• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.2C
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• pp.172-181
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• 2010

In this paper, we propose an adaptive block quantization method. The propose method perfrect reconstructs side information without high complexity in the encoder side, as transmitting motion vectors from a decoder to an encoder side. Also, at the encoder side, residual signals between reconstructed side information and original frame are adaptively quantized to minimize parity bits to be transmitted to the decoder. The proposed method can effectively allocate bits based on bit error rate of side information. Also, we can achieved bit-saving by transmission of parity bits based on the error correction ability of the LDPC channel decoder, because we can know bit error rate and positions of error bit in encoder side. Experimental results show that the proposed algorithm achieves bit-saving by around 66% and delay of feedback channel, compared with the convntional algorithm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.2
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• pp.383-393
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• 2010

DVC (Distributed Video Coding) allows us to explore the video statistics at the decoder side, resulting in a less complex encoder and more complex decoder. In this approach, it is important to generate a good prediction to the current Wyner-Ziv frame, called side information, which plays a crucial role in the overall performance of a DVC system. Conventional MCFI (motion compensated frame interpolation) techniques, which explore temporal correlations between neighbor frames of the current frame, preform the block-based or object-based motion estimation, but, they do not include the basis frame for the Wyner-Ziv frame. This paper proposes an efficient way to get better side information, by finding the average frame between neighbor frames and by comparing adaptively the candidate blocks. Through computer simulations, it is shown that the proposed method can improve the performance up to 0.4dB and provide better subjective and objective visual qualities in Wyner-Ziv CODEC.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.01a
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• pp.1-3
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• 2016

낸드 플래시 메모리는 저 전력, 빠른 동작 속도, 높은 신뢰성, 가벼운 무게와 같은 특성을 가지는 비휘발성 메모리로써 폭넓은 분야에서 사용이 증가하고 있다. 그러나 낸드 플래시 메모리는 기존의 보조 기억 장치와 달리 쓰기 전 소거와 낮은 수명에 대한 문제가 존재한다. 기존의 많은 연구에서는 가비지 컬렉션을 통해 수명을 연장하기 위해 노력하였다. 본 논문에서는 낸드 플래시 메모리에 삭제 구간 정보를 활용한 가비지 컬렉션 기법을 제안한다. 제안하는 기법은 "N 삭제 구간 정보"를 이용하여 효과적인 희생블록을 선정하는 특징이 있다. 제안하는 기법은 GA 기법과 비교하여 평균 페이지 이주비용은 최대 50.1% 감소하였으며, 블록 당 소거 횟수의 표준 편차는 최대 233% 감소하였다. 또한, 낸드 플래시 메모리 시스템의 첫 번째 배드 블록 발생 시간은 최대 22.7% 연장하였고, 시스템 수명은 최대 16.7% 연장하였다.

• Journal of Convergence for Information Technology
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• v.7 no.2
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• pp.25-29
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• 2017

The purpose of this study was to investigate the effect of a new designed splint on the hand function. A new design splint that enlarges the area between thumb and index finger was manufactured using 3D printing. After wearing a new splint the patient was possible to open thumb and hold a small object. She showed improvement in overall hand function and could move eight blocks in box and block test. But grasping a cup without a handle has become more difficult than before. Also there is a disadvantage that it could not be fixed by water. This study is meaningful in that it is the first splint application study using 3D printing. In the future, we expect that various patient-specific splints will be developed through 3D printing in the field of occupational therapy.

• Journal of the Korean Society for Railway
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• v.9 no.5 s.36
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• pp.612-617
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• 2006

As the on-board electric devices determine the performances of vehicles, production of reliable devices is important. To keep the reliability of devices constant, management of performance evaluation of the on-board devices is crucial. Because temperature has a serious effect on failures of the components of the devices, its measurement is the first step for good management. In this study, we described performance characteristics of domestic auxiliary block developed through G7 project. We measured the performances of auxiliary block during test running by the developed on-line measurement system. After we save the input real-time data from each signal of Korean High Speed Train through the network line, we can acquire necessary information through post-processing program. We verify the motor block characteristics of Korean High Speed Train by this system.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.621-624
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• 2016

시각장애인의 인구비율은 전체 장애인 인구의 약 10%로 적지 않은 비율을 차지한다. 이러한 시각장애인들에게 가장 위험한 요소는 주변의 물체들이다. 하지만 현재 제시되어 있는 안전 보조 장치(보도블록 등)는 시각 장애인들 스스로가 전방에 어떠한 물체가 있는지 인지하기 어렵다. 본 논문에서는 딥러닝을 이용하여 위험물체에 대한 학습모델을 생성 한 뒤 햅틱 모션 및 음성 안내를 통하여 실시간으로 시각장애인이 위험상황을 인지할 수 있는 시스템을 제안한다.

• Journal of the Korean Society for Railway
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• v.7 no.4
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• pp.356-359
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• 2004

In this paper, as the first step to assess and enhance the reliability of Korea High Speed Train, auxiliary power system is selected and reliability analysis is carried out. The auxiliary power system is classified into subsystems and functional analysis is conducted. Reliability block diagrams are drawn and reliability parametric analysis is performed. Analysis results show that the reliability of auxiliary power system depends on critical items. To grow the system reliability, activities should be concentrated on improvement of critical items.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.2
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• pp.53-64
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• 2011

In this paper, we propose a channel estimation of side information method based received motion vectors for distributed video coding. The proposed decoder estimates motion vectors of side information and transmits it to the encoder. As the proposed encoder generates side information which is the same to one in the decoder with received motion vectors, accuracy of side information of the decoder is assessed and it is transmitted to decoder. The proposed decoder can also estimate accurate crossover probability with received error information. As the proposed method conducts correct belief propagation, computational complexity of the channel decoder decreases and error correction capability is significantly improved with the smaller amount of parity bits. Experimental results show that the proposed algorithm is better in rate-distortion performance and it is faster than several conventional distributed video coding methods.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.6
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• pp.445-452
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• 2014

This paper discusses the multifrontal direct solution method with out of core storage for large scale structural analysis in a limited computing resource. Large scale structural analysis requires huge amount of memory space and computation, so out of core solution method is needed in limited computing resource. In this research, out of core multifrontal solution algorithm which utilize the small size of physical memory and minimize the amount of access of low speed out of core storage is introduced. Three ideas, which are stack space in lower trianglar part of square factorization matrix, inverse stack data structure and selective data caching and recovery by data block size, are proposed.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.07a
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• pp.364-367
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• 2010

분산 비디오 부호화(Distributed Video Coding: DVC)는 복호화보다 훨씬 적은 계산량으로 부호화를 가능하게 함으로써 계산 성능 및 전력이 제한된 환경을 위한 비디오 부호화 기법으로 주목 받고 있다. 그러나 DVC의 부호화 성능은 아직 기존의 비디오 압축 표준에 많이 미치지 못하고 있으며 이를 극복하기 위한 많은 연구가 진행되고 있다. 본 논문에서는 DVC의 부호화 성능 개선을 위한 율-왜곡 기반의 영역별 선택적 부호화 기법을 제안한다. 제안 기법은 복호기 측에서 보조정보를 얻는 과정에서 얻어지는 움직임 벡터가 부호기 측으로 피드백된다는 가정하에 이를 이용하여 움직임 보상 예측 신호를 구하고 율-왜곡(Rate-Distortion) 기반의 블록 단위로 선택적 부호화를 수행한다. 모의실험을 통하여 본 논문에서 제안한 움직임 정보 피드백을 이용한 율-왜곡 기반의 선택적 블록 부호화 기법이 기존의 DVC 부호화 기법보다 시퀀스에 따라 최대 약 2.25 dB 개선된 성능을 가짐을 보인다.