• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.5B
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• pp.296-303
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• 2008

In this paper, we propose a novel Route_Reconf message as the RSVP message to maintain an RSVP session for hard handoff and consider a path-comparing route(PCR) algorithm to find an intermediate node in the charge of down-link re-establishment. And, we consider information form each mode for the PCR algorithm, which also reduces the frequency and amount of exchanged RSVP message to minimize packet loss and delay between an intermediate node and a receiver. According to the proposed algorithm, a new support node(NSN) and an existing support node(ESN) along the RSVP path can be found; the former is a supporting RSVP session node newly searched and the latter is the last supporting node holding the previous session after handoff. On receiving the Route_Reconf message at the ESN, a new allocated route from a NSN to the MN waiting for the handoff via a new access router is configured by the ESN.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.11
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• pp.102-110
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• 1992

In this paper, a new method of character recognition is proposed. It uses density information, in addition to positional and directional information generally used, to recognize a character. Four directional feature primitives are extracted from the thinning templates on the observation that the output of the templates have directional property in general. A simple and fast feature extraction scheme is possible. Features are organized from recursive nonary tree(N-tree) that corresponds to normalized character area. Each node of the N-tree has four directional features that are sum of the features of it's nine sub-nodes. Every feature primitive from the templates are added to the corresponding leaf and then summed to the upper nodes successively. Recognition can be accomplished by using appropriate feature level of N-tree. Also, effectiveness of each node's feature vector was tested by experiment. A method to implement the proposed feature vector organization algorithm into hardware is proposed as well. The third generation node, which is 4$\times$4, is used as a unit processing element to extract features, and it was implemented in hardware. As a result, we could observe that it is possible to extract feature vector for real-time processing.

• Journal of Korea Multimedia Society
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• v.10 no.1
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• pp.36-48
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• 2007

This paper proposed 3D keyframe animation using orientation interpolator. 3D keyframe animation consists of a number of transform nodes that have geometrical node of initial model and several interpolator nodes that represent the object moving. In the proposed algorithm, we randomly selects transform nodes with orientation interpolator node and performs to resample quaternion components for haying uniform key time. And then, watermark bits are embedded into quaternion components with large rotation angles. Experimental results verified that the watermark embedded by the proposed algorithm had good robustness against geometrical attacks and timeline attacks and also PSNR of keyvalue in orientation interpolator node is above 42dB.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.4B
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• pp.386-390
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• 2011

Modem warfares have changed from PCW (platform Centric Warfare) to NCW (Network Centric Warfare). Therefore, it is more important to operate and manage the network. This paper proposed a node management scheme in military wireless networks. In military wireless networks, nodes can join and leave the networks easily. It causes a degradation of network capacity. This paper figured out a problem caused by node which is leaving the network. This paper proposed a RSSI based method of estimating and detecting the leaving nodes in the networks. Finally, an experimental result was demonstrated to show the efficiency of the proposed method.

• The Journal of the Acoustical Society of Korea
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• v.29 no.5
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• pp.295-302
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• 2010

This paper proposes a multiple access method based on Time Reversal Mirror (TRM) technique when the multiple sensor nodes exist. Proposed method increases system sum capacity using energy focusing effects of the TRM. Simulation results show that proposed algorithm obtains higher system sum capacity than Orthogonal Frequency Division Multiple Access (OFDMA), e.g., 27 bps/Hz higher than the OFDMA method when the number of sensor node is 30, the number of transducer is 8, and is SINR 16 dB.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.9B
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• pp.569-576
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• 2007

This paper is on the enhancement of our heuristics for GOSST problem that could apply to the design of communication networks offering graduated services. This problem hewn as one of NP-Hard problems finds a network topology meeting the G-Condition with minimum construction cost. In our prior research, we proposed two heuristics. We suggest methods of selecting G-Node and disconnections for Global or Local locating heuristic in this research. The ameliorated Local locating heuristic retrenches 17% more network construction cost saving ratio and the reformed Global locating heuristic does 14% more than our primitives.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.9B
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• pp.589-597
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• 2007

In this paper, a WDM metro ring consisting of access nodes with $FT-FR^n$ (Fixed Transmitter - n Fixed Receivers) is considered. A trade-off exists between node throughput and transmission fairness because the access nodes share wavelength channels. In order to eliminate the transmission unfairness and to increase throughput, the p-persistent medium access control (MAC) protocol is proposed: each node uses an empty optical slot to transmit a packet and make it available with the extraction of a transferred packet at the source access node, called source-stripping. The local empty slot can be used to transfer a head-of-line packet in the local buffer with probability p or it is used for the next downstream nodes with 1-p. The proposed MAC protocol provides better node throughput than the non-persistent protocol and exhibits better fairness index than the 1-persistent protocol in WDM ring networks. In addition, numerical analysis shows that the proposed MAC protocol maximizes the node throughput under uniform traffic conditions. For more detailed results, we use the network simulation under Poisson and self-similar traffic. Furthermore, unpredictable traffic constructed by the combination of the former and the latter is also considered. The reasonable probability of the p-persistent protocol for a given architecture can be determined through simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.6
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• pp.1085-1094
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• 1994

We propose a traffic flow control scheme of B-NT with temporary cell buffering and selective cell discarding to prevent congestion state of the network nodes in B-ISDN systems to reduce or suppress output cell strams towards T interface. We define the states of the network nodes as normal, pre-congestion, and congestion. In a pre-congestion state, the loss-sensitive traffic is temporarily buffered to slow down the rate of the output traffic streams. In a congestion state, the delay-sensitive traffic is selectively discarded to suppress the output traffic streams as possible in addition to the cell buffering. We model the input cell streams and the states of the network nodes with Interrupted Bernoulli Process and 3-state Markov chain to analyze the performance of the proposed scheme in the B-NT system. The appropriate size of the cell buffer is explored by means of simulation and the influence on the performance of the proposed scheme by the network node state is discussed. As results, more than 2,00 cells of buffer size is needed for the control of medium of lower than the medium, degree of congestion occurrence in the network node while the control of high degree of congestion occurrence is nearly impossible.

• Structural Engineering and Mechanics
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• v.41 no.3
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• pp.395-406
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• 2012

Basic problem of pile foundation is three dimensional in nature. Three dimensional finite element formulation is employed for the analysis of pile groups. Pile, pile-cap and soil are modeled using 20 node element, whereas interface between pile or pile cap and soil is modeled using 16 node surface element. A parametric study is carried out to consider the effect of pile spacing, number of piles, arrangement of pile and soil modulus on the response of pile group. Results indicate that the response of pile group is dependent on these parameters.

• ETRI Journal
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• v.36 no.2
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• pp.321-324
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• 2014

This letter describes a two-phase clock oxide thin-film transistor shift register that executes a robust operation over a wide threshold voltage range and clock coupling noises. The proposed circuit employs an additional Q generation block to avoid the clock coupling noise effects. A SMART-SPICE simulation shows that the stable shift register operation is established for the clock coupling noises and the threshold voltage variation from -4 V to 5 V at a line time of $5{\mu}s$. The magnitude of coupling noises on the Q(15) node and Qb(15) node of the 15th stage is respectively -12.6 dB and -26.1 dB at 100 kHz in the proposed circuit, compared to 6.8 dB and 10.9 dB in a conventional one. In addition, the estimated power consumption is 1.74 mW for the proposed 16-stage shift registers at $V_{TH}=-1.56V$, compared to 11.5 mW for the conventional circuits.