• Title/Summary/Keyword: channel feedback

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A Fast Distributed Video Decoding by Frame Adaptive Parity Bit Request Estimation (프레임간 적응적 연산을 이용한 패리티 비트의 예측에 의한 고속 분산 복호화)

  • Kim, Man-Jae;Kim, Jin-Soo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2011.10a
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    • pp.161-162
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    • 2011
  • Recently, many research works are focusing on DVC (Distributed Video Coding) system for low complexity encoder. However the feedback channel-based parity bit control is a major cause of the high decoding time latency. Spatial and temporal correlation is high in video and, therefore, the statistical property can be applied for the parity bit request of LDPCA frame. By introducing frame adaptive parity bit request estimation method, this paper proposes a new method for reducing the decoding time latency. Through computer simulations, it is shown that the proposed method achieves about 80% of complexity reduction, compared to the conventional no-estimation method.

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Sensory Motor Coordination System for Robotic Grasping (로봇 손의 힘 조절을 위한 생물학적 감각-운동 협응)

  • 김태형;김태선;수동성;이종호
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.53 no.2
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    • pp.127-134
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    • 2004
  • In this paper, human motor behaving model based sensory motor coordination(SMC) algorithm is implemented on robotic grasping task. Compare to conventional SMC models which connect sensor to motor directly, the proposed method used biologically inspired human behaving system in conjunction with SMC algorithm for fast grasping force control of robot arm. To characterize various grasping objects, pressure sensors on hand gripper were used. Measured sensory data are simultaneously transferred to perceptual mechanism(PM) and long term memory(LTM), and then the sensory information is forwarded to the fastest channel among several information-processing flows in human motor system. In this model, two motor learning routes are proposed. One of the route uses PM and the other uses short term memory(STM) and LTM structure. Through motor learning procedure, successful information is transferred from STM to LTM. Also, LTM data are used for next moor plan as reference information. STM is designed to single layered perception neural network to generate fast motor plan and receive required data which comes from LTM. Experimental results showed that proposed method can control of the grasping force adaptable to various shapes and types of greasing objects, and also it showed quicker grasping-behavior lumining time compare to simple feedback system.

DOA estimation based beamforming technique for DTV reception performance enhancement (입사각 추정 기반 빔형성을 이용한 DTV 수신성능 개선)

  • 문성훈;한동석
    • Journal of Broadcast Engineering
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    • v.8 no.2
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    • pp.136-145
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    • 2003
  • This paper proposes a DTV receiver using beamforming techniques to improve indoor and mobile reception. The proposed DTV receiver estimates the directions of arrival (DOAs) of incoming signals using Capon's DOA estimation method and generates an adaptive antenna beam pattern to the estimated DOA of the mainpath signal to Improve the channel condition. After beamforming, a following decision feedback equalizer (DFE) removes the remaining multipath components. The proposed receiver can be implemented with a conventional DTV receiver without anymodification. The performance of the proposed receiver is analyzed with modified Brazilian field test models, which include DOA information of Incoming signals. Simulation results show that the proposed receiver can satisfy the threshold of visibility (TOV) when input signal to noise ratio is slightly over 10 dB.

Research on Silicon Nanowire Transistors for Future Wearable Electronic Systems (차세대 웨어러블 전자시스템용 실리콘 나노선 트랜지스터 연구)

  • Im, Kyeungmin;Kim, Minsuk;Kim, Yoonjoong;Lim, Doohyeok;Kim, Sangsig
    • Vacuum Magazine
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    • v.3 no.3
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    • pp.15-18
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    • 2016
  • In future wearable electronic systems, 3-dimensional (3D) devices have attracted much attention due to their high density integration and low-power functionality. Among 3D devices, gate-all-around (GAA) nanowire transistor provides superior gate controllability, resulting in suppressing short channel effect and other drawbacks in 2D metal-oxide-semiconductor field-effect transistor (MOSFET). Silicon nanowires (SiNWs) are the most promising building block for GAA structure device due to their compatibility with the current Si-based ultra large scale integration (ULSI) technology. Moreover, the theoretical limit for subthreshold swing (SS) of MOSFET is 60 mV/dec at room temperature, which causes the increase in Ioff current. To overcome theoretical limit for the SS, it is crucial that research into new types of device concepts should be performed. In our present studies, we have experimentally demonstrated feedback FET (FBFET) and tunnel FET (TFET) with sub-60 mV/dec based on SiNWs. Also, we fabricated SiNW based complementary TFET (c-TFET) and SiNW complementary metal-oxide-semiconductor (CMOS) inverter. Our research demonstrates the promising potential of SiNW electronic devices for future wearable electronic systems.

A Flexible Network Access Scheme for M2M Communications in Heterogeneous Wireless Networks

  • Tian, Hui;Xie, Wei;Xu, Youyun;Xu, Kui;Han, Peng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.10
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    • pp.3789-3809
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    • 2015
  • In this paper, we deal with the problem of M2M gateways' network selection for different types of M2M traffic in heterogeneous wireless networks. Based on the difference in traffic's quality of service (QoS) requirements, the M2M traffic produced by various applications is mainly classified as two categories: flexible traffic and rigid traffic. Then, game theory is adopted to solve the problem of network-channel selection with the coexistence of flexible and rigid traffic, named as flexible network access (FNA). We prove the formulated discrete game is a potential game. The existence and feasibility of the Nash equilibrium (NE) of the proposed game are also analyzed. Then, an iterative algorithm based on optimal reaction criterion and a distributed algorithm with limited feedback based on learning automata are presented to obtain the NE of the proposed game. In simulations, the proposed iterative algorithm can achieve a near optimal sum utility of whole network with low complexity compared to the exhaustive search. In addition, the simulation results show that our proposed algorithms outperform existing methods in terms of sum utility and load balance.

Wearable Band Sensor for Posture Recognition towards Prosthetic Control (의수 제어용 동작 인식을 위한 웨어러블 밴드 센서)

  • Lee, Seulah;Choi, Youngjin
    • The Journal of Korea Robotics Society
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    • v.13 no.4
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    • pp.265-271
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    • 2018
  • The recent prosthetic technologies pursue to control multi-DOFs (degrees-of-freedom) hand and wrist. However, challenges such as high cost, wear-ability, and motion intent recognition for feedback control still remain for the use in daily living activities. The paper proposes a multi-channel knit band sensor to worn easily for surface EMG-based prosthetic control. The knitted electrodes were fabricated with conductive yarn, and the band except the electrodes are knitted using non-conductive yarn which has moisture wicking property. Two types of the knit bands are fabricated such as sixteen-electrodes for eight-channels and thirty-two electrodes for sixteen-channels. In order to substantiate the performance of the biopotential signal acquisition, several experiments are conducted. Signal to noise ratio (SNR) value of the knit band sensor was 18.48 dB. According to various forearm motions including hand and wrist, sixteen-channels EMG signals could be clearly distinguishable. In addition, the pattern recognition performance to control myoelectric prosthesis was verified in that overall classification accuracy of the RMS (root mean squares) filtered EMG signals (97.84%) was higher than that of the raw EMG signals (87.06%).

A Study on Big Data Processing Technology Based on Open Source for Expansion of LIMS (실험실정보관리시스템의 확장을 위한 오픈 소스 기반의 빅데이터 처리 기술에 관한 연구)

  • Kim, Soon-Gohn
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.14 no.2
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    • pp.161-167
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    • 2021
  • Laboratory Information Management System(LIMS) is a centralized database for storing, processing, retrieving, and analyzing laboratory data, and refers to a computer system or system specially designed for laboratories performing inspection, analysis, and testing tasks. In particular, LIMS is equipped with a function to support the operation of the laboratory, and it requires workflow management or data tracking support. In this paper, we collect data on websites and various channels using crawling technology, one of the automated big data collection technologies for the operation of the laboratory. Among the collected test methods and contents, useful test methods and contents useful that the tester can utilize are recommended. In addition, we implement a complementary LIMS platform capable of verifying the collection channel by managing the feedback.

A Causality Analysis of the Tangerine Market by Distribution Channel (감귤시장의 유통단계별 가격 인과성 분석)

  • Kang, Seok-Kyu;Ko, Bong-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.3
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    • pp.376-381
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    • 2018
  • The purpose of this study is to investigate price transmissions between wholesale and retail markets regarding Jeju tangerines by employing co-integration analysis and vector error correction model. The results of this study are summarized as follows: First, the long-run equilibrium relationship was found among wholesale and retail markets in time series for level by distribution channel. Second, a short-run causality relationship was observed between wholesale and retail markets. Third, the long-run causality relationship between wholesale market and retail markets was found bidirectional and feedback effect. These results imply that the wholesale price performs a central role in establishing price in the tangerine market, and the wholesale market influences tangerine price. In conclusion, for the development of a competitive tangerine industry, it is necessary to aggressively promote the policy of supply and demand control of tangerine production through organizing producers.

Performance Improvement of Downlink Real-Time Traffic Transmission Using MIMO-OFDMA Systems Based on Beamforming (Beamforming 기반 MIMO-OFDMA 시스템을 이용한 하향링크 실시간 트래픽 전송 성능 개선)

  • Yang Suck-Chel;Park Dae-Jin;Shin Yo-An
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.43 no.3 s.345
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    • pp.1-9
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    • 2006
  • In this paper, we propose a MIMO-OFDMA (Multi Input Multi Output-Orthogonal Frequency Division Multiple Access) system based on beamforming for performance improvement of downlink real-time traffic transmission in harsh channel conditions with low CIR (Carrier-to-Interference Ratio). In the proposed system, we first consider the M-GTA-SBA (Modified-Grouped Transmit Antenna-Simple Bit Allocation) using effective CSI (Channel State Information) calculation procedure based on spatial resource grouping, which is adequate for the combination of MRT (Maximum Ratio Transmission) in the transmitter and MRC (Maximum Ratio Combining) in the receiver. In addition, to reduce feedback information for the beamforming, we also apply QEGT (Quantized Equal Gain Transmission) based on quantization of amplitudes and phases of beam weights. Furthermore, considering multi-user environments, we propose the P-SRA (Proposed-Simple Resource Allocation) algorithm for fair and efficient resource allocation. Simulation results reveal that the proposed MIMO-OFDMA system achieves significant improvement of spectral efficiency in low CRI region as compared to a typical open-loop MIMO-OFDMA system using pseudo-orthogonal space time block code and H-ARQ IR (Hybrid-Automatic Repeat Request Incremental Redundancy).

Performance Analysis of the Channel Equalizers for Partial Response Channels (부분 응답 채널을 위한 채널 등화기들의 성능 분석에 관한 연구)

  • Lee, Sang-Kyung;Lee, Jae-Chon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.8A
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    • pp.739-752
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    • 2002
  • Recently, to utilize the limited bandwidth effectively, the concept of partial response (PR) signaling has widely been adopted in both the high-speed data transmission and high-density digital recording/playback systems such as digital microwave, digital subscriber loops, hard disk drives, digital VCR's and digital versatile recordable disks and so on. This paper is concerned with adaptive equalization of partial response channels particularly for the magnetic recording channels. Specifically we study how the PR channel equalizers work for different choices of desired or reference signals used for adjusting the equalizer weights. In doing so, we consider three different configurations that are actually implemented in the commercial products mentioned above. First of all, we show how to compute the theoretical values of the optimum Wiener solutions derived by minimizing the mean-squared error (MSE) at the equalizer output. Noting that this equalizer MSE measure cannot be used to fairly compare the three configurations, we propose to use the data MSE that is computer just before the final detector for the underlying PR system. We also express the data MSE in terms of the channel impulse response values, source data power and additive noise power, thereby making it possible to compare the performance of the configurations under study. The results of extensive computer simulation indicate that our theoretical derivation is correct with high precision. Comparing the three configurations, it also turns out that one of the three configurations needs to be further improved in performance although it has an apparent advantage over the others in terms of memory size when implemented using RAM's for the decision feedback part.