at gate port and$f_{RF2}$ signal is output at a drain port of second stage. -
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Lee, Jong-Wook;Kim, Sung-Won;Kim, Kyoung-Woon;Seol, Gyung-Seon;Kwon, Young-Woo;Seo, Kwang-Seok 495
This paper reports a high power 60 GHz push-push oscillator fabricated using 0.12 um metamorphic high electron-mobility transistors (mHEMTs). The devices with a$0.1{\mu}m$ gate-length exhibited good DC and RF characteristics such as a maximum drain current of 700 mA/mm, a peak gm of 660 mS/mm, and an$f_T$ of 170 GHz. By combining two sub-oscillators having$6{\times}50{\mu}m$ periphery mHEMT, the push-push oscillator achieved a 6.3 dBm of output power at 59.5 GHz with more than -35 dBc fundamental suppression. This is one of the highest output power obtained using mHEMT technology without buffer amplifier, and demonstrates the potential of mHEMT technology for cost effective millimeter-wave commercial applications. -
This paper presents a fast switching CMOS frequency synthesizer with a new coarse tuning method for PHS applications. To achieve the fast lock-time and the low phase noise performance, an efficient bandwidth control scheme is proposed. Charge pump up/down current mismatches are compensated with the current mismatch compensation block. Also, the proposed coarse tuning method selects the optimal tuning capacitances of the LC-VCO to optimize the phase noise and the lock-time. The measured lock-time is about
$20{\mu}s$ . This chip is fabricated with$0.25{\mu}m$ CMOS technology, and the die area is$0.7mm{\times}2.1mm$ . The power consumption is 54mW at 2.7V supply voltage. -
In this paper low power high gain amplifier is suitable for application in low power systems was designed and fabricated. The amplifier used both subthreshold bias for low power and positive feedback Q-enhancement technique for high gain. The amplifier used TSCM
$0.18{\mu}m$ RF CMOS technology measures a power gain of 32.3dB, a quality factor of 366 and a power consumption of 3mW in a supply voltage of 1.8V. -
This paper presents the design and fabrication of a LC voltage-controlled oscillator (VCO) using 1-poly 6-metal mixed signal CMOS process. To obtain the high-quality factor inductor in LC resonator, patterned-ground shields (PGS) is placed under the symmetric inductor to reduce the effect from image current of resistive Si substrate. Moreover, due to the incapability of using thick top metal layer of which the thickness is over
$2{\mu}m$ , as used in many RF CMOS process, the structure of dual-metal layer in which we make electrically short circuit between the top metal and the next metal below it by a great number of via materials along the metal traces is adopted. The circuit operated from 2.63 GHz to 3.09 GHz tuned by accumulation-mode MOS varactor. The corresponding tuning range was 460 MHz. The measured phase noise was -115 dBc/Hz @ 1MHz offset at 2.63 GHz carrier frequency and the current consumption and the corresponding power consumption were about 2.6 mA and 4.68 mW respectively. -
In this paper, the linearization technique for CMOS low-noise amplifier (LNA) using the derivative superposition method through the multiple gated transistors configuration is presented. LNA based on 0.13um RF CMOS process has been implemented with a modified cascode configuration using multiple gated common source transistors to fulfill a high linearity. Compared with a conventional cascode type LNA, the third order input intercept point (IIP3) per DC power consumption (IIP3/DC) is improved by 3.85 dB. The LNA achieved 2.5-dBm IIP3 with 13.4-dB gain, 3.6 dB NF at 2.4 GHz consuming 8.56 mA from a 1.5-V supply.
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High performance delta-sigma modulator is developed for audio-codec applications(i.e.. 16-bit resolution at a 20kHz signal bandwidth). The modulator is realized with fully-differential switched capacitor integrators. All stages employ a single-stage folded-cascode amplifier. The presented delta-sigma modulator when clocked at 3.2MHz achieves 85.2dB peak-SNDR and 94.8dB SNR. This modulator is designed in a SAMSUNG
$0.18{\mu}m$ CMOS process. Finally, this paper shows the test setup and FFT result gained from delta-sigma modulator chip designed for audio applications. -
FLL (Frequency Locked Loop) is the core block for high-speed transceiver. It incorporates a PLL for fine locking action, and a coarse controller for coarse locking action. A coarse controller compares frequencies coarsely and is applied to detected frequency difference directly. Compare to conventional FLL, frequency is applied to proposed FLL. Proposed FLL in this paper achieves only 5 cycles for coarse lock and total frequency locking time is 5 times faster than conventional FLL. Thus, proposed FLL is more useful to Ethernet transceiver application that requires high-speed data transfer than conventional FLL. Proposed FLL is based on
$0.18{\mu}m$ process. -
Byun, San-Ho;Ryu, Seong-Young;Choi, Young-Kil;Roh, Hyung-Dong;Lee, Hyun-Tae;Kang, Kyoung-Sik;Roh, Jeong-Jin 511
Three stage(CIC-FIR-FIR) decimation filter in delta-sigma A/D converter for audio is designed. A canonical signed digit(CSD) code method is used to minimize area of multipliers. This filter is designed in 0.25um CMOS process and incorporates$1.36\;mm^2$ of active area. Measured results show that this decimation filter is suitable for digital audio A/D converters. -
As power supply managements become more important than before, supplying a stable system voltage is becoming more and more critical. In this study we propose to use the advantage of weak inversion region of MOS transistors. Analog system, which uses weak inversion region, could work in low voltage environment and reduce power consumption. The proposed buck-converter in weak inversion region of MOS transistor has been verified by silicon chip.
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A THz near-field microscope(THz NFM) is developed by a combination of THz time-domain spectroscopy and AFM(Atomic Force Microscopy). We have observed 80nm lateral resolution, demonstrating that the THz NFM technique has a great potential as a important probing tool for the analysis of the biological and semiconductor nanostructures.
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Park, Hong-Kyu;Kim, Jeong-Hoi;Jung, Eun-A;Han, Hae-Wook;Choi, Won-Jun;Lee, Jung-Il;Song, Jin-Dong 517
Optically pumped THz emission has been observed in a wide range of semiconductors, and this process is an important practical source of pulsed THz radiation for time-domain THz spectroscopy and THz imaging. We show that InAs quantum dots on GaAs can be used to significantly enhance THz emission compared with a bare GaAs surface. -
In this paper, we propose a voltage-controlled ring oscillator (VCO) for a 900 MHz low-noise fractional-N frequency synthesizer. The VCO delay cell is based on an nMOS source-coupled pair with load elements [1] and a combined tail current sources which consist of a large and a small current source to control the integer and fractional behaviors, respectively. The Spectre simulation results of the scheme in a 0.18um CMOS process show the accurate control of the KVCO better than the conventional one.
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This paper presents behavioral models using SIMULINK and Verilog-a for a PLL based fractional-N frequency synthesizer. The SIMULINK modeling was built in the frequency-time mixed domain whereas the Verilog-a modeling was built purely in the time domain. The simulated results of the two models were verified to show the same performance within the error tolerance. This top-down design method can provide the readiness for the transistor-level design.
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Successive approximation A/D converters have an advantage of small chip area and simple algorithm. We propose an improved non-redundant successive approximation register (SAR) which can be incorporated in successive approximation A/D converters. The proposed SAR validates the preset state as the
$1^{st}$ reference voltage to the comparator. Two redundant clock cycles in the typical design could be eliminated in the proposed A/D converter. -
A macro model for Savtchenko switching mode MRAM (toggling MRAM) cells which can be utilized to develop the core architecture and the peripheral circuitry is proposed, and a writing scheme suitable to the toggling characteristic is developed. The sensing and writing operations of the toggling MRAM adopting the macro model are verified by Spectre simulations.
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In this paper, we propose an IP design and implementation of System on a chip(SoC) for Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT) processor using adder-based DA(Adder-based Distributed Arithmetic). To reduced hardware cost and to improve operating speed, the combined DCT/ DWT processor used the bit-serial method and DA module. The transform of coefficient equation result in reduction in hardware cost and has a regularity in implementation. We use Verilog-HDL and Xilinx ISE for simulation and implement FPGA on SoCMaster-3.
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An efficient sensing scheme adoptable in DC-DC converter is described. The output voltage of the whole DC-DC converter is fed back to the input voltage of the sensor. The comparison in the sensor is accomplished by a current push-pull action. With a fixed reference, the comparator can be embodied based on (W/L) ratios. The current-mode scheme benefits the system better than a conventional voltage-mode one in terms of small area, low power consumption.
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This paper presents our implemented, synthesized and tested on demand and partial reconfiguration approaches for FIR filters using Xilinx Virtex FPGAs. Our scope is to implement a low-power, area-efficient autonomously reconfigurable digital signal processing architecture that is tailored for the realization of arbitrary response FIR filters on Xilinx Virtex4 FPGAs. The implementation of design addresses area efficiency and flexibility allowing dynamically inserting and/or removing the partial modules to implement the partial reconfigurable FIR filters with various taps. This partial reconfigurable FIR filter design shows the configuration time improvement, good area efficiency and flexibility by using the dynamic partial reconfiguration method.
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This paper presents the architecture design of a high-speed, low-complexity 128-point radix-
$2^4$ FFT processor for ultra-wideband (UWB) systems. The proposed high-speed, low-complexity FFT architecture can provide a higher throughput rate and low hardware complexity by using 2-parallel data-path scheme and single-path delay-feedback (SDF) structure. This paper presents the key ideas applied to the design of high-speed, low-complexity FFT processor, especially that for achieving high throughput rate and reducing hardware complexity. The proposed FFT processor has been designed and implemented with the 0.18-m CMOS technology in a supply voltage of 1.8 V. The throughput rate of proposed FFT processor is up to 1 Gsample/s while it requires much smaller hardware complexity. -
Design and Implementation of Inter-IC Bus Interface for Efficient Bus Control in the Embedded SystemIn the embedded system, external device interface that operates serial protocol with lower speed than the general computers is used commonly. This paper describes I2C bus protocol that is a bi-directional serial bus with a two-pin interface. The I2C bus requires a minimum amount of hardware to relay status and reliability information concerning the processor subsystem to an external device.
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The dependence of cutoff frequency and maximum oscillation frequency of
$0.13{\mu}m$ CMOS transistors on layout parameters such as the unit gate width and gate finger number is measured and analyzed in this paper. This information will be very useful for high performance RF IC design. -
In this paper, I propose the field emission tip for the E-beam array system that is made by carbon nanotubes(CNT). CNT is one of the most expected future materials, because of its great mechanical, chemical and electrical characteristics. So CNT can be used for many applications such as electron emitter, sensor, single electron transistor and AFM tip. And CNT will be applied to our E-beam array system as field emission tip so we will improve the system's electrical characteristics.
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Pentacene thin film transistors fabricated without photolithographic patterning were fabricated on the plastic substrates. Both the organic/inorganic thin films and metallic electrode were patterned by shifting the position of the shadow mask which accompanies the substrate throughout the deposition process. By using an optically transparent zirconium oxide (
$ZrO_2$ ) as a gate insulator and octadecyltrimethoxysilane (OTMS) as an organic molecule for self-assembled monolayer (SAM) to increase the adhesion between the plastic substrate and gate insulator and the mobility with surface treatment, high-performance transistor with field effect mobility$.66\;cm^2$ /V s and$I_{on}/I_{off}$ >$10^5$ was formed on the plastic substrate. This technique will be applicable to all structure deposited at low temperature and suitable for an easy process for flexible display. -
The improved model that external capacitances are connected to a conventional BSIM3v3 RF Macro model with Rg and Rsub is developed in this paper. The extracted external capacitances and resistances are modeled by scalable fitting equations. The modeled S-parameters of
$0.13{\mu}m$ NMOSFET agree well with measured ones from 10MHz to 10GHz, verifying the accuracy of the improved model. -
In this paper, cost effective parallel-branch inductor has been proposed and developed in order to increase the quality factor of the conventional spiral inductor. This parallel-branch inductor is composed of only two metals. The presented parallel-branch inductor shows 12% improvement in the quality factor with the same area as the conventional inductor. Also, we improve the parallel-branch inductor for high frequency applications.
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Kim, Han-Hyoung;Yang, Seung-Kook;Yoo, Han-Suk;Lee, Seung-Yong;O, Beom-Hoan;Lee, Seung-Gol;Lee, El-Hang;Park, Se-Geun 549
It has become topic continuously at MEMS or semiconductor process to form three-dimensional multilayer structure. In this paper, we devised the new polymer pattern method that has multilayer structure. This is method that uses different kind of polymeric material. Specially, polymers used in this study that we propose became all pattern by photolithography, prevented that process increases. Here, polymer that we use used polymer of epoxy order called "SU-8" and polymer of novolak resin called "AZ-1518". The result, "SU-8" was formed pattern to 3.5um thickness, and "AZ-1518" about pattern 3um thickness. Also, It was been 6um thickness at same pattern area. -
Yang, Seung-Kook;Lee, Seung-Yong;Yu, Han-Suk;Kim, Han-Hyung;Song, Ho-Young;Lee, Jong-Geun;Park, Se-Geun 551
Plasma-induced charging damage was been measured during TaN gate electrode of MISFET(TaN/$HfO_2$ /Si) or interconnection metal etching step using large antenna structures. The results of these experiments were obtained that$HfO_2$ gate dielectric layer was affected about plasma charging effects and damage increased with F-N tunneling. Therefore, the etching conditions should be optimized to avoid the defects caused by plasma charging. -
Kim, Sung-Won;Seol, Gyung-Sun;Kim, Kyoung-Woon;Choi, Woo-Yeol;Kwon, Young-Woo;Seo, Kwang-Seok 553
In this paper, 77 GHz CPW power amplifier MMIC, which are consisted of a 2 stage driver stage and a power stage employing$8{\times}50um$ gate width, have been successfully developed by using 120nm$In_{0.4}AlAs/In_{0.35}GaAs$ Metamorphic high electron mobility transistors (MHEMTs). The devices show an extrinsic transconductance$g_m$ of 660 mS/mm, a maximum drain current of 700 mA/mm, and a gate drain breakdown voltage of -8.5 V. A cut-off frequency ($f_T$ ) of 172 GHz and a maximum oscillation frequency ($f_{max}$ ) of over 300 GHz are achieved. The fabricated PA exhibited high power gain of 20dB only with 3 stages. The output power is measured to be 12.5 dBm. -
In this paper, we have proposed a novel process using two-step electron beam lithography to fabricate 20 nm T-gates for high performance MODFETs. Two-step lithography reduces electron forward scattering by defining the foot on a thin (100 nm) bottom-layer of polymethyl methacrylate (PMMA) at the second step, the T-gate head having been developed at the first step. Adopting a low temperature development technique for the second step reduces the detrimental effect of head exposure on foot definition. We have shown that 20 nm T-gate can be patterned with this process.
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Goo, Nam-Hee;Song, Seung-Hyun;Choi, Gil-Bok;Song, Keun-Kyoo;Kim, Bo-Sung;Shin, Sung-Sik;Jeong, Yoon-Ha 557
In this paper, the hysteresis characteristics by bias stress in organic thin film transistors using inkjet printing were investigated. Electron trapping increased threshold voltage for positive gate bias stress and hole trapping decreased threshold voltage for negative gate bias stress. From these phenomena, highly reproducible measurement method which minimized threshold voltage shift by choosing the proper range of gate voltage was suggested. Using this measurement method, we found that electron trapping as well as hole trapping had important influence on hysteresis characteristics. -
The paper presents solutions of conventional piezoresistive pressure sensors. Deflection of diaphragm by external stress causes some problems, because the electrode is deposited on the diaphragm formed piezoresistors. To solve these problems, piezoresistors is formed by two implantation steps. To fabricate diaphragm, the backside silicon etching step is done by immersing the wafer into TMAH solution.
$30{\mu}m$ thick diaphragm is obtained. Sensitivity of the piezoresistive pressure sensor fabricated is 48.6 mV/V-psi. -
This paper presents an SRAM which uses the technique to equalize the internal cell node by adding an NMOS transistor. Accordingly, the write driver operates rapidly in a differential current of bit lines, and the operation speed of SRAM improves. An SRAM was implemented with a memory cell, a sense amplifier and a write driver. The SRAM obtained the performance of 18% power reduction and improvement of 56% operation speed. And Power delay product was reduced with 63%. The proposed SRAM was designed based on a 0.35um 1P4M CMOS technology.
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Kang, Hyung-Geun;Jeon, Sung-Chae;Jin, Seoung-Oh;Lim, Gyu-Ho;Woo, Eum-Chan;Huh, Young;Sung, Kwan-Young;Park, Mu-Hun;Ha, Pan-Bong;Kim, Young-Hee 563
A single photon counting type image sensor which is applicable for medical diagnosis with digitally obtained image and industrial purpose has been designed using$0.25{\mu}m$ triple well CMOS process. -
In this work, We study electrical characterization of
$HfO_2$ /Hf/Si films grown by Atomic Layer Deposition(ALD). Through AES(Auger Electron Spectroscopy), capacitance-voltage(C-V) and current-voltage(I-V) analysis, the role of Hf layer for the better$HfO_2$ /Si interface property was investigated. We found that Hf metal layer in our structure effectively suppressed the generation of interfacial$SiO_2$ layer between$HfO_2$ film and silicon substrate. -
We investigate the structures and the formation energy of inversion domain boundaries (IDBs) using the Tersoff empirical potential. Four kinds of IDBs ( A and B types for IDB* and Holt ) are considered. The IDBs with A type are energetically favorable compared to B type with the structural instability. The IDB* is also more stable than the Holt type in spite of fourfold and eightfold rings of bonds. We calculate the atomic configurations of the Holt IDBs induced by the interactions of the IDB* with the stacking faults
$I_1$ and$I_2$ . The stacking fault$I_2$ interacted with$I_1$ on the IDB induces the structural transformation from IDB* to Holt type. -
Effects of the evaporation rate of MgO films using electron beam were investigated on the MgO properties and the discharge characteristics of the plasma display panel (PDP). The evaporation rate was changed from
$3{\AA}$ /sec to$15{\AA}$ /sec at a substrate temperature of$300^{\circ}C$ . MgO properties such as crystal orientation, surface roughness, contact angle, and film structure were inspected using XPS, AFM, drop shape analysis and SEM. We also studied the relation between MgO properties and PDP discharging characteristics. The minimum firing voltage and maximum efficacy were obtained at evaporation rate of$5{\AA}$ /sec. In the MgO film deposited at$5{\AA}$ /sec, (200) orientation was most intensive and surface roughness was minimum. -
A simulation tool for design space exploration of a real-time reconfiguration system was developed in this paper. We described an algorithm for a partial real-time reconfiguration to utilize already existing configured functional units and applied it to H.263 encoder application. This scheme allows us to find a starting configuration for the further optimization without actually building a prototype.
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A low-power power-aware scalable pipelined Booth recoded multiply & Accumulate unit (PA-MAC) detects the input operands for their dynamic range and accordingly implements a 16-bit, 8-bit or 4-bit multiplication and accumulation operation. The multiplication mode is determined by the dynamic - range detection unit. For the computations, although an area of the proposed PA-MAC is lager than a non-scalable MAC respectively, the proposed PA-MAC proves to be globally more power efficient than a non-scalable MAC.
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It was analyzed qualitatively the light extraction in GaN-on-sapphire LEDs based on a simple model. The light extraction efficiency in the LEDs is simulated numerically by using ray tracing method. In the present study, the extraction efficiency was simulated on three different types of LEDs, which a have a different pattered sapphire substrate. And, the role of the patterned sapphire substrate are analyzed and discussed. Based on the analysis, the improvements of extraction efficiency in the LED structures were discussed and these analyses are helpful in the design of high brightness GaN LEDs.
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Simple nonoverlapped source/drain-to-gate MOSFETs to suppress GIDL (gate-induced drain leakage) is simulated with SILVACO simulation tool. Changing spacer thickness for adjusting length of Drain to Gate nonoverlapped region, this simulation observes on/off characteristic of nonoverlapped source/drain-to-gate MOSFETs. Off current is dramatically decreased with S/D to gate nonoverlapped length increasing. The result shows that maximum on/off current ratio is achieved by adjusting nonoverlapped length.
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In this paper, we investigate three different types of multi-fingered layout nMOSFET devices with varying
$W_f$ (unit finger width) and$N_f$ (number of finger). Using layout modification, we improve$f_T$ (current gain cutoff frequency) value of 15GHz without scaling down, and moreover, we decrease$NF_{min}$ (minimum noise figure) by 0.23dB at 5GHz. The RF noise can be reduced by increasing$f_T$ , choosing proper finger width, and reducing the gate resistance. For the same total gate width using multi-fingered layout, the increase of finger width shows high$f_T$ due to the reduced parasitic capacitance. However, this does not result in low$NF_{min}$ since the gate resistance generating high thermal noise becomes larger under wider finger width. We can obtain good RF characteristics for MOSFETs by using a layout optimization technique. -
This paper presents transistor matching in 70 nm nMOS. To adopt radio frequency(RF) applications, the RF performance, especially the current gain cutoff frequency(
$f_T$ ), is examined experimentally through a wafer. It is proved that the RF performance variation of 70 nm nMOS is dependent to the device geometry, the total width(W). The RF performance variation of 70 nm nMOS is inversely proportional to square root of total width(W). Also, decreasing of the number of fingers($N_f$ ) is helpful to decrease the variation of 70 nm nMOS. -
본 논문에서는 MEMS 용량형 변위 센서의 제작과 함께, 미세 변위 측정을 위한 테스트 샘플을 제작하였다. 아래의 그림 1, 2는 각각 스테이지에 장착할 MEMS 용량형 변위 센서 및 미세 변위 측정을 위한 테스트 샘플의 개념도를 보여주고 있다. 테스트 샘플의 감지 부분은 스테이지에 장착할 센서와 정확히 일치를 시켰으며, 미세 변위를 주기 위해서 comb-drive actuator 형태의 운동부를 두었다. 운동부에서는 DC 및 AC 전압을 인가함으로써 미세 변위를 얻을 수 있었으며, 사용된 DC 전압은 20V였으며, 1.4kHz의 AC 전압을 크기를 변화시키며 인가하였다.
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This paper presents the new structural zener triggered silicon-controlled rectifier (ZTSCR) electrostatic discharge (ESD) protection circuit. The proposed ESD protection circuit has lower triggering voltage than conventional circuits. The proposed ZTSCR has the triggering voltage of 4V. In the ESD event, this proposed novel ZTSCR ESD protection device could trigger quickly and provide an effective discharging path.
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A novel Triple-Well P-type Triggered Silicon Controlled Rectifier (TWPTSCR) for on-chip ESD protection implemented with a triple-well CMOS technology is presented. Unlike conventional SCR devices, the proposed TWPTSCR offers a reduced triggering voltage level as well as the enhanced ESD performance of the SCR devices. From the experimental results, the TWPTSCR with a device width of 20um has the triggering voltage of 1.1V.
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Schottky diodes for Radio-frequency identification (RFID) tag integration on chip were designed and fabricated using Samsung electronics System LSI standard
$0.18{\mu}m$ CMOS process. Schottky diodes were designed as interdigitated fingers array by CMOS layout design rule. 64 types of Schottky diode were designed and fabricated with the variation of finger width, length and numbers with a$0.6{\mu}m$ guard ring enclosing n-well. Titanium was used as Schottky contact metal to lower the Schottky barrier height. Barrier height of the fabricated Schottky diode was 0.57eV. DC current - voltage measurements showed that the fabricated Schottky diode had a good rectifying properties with a breakdown voltage of -9.15 V and a threshold voltage of 0.25 V. -
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A novel Si via structure is suggested and fabricated for 3D MEMS package using the doped silicon as an interconnection material. Oxide isolations which define Si via are formed simultaneously when fabricating the MEMS structure by using DRIE and oxidation. Silicon Direct Bonding Multi-stacking process is used for stacked package, which consists of a substrate, MEMS structure layer and a cover layer. The bonded wafers are thinned by lapping and polishing. A via with the size of
$20{\mu}m$ is fabricated and the electrical and mechanical characteristics of via are under testing. -
This paper describes a development of a new
$1.4{\times}1.1$ and$2.0{\times}1.4mm$ RF SAW filters made by PCB substrate instead of HTCC package, and this technology can reduce the cost of materials down to 40%. We have investigated the multi-layered PCB substrate structures and raw materials to find out the optimal flip-bonding condition between the$LiTaO_3$ wafer and PCB substrates. Also the optimal materials and processing conditions of epoxy laminating film were found out through the experiments which can reduce the bending moment caused by the difference of the thermal expansion between the PCB substrate and laminating film. The new PCB SAW filter shows good electrical and reliability performances with respect to the present SAW filters. -
본 연구는 솔더의 리프로우 현상으로부터 제안되었다. 솔더는 원형 흡착 층 위에서 녹게 되면 단위 면적당 표면 에너지를 최소화 하려는 특성 때문에 구형이 되는데, 이는 자기정렬 기구의 핵심이기도 하다. 본 연구에서 제안되는 새로운 설계가 기존의 설계와 가장 큰 차이점은 그림 1에서 처럼 솔더의 리프로우에 의해 측면 접합을 한다는 것이다. 대부분의 기존 실장 기술은 접합 면과 피 접합 면이 서로 마주보고 있으며 서로 맞닿아야만 접합이 이루어 지는 "intimate contact" 원리인 반면, 본 연구에서 제안된 개념은 접합 면과 피 접합 면이 쏠더에 의해 끼워진 상태에서 측면 접합되는 원리이 기 때문에 접합 면끼리 서로 인접하지 않아도 접 합은 자연적으로 완성되어 접합면의 표면상태에 충분히 둔감하다는 장점을 가질 수 있다. 그림 1의 (b)는 개념도 (a)를 구현하기 위한 제작 공정을 보여준다. 버섯 모양의 구조물을 형성하는 공정과 측벽에 UBM을 선택적으로 형성하는 공정이 핵심 공정이며 이외의 접합 공정은 기존의 방법과 달리 매우 간단하게 완성시킬 수 있다. 본 논문에서는 기본적으로 제안된 방법으로 구현되는 실장결과와 그 기본적인 기계적 강도, 기밀 특성을 살펴 보았다. 그리고 RF 소자의 실장에 있어서 제안된 방법에 의한 전기적 연결의 기초 결과에 대해서 논의한다.
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A physics-based equivalent circuit model for LTCC Helical type Inductors is presented. All of the electromagnetic couplings between conductors are included in the model and the number of optimized parameters is minimized. The model can predict the measured results upto 12 GHz.
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A small size broadband microstrip patch antenna with small ground plane has been fabricated using MEMS. Multiple layer of high and low dielectric substrates are used to realize small size and broadband characteristics. The microstrip patch is divided into 4 pieces and each patch is connected to each other using a metal microstrip line. The fabrication process is very simple and only one mask is needed. Two types of microtrip antennas are fabricated. Type A is the microstrip antenna with metal lines and type B is the microstrip antenna without metal lines. The size of proposed microstip antenna is
$8*12*2mm^3$ and the experimental results show that the antenna type A and type B have the bandwidth of 420MHz at 5.3 GHz and 480MHz at 5.66 GHz, respectively. -
Voltage Controlled Oscillator(VCO) plays an important role in today's communication systems. Especially, a Clock Generator(CG) in phase-locked loop(PLL) is usually realized by the VCO. This paper proposes a new VCO with a controllable duty cycle buffer, that can be adopted in low-power high-speed communication systems. Delay cell of the VCO is implemented with gilbert cell. Frequency dynamic range of the VCO is in the range of approximately
$50MHz{\sim}500MHz$ . Parameters with N-well CMOS 0.18-um process with 1.8V supply voltage was used for the simulations. -
A CMOS phase-locked loop (PLL) which synthesizes frequencies between
$6.336{\sim}8.976GHz$ in steps of 528MHz and settles in approximately 150ns using the 528MHz reference clock is presented. Frequency hopping between the bands in the each mode is critical point to design the PLL in multi-band orthogonal frequency division multiplexing (OFDM) because frequency switching between each band is less than 9.5ns. To achieve the fast loop settling, integer-N PLL that operates with the high reference frequency to meet the settling requirement is implemented. Two PLLs that operate at 9GHz and 528MHz is integrated and shows the band hopping lower than 1ns. -
A 77GHz MMIC transceiver module consisting of a power amplifier, a low noise amplifier, a drive amplifier, a frequency doubler and a down-mixer has been developed for automotive forward-looking radar sensor. The MMIC chip set was fabricated using
$0.15{\mu}m$ gate-length InGaAs/InAlAs/GaAs mHEMT process based on 4-inch substrate. The power amplifier demonstrated a measured small signal gain of over 20dB from$76{\sim}77GHz$ with 15.5dBm output power. The chip size is$2mm{\times}2mm$ . The low noise amplifier achieved a gain of 20dB in a band between$76{\sim}77\;GHz$ with an output power of 10dBm. The chip size is$2.2mm{\times}2mm$ . The driver amplifier exhibited a gain of 23dB over a$76{\sim}77\;GHz$ band with an output power of 13dBm. The chip size is$2.1mm{\times}2mm$ . The frequency doubler achieved an output power of -16dBm at 76.5GHz with a conversion gain of -16dB for an input power of 10dBm and a 38.25GHz input frequency. The chip size is$1.2mm{\times}1.2mm$ . The down-mixer demonstrated a measured conversion gain of over -9dB. The chip size is$1.3mm{\times}1.9mm$ . The transceiver module achieved an output power of 10dBm in a band between$76{\sim}77GHz$ with a receiver P1dB of -28dBm. The module size is$8{\times}9.5{\times}2.4mm^3$ . This MMIC transceiver module is suitable for the 77GHz automotive radar systems and related applications in W-band. -
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In this paper, BSIM4's IIR(Intrinsic Input Resistance) model that has a difficulty to predict
$Z_{11}$ exactly is investigated by analyzing S-parameter measurement. Then a BSIM4 macro model for 70nm RF MOSFETs is proposed. That model uses external effective gate resistance which is composed of R and parallel RC. Comparison between simulation results using proposed model and IIR model is shown. The proposed model shows a better agreement between measured and simulated results up to 20GHz. -
Nowadays, the need of multi-mode/multi-band transceiver is rapidly increasing, so we design a direct conversion RF front-end for multi-mode/multi-band receiver that support WCDMA/CDMA2000/WIBRO standard. It consists of variable gain reconfigurable LNA and single input double balanced Mixer and complementary differential LC Oscillator. The circuit is implemented in 0.18 um RF CMOS technology and is suitable for low-cost mode/multi-band.
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A CMOS quadrature Up-converter for a direct-conversion receiver of 5.15-5.825GHz wireless LAN is described. The Up-converter consists of two sub-harmonic mixers, for I and Q channels, and an LO generation network. In order to decrease the number of inductor, I and Q path are merged. The simulation results including all the parasitics show -17.3dB conversion gain at center and -8 dBv oIP3 while consuming 22.968mW under 1.8V supply. The quadrature Up-converter is under fabrication with the other transmitter blocks in a
$0.18{\mu}m$ CMOS technology. -
This paper presents a design of a 6-bit 2.704Gsamples/s D/A converter (DAC) for DS-CDMA UWB transceivers. The proposed DAC was designed with a current steering segmented 4+2 architecture for high frequency sampling rate. For low glitches, optimized deglitch circuit is adopted for the selection of current sources. The measured integral nonlinearity (INL) is -0.081 LSB and the measured differential nonlinearity (DNL) is -0.065 LSB. The DAC implemented in a 0.13um CMOS technology shows s spurious free dynamic range (SFDR) of 50dB from dc to Nyquist frequency. The prototype DAC consumes 28mW for a Nyquist sinusoidal output signal at a 2.704Gsamples/s. The chip has an active area of
$0.76mm^2$ . -
This paper presents the design of LVDS(Low-Voltage-Differential-Signaling) driver circuit for Gb/s-per-pin operation using BiCMOS process technology. To reduce chip area, LVDS driver's switching devices were replaced with lateral bipolar devices. The designed lateral bipolar transister's common emitter current gain(
$\beta$ ) is 20 and device's emitter size is 2*10um. Also the proposed LVDS driver is operated at 2.5V and the maximum data rate is 2.8Gb/s approximately. -
In this paper, we introduce the design and fabrication of V-band power amplifier MMIC with excellent gain-flatness for IEEE 802.15.3c WPAN system. The V-band power amplifier was designed using ETRI'
$0.12{\mu}m$ PHEMT process. The PHEMT shows a peak transconductance ($G_{m,peak}$ ) of 500 mS/mm, a threshold voltage of -1.2 V, and a drain saturation current of 49 mA for 2 fingers and$100{\mu}m$ total gate width (2f100) at$V_{ds}$ =2 V. The RF characteristics of the PHEMT show a cutoff frequency,$f_T$ , of 97 GHz, and a maximum oscillation frequency,$f_{max}$ , of 166 GHz. The gains of the each stages of the amplifier were modified to have broadband characteristics of input/output matching for first and fourth stages and get more gains of edge regions of operating frequency range for second and third stages in order to make the gain-flatness of the amplifier excellently for wide band. The performances of the fabricated 60 GHz power amplifier MMIC are operating frequency of$56.25{\sim}62.25\;GHz$ , bandwidth of 6 GHz, small signal gain ($S_{21}$ ) of$16.5{\sim}17.2\;dB$ , gain flatness of 0.7 dB, an input reflection coefficient ($S_{11}$ ) of$-16{\sim}-9\;dB$ , output reflection coefficient ($S_{22}$ ) of$-16{\sim}-4\;dB$ and output power ($P_{out}$ ) of 13 dBm. The chip size of the amplifier MMIC was$3.7{\times}1.4mm^2$ . -
An Ultra low power super-regenerative oscillator was implemented with on-chip inductor and quench signal generator. The super-regenerative oscillator detects the signal level as low as -70dBm while consuming only 0.48mA at 1.5V supply voltage. These results indicate that the super-regenerative oscillator can be outstanding candidate the simple, ultra low power receiver design.
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A low-voltage switched-capacitor
$2^{nd}$ -order$\Sigma\Delta$ modulator using full feed-forward is introduced. It has two advantages: the unity signal transfer function and reduced signal swings inside the$\Sigma\Delta$ loop. These features greatly relax the DC gain and output swing requirements for Op-Amp in the low-voltage$\Sigma\Delta$ modulator. Implemented by a 0.18-${\mu}m$ CMOS technology, the$\Sigma\Delta$ modulator satisfies performance requirements for WCDMA and CDMA2000 standards. -
This paper presented a hardware implementation of ARIA, which is Korean standard block ciphering algorithm. In this work, we proposed a improved architecture based on pipeline structure and confirmed that the design operates in a clock frequency of 101.7MHz and in throughput of 957Mbps in Xilinx FPGA XCV-1600E.
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In this paper, acquiring the more desirable to adopt design SoC for the fast hierarchical motion estimation, we exploit foreground and background search algorithm (FBSA) base on the dual arithmetic processor element(DAPE). It is possible to estimate the large search area motion displacement using a half of number PE in general operation methods. And the proposed architecture of MHME improve the VLSI design hardware through the proposed FBSA structure with DAPE to remove the local memory. The proposed FBSA which use bit array processing in search area can improve structure as like multiple processor array unit(MPAU).
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A new specification-based analog and mixed-signal test technique using high performance current sensors is proposed. The proposed technique using current sensors built in external ATE has little hardware overhead in circuit under test and high testability without time consuming operation of test point placement algorithm.
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A self-biased CMOS current reference is described which provides supply and temperature independent bias current. The supply independency is obtained by subtracting two bias currents which have the same supply dependency. Unlike the conventional self-bias CMOS current reference, excellent supply independency can be obtained even with the minimum channel length devices and thus smaller area implementation becomes possible. The supply independent bias current is then applied to a temperature compensating circuit and as a result supply and temperature independent bias current is obtained. The current reference has been implemented in a
$0.25{\mu}m$ standard CMOS technology. The active silicon area is only$45{\mu}m{\times}45{\mu}m$ . The simulated temperature coefficient is 64ppm/$^{\circ}C$ in temperature range between$0^{\circ}C$ and$120^{\circ}C$ . Supply voltage can be as low as 1.3V and the supply dependency of the current reference is measured to be smaller than 4500ppm/V. While providing$10.25{\mu}A$ output current, the current reference consumes$160{\mu}W$ . -
A novel 1.2V class-AB output stage for the SW-OpAmp technique was presented. By using current mirrors and simple current extraction circuits, the proposed circuit boosts DM signal currents while eliminates CM ones to perform class-AB operation. Hspice simulation results verify the versatility of the proposed circuit technique.
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Two-dimensional (2D) photonic quasicrystals (PQCs) were fabricated by a holographic nanolithography techniques. Using two laser beams with different angles incident on the sample, micro-cavities with 2D internal nanostructures are patterned with a few micrometer periods.
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In this paper, WiBro system which is one of the mobile wireless metropolitan area network systems is presented. WiBro is an OFDMA system which has a sub-channelization process unlike conventional OFDM systems. The sub-channelization is the time consuming processing, so a time-efficient hardware architecture is needed. WiBro RAS(Radio Access Station) demodulator is designed with Verilog HDL, and the gate count is 81k using the
$0.18{\mu}m$ processing. -
The oscillation amplitude of a probe tip is an important parameter to determine the resolution of atomic force microscopy (AFM) techniques. In this work, we introduce a new method for the measurement of the oscillation amplitude of a quartz tuning fork tip sub-nanometer resolution.
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This paper presents the design results of peripheral circuits of non-volatile memory of nano floating gate cells. The designed peripheral circuits included command decoder, decoders, sense amplifiers and oscillator, which are targeted with 0.35um technology EEPROM process for operating test and reliable test. The simulation results show each operation and test mode of output voltage for word line, bit line, well and operating of sense amplifier.
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An analysis is made of a new 1Gbps MB-OFDM system having same bandwidth and transmission power as conventional 480Mbps system.
$2{\times}2$ MIMO scheme and MLD with soft decision demodulation algorithm are proposed in this paper. As a result of hardware implementation, it showed as same performance as conventional MB-OFDM system, while presenting doubled data rates and low complexity. -
In this paper, 4-way data path 128 point pipelined FFT processor with 4-way structure is proposed. The proposed FFT processor has 4-way structure in order to meet data requirement of MB-OFDM system at 132MHz operating frequency. The FFT processor is based on R4MDC and extended to suit 4-way data path. The FFT processor is designed by Verilog HDL and the gate count is about 88k.
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A Pre-emphasis transmitter for DRAM bus system has achieved 3.2Gbps/pin operation at 1.8V supply voltage with 0.18um CMOS process. The transmitter has 800MHz PLL to generate 4 phase clocks. The 4 phase clocks are used for input clock of PRBS and multiplexing. One tap pre-emphasis is used to reduce inter symbol interference (ISI) caused by channel low pass effects. The analog calibration makes the optimized driver impedance independent with the PVT variation.
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A parallel analog Viterbi decoder which decodes PR (1,2,2,1) signal of optical disc has been fabricated into chip. The proposed parallel analog Viterbi decoder implements the functions of the conventional digital Viterbi decoder utilizing the analog parallel processing circuits. In this paper, the analog parallel Viterbi decoding technology is applied for the PR signal. The benefit of analog processing is the low power consumption and the less silicon consumption. The test results of the fabricated chip are reported in this paper.
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A Novel level-shifter circuit for Display Panel Driver is presented. A Proposed level-shifter is for the high speed and high-voltage driving capability. In order to achieve this purpose, the proposed level-shifter restricts and separates the Vgs of the output driver's pull-up PMOS and pull-down NMOS with Zener diode. And a speed-up PMOS transistor is introduced to reduce delay. The control signal of speed-up PMOS was designed by bootstrapping method to minimize the gate to source (Vgs) voltage to avoid Vgs breakdown.
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The low crosstalk row-decoder is studied for PoRAM applications. Because polymer-based memories can be more densely integrated than established silicon-based ones, PoRAM is highly sensitive for the crosstalk problem. To overcome the problem and to suggest the suitable decoder for PoRAM, this paper shows the comparison of the row-path characteristics for both the 2-stage dynamic logic decoder and the 2-stage static logic decoder. Moreover, to suppress the Glitch effect which is observed by using the static logic decoder, the Master-Slave(M/S) D-Flip/Flop(D-F/F) is applied as a deglitch. Finally, the improved output result of the 2-stage static logic decoder with the M/S D-F/F is shown..
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This paper introduces a CMOS clock driver that shows a high efficiency of electric power (lower power consumption) with the supply of lower voltage(VDD), by taking advantage of charge recycling technology. Comparing with the existing structure, this driver showed the improved maximum efficiency of electric power; 72% and 68%, with the supplied voltage of 1.8v and 1.2v, respectively. Since the output waveform shows the tri-state operating region, utilization is expected in the digital integrated circuits.
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This paper presents a reconfigurable digital signal processing(rDSP) architecture that is effective for implementing adaptive digital signal processing in the applications of smart health care system. This rDSP architecture employs an evolution capability of FIR filters using genetic algorithm. Parallel genetic algorithm based rDSP architecture evolves FIR filters to explore optimal configuration of filter combination, associated parameters, and structure of feature space adaptively to noisy environments for an adaptive signal processing. The proposed DSP architecture is implemented using Xilinx Virtex4 FPGA device and SMIC 0.18um CMOS Technology.
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By adding user interface to the usual router, an improved functional router is implemented In this paper, we design the DWT(Discrete Wavelet Transform) for JPEG2000 CODEC. The DWT is developed based on ARM-based Excalibur, and the system contains DMA processor, Slave interface, DWT filter, Controller. The architecture of the prposed DWT is verified using Altera QuartusII.
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Radio Frequency Identification (RFID) is an automatic identification method, relying on storing and remotely retrieving data using devices called RFID tags or transponders. RFID systems is coming into increasing use in industry and logistics. This paper discuses implementation of multi-protocol RFID reader SoC. The SoC contains multi-protocol RFID RFID reader, CPU, UART, memory.
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Koo, Bon-Tae;Lee, Ju-Hyeon;Choe, Min-Seok;Lee, Seok-Ho;Kim, Jin-Gyu;Kim, Seong-Min;Park, Gi-Hyeok;Kim, Deok-Hwan;Gwon, Yeong-Su;Eom, Nak-Ung 669
This paper describes the functions and design technology of the T-DMB (Terrestrial Digital Multimedia Broadcasting) receiver. T-DMB is a novel broadcasting media that can provide high-quality video and audio services. In this paper, we will describe the VLSI implementation of RF, Baseband and Multimedia Chip for T-DMB Receiver. The designed DMB SoC has low power consumption and has been implemented using a standard-cell library in 0.18um CMOS technology. -
Recently Communication with using IrDA is bing used in various fields. In this paper I designed a receiver by fabricating hardware that used to be fabricated through software, so anyone who don't have knowledge on IrDA can receive Ir Signal easily. This receiver can communicate with CPU through 8 bit data and 3 bit address. Also this receiver can use user-needed CLK because this receiver embodied 16 bit CLK Prescaler.
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IPTV (Internet Protocol Television) is an efficient system which serves various contents to subscribing consumers by using the IP over a broadband connection. The IPTV services can be multi-channel broadcasting service, VoD, T-Commerce, video conference, on-line game and so on. TV Anytime metadata provides various description tools for TV program contents by which TV program contents can serve more information. In this paper, we mention about the overview and feature of IPTV and TV Anytime metadata, propose the essential functions in the EPG program of IPTV and survey the description tools for the proposed functions in EPG. Finally, we show the authored metadata and the implementation of advanced EPG application.
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이 논문에서는 가장 많이 알려진 tracking 알고리즘인 Particle-Filter 의 단점을 motion vector 를 기반으로 예측한 sampling 방법과 K-means clustering 을 이용하여 해결하려고 한다. Tracking 에서의 문제는 다중의 유사한 객체들이 merge 후 split 될 때 제대로 추적을 하지 못하고 한 객체만을 추적 한다는 데에 있었다. 그리고 split 되어 객체별로 추적이 가능하더라도 이전에 추적한 객체를 올바로 labeling 하지 못하는 문제가 있다는 것이다. 이 merge-split 문제는 개량된 K-means clustering 을 이용하고, labeling 문제는 motion vector 를 이용한 개량된 sampling 방법으로 개선하였다.
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일반적으로 축구 비디오 데이터는 멀티모달과 멀티레이어 속성을 지닌다. 이러한 데이터를 다루기 적합한 모델은 동적 베이지안 네트워크(Dynamic Bayesian Network: DBN) 형태의 위계적 은닉 마르코프 모델(Hierarchical Hidden Markov Model: HHMM)이다. 이러한 HHMM 중 다중속성의 특징들이 서로 상호작용하는 PHHMM(Product Hierarchical Hidden Markov Model)이 있다. 본 논문에서는 PHHMM 을 축구 경기의 Play/Break 이벤트 검색 및 분석에 적용하였고 바람직한 결과를 얻었다.
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본 논문은 비디오기반의 얼굴인식에 있어서 환경의 변화나 왜곡, 노이즈 등으로 발생할 수 있는 부분적인 가림현상(Partial Occlusion)에 대한 처리기법을 제시한다. 인증되는 각 사람은 하나의 Manifold 를 구성하며 각 Manifold 는 m 개의 pose-Manifold 로 구성된다. Pose-Manifold 를 구성하기 위한 학습데이터는 매우 유사한 포즈들로 구성되기 때문에 얼굴을 이루는 영역의 픽셀에 대한 Intensity 의 변화는 크지 않다. 입력되는 이미지의 Intensity 를 학습데이터의 Intensity 의 변화량을 고려한 Intensity Distortion 을 이용하면 Occlusion 이 발생한 영역을 찾을 수 있고, Occlusion 이 발생한 정도에 따라 가중치를 부여할 수 있다. 이렇게 Occlusion 에 따라 영역에 중요도를 다르게 하여 얼굴인식률을 높이고자 한다. 실험에서는 제시하는 Mask 를 사용하지 않았을 경우와 기존에 제시된 알고리즘과의 성능을 비교한다.
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Recently, various AR-based product design methodologies have been introduced. In this paper, we propose technologies for enhancing robust augmentation and immersive realization of virtual objects. A robust augmentation technology is developed for various lighting conditions and a partial solution is proposed for the hand occlusion problem that occurs when the virtual objects overlay the user' hands. It provides more immersive or natural images to the users. Finally, vibratory haptic cues by page motors as well as button clicking force feedback by modulating pneumatic pressures are proposed while interacting with virtual widgets. Also our system reduces gabs between modeling spaces and user spaces. An immersive game-phone model is selected to demonstrate that the users can control the direction of the car in the racing game by tilting a tangible object with the proposed augmented haptic and robust non-occluded visual feedback. The proposed methodologies will be contributed to the immersive realization of the conventional AR system.
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This paper presents implementation of the lifting based DWT processor interface which the process of JPEG2000. The proposed architecture uses Excalibur device produced Altera. This study describes CIS(CMOS Image Sensor), DMA(Direct Memory Access) and DWT control logic
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Relational discriminant analysis is a way of representing an object based on the dissimilarity measures among the prototypes extracted from feature vectors instead of the vectors themselves. Thus, by appropriately selecting a few number of representatives and by defining the dissimilarity measure, in this paper we propose a method of reducing the dimensionality and getting to achieve a better classification performance in both speed and accuracy. Our experimental results demonstrate that the proposed mechanism increases the performance as compared with the conventional approaches for samples involving artificial data sets.
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Generally many devices reproduce images in the various ways. Therefore many devices can reproduce restrict range of colors according to their device characters. And the restrict range of color is called as a color gamut. Owing to these color gamuts have the differences between devices, color gamut mapping is needed. In this paper, we attempted an experiment about a gamut mapping from a CRT monitor to a LCD monitor.
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The high definition digital TV display devices need real-time gamut mapping. This paper proposes a gamut mapping algorithm that used three dimensional reduced resolution look up table and tetrahedral interpolation for real-time processing. The proposed hardware architecture is successfully implemented in FPGA and ASIC.
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In this paper, we propose a new scheme to generate multi-view images using a depth-image-based rendering (DIBR) technique. In order to improve the quality of multi-view images at newly exposed areas during mesh-based rendering, we preprocess the depth map using a Gaussian smoothing filter. Previous algorithms apply a smoothing filter to the whole depth map even if the depth map is collapsed. After extracting objects from the depth map, we apply the smoothing filter to their boundaries. Finally, we cannot only maintain the depth quality, but also generate high quality multi-view images. Experimental results show that our proposed algorithm outperforms previous works and supports an efficient depth keying technique.
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In this paper, we embodied the environment monitoring system that can acquire correct data in real-time. And we used module that is 2.4GHz IEEE 802.15.4 / Zigbee network for radio communication between nodes. The nodes sense the data of temperature, humidity, illumination periodically. The nodes store the data in their buffer and transmit. We confirmed that the system is in real-time as it is changed instantly due to the varying environment by the simulation Therefore, we can construct the efficient and correct system as applied this system to monitor the environment.
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RFID/USN means a way of attaching RFID to all required objects to identify them and exchanging the required information through the network. High frequency (13.56MHz) has been commonly used in the field of processing management in Korea, and extremely short wave (433.92MHz) has been used for harbor logistics management by being attached to containers in the US. As for SCM field where we need to have a broader understanding, the research on
$860{\sim}960MHz$ , a sort of extremely short wave has been most actively conducted. Therefore, in-this study, in order to understand the features of all frequencies ranging and to design and implementation of RFID Middle System suitable for realizing u-Logistics by using those diverse frequencies. -
Kim, Sang-Tae;Kim, Hyun-Deok;Park, Won-Kyu;Park, Yoon-Jung;Kim, Young-Cheol;Jung, Youn-Wha;Kim, Won-Gi;Park, Hong-Bae 705
A novel plug and play system for a mobile device has been proposed and demonstrated to provide an easy inter-operation between the mobile device and external modules. It supports an automatic installation and execution of the device drivers stored in the external modules into the mobile devices when the external module is connected to the mobile device. It also enables an automatic removal of the derivers when the external module is disconnected from the mobile device, which makes the user use the resource of the mobile devices more efficiently. -
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Lee, Jun-Gu;Hwang, Seok-Jung;An, Sun-Sin;Kim, Seon-Uk;Gang, U-Sik;Yang, Jin-Yeong;Gu, Si-Gyeong;Gu, Ji-Hun;Park, Gyeong-Ho 709
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In this paper, we propose algorithm that improves energy efficiency of sensor node. That is, sensor node suggests algorithm that minimizes unnecessary surrounding feeler, and when passes information to neighborhood node, transmit forecasting position of node.
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본 논문에서는 PXA255 ARM칩을 내장한 임베디드 RFID R/W 시스템 및 무선랜과 연동이 가능한 RFID 미들웨어 및 근태관리 소프트웨어를 개발하였다. 개발한 임베디드 형태의 RFID R/W 시스템은 PXA255 임베디드 시스템을 중심으로 13.56Mhz의 RFID R/W, 서버와 데이터 통신을 위한 무선랜 및 TFT-LCD로 구성되어 있다. 임베디드 RFID R/W 시스템은 Tag정보를 시리얼단자로 통해 입력받으면 이를 무선랜을 이용하여 서버로 데이터를 전송하고 다시 서버로부터 처리된 결과 이미지를 받아서 TFT-LCD화면에 표시한다. 임베디드 RFID R/W 미들웨어는 RFID R/W 취득한 Tag정보를 PXA255 임베디드 시스템에 전송하고, 임베디드 시스템은 클라이언트 소켓 프로그램을 작동시켜 무선랜을 통해 윈도우 서버에 접속한 후 Tag정보를 전송한다. 윈도우 서버 프로그램은 Tag정보와 적합한 데이터를 탐색한 후 이를 무선랜을 통해서 임베디드 시스템의 TFT-LCD창에 표시할 수 있는 미들웨어를 개발하였다.
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In this paper, we present an RTOS named HEART (Highly Expandable AOP-based Real-Time operating system). It is modularized into a single base and multiple optional features. The base implements a core functionality and each feature implements a specific functionality of RTOS such as interrupt nesting, multithreading, inter-thread communication, and etc. Users can customize HEART just by selecting needed features. Then a specialized version of HEART is automatically generated. We argue that HEART enables the rapid construction of optimized and application-specific RTOSes for diverse embedded systems.
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Ad hoc networks does not need any wired network infrastructure. Therefore, they have been developed in temporary networks or mainly in military networks. Infostations offer geographically intermittent coverage at high speeds. Up-to-date there have been frequent big forest fires in Korea mountain areas. It is very important to detect them early to prevent them from being big disasters. In this paper, we propose a disaster emergency management system using sensor attached wild boars' mobility combined with infostation system. We also make a numerical analysis of the performance of the system.
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FPD 산업의 폭발적인 성장과 함께 어떻게 하면 불량률을 낮출수 있는가에 생산업체의 관심이 지대하다. FPD공정에서 품질을 결정하는 여러 요인 가운데 박막 두께의 제어가 차지하는 비중이 크다. 논문에서는 광학적 방법인 광 간섭 두께 측정기를 이용하여 얻은 시료의 광학적 특성을 레퍼런스 데이터와 비교하는 과정을 통해 시료의 두께를 측정함으로써 불량여부를 판별한다.
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Exploiting the instruction level parallelism encountered with the limit. Single chip multiprocessor was introduced to overcome the limit of traditional processor using the instruction level parallelism. Also, a branch miss prediction is one of the causes that reduce the processor performance. In order to overcome the problems, in this paper, we make single chip multiprocessor having the idle core execute the two control flow of conditional branch. This scheme is a kind of multi-path execution technique based on single chip multiprocessor architecture.
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In this paper, we analyzed the color restoration method to be used in the Multi-Scale Retinex and proposed new color restoration method. and, we compared the result of the algorithm to be proposed with conventional algorithm through the experiment.
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multimedia applications has been targeted for exploiting single instruction multiple data extensions to instruction architectures for the most of the modern microprocessor. In this paper, the newest video coding standard, H.264/AVC baseline profile decoder has been implemented and optimized exploiting INTEL MMX technology to show the overall system speedup by the SIMD style coding
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Limitations on the Linear Discriminant Analysis (LDA) for face recognition, such as the loss of generalization and the computational infeasibility, are addressed and illustrated for small number of samples. The Principal Component Analysis (PCA) followed by the LDA mapping may be an alternative that can overcome this limitation. We also show that processing time is reduced by wavelet transform.
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The Face Area Detection has an extensive error range of abstraction probabilities by image illuminations and background conditions. In this paper, to reduce error ranges of abstraction probabilities by factors such as illuminations and backgrounds, we made use of Retinex and the Face Area Detection algorithm together. In comparison with other previous methods[4], our proposed algorithm showed stabler and elevated detection rate.
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This paper present a method of education configuration for U-learning. The proposed U-Learning configuration is more upgrade than earlier method. For the future, it is demanded that more advanced U-Learning systems and configuration toward to next generation education system, namely blended teaching and learning system.
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This paper present a method of education configuration for U-learning. The proposed U-Learning configuration is more upgrade than earlier method. For the future, it is demanded that more advanced U-Learning systems and configuration toward to next generation education system, namely blended teaching and learning system.
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본 논문에서는 입력한 데이터를 분석하고 비교하여 손 모양 데이터 편집기의 기준 손 모양을 결정하는 방법을 제안한다. 즉, 입력한 손 모양 데이터에 대해 빈도수 혹은 평균값을 사용하여 기준 손 모양을 결정하는 방법을 제안한다. 입력한 손 모양 데이터로부터 제안한 방법을 통해 얻어진 손 모양이 실제 표현하고 자 한 손 모양과 일치하는지 실험을 통해 비교하였는데, 6,135개의 입력 데이터에 대해 두 가지 방법 모두 90.6% 일치하였다.
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In this paper, we suggested a method for game operation tools by Ultrasonic sensor. Various ideas are necessary for the development that a game is industrial. I use a Ultrasonic sensor in this study and use a model case, and an operation is going to hold a case shooting play. Therefore, I showed a former circuit and a formula related to this.
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This paper presents implementation of parallel processing system for image processing. The parallel processing system proposed consisted of 16 processing elements, and multi-access memory system, and interface modules. The multi-access memory system we introduced is made up of a memory module selection, a data routing module, and an address calculation and routing module.
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Color Data Compression for Three-dimensional Mesh Models Using Connectivity and Geometry InformationIn this paper, we propose a new predictive coding scheme for color data of three-dimensional (3-D) mesh models. We exploit connectivity and geometry information to improve coding efficiency. After ordering all vertices in a 3-D mesh model with a vertex traversal technique, we employ a geometry predictor to compress the color data. The predicted color can be acquired by a weighted sum of reconstructed colors for adjacent vertices using both angles and distances between the current vertex and adjacent vertices.
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In this paper, we describe photonic sensor interface and driver program based on SOPC(System on a programmable chip) platform. This platform uses device that has ARM922T processor and APEX FPGA area on a chip. As for driver program development, three different methods are tried such as simple firmware, real-time OS based program and embedded Linux based program, and results are compared for SoC implementation.
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TFRC is an equation-based rate control scheme originally developed for video transmission over wired networks. When applied to the wireless networks, it suffers from performance degradation. In this thesis, we propose an end-to-end loss discrimination algorithm to improve the performance of TFRC over wireless networks. The proposed WLD-TFRC scheme combines Spike and WLD(Wireless Loss Discount) algorithms to discriminate wireless loss from congestion loss, and to discount feedback loss event rate. Experimental results show that WLD-TFRC outperforms the original TFRC and effectively reduce the degradation of the video quality caused by the wireless link status.
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In this paper, we propose a improved tree construction algorithm on End Host Multicast. By using concurrent connection information of nodes at RP, we could diminish the RDP and the amount of control messages used for tree construction at the same time.
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In this paper, We design the high performance 2D product Iterative decoder using three different external value design. We improved the external value operation in two ways to reduce the delay and speed. In this proposed operation, each design has been simulated on Matlab and MaxPlusII, and implemented on the FPGA to measure their performance.
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In this paper, the palmprint classification and recognition method based on PCA (Principal Components Analysis) using the dimension reduction of singular vector is proposed. And the 135dpi palmprint image which is obtained by the palmprint acquisition device is used for the effectual palmprint recognition system. The proposed system consists of the palmprint acquisition device, DB generation algorithm and the palmprint recognition algorithm. The palmprint recognition step is limited 2 times. As a results, GAR and FAR are 98.5% and 0.036%.
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In this paper, The author designed on high speed VLD(Variable Length Decoder) using shift buffer. Variable Length Decoder is received N bit data from input block and decode the input signal using Shifting Buffer, Length Decoder and Symbol Decoder blocks. The inner part of shifting buffer in proposed Variable Length Decoder is filled input data and then operating therefore, the proposed structure can improve the decoded speed. And in this paper we applying pipeline structure therefore data is decoded in every clock.
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생활의 일부라 할 수 있는 교통시스템은 도시화, 산업화가 진행됨에 따라 더욱 복잡해지고 있다. 이를 보완하기 위해 내비게이션, 텔레메틱스와 같은 다양한 보조 수단이 개발되고 있다. 하지만 이러한 운전자 보조 시스템은 개별화된 특성을 반영하지 않으며, 가장 일반적인 경우에 치중되어 있다. 본 논문에서는 개별화되고 사용자 중심적인 운전자 보조 시스템을 제안하며, 어떠한 정보가 이에 활용될 수 있는지를 고찰해 보았다. 또한 이런 정보를 해결하기 위한 소프트 컴퓨팅 기법을 제안하고자 한다.
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The rapid growth of Hardware technologies and Network fitted to us Ubiquitous Computing Life[1]. Ubiquitous Computing integrates computation into the environment, rather than having computers which are distinct objects. There are many computational things like a Sensor Network, RFID, GPS, Mobile devices, and so on. Ubiquitous Data Integration and Management are new paradigms. The goals of UDI Service Platform are data protection for the distributed data on pervasive computing devices and data distribution to appropriate users with best distribution policies. To implement the idea we evaluate the logical schema Cyber View that is a management tool.
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The ecology of Physically Embedded Intelligent Systems (PEIS) is a new multi robotic framework conceived by integrating insights from the fields of autonomous robotics and ambient intelligence. A PEIS-Ecology is a network of intelligent robotic devices that can provide the user with assistance, information, communication, and entertainment services. In this paper we introduce the concept of PEIS Ecology, and illustrate a concrete realization of a PEIS-Ecology.
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In this paper we propose a new routing protocol, which takes residue energy of nodes into account in order to prevent node failures resulting from energy shortage. Our routing protocol examines the smallest value of node residue energy (
$E_m$ ) from each of all possible routing paths and selects the path which has the largest value of$E_m$ . We prove, through simulation, that our routing protocol extends the lifetime of nodes which have limited amount of energy, reducing chances of path replacement. It is also shown that our proposed protocol helps alleviate network performance degradation. -
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IPv6 nodes use the Neighbor Discovery Protocol (NDP) to discover other nodes on the link, to determine their link-layer addresses to find routers, and to maintain reachability information about the paths to active neighbors. If not secured, NDP is vulnerable to various attacks. This document specifies security mechanisms for NDP. Unlike those in the original NDP specifications, these mechanisms do not use IPsec.
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Devices which coupled in network environment should be operated in various service-oriented ways by several services. In this paper, we propose service-oriented application architecture which based on OSGi. OSGi is very well defined industrial standard by using platform independent technology.
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Ad hoc network does not need any preexisting network infrastructure, and it has been developed as temporal networks in the various fields. Infostation is an efficient system to transfer information which does not have delay sensitive characteristics. In this paper, we propose a disaster emergency management system using sensor attached animals' mobility combined with infostation system. We also analyze the performance of the proposed system. From the performance analysis results, we expect that the proposed system will be very useful to early detect big forest fires which occurs frequently in Korea mountain areas.
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In this thesis, we design and implement a Flash Cache Core Module (FCCM) which operates on the YAFFS NAND flash memory. The FCCM applies memory replacement policy and prefetching policy based on the page reference pattern of applications. Also, implement the Clean-First memory replacement technique considering the characteristics of flash memory. In this method the decision is made according to page hit to apply prefetched waiting area. The FCCM decrease I/O hit frequency up to 37%, Compared with the linux cache and prefetching policy. Also, it operated using less memory for prefetching(maximum 24% and average 16%) compared with the linux kernel.
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In comparison with a existing passive Healthcare system, a healthcare system applied OSGi framework is spontaneous and excellently expandable. But, OSGi-based healthcare system has security vulnerability which OSGi has the technical feature and restriction in the service support area. In this paper, in order to overcome these vulnerability, we propose the technique that applies JXTA standardized P2P platform in OSGi-based healthcare system.
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This treatise proposed environment for Embedded system's development. Virtual platform can help to solve problem that hardware designer can experience at design process of hardware. Compose circuit of most suitable that is verified before mix parts by various kinds method and compose circuit by board level because can do simulation with software and software that is optimized to hardware and offer flexibility that can test. Therefore, can shorten expense that is cost in development and time. Embody development platform for 8051 systems for verification of development platform, and compose and verified system in various kinds structure.
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Recently, Healthcare system has not been standardized and has been developed as an embedded system lacking interoperability. We are finally going to face such problems as having excessive load in using network caused by the uncontrolled spread of system and un-guaranteed interoperability among the heterogenous systems. We suggest the possibility that OSGi (Open Service Gateway initiative : the international standardization of service middleware) can be accepted as a solution for the above problems.
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본 논문에서는 적응적 재구성 필터를 이용한 심전도 신호의 잡음제거 알고리즘을 개발하고 이를 임베디드 보드 상에서 구현하였다. 구현된 시스템의 검증을 위해, 제안된 알고리즘은 PC 상에서 소프트웨어만으로 구현했을 때와 적응적 재구성 필터를 소프트웨어와 FPGA 로 구현했을 때의 실행시간 및 잡음제거 성능을 비교하였다. 실험결과 FPGA 상에서 구현된 시스템은 PC 상에서 구현된 프로그램과 비교하여 동일 잡음제거 성능을 가질 때 약 5배정도의 실행시간 향상을 보였다.
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본 논문은 요즘 유행하는 웰빙(Well Being)에 대한 관심과 점점 고조되는 사람의 체질구분에 대해 퍼지이론(Fuzzy Theory)를 통해 연구하였다. 또한 각 체질구분에 따른 음식궁합을 따져서 보다 개인적 웰빙음식이 무엇이 있나에 대해 연구하였다. 사람마다 각각에 체질을 가지고 있다. 또한 자신의 체질이 아니더라도, 다른 체질에 대한 특성을 가질 수 있다. 이런 점에서 퍼지이론을 사용하여 체질을 구분할 수 있다. 퍼지이론의 큰 장점이 문제점 해결시 참<1>, 거짓<0>으로 해결하지 않기 때문에 여러 가지 문제 해결점을 가진다는 것이다. 공통적으로 해당하는 체질문항일 경우 퍼지 소속함수 값을 각각 다르게 주어서 최종 포인트에 대한 Fuzzy set 의 크기를 따져 체질구분을 하고, 그에 따른 음식궁합을 규정한다.
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본 논문은 심전도의 리드III 파형을 이용하여 신원확인이 가능한 생체인식 기술을 제안한다. 인식을 위한 심전도의 리드III파형을 특징추출하기 위해
$4{\sim}30Hz$ 의 대역통과 필터를 사용하여 피크(peak)점만 남겨놓고 모든 잡음을 제거한 후, AAV(absolute amplitude value)를 이용하여 피크점의 값을 추출한다. 추출된 피크 점은 원신호의 피크점과 같으므로 이를 기준으로 전체파형을 특징추출을 위한 단위 파형으로 분리한다. 분리된 신호는 정의된 4가지 형태(type)의 파형 중 가장 유사한 파형타입으로 분류되며, 분류된 형태를 기준으로 꼭지점, 최대 피크점, 최소 피크점, 최대.최소 피크점 비, 파형 간격(interval) 및 파형의 세부 모양 등 총22가지의 특징들을 추출한다. 추출된 특징들은 오류역전파 신경회로망(back-propagation neural network)의 입력으로 사용되었으며, 성인남녀 31명을 대상으로 제한된 파형 내에서 실험한 결과 100%의 인식률을 보였다. -
본 논문에서는 인공 신경망을 이용한 동작 패턴 분류 시스템을 개발하였다. 이 시스템은 자이로 센서와 가속도 센서를 사용하며 3축의 자이로(각속도) 및 가속도를 측정할 수 있는 센서 모듈과 측정된 데이터를 이용해서 동작 패턴을 분류해 주는 신경망 알고리즘으로 구성된다.
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Recently, blocking harmful contents such as adult images has been widely researched. However, most of adult image blocking methods use flush color model without shape information. In this paper, we present a new adult image blocking methods based on shape and color information. In the first step, the shape is considered. In the second step, adult images are detected using skin color model. Considering both shape and color, the detection rate can be increased. We evaluate adult image detection performance using sample images.
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In this paper, a codec design method is pro-posed for the face images based on JPEG and its application to face recognition is presented. Quantization table design is dis-cussed using R-D optimization for Yale face data. For the usage in the embedded systems, fast codec design is also considered. The proposed codec has better performance than JPEG codec for face images. Through the recognition experiment using PCA and LDA, it has been shown that the proposed codec has better performance than JPEG codec.
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This thesis implemented security systems of voice awareness which is higher accessible than existing security system using biological authentication system and is inexpensive in module of security device, and has an advantage in usability. Proposed the security systems of voice awareness implemented algorithm for characteristic extraction of inputted speaker's voice signal verification, and also implemented database of access control that is founded on extractible output. And a security system of voice awareness has a function of an authority of access control to system.
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The present study purposes to develop HMI software that runs on Windows CE .NET platform without being bound to specific HMI equipment and accesses data in PLC equipment through interoperation with an OPC-DA server. As the OPC-DA server reads data in PLC equipment, HMI system does not need to be configured differently for different equipments. In addition, when the interface environment of specific equipment changes, it does not require the application of new equipment or the change of communication protocol. As HMI system runs on Windows CE .NET platform, it can be configured using common embedded devices based on Windows CE .NET platform. HMI software reads data in PLC equipment through RS-232C communication interface. In addition, because it connects to an OPC-DA server through Ethernet communication interface, it can access data in PLC equipment as long as Ethernet is usable.
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This paper presents a multiple branch predictor with perceptrons. We describe our design and evaluate it with the SPEC 2000 benchmarks. Our predictor achieves increased accuracy than the previous multiple branch predictors.
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In many of ITS(Intelligent Tutoring System), they only evaluate student level or simple some student character. We propose student model for considering many student characteristics. Our student model contains student level and student's weak problem type, domain field, problem situation. We can provide optimum problem to individual student by student model.
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While use of computers to teach English in a conventional educational environment promotes motivation and effective learning in students, the method generates problems such as provision of learning materials without consideration of teaching methods and evaluation without consideration of individual differences in students. To solve these problems and produce a superior system, we propose knowledge representation of expert module for an Intelligent Tutoring System (ITS).
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An H.264 algorithm is commonly used for video compression applications. This algorithm requires a large number of data computations, for example, the sum of absolute difference (SAD) operation. We analyzed H.264 reference encoding workloads. The H.264 encoding program has 8.78% SAD operation. The SAD operation is to sum up 16 difference-values in H.264
$4{\times}4$ sub-blocks. In order to accelerate SAD operations, we implemented an application specific instruction-set processor (ASIP) that can execute SAD and data transfer instructions. The proposed coprocessor has an absolute value generator and a carry save adder (CSA) unit to sum up 8 difference-values per one clock cycle. We completed SAD operation in 2 clock cycles. Experimental results show that the performance is improved by 34% of total execution time. -
This study is study about implementation of the production work management system that used RFID. A RFID Card system is used, and a collection totalizes and all data by real time, and, in production planning and work indication, work process time analyzes production present situation information by line by process automatically, and it is solution to be able to do an inquiry. The production related time that was hard to be measured are produced in the existing production management system exactly, and a grafting with solution of ERP, SCM, CMMS, etc is the study that is going to establish the possible most suitable system.
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In this paper, an EMG (Electromyography) sensor for utilizing an EMGl-based HCI are described. The EMG sensor is a dry type and has high gain (1000-10000). Therefore, this sensor can be properly applied to HCI devices using EMG signals without additional amplification circuit.
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In Magnetic Resonance Imaging(MRI), the QRS complex of ECG is used as a trigger signal for MRI scan. But, gradient and RF(radio frequency) artifacts which are caused to static and dynamic field in MRI scanner cause interference in the ECG. Also, the signal shape of theses artifacts can be similar to the QRS-complex, causing possible misinterpretation during patient monitoring and false gating of the MRI. In case of using general FIR or IIR band-pass filters for minimizing the artifacts, artifact-reduction-ratio is not excellent. So, an adaptive real-time digital filter is proposed for reduction of noise by gradient and RF(radio frequency) artifacts. The proposed filter for MRI-Gating is based on the noise-canceller with NLMS(Normalized Least Mean Square) algorithm. The reference signals of the adaptive noise canceller are a combination of the noisy three channel ECG signals. In conclusions, the proposed method showed the acceptable quality of ECG signal with sufficient SNR for gating the MRI and possibility of real time implementation.
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The purpose of this study is to develop an automatic algorithm to detect the arousal events. The proposed method is based on time-frequency analysis and the support vector machine classifier using single channel electroencephalogram. To extract features, first we computed 6 indices to find out the information of sleep states. Next powers of each of 4 frequency bands were computed using spectrogram of arousal region. And finally we computed variations of power of EEG frequency to detect arousals. The performance has been assessed using polysomnographic recordings of twenty patients with sleep apnea, snoring and excessive daytime sleepiness. We have shown that proposed method was effective for detecting the arousal events.
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Ubiquitous healthcare monitoring and measuring system based on wireless sensor network was implemented and tested. The system can measure the ECG and body temperature of patients or elderly persons and transfer the data wirelessly in ad-hoc network to remote base-station connected to doctor's PDA/PC or hospital server, using wireless sensor motes. The data obtained can be analyzed by doctors and care providers to monitor a health status of patient in real time environment. To prove the capabilities of the wireless sensor network platform for ubiquitous healthcare applications, the performance of our monitoring and measuring system was tested with positive results.
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The Freelz is an EMG (ElectroMyoGraphy)-based controller for the tetraplegic utilizing a power wheelchair by teeth-clenching. The EMG signals activated by teeth-clenching are acquired around user's temples. The controller contains hardwares and softwares for acquiring EMGs, classifying patterns, and controlling a power wheelchair. Also, a comparison test is executed with a conventional controlling method for the tetraplegic.
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In this paper, we propose an algorithm that applies Rolle's theorem to automatically detect and label peak III and V of the normal, suprathreshold auditory brainstem response (ABR). ABR waveform were recorded from 55 normal-hearing ears at screening levels varying from 30 to 60 dBnHL. For each ABR waveform, the peak-finding algorithm proceeded in fourth steps: (1) Select maximum and minimum values of the target ABR waveform, (2) divide this range into n equal parts, (3) effective candidate peaks in the ABR waveform are identified using Rolle's theorem (4) peak III and V are identified from these candidate peaks based on their latency and morphology. As a result, proposed auto dectection method showed high correlation and accuracy with manual detection method performed by clinician. By using proposed algorithm, clinician can detect and label peak III and V faster and more efficient than manual detection method.
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This paper presents a vehicle control algorithm for Personal Rapid Transit (PRT) system. PRT system is a one-way direction network system which is composed of guideway branches, merging/diverging points. Vehicle control algorithm can be divided into two kinds. Those are merging control algorithm and the other. We emphasized on the merging control algorithm. For that, we first devised a front/virtual front vehicle finding strategies. Properly determined front/virtual front vehicle is the starting point of vehicle control. The objects of merging control are to avoid collision and to pass the merging point fluently. Which implies that jerk constraint and limits of acceleration and deceleration etc. are should be considered. To verify the validation of the vehicle algorithm, we executed simulations and presented test results.
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A distributed web caching system can transmit information to a user quickly and stably, avoiding a congested internet network by storing and later supplying requested content to a cache that is distributed and shared like a proxy server. This paper proposes a client-based distributed web caching system that assigns an object and controls the load using a user's direct connection to shared caches, without the aid of additional domain name system (DNS) requests. The proposed system simplifies information transmission by reducing both DNS queries and delay time.
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In this paper, we introduce a canonical framework of the large-scaled web-based sensor gateway and practically implement it as the environment monitoring system. The system consists of a central management server, up to 250 local embedded subsystems and up to 250 sensor or actuator nodes for each subsystem. The node information is gathered periodically through a well-defined protocol on the sensor network and converted to the web contents and the SNMP MIB objects according to its data type. The MIB objects are well-defined and include system, network, sensor, actuator and alarm specific data classes. Because there is an increasing trend that a large number of sites are willing to adapt unmanned sensing and control, the developed system will play a key role to efficiently manage a large scale sensor networked system such as environment monitoring systems or countermeasure systems against disaster and calamities.
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In this paper, It is proposed collecting, processing, and learning of data with PIC16F877 and Acode 300[3], constructing database in PC. The PIC16F877 microcontroller nodes are the radio sensor and the DC motor controller. The PC of flexible factory level construct the data-table for object-oriented optimal environment control. The DC Motor control command is decision with back-propagation.
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For non-contact structure vibration displacement measurement system, an algorithm for image processing using high speed CCD camera is introduced. The system sets the target to the structure, take picture using camera and image processing is performed to display the vibration data. The algorithm flow is basic preprocessing, projection data generation and curve fitting to find three crossing points for calibration or one center point in limited area.
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This paper proposes a method of assembling parts using visual servoing in dynamic environment. We use SSD(Sum of Square Difference) based on adaptive template in order to detect a moving object in the case where the robot and the object both move. And the control input of the robot is obtained from the feed-back signal of the feature movement and the feed-forward signal of the camera movement in image plane.
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Our paper proposes a novel moving object tracking scheme for biped robot using a single camera. For walking control of a biped robot we analyze the dynamics of a three-dimensional inverted pendulum model. This analysis leads us a simple linear dynamics. And, the control parameter of the biped robot is derived from the feedback signal which converges the position of a image feature to the feature position of a desired image and the feedforward signal which compensates the motion component due to the moving object.
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This paper has proposed a serial 8-bit DAC for column driver circuits of mobile displays using LTPS TFTs. The DAC circuit takes very small area by using parasitic capacitance of column lines as sampling and holding capacitors. Moreover, the proposed DAC does not need the analog buffer, because the DAC operation is performed on the column lines. For the data driver circuits of 2-inch qVGA OLED panel, the DAC area is
$84um{\times}800um$ and the simulated DAC power consumption is 8.5mW with 10-V supply voltage. -
다채널 스피커를 위한 자동검사 시스템은 아날로그 음향신호를 디지털로 바꾸고 이를 시리얼로 전송한 후 각각의 스피커를 통해서 출력하는 다채널음향 신호의 시리얼 전송기술을 기반으로 한다. 각각의 스피커에는 소형 진동 센서가 장치되어 있어 출력되는 음향신호의 이상 유무를 판별하여 스피커의 방송 상태를 자동으로 검사할 수 있다.
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Lee, Byeung-Leul;Won, Jongw-Ha;Cho, Jin-Woo;Jeong, Hee-Mun;Cho, Yong-Chol;Lee, Jin-Ho;Go, Young-Chol 845
In this paper, we describe a capacitive position sensing and motion control scheme of a MEMS scanner used for laser display application. The laser displays can be made by scanning laser beams much the same way a CRT scans electron beams. So the accuracy of the scanner motion determines the quality of the displayed image. The MEMS scanner under consideration is composed of electrostatic comb electrodes with initial gap and requires large driving voltage. Due to the under-damping and nonlinear driving characteristics, the scanner motion is subject to be an unwanted oscillation. For the linear scanner motion, we devise a differential charge amplifier and phase compensator. The experimental results show that the implemented feedback control system provides sufficient electrical damping and improves the dynamic performance of the scanner. -
Design of R-type thermocouple interface with cold-junction compensator and its broken wire detectionCha, Hyeong-Woo;Kim, Young-Sun;Park, So-Hyun;Hyun, Pil-Soo;Kim, Dae-Han;Yun, Young-Sik;Ryu, Ho-Young;Kim, Byung-Ju 847
R-type thermocouple(TC) interface circuits with cold-junction compensator(CJC) and its broken wires detection was developed. The circuit consists of a CJC device, a instrumentation amplifier(IA), and two resistor and a diode for broken wire detection. The experiment results show that the interface circuit has a good CJC function on the temperature range for$20^{\circ}C$ to$1400^{\circ}C$ . At the range the output voltage of the IA was -14V when the TC was broken. At normal operation condition the output voltage of IA was 0V to 10V for the temperature range. -
This thesis presents a new analysis method of Vegas network model in single link single source and a new version of Vegas for expanding asymptotically stable region. Actually since original Vegas model is difficult to analysis, we use a modified Vegas network model. Since there is a few tools to analyze nonlinear system with delay, developing other methods is very important and useful. We used state space model in discrete time. Using by Jury's criterion, we could find asymptotically stable region of Vegas network model. And it was a if and only if condition. Moreover, we proposed a new version of Vegas algorithm. To expand asymptotically stable region we modified the original Vegas model. The new analysis method and new Vegas algorithm were justified by ns-2 simulation. And as compare with other result, we could know our method has many advantages.
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Due to a recently developed approach to autopilot controller design for highly-maneuvering BTT (bank-to-turn) missiles, we now can derive explicitly the final-phase optimal guidance (OG) law considering the autopilot dynamics through direct use of the well-known linear optimal control theory. The proposed OG law can decrease the miss distance (MD) remarkably with small acceleration and roll rate profile at the time of interception.
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Magnetic nerve stimulation treatment is much backward real condition than other field. Specially, successful medical treatment introduction of magnetic field (MF) can was refered long ago in Avicenna's work, and is thought as age of medicine magnetology development recently. These development is achieved through biologist and biophysicist and clinician's joint effort, but, new mountings and relationship air tassel are developed steadily. Magnetic nerve stimulation treatment field designs treatment system by each function during long wave high-amplitude (traditional magneto therapy of greatly great that strong that) short time that CMF, VMF, PMF field etc. are representative but are HPMT technology in this research and manufacture and special quality did comparative analysis.
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Estrangement hierarchical by bipolarization is deepened and time space that social welfare by graying corresponds great so. Specially, is real condition that indifference by patient's increase which is solitary life string is come to involve by social problem. Together, Jaetaek bone fracture patient's ratio is zooming. Domestic BT technology, medical treatment solution technology offer more important role than role assistance enemy of modern technology and utilize by creative technology can . Specially, if apply supersonic waves in bone fracture treatment, there is treatise data that can reduce bone fracture treatment period of bone that bone does not stick well about 40%. Supersonic waves operation frequency used on both end because do 1m Hz, 1.3mHz, supersonic waves origination that have 1.5mHz's Piezo-ceramic crystal tranducer material each 4 premature senilitys in this research, and outside diameter according to impedance and Phase d used Gakgak4mm, 5.4mm, Dukke0.5mm, transformer deuce of length 70mm. Manufactured, and investigated supersonic waves distribution chart by capacity 50m W. Supersonic waves used by diagnosis mainly but is seen to become convenient medical treatment mounting in bone fracture patient's treatment if supplement clinically. If supplement system furthermore, is going to apply to osteoporosis patient, and this research tried to design poetic theme width directly and study rain standardization special quality and approach basic form because do modelling.
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We developed a cuffless and noninvasive measurement technique of blood pressure using tonometric pressure sensor. With observation that the maximum value of pulse pressure is not obtained at mean arterial pressure(MAP), we have figured out MAP based on the physiological characteristic including the elasticity of wrist tisse. Detecting only one part of the body and using only one device are quite advantageous over other BP measurement techniques. Our technique makes new way for the cuffless BP measurement.
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본 논문에서는 차동증폭기와 대역통과 필터를 이용한 심전도측정 시스템의 구현하고 동작을 확인하였다. 구현된 하드웨어의 성능평가를 위해 동일한 입력 신호에 대한 시뮬레이션 결과와 실제 출력을 비교 하였다. 또한, 실제 동작을 확인하기 위하여 심전도 신호 중 리드 II(lead II)파형을 추출하였다. 설계된 회로는 소형화 및 경량화가 가능하기 때문에, 유비쿼터스 환경에 서 이동 중 심전도신호의 측정에 적용가능하며 능동형 게임의 감성추출에도 적용 가능할 것으로 본다.
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The aim of this study is to acquire useful information of lower urinary tract symptom(LUTS) diagnosis through urophonogaphy signal as noninvasive method. The system was implemented to measure urophonography signal, urinary volume and uroflow. The slope of the log-log plot of power spectrum density changed rapidly from
$2.01{\sim}2.07$ to over 3.32 when the occlusion rate was 2 mm to 3.8 mm. This information combined with the uroflow parameters could give a useful prediction of lower urinary tract symptoms. -
The aim of this study was to implement the system that could evaluate the function of urinary tract with noninvasive and comfort methods. There for in this study hardware device and computer software have been developed that enables the analysis of the urine flow rate and vesical pressure signal measured during voiding. These signals were recorded simultaneously and transmitted to the PC. For the measurement system evaluation, the model system for the lower urinary system of men was designed. From the evaluation of the model system, vesical pressure was correlated with the occlusion degree. In a pilot study on 5 male subjects, means of standard deviation was 1.06, average error rate was 2.09 and coefficient variation was 2.09.
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We have developed the elastic measurement system that diagnose the abdominal region, DAM. It cause the Chronic gastro-intestinal disease. For the purpose of detecting the disease, we use the ultrasonic sensor for the collecting response signal and CPLD for the minimum rining. This system has a digital TGC(time gain compensator). We were display the elastic signal to a graph on the LABVIEW.
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In this study, we proposed an algorithm which can detect the walking event in hemiplegic patient using three axis acceleration signal. Twenty hemiplegic patients were participated in an experiment on a level corridor. To evaluate the accuracy, we compared the time difference between the detected event and signal from FSR-Sensor. Consequently, the mean difference of 46.1ms was obtained and it suggests that the proposed method is effective to detect the walking event in hemiplegic patient. In future, these results could be used to evaluate the walking ability in hemiplegic patient in clinical practice.
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In this paper, we designed bio-signal acquisition system in Magnetic Resonance Imager(MRI) Environment. In MRI Environment, Strong RF Pulse and Gradient Field Switching Noise exist and can cause distortion of ECG. By this, ECG can lose their important information. So we proposed a bio-signal acquisition system with robust immunity to RF pulse and gradient switching noise. In conclusions, the proposed system showed the prevent saturation of measured biosignal and possibility of using cardiac gating and respiration gating method.
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In this paper, we have developed a ventricular fibrillation detection system based on DSP processor. The developed system was able to detect VF in real time correctly and quickly. We compared the performance of the floating point simulation with that of fixed point simulation. The computational cost of fixed point simulation was remarkably reduced than that of floating point simulation.
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In this paper, we propose a multimodal biometric embedded system. It is designed to support face, iris, fingerprint and vascular pattern recognition. We use a S3C2440A based on ARM926T core processor that is made in Samsung. The system has support various external device interfaces for multi biometric sensors, and RFID/Smart Card reader/writer. Additionally, it has a 6" LCD panel and numeric keypad for easy GUI. The embedded system offers useful environments to develop better biometric algorithms for stand alone biometric system and accelerator hardware modules for real time operation.
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In this paper, we propose a skin lesion detection to develop the system of fluorescence image analysis to identify the fluorescence of topical methyl aminolevulinate(MAL) idduced PpIX in patients with BCC accurately. By fluorescence image analysis we define the border between tumo and tumor-free areas on fluorescence image after topical application of MAL ointment. We excised both the tumor and peri-tumoral areas widely from the 10 patients with BCC, and divided tissue samples into 3 area, such as tumor area, suspected tumor area, tumor-free area, respectively. Our proposed method migt play a role as an adjunctive tool to define the border between tumor and tumor-free areas for Mohs' micrographic surgery.
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The subject of this paper is to recognize the stable state of EEG using wavelet transform and power spectrum analysis. An alpha wave, showed in stable state, is dominant wave for a human EEG and a beta wave displayed excited state. We decomposed EEG signal into an alpha wave and a beta wave in the process of wavelet transform. And we calculated each power spectrum of EEG signal, an alpha wave and a beta wave using Fast Fourier Transform. We recognized the stable state by making a comparison between power spectrum ratios respectively.
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According as society looks graying trend gradually, more shaped system that can achieve measuring health-state of old people more harmoniously construction required in field of old people's welfare and medical treatment. Health-state is measured by two methods of contact and non-contact. The first, for example measurement of blood pressure or electrocardiogram, requires that measuring equipments are attached on human body but the second, for example X-Ray or MRI, is not. But both of methods are have some of defect, for example attaching equipments, needing of the special equipments or the necessary time, etc. Therefore desirable method of monitoring system must have minimum interrupt about daily life. This study suggest the system that can monitor the user, especially old people's outward aging and health-state by use the PAN TILTER and CCD camera.
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In this paper, we propose the real-time system that detects and recognizes the human face by PTZ camara. Generally, Face detection algorithms are disturbed by variable illuminations in a image. To avoid those, we use the robust adaboost algorithm for face detection. For recognition, we use PCA algorithm. we focus on the real-time system. It will be necessary in many applications.
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The purpose of this study is to develop the optimal system(AAC device), which helps a person with a profound communication disorder to communicate with other people. Therefore, this system includes the user interface enhancement that is the user adaptation mode algorithm. The symbol is made with a text and an icon which is converted into Korean. The message contiol operates scanning and adjusts rate control of row-column scanning and linear scanning. This embedded system includes voice input/output and voice recording as well suggested method that could apply optimal device access algorithm from clinical environment. Therefore, we are experting that even the current system itself will be able to improve the life quality of people who need to communicate with the help of devices.
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Kim, Hyun-Kyu;Kim, Hyun-Joon;Kim, Hyung-Tae;Choi, Tae-Jong;Byeon, Mi-Kyeong;Min, Hong-Ki;Park, Young-Bae;Huh, Woong 887
In this paper, we devised mac-yule detection system which provide resting state mac-yule. The devised system composed of signal transformation part, signal processing part, and PC based display part. Hardware part consisit of PPG, ECG, EEG, EMG, and RSP. Also, software system consist of bio-signal processing software which detecting mac-yule. EEG-$\alpha$ ,$\beta$ wave analysis algorithm that use wavelet transformation, RSP detecting algorithm which used zero-crossing method. -
This paper pertains to introducing the design of adaptive filters for the cancellation of muscle noise among several types of noise sources from the ECG signal. We used EMG signals measured along with ECG at the same time to use it as the reference input to the adaptive filter for the experiments. PSD results showed that the statistical characteristics of ECG are closely correlated with those of EMG.
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Photoplethsymogram (PPG) drifts due to the changes in respiration and blood perfusion as well as external light. This hinders a proper PPG measurement. We controlled DC drifts by controlling the signal ground of PPG signals. A microprocessor-based system successfully controlled DC drifts of PPG signals.
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DSP based on a 8 bit microprocessor was studied for ECG and PPG signals. Digital filtering has an advantage of reducing hardware components in system-on-chip design. However, low resolution such as in 8 bit data has much difficulties in DSP. We demonstrated a comparable performance of DSP filtering compared with analog filters.
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This paper proposes a new method to measure the ECG signal from the driver. The ECG signal is often measured in the room. But it is mixed with many kinds of noise when we measure it during the vehicle moving. We classified noise occupied most many parts as the experimental among them. And we designed one suitable filter for each noise. It used ALE(Adaptive Line Enhancement) to remove the noise occurred to electromagnetic wave in vehicle. To remove the noise occurred to steering or vibration of vehicle, we used Wavelet transformation after ALE(preprocessing filter).
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This paper proposes a new power-stage circuit that can be available for modularization of the power regulator which is used at the software-controlled unregulated bus system. And we analyze the proposed power-stage operation according to its operating modes and verify it by performing software simulation and hardware experiment using prototype. By constructing a parallel-module converter which is composed of proposed power-stages, we verify the operations and usefulness of the proposed power-stage.
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This paper is about a vision system that exhibits automatic examination of the conditions of shaft's worm. The system is composed of three part : image acquisition, vision algorithm, and user interface. The image acquisition part is composed of motor control, illumination and optics. The vision algorithm examines the parts using shaft image. User interface is divided into two parts, user interface for feature registering with control value settings and user interface for examination operation. The automatic inspection system introduced in this paper can be used as a tool for final examination of shaft worm.
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In this paper, we propose an attractive novel numerical int egration method that is largely devoid of ill conditioning and is suitable for any nonlinear problem. Since the method is exact for linear problems, it is especially precise for quasilinear problems, which are frequently encountered in the real world. The method is based on a new approach to the computat ion of a matrix exponential. It does not require excessive computational resources and lends itself to a short and robust piece of software that can be easily inserted into large simulation packages.
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We describe a method for localizing a mobile robot in its working environment using a vision system and Virtual Reality Modeling Language (VRML). The robot identifies landmarks in the environment, using image processing and neural network pattern matching techniques, and then its performs self-positioning with a vision system based on a well-known localization algorithm. After the self-positioning procedure, the 2-D scene of the vision is overlaid with the VRML scene. This paper describes how to realize the self-positioning, and shows the overlap between the 2-D and VRML scenes. The method successfully defines a robot's path.
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In this paper, the transfer function to the vehicle is derived from using system identification algorithm in connection with the driving vehicle. We design the adaptive cruise controller using the derived transfer function, and make it possible to monitoring and control the vehicle in real time using embedded system and technology of Internet.
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The recent growth in the portable display industry has been dominated by flexible display, moreover, several developing of using LCD technology has been in making the flexible display work effectively, however flexible device is not practical. Recently, the study on the multi-display screen has been published as the needs of larger screen in mobile device has been increased. The multi-display screen which is composed of two LCD panels, has the characteristics of the seamless gap between two panels. To meet the needs of this multi-display, in this paper, the study is performed to design the seamless device which consist of LCD panels, light film, back light and driver, and finally, we evaluated the effectiveness of seamless folding mechanism.
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This paper proposes a flexible IED platform which is implemented with a network processor and a DSP. DSP algorithms are downloaded through the embedded Linux based network processor remotely from ethernet. This architecture gives the best flexibility to adaptively accommodate the various algorithms needed in the IED environment. The developed IED platform can simultaneously measure data of the maximum of forty channels. The developed IED platform shows the successful operation, which measures and transfers the 8 channels data of 16bit samples sampled at 3.84kHz per each channel. The detailed performance analysis of the developed IED platform shows the about 10% processing load of CPU running at 533MHz.
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본 논문은 원자력 발전소의 금속파편감시계통(LPMS)에서 충격신호의 탐지를 위해 사용되는 하드웨어 구현에 관한 것이다. 본 논문에서 구현한 것은 LPMS의 하드웨어 중에서 입력된 신호를 디지털로 변환하여 충격신호의 트리거 판단기능을 하는 DAM(Data acquisition module)보드이다. 본 논문에서 구현한 DAM은 디지털 필터와 트리거 판단을 위한 알고리즘이 DSP에서 실시간으로 처리되어 LPMS의 기능을 업그레이드 하였다.
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It is possible to make a practical application for many services by using Home Networking. It's brings much improve the quality of our life. Remote control communication should be made by Home Network but present networks are generally using wireless Internet. But, this method don't use exist home and not install wireless internet. Because It need to many devices. Therefore, in this paper we implement gas valve remote control system using RPM(Radio Packet Modem). We can easily installing systems and operating. This system provide different solution for Home networking.
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This paper presents a novel scheme that quickly searches for the sweet spot of multiple array antennas, and locks on to it for high-speed millimeter wavelength transmissions. The proposed method utilizes a modified genetic algorithm, which selects a superior initial group through preprocessing in order to solve the local solution in a genetic algorithm. TDD (Time Division Duplex) is utilized as the transfer method and data controller for the antenna. Once the initial communication is completed for the specific number of individuals, no longer antenna's data will be transmitted until each station processes GA in order to produce the next generation. After reproduction, individuals of the next generation become the data, and communication between each station is made again. Simulation results confirmed the efficiency of the proposed method.
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Jang, Chul-Woong;Jung, Ki-Ho;Yeom, Moon-Jin;Shim, Hyun-Min;Hong, Yeong-Ki;Shim, Jae-Hong;Lee, Eung-Hyuk 923
In this paper, we propose the sensor fusing method for the obstacle avoidance of guiding robot for the visually impaired In our system, we acquire obstacles distances information using ultrasonic sensors, and its width is acquired by image sensor. We also compute avoidance angle using are distance and width information gained by sensor. After the robot avoid the obstacle by computed angle, the robot returns to its original path using odometry. The robot consists of the SA1110-based controller, sensory part using sonar array and image sensor, and motion part using differential drive for climbing stairs. This system use the embedded linux for OS, and also is developed by the QT/Embedded for GUI. -
In the multi-agent system for a single task, the action selection can be made for the real-time environment by using the global coordination space, global coordination graph and MAX-PLUS algorithm. However, there are some difficulties in multi-agent system for multi-tasking. In this paper, a real-time decision making method is suggested by using coordination space, coordination graph and dynamic coordinated state of multi-agent system including many agents and multiple tasks. Specifically, we propose locally dynamic coordinated state to effectively use MAX-PLUS algorithm for multiple tasks completion. Our technique is shown to be valid in the box pushing simulation of a multi-agent system.
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In this paper, we propose a dynamic emotion system involving the state equation and the output equation from the control theory. In our emotion system, the state equation accepts external stimulus and generates emotions. And the output equation modifies the intensity of emotions in accordance with personalities and circumstances. The validity of the proposed emotion system is shown by two simulation works which express emotions according to personalities and circumstances.
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In this paper, we propose a planning algorithm which automatically generates robust behavior plans for service robots in the dynamically changing environments. The proposed method searches for paths to perform the given tasks in the physical space and the configuration space where tasks are described. And then, the characteristics of paths for successfully performed task are abstracted and generalized to build an ordered-tree structure. The resulting robust behavior plans guarantee that the given tasks are successfully performed. The validity of our method is tested by simulation work for a pushing-box task.
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This paper proposes a task modeling architecture -.uFlow-.for home service robots that facilitates the developmental process and let developers implement their services with ease and efficiency.
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High level perceptual tasks such as context understanding, SLAM and object recognition are essential for intelligent robot to provide services for human supports. Those intelligent robots often use camera sensor for vision information, sonar or laser sensor for range information, encoder for angular velocity of wheel and so on. The information is generated at different time intervals by the different H/W devices and S/W algorithms. The generation of high level information requires the specific mixture of low level information. And the information should be represented to be useful for robots to use in their ecological niche. In conventional robot systems, perceptual module requires the resource to use by tightly coupling whenever it is needed. So the resource and information cannot be easily shared and even could be invalid for the delayed information. In this paper, we propose a synchronization system of robot-centered information for context understanding. Our system represents information for the robot capacity and synchronizes the information that is asynchronously generated, where is employed the black-board architecture.
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In this paper, we have applied a real-time face processor includes detection, recognition, and learning to a intelligent store management service robot. We use the Haar classifier and adaboost learning algorithm for face detection. For face recognition and learning, a PCA algorithm and a SVDD algorithm is used. We have developed a store management service robot and applied these algorithms to verify the performance.
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There are lots of intelligent service robots in these days. People are unwilling to do routine works, dangerous works, and difficult works. But a robot can do these works instead of human. We introduce a intelligent service robot for unmanned store management. The robot can detect and recognize a person, deliver some goods, manage a store, and answer the telephone. We have developed the robot and tested the performance.
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Many researches on path planning and obstacle avoidance for the fundamentals of mobile robot have been done. In this paper, we propose the algorithm of path planning and obstacle avoidance for mobile robot. We call the proposed method Random Access Sequence(RAS) method. RAS method using obstacle information from variable sensors is useful to get minimum path length to goal.
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A depth measurement system to recognize 3D shape of objects using single camera, line laser and a rotating mirror has been investigated. The camera and the light source are fixed, facing the rotating mirror. The laser light is reflected by the mirror and projected to the scene objects whose locations are to be determined. The camera detects the laser light location on object surfaces through the same mirror. The scan over the area to be measured is done by mirror rotation. The Segmentation process of object recognition is performed using the depth data of restored 3D data. The Object recognition domain can be reduced by separating area of interest objects from complex background.
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In this paper, we implemented the autonomous mobile robot which can recognize and avoid obstacles, then move to its destination using a camera and ultrasonic sensors. The mobile robot can avoid both stationary obstacles with a camera and moving obstacles with ultrasonic sensors. It can find the self-location with the map-based system, that is, it attempts to localize by collecting sensor data, then updating some belief about its position with respect to a map of the environment.
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There are some difficulties to track an object with one-axis two-wheel drive method. When one-axis two-wheel drive robot wants to approach to the object, it should turn direction of the robot. At this time, direction of camera also would be changed. In this paper, we introduce omni-directional driving system that can move freely without turning the robot body, and propose the optimal approaching method.
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This paper proposes a robust posture stabilization control method for wheeled mobile robots. To solve the robust posture stabilization, we introduce reference generation mode, reference tracking mode, and reference regulation mode. In reference generation mode, a kinematic time-invariant controller is used to generate the reference trajectory which starts from the initial posture of the actual robot to the desired posture. In reference tracking mode, a sliding mode position controller is employed in such a way that the actual robot can follow the reference trajectory in the desired forward or backward moving direction, even in the presence of the disturbances in the dynamics. In reference regulation mode, a sliding mode heading direction controller is used such that the actual robot can maintain the desired posture against the disturbances. In this way, robust posture stabilization can be achieved at almost all global regions.
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Currently, most of TIDS(Train Information Display System) is operated colored-LED type equipment in Korea. This current TIDS equipment has not graceful display and causes passengers' fatigues, high operating and maintenance costs, and et al. To address these several, we are developed new colored-LCD type TIDS equipment. According to our developed new TIDS equipment, we can achieve high resolution and graceful color stone of information display.
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Railway signaling systems are so vital to ensure the safe operation of railroad and the assurance and demonstration of the safety is so important. The safety management process shall consist of a number of phases and activities, which are linked to form the safety life-cycle. The basic processes of safety management and safety activity throughout the lifecycle are 'risk analysis' and 'hazard control'. The safety managements and activities for the two kinds of aspects are implemented throughout the whole steps of system lifecycle. The risk analyses and hazard controls like those are needed, these activities have to be carried out through the whole of system lifecycle.
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Guaranteeing survivability is the most important issue in designing and operating optical transmission network. For dual system of optical transmission network, there should be two routes of the optical to prepare an error in one cable route. If a route is selected based on the standard of unused optical core when choosing an optical cable, dual optical cable routes could be installed in duplicated line. This paper simulates the installation of duplicated line when designing an optical transmission network, detects the status of duplicated line that could happen during transfer construction and switching and accomplishes a system that can confirm the location based on a map.
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In indoor location awareness system, Generally the system uses the difference of ultrasonic waves and RF arrival times. In this paper, We researched the interference minimization method between node in indoor location awareness system.
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PC users could experience some inconvenience when they use their PC that was physically connected to network printers shared by other people in the network due to the overload. This paper shows how to resolve this kind of overload problem and established the embedded printer system based on embedded Linux system which performs the printer server in order for any users in the office to do printing work more smoothly via current network. It's own capabilities and functions were verified throughout the various tests in practical environment.
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The AMBA(Advanced Microcontroller Bus Architecture) system is one of the most important elements having an influence upon system performance in ARM-based SoC environments. The system guarantees easy connection and good performance as a 32-bit bus system for ARM processors. In this paper, we analyze arbitration algorithms for the AHB bus of the AMBA system and propose an efficient algorithm to improve the performance of the bus system.
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By combining a digital DLL and an analog DLL in 2-stage, an improved DLL is implemented in this paper. The proposed DLL is composed of a RDLL (Register Controlled DLL) and a conventional analog DLL. The phase comparator used in the DLL is built with sense-amp based D flip-flops for high speed operation. The proposed DLL circuits have been designed, simulated in 0.18um, 1.8V TSMC CMOS library. The implemented DLL have demonstrated the fast lock-on time of 1us and low jitter of 72ps.
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As billion transistors system-on-chip (SoC) design becomes a reality, the productivity gap between rapidly increasing design complexity and designer productivity lagging behind is becoming a more serious problem to be solved. To reduce the gap, we present a system that generates executable transaction level models automatically. It speed up the SoC design space exploration process at various abstraction levels.
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This paper proposes a novel system to send images in a narrow band network and to measure water level. In order to send images in narrow band network, we use JPEG compression technique based on the difference image. The difference image is obtained by subtracting the current image from the predefined reference image. The water level is measured to make use of the camera calibration and the edge information of the received image.
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This paper develops a recognition system of assembly parts using a hardware independent image module. Using a shared memory, the image module consists of the image acquiring process and the image processing process. We preprocess an acquisition image from the module, approximate the image edges to an ellipse, and then recognize an assembly part by matching the ellipse to a model base one.
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Min, K.W.;Chung, D.S.;Song, B.G.;Kim, S.L.;Kang, H.S.;Baik, C.W.;Jeong, T.W.;Kim, J.W.;Jin, Y.W.;Cho, J.D. 971
We have demonstrated Carbon Nanotube Back Light Unit (CNT-BLU) which has a triode structure. Local dimming scheme was introduced to the BLU driving system. With this driving method, contrast ratio enhanced 20 times higher than that of conventional Cold Cathode Fluorescent Lamp (CCFL) BLU. -
In this paper, Computer-aided Maintenance Equipments, which are being used in maintenance, are applied to analyze failures in train control systems, resulting in long time delays of trains. It can be expected to extend and apply CAMS (Computer Aided Maintenance System) in the hereafter efficient operation and maintenance of high-speed railway train control systems, by comparison between the analysis result of fundamental causes, from high-speed railway train control system failures occurred during the operational process, and predictive result of failure causes, based on the recording data of CAMS when failures were occurred.
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The passive type RFID (Radio Frequency Identification) System using Surface Acoustic Wave (SAW) tag at 900 MHz in the range of more than 1 m was fabricated. To improve interrogation range of the system propose a method to increase isolation between transmitter and receiver. This method using a direct conversion architecture achieves a leakage rejection of 10 dB increased compared with conventional system. Measured interrogation range is more than 1 m.
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In this study, the synthesis and semiconducting properties of cation and defect-doped KTaO3 film is reported. KTaO3is an important material for optoelectronic and tunable microwave applications. It is an incipient ferroelectric with a cubic structure that becomes ferroelectric when doped with Nb. the films were grown on (001) MgO single crystal substrates using pulsed-laser deposition. Semiconducting behavior is achieved by inducing oxygen vacancies in the KTaO3 lattice via growth in a hydrogen atmosphere. The resistivity of semiconducting KTaO3:Ca films was as low as 10cm, and n-type semiconducting behavior was indicated. Hall mobility and carrier concentration were 0.27 cm2/Vs and 3.21018cm-3.
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Multi-band VCO with fast response adaptive frequency calibration (AFC) technique is designed in 1.8V
$0.18{\mu}m$ CMOS process. The possible operation is verified for 5.8GHz band, 5.2GHz band, and 2.4GHz band using the switchable L-C resonators for 802.11a/b/g WLAN applications. To linearize its frequency-voltage gain, optimized multiple MOS varactor biasing technique is used. In order to operate in each band frequency range with reduced VCO gain, 4-bit digitally controlled switched-capacitor bank is used and a wide-range digital logic quadricorrelator is implemented for fast frequency detector. -
The epitaxial
$KTa_{0.524}Nb_{0.446}Ti_{0.03}O_3$ films with 3% Ti were investigated. Titanium (+4) substitution on the Nb/Ta site should reduce dielectric losses of KTN: Ti film by introducing an acceptor state. This acceptor state traps electrons due to oxygen vacancies that form during oxide film growth. KTN:Ti films were grown using pulsed laser deposition, and then annealed at different temperatures in oxygen ambient. The crystallinity, and surface morphology of KTN:Ti film were investigated using x-ray diffraction, and atomic force microscopy. The dielectric properties of Ti doped KTN films measured for unannealed and annealed films will be reported. Tunability and dielectric loss of as-deposited KTN:Ti film were determined to be 10% and 0.0134, respectively. For films annealed at$800^{\circ}C$ and$900^{\circ}C$ , the dielectric loss decreased but with a decrease in tunability as well. -
This paper presents a design and MPW implementation of 3D Graphics Floating Point IPs. Designed IPs include adder, subtractor, multiplier, divider, and reciprocal unit. The IPs have pipelined structures. The IPs meet the accuracy required in OpenGL ES. The operation frequency of the IPs is 100MHz. The IPs can be efficiently used in 3D graphics accelerators.
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This paper presents a design of 3D Graphics Geometry processor. A geometry processor needs to cope with a large amount of computation and consists of transformation processor and lighting processor. To deal with the huge computation, a vector processing structure based on pipeline chaining is proposed. The proposed geometry processor performs 4.3M vertices/sec at 100MHz using 11 floating-point units.
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Multiprocessor system is efficient and high performance architecture to overcome a limitation of single core SoC. In this paper, we propose a multiprocessor SoC (MPSoC) architecture which provides the low complexity and the high performance. The dynamic routing scheme has a serious problem in which the complexity of routing increases exponentially. We solve this problem by making a cluster with several PEs (Processing Element). In inter-cluster network, we use deterministic routing scheme and in intra-cluster network, we use dynamic routing scheme. In order to control the hierarchical network, we propose efficient router architecture by using smart crossbar switch. We modeled 2-D mesh topology and used simulator based on C/C++. The results of this routing scheme show that our approach has less complexity and improved throughput as compared with the pure deterministic routing architecture and the pure dynamic routing architecture.
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현대 Mobile module에 알맞은 IP들은 고속에서 얼마나 소비 전력을 낮춰주느냐 하는 방향으로 진화하고 있다. 본 논문에서는 저전력 구현을 위해 digital block에서의 신호를 제어해주는 방법을 사용한 UWB system용 6B 2.5Gsample/s Flash ADC를 소개한다. 소개된 ADC는 2.5GS/s의 clock, 1240MHz의 input 신호에서 36,7dB의 SNDR과 5.80 비트의 ENOB를 가지며 385mW의 전력을 소모한다.
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Kim, Jung-Hak;Chung, Ho-Ryun;Ha, Chung-Gyun;Lee, Joo-Chul;Lee, Wook;Lee, Hwan-Woo;Yang, Hwi-Chan 995
This paper presents a design of the PMOLED(Passive Matrix Organic light emitting diodes) driver IC improving the terminal current offset. The proposed methods are improving the design of the usual data output circuit. This methods can be avoidance brightness non-uniformity problem. -
Kim, Jung-Hak;Chung, Ho-Ryun;Ha, Chung-Gyun;Lee, Joo-Chul;Lee, Wook;Lee, Hwan-Woo;Yang, Hwi-Chan 997
This paper proposes an design of the OLED(Organic Light Emitting Diodes) driver IC using novel verification method. This method using the HDL(hardware description language) simulator, PLI(Programing Language Interface) and image viewer. The proposed method can be used efficiently to function verification in display driver IC. -
The LDPC Code is focusing a powerful FEC(Forward Error Correction) codes for 4G Mobile Communication system. LDPC codes are used minimizing channel errors by modeling AWGN Channel as VDSL system. The performance of LDPC code is better than that of turbo code in long code word on iterative decoding algorithm. LDPC code are encoded by sparse parity check matrix. there are decoding algorithms for a LDPC code, Bit Flipping, Message passing, Sum-Product. Because LDPC Codes use low density parity bit, mathematical complexity is low and relating processing time becomes shorten.
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As most of the powerline modems use spread spectrum modulation method which has strong immunity against the narrowband fading, or psk modulation method, the amplitude of the signal contains no useful informations. In this paper, we used class D amplifier to implement the drive circuit of the analog front end, and showed that it has great superiority over other existing drive circuits in rapidly impedance changing power line channel.
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In this paper we extract the position value of the tracking object using the hierarchical optic-digital algorithm and to control the main visual angle and Pan/Tilt. And then we propose the optic-digital stereo object tracking system for adaptive extracting the moving-target.
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This paper proposes a method of position estimating through compensating the autonomous mobile robot's noise. Proposed method is that estimated position error by modified Kalman filter method using neural network. We use a neural network for measurement noise covariance and system noise covariance. In order to verify the effectiveness of the proposed method, we performed experiments for position estimation. The results show that convergence and position error is reduced than the Kalman filter method.
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This paper presents a optimal path search of mobile robot using energy efficiency. Proposed method has two goals that determining the velocity of mobile robot and finding the optimal path. We model the relationship of motors' speed and power consumption with quadratic polynomials. In order to verify the effectiveness of the proposed method, we performed simulations on the energy consumption of different paths.
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In this paper we present the results of measurements that have been performed in order to obtain more accurate indoor channel models to feed realistic simulation for the wireless sensor network technology. This may contribute to obtain more reliable results and analysis of wireless sensor networks.
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In this paper, implementation process of standard platform for T-DMB Receiver in low-cost and small-size are following: First, implement SoC for 32 bit RISC CPU and 16 bit DSP, Hardware H.264 CODEC, Post Processor or Video Display, Audio Processor, I/O Device. Second, implement Real Time OS for flexible application. Third, propose simple architecture for interface with peripheral devices using one-chip processor.
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Mobilecomputer offers more fundamental role than role assistance enemy of modern technology equipment and new Information Technology can reconsider, and reconstruct creatively accuracy of physiological concept. That military register symptoms are developed of disease, before far before rehalibitation, offer possibility that can intervene in process that motive change of military register symptoms after rehalibitation. But, that many parameters become analysis target and mathematical settlement and equalization system of neted data of that is huge, same time collection of all datas can lift difficulty etc.. These main weakness puts in structural relation between elements that compose system. Therefore, dynamics research that time urea of systematic adjustment has selected method code Tuesday nerve dynamics enemy who groping of approach that become analysis point is proper and do with recycling bioelectricity signal. Nature model of do living body signal digital analysis chapter as research result could be developed and scientific foundation groping could apply HSS (Hardware-software system) by rehalibitation purpose. Special quality that is done radish form Tuesday of bioelectricity signal formation furthermore studied, and by the result, fundamental process of bodysignal in do structure circuit form of analog - digital water supply height modelling do can
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The important parameters deciding the fluctuation of Accumulation style surgical operation of ventriculus laser beam are smoothing capacitor, frequency and he characteristics of laser resonator. In this thesis, we control the fluctuation of medical
$CO_2C$ laser in realtime by changing Duty-Ratio of IGBT and switching frequency with fixed the smoothing capacitor to improve the fluctuation of laser beam. We detect the light on laser resonator using a CdS photo sensor to improve ripple factor of laser beam and feedback fluctuated signals refined by a band pass filter into the control circuit to stabilize fluctuation actively. There is much to be desired in the realtime controlling technique of the light on Accumulation style surgical operation of ventriculus laser discharge tube in electrical signal. We propose switching control technique with microprocessor and photo sensing technique by controlling switch devices optimum operation and feedback signals detected by a photo sensor into the laser power supply in order to improve ripple factor of the$CO_2$ laser beam. -
We measured EEG, extracted the feature vectors using alpha and beta rhythm from the measured EEG and pattern recognition was simulated by using the feature vector and the algorithms which are conventional LVQ and Forward only Counter Propagation Networks. And then the successful rate of pattern class of EEG data had about 76 %.
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The proposed algorithm consists of two parts. One is to set up a decision tree to represent the various switching operations available. Another is to identify the most effective the set of switches using proposed search technique and a feeder load balance index. Test results on the KEPCO's 108 bus distribution system show that the performance is efficient and robust
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In industrial control system used by Programmable Logic Controller(PLC), Ladder Diagram(LD) is the most widely utilized and plays an important role in industrial control system. But recently, the study about Sequential Function Chart(SFC) is performed actively. When we program by SFC, generally, we design one routine from start to end. This method is difficult to design, and we often make mistakes. In this paper, we propose the method that we compose each sub-system after we design each sub-system, and we analysis the difference of the method used this paper from conventional method.
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The present study purposed to design a system that enables the selection and the operation of OPC systems actively while allowing the use of legacy systems as they are. In addition, this study will design a standardized structure of information collected when using OPC protocol and, for this, use not only OPC-DA but also OPC-XMLDA to integrate data.
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The approach, for ensuring the quality and safety of a railway software can be considered with two points of views seeing from products, and from processes. The process point of view is to validate maturity of the organizations in accordance to the judging processes of organizations, which are specified by CMMI(Capability Maturity Model Integration) or SPICE(Software Process Improvement and Capability dEtermination : ISO/IEC15504). In this paper, we are trying to find approaches to estimate the maturity of manufacturer and assessment organization in the railway system.
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A case study in low-power PostPC Platform is presented. We introduce an S3C2460 Mobile SoC Processor and Implementation of Embedded Linux on out platform. This Processor is designed to Multimedia & Telecommunication Applications. We focuse on the verification of S3C2460 Processor and operation of Embedded Linux OS on it.
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A 3D model based face recognition system is generally inefficient in computation time because 3D face model consists of a large number of vertices. In this paper, we propose a novel 3D face representation algorithm to reduce the number of vertices and optimize its computation time.
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The paper demonstrates OFDM with LDPC and adaptive modulation applied to Multiple-Input Multiple-Output (MIMO) system. An optimization algorithm to obtain a bit and power allocation for each subcarrier assuming instantaneous channel knowledge is used. The experimental results are shown the potential of our proposed system.
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We analyzed the performance of hierarchical cellular system with multi traffic(voice traffic, data traffic). We executed the computer simulation by the various ratio of traffic generation(voice traffic, data traffic). We generated data traffic at microcell. The more voice traffic generated, the higher the block probability of data traffic became at macrocell.
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This paper treats the guide path tracking problem of an experimental automated guided vehicle. An experimental guide path is made of aluminium foil which has width of 2[cm]. A digital Proportional and Derivative controller is used to manipulate the steering system and it is verified by laboratory experiments that the designed AGV tracks the guide path withen the range of 3.2[cm] deviation.
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In this study, we have been constructed measuring system for interference for TV broadcasting signals between Korea and Japan. In Busan, we have been measured 14 channel of Japan TV broadcasting signals during 4 days. The quality of image is that 2.5 level is maximum grade, and the quality of sound is that 3 level is maximum grade. And we have been observed Japan TV broadcasting signals, in Busan, Ulsan, and Pohang. There are detected 40 channels. The 19, 24, 29, 36, 39 channels have 3.0 grade image quality and The maximum field strength is
$71dB{\mu}V$ /m. -
In a packet based wireless system, an adaptive modulation and coding (AMC) scheme is often employed with the use of channel quality information (CQI). However, the AMC can be operated improperly due to delayed CQI, causing performance degradation. In this paper, we consider the use of predicted CQI for the AMC considering the feedback delay and channel characteristics. We also consider the use of a hybrid automatic repeat request scheme with the proposed AMC for further improvement in high mobility environments.
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The IEEE 802.11e medium access control (MAC) is an emerging standard to support Quality of Service (QoS). A HCCA (HCF controlled channel access) scheduler of the standard IEEE 802.11e is only efficient for flows with strict constant bit rate (CBR) characteristics. In this paper, we propose a new HCCA scheduling scheme that aims to be efficient for both CBR and VBR flows. The proposed scheme uses fuzzy queue length predictions to tune its time allocation to stations. We present a set of simulations and provide performance comparisons with the reference HCCA scheduler.
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In this paper, we present an iterative phase offset estimation algorithm based on a space-time block code and turbo coded system. External single phase estimator receives soft information from the turbo decoder and estimates phase offset with LMS algorithm. The estimated phase offset value is used for space-time decoder. Simulation results show the phase estimation gain in a flat fading channel.
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In this paper, we present the analysis of Tree-LDPC codes using EXIT(Extrinsic information transfer) charts methods. Two different EXIT charts schemes are compared. One is based on the closed form equation and the other is based on Monte-Carlo simulation. The thresholds by these two schemes match well with the threshold by DE(density evolution) scheme. Simulation performance is also shown with the obtained thresholds.
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In this paper, we propose a puncturing scheme to design low-density parity-matrix (LDPC) codes for unequal error protection (UEP). Two different puncturing schemes are compared. Simulation results show that proposed puncturing scheme outperforms regular puncturing scheme for more important bits. Future work is to find an optimized puncturing patten for UEP irregular LDPC codes.
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In this paper we consider a family {
$H_m$ },m =1,2,..., of generalized Hadamard matrices of order$P^m$ , where p is a prime number, and construct the corresponding family {$C^*_m$ } of generalize p-ary Hadarmard codes which meet the Plotkin bound. Index terms: Cyclotomic fields, cocyclic matrices, Butson-Hadamard matrices, generalized Hadamard codes, decoding.