• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.1
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• pp.37-43
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• 2023

Compressed still image or video bitstreams require protection from channel errors in a wireless channel. Embedded Zerotree Coding(EZW), SPIHT could have provided unprecedented high performance in image compression with low complexity. If bit error is generated by dint of wireless channel transmission problem, the loss of synchronization on between encoder and decoder causes serious performance degradation. But wavelet zerotree coding algorithms are producing variable-length codewords, extremely sensitive to bit errors. The idea is to partition the lifting coefficients. A many partition of lifting transform coefficients distributes channel error from wireless channel to each partition. Therefore synchronization problem that caused quality deterioration in still image and video stream was improved.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.171-174
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• 1998

A class of non-parametric detectors based on quantized m-dimensional noise sample space is introduced. Due to assuming the nongaussian noise as a channel model, it is not easy to design the detector through estimating the unknown functional form of noise; instead equiprobably partitioning m-dimensional noise into a finite number of regions, using a VQ and quantiles obtained by RMSA algorithm is used in this paper to design detectors. To show the comparison of performance between single sample detector and system suggested here, Monte-Carlo simulations were used. The effect of signal pulse shape on the receiver performance is analyzed too.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.517-520
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• 2003

Orthogonal Frequency Division Multiplexing (OFDM) is a promising technology for high speed multimedia communication in a frequency selective multipath channel. In this paper, Software IPs for the synchronizer of IEEE 802.11a Wireless LAN system are designed and optimized for TI's TMS320C6201 fixed point DSP. As a result of the execution cycles of the target DSP for each functions of the system, an efficient HW/SW partitioning method can be considered.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06a
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• pp.295-297
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• 2006

유비쿼터스 시대의 도래와 이동통신 기술의 발달로 인해 VOD 기술의 응용분야 또한 점차 무선 환경으로 확대되어 가고 있다. 이에 따라 브로드캐스트 기법을 통한 VOD 서비스의 중요성 또한 점차 중요해지는 추세다. 하지만 기존의 개발된 브로드캐스트 기법은 알고리즘이 복잡하기 때문에 자원이 부족한 무선 네트워크 환경에는 적용하기 어려운 단점이 있다. 따라서 본 논문에서는 무선 환경에 적용 가능한 새로운 브로드캐스트 채널분할 기법을 제안한다.

• Journal of Communications and Networks
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• v.5 no.1
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• pp.43-54
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• 2003

Due to insufficient available bandwidth resources and the continuously growing demand for cellular communication services, the channel assignment problem has become increasingly important. To trace the optimal assignment, several heuristic strategies have been proposed. So far, most of them focus on the small-scale systems containing no more than 25 cells and they use an anachronistic cost model, which does not satisfy the requirements ity. Solving the small-scale channel assignment problems could not be applied into existing large scale cellular networks' practice. This article proposes a decomposition approach to solve the fixed channel assignment problem (FCAP) for large-scale cellular networks through partitioning the whole cellular network into several smaller sub-networks and then designing a sequential branch-and-bound algorithm that is made to solve the FCAP for them sequentially. The key issue of partition is to minimize the dependences of the sub-networks so that the proposed heuristics for solving smaller problems will suffer fewer constraints in searching for better assignments. The proposed algorithms perform well based on experimental results and they were applied to the Taiwan Cellular Cooperation (TCC) in ChungLi city to find better assignments for its network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.6B
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• pp.610-615
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• 2002

This paper considers a communication system consisting of a vector quantizer with selected code vectors with mapped into points in the modulated signal space. The modulated signal is transmitted over a Rayleigh flat fading channel. We optimize the modulated signal constellation to minimize the overall distortion of the system with the fixed vector quantization codebook. The optimization is obtained by partitioning the modulated signal space. Simulation results show that the signal constellation based on the proposed optimization scheme outperforms the conventional methods.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.4
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• pp.628-635
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• 1990

This paper describes a new gate array layout system, HAN-LACAD-G(HANyang LAyout CAD system for Gate array). HAN-LACAD-G is composed of placer, global router, detailed router, and output processor. In placement design, initial placement is performed by repetitive clustering and min-cut partitioning followed by placement improvement using the concept of pairwise interchange. In global routing phase, pins are assigned in each channel considering the routing congestion estimation and overflows in feedthroughs are restricted. For the detailed routing, we use layer and three layer channel routing techniques. Layout results are displayed graphically and modified interactively by the user using the layout editor.

• Bulletin of the Korean Chemical Society
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• v.27 no.12
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• pp.1997-2001
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• 2006

The photodissociation dynamics of formic acid (HCOOH) at 206 nm have been investigated from rotationally resolved laser induced fluorescence spectra of OH ($^2\Pi$) fragments produced exclusively in the ground state. From the spectra, the rotational energy of the fragments was measured to be $820\;{\pm}\;50\;cm^{-1}$. The translational energy released in the products, which is 87% of the total available energy of the system, was also measured from analyses of the Doppler profiles. Joining these data with quantum chemical molecular orbital calculations, we have concluded that the dissociation should take place along the S1 surface with an exit channel barrier and also that the energy partitioning is determined at the exit channel.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.12
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• pp.1631-1637
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• 2019

In this paper, we propose a low-complexity robust maximum likelihood (ML) receiver for generalized spatial modulation. The proposed receiver performs the transmit antenna partition to lower the computational loads. After we divide the transmit antenna combinations into two parts, one of which is "the likely TAC part," and the other of which is "the unlikely TAC part", based on the minimum mean square error (MMSE) filtering output. We first perform the maximum likelihood detection only in the likely TAC part. Then we evaluate the reliability of the solution found in the first search, and based its reliability we decide whether we continue the search in the unlikely TAC part. This partitioned search strategy maintains the performance of the conventional robust maximum likelihood receiver and simultaneously lowers computational loads. Through simulation, we found that our newly-proposed receiver achieves considerable gains over the conventional robust ML detector in terms of the computational loads while providing almost the same performance.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.1
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• pp.79-86
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• 1993

Twelve docked and 12 intact Najdi lambs of equal numbers of males and females were slaughtered at 40 kg shorn shrunk body weight, Lipid in all empty body fat components; namely, subcutaneous, intermuscular, intramuscular, omental, mesenteric, channel, perirenal, pericardial, tail, viscera, bone and hide, were determined. Except for ram lambs, which had a lower percentage of lipid in intermuscular partition in loin cut, sex did not influence the relative proportion of subcutaneous or intermuscular fat in each wholesale cut. The data also showed that docking did not change the distribution of lipid in intermuscular and intramuscular fat partitions in each wholesale cut. Docked lambs tended to accumulate lower proportions of the lipid in subcutaneous fat component in the cuts located along the dorsal line than intact lambs. The total amount of lipid deposited in the empty body of ewe lamb was heavier in weight than that of ram lamb. Docking had no effect on the distribution of total lipid in the empty body, except for subcutaneous fat component, being greater in docked lambs than did intact ones. Generally, the highest proportion of fat was associated with subcutaneous depot followed, in order, by intermuscular, mesenteric, tail, intramuscular and omental fat partitions.