• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.2
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• pp.149-159
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• 2001

The conventional block-based motion prediction suffers, especially in low bit-rate video application, from shortcomings such as blocking artifacts of motion field and unstable motion estimation. To overcome the deficiency, this paper proposes one method of adopting a new motion compensation scheme based on the irregular triangular mesh structure while keeping the current block-based DCT coding structure of H.263 as much as possible. To represent the reconstructed previous frame using minimal number of control points, the proposed method designs content-adaptive irregular triangular meshes, and then, estimate the motion vector of each control point using the affine transformation-based matching. The predicted current frame is obtained by applying the affine transformation to each triangular mesh. Experiment with the several real video sequences shows improvement both in objective and subjective picture quality over the conventional block-based H.263 method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.2
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• pp.183-190
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• 2013

In this paper, we propose a spatially adaptive noise detection and removal algorithm for a single degraded image. Under the assumption that an observed image is Gaussian-distributed, the noise information is estimated by local statistics of degraded image, and the degree of the additive noise is detected by the local statistics of the estimated noise. In addition, we describe a noise removal method taking a modified Gaussian filter which is adaptively determined by filter parameters and window size. The experimental results demonstrate the capability of the proposed algorithm.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.07a
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• pp.99-101
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• 2011

본 논문에서는 WiMAX 의 신호세기(CINR: Carrier to Interference + Noise Ratio)의 변화와 예측 방법에 대해 연구한다. WiMAX 와 같은 무선 네트워크에서는 신호세기가 불규칙하게 변화하기 때문에 비디오 스트리밍시 에러나 지연이 발생할 수 있다. CINR 은 클라이언트 측의 가용 대역폭을 결정하는 중요한 요소이다. 하지만 기존의 RTCP(Real-time Transport Control Protocol)를 이용한 비트율 제어는 RTT(Round Trip time), PLR(Packet Loss Rate) 등의 정보를 사용하기 때문에 부정확하거나 지연이 발생될 수 있다. 이를 보완하기 위한 CINR 을 직접 비트율 제어에 사용하는 방법에 대해 연구하기에 앞서, 본 논문에서는 CINR 을 분석하고 미래의 값을 예측하는 방법에 대해 연구한다. 본 논문의 분석을 통해 CINR 의 예측을 비교적 정확하게 수행할 수 있다면 앞으로의 가용 대역폭을 비교적 정확하게 예측할 수 있고 효율적인 비디오 스트리밍 시스템을 제안할 수 있다.

• Journal of the Korean Geographical Society
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• v.39
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• pp.93-114
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• 1989

거의 해마다 내습하는 태풍위험을 제주지역 농부들이 어떻게 인식하고 그에 적응하고 있는지 아울러 이와같이 연례행사처럼 발생하는 태풍재해 문제 해결에 있어 정부관계기관의 역할에 대한 그들의 인식은 어떠한가를 살펴보는 것이 본 연구의 목적이다. 우선 위 연구과제를 살피기 위하여 다음과 같은 세 가지 가설이 전제되었다. 첫째, 태풍과 같은 자연발생적 위협과 빈번한 접촉내지 오랜 경험은 인간에게 위험과 손실을 준다는 자각으로 이끌며 또한 장차 발생의 정확한 예측에 비교적 밀접한 관계를 갖는다. 그리고 이러한 경험들은 그와같은 자연발생적 위협으로부터 일시 피하거나 위협지역으로부터 아주 떠나 버린다기 보다 오히려 적응이라는 선택을 취한다. 둘째, 인간이 이와같은 위협지역 제주도와 같이 사회문화적인 특성이 뚜렷한 지역에 삶의 터전을 가지고 있는 것은 경제적 요인에서라기보다도 사회문화적 바탕에서 그 원인을 찾을 수 있다. 셋째로, 정부의 이와같은 자연발생적 재해문제 해결은 해당 지역 거주주민들과 보다 긴밀한 컴뮤니케이션과 함께 정부나 컴뮤니티를 통한 자연재해에 관한 계몽교육을 강화함으로서 그 역할이 효과적으로 수행될 수 있다. 총 113명의 농업을 주업으로 하는 가구주들을 제주도의 상습태풍재해지구에서 무작위 단게별군집(Random-cluster Stratified Sampling)방법에 의하여 선별하고 태풍위협에 대한 개인별 재해인식과 인간 적응을 알아보기 위하여 작성된 설문서를 통하여 각기 면담, 연구분석자료가 수집되었다. 제주농부들의 태풍에 대한 자각과 적응은 제주도 나름의 풍토에서 오랜 삶의 경험을 토대로 얻어진 결과라는 것이 입증되었다. 한편, 장차 태풍 내습에 대한 그들의 예측은 상당히 정확하였으며, 태풍재해에 대한 적응은 동기적이고 예방적 즉, 농부들은 재해의 근원적 소멸을 위해 재해지역을 떠난다기보다 오히려 피해를 감수하고 있었으며 또한 그들의 기본 영농방법이나 작물의 대체를 급격히 전환한다기 보다 부분적으로 수정, 변경시켜 나가고 있는 것으로 나타났다. 한편, 그들의 적응과정은 현대적 영농기술과 그들 특유의 전통적 방법을 혼합 병행하고 있었으며 가족이나 친척 이웃과의 유대관계가 재해지역에 거주하는 지배적 이유로 나타났다. 또 한편, 해당연구지역 농부들은 태풍피해에 대한 정부의 보조를 알고는 있으나 그것이 재해문제를 해결하는데 있어서 효율적이라고 생각치 않고 있다. 그들은 더욱 많은 재정적 보조를 희망하는 것만큼 연례저긍로 내습, 피해를 주고 있는 태풍재해 문제에 대한 정부의 적극적이고 좀더 효과적 예방 대책을 요구하고 있다.

• Korean Journal of Social Welfare
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• v.38
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• pp.180-205
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• 1999

The first purpose of this study was to examine a relationship between coping strategies and adaptation in mothers of handicapped children. The second purpose was to assess the relative contribution of coping strategies to maternal adaptation, controlling other variables that previously have been found to be important in determining maternal adaptation. Finally, the unique effect of coping strategies as predictors of maternal adaptation was examined. The subjects consisted of 92 mothers of handicapped children. They were asked to complete several self-report measures that were used to assess the variables of interest. The results indicated that coping was significantly related to maternal adaptation. Specifically, the use of confrontive coping, accepting responsibility, and escape-avoidance coping strategy were related to poorer maternal adaptation. On the other hand, painful problem solving and positive reappraisal strategy were related to better maternal adaptation. The step-wise regression results further indicated that coping strategies were significantly predict maternal adaptation. Specifical1y confrontive coping, accepting responsibility, and positive reappraisal coping strategy contributed significantly to the prediction of maternal adaptation compared to the other variables. Finally, the confrontive coping, accepting responsibility, positive reappraisal strategies turned out to contribute substantially to maternal adaptation even after several other variables were statistically controlled in conservative way. Implications of the findings for social work interventions was discussed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.8
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• pp.1527-1533
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• 2009

In this paper, we design directional search pattern using motion direction biased characteristics of MVP distribution, and proposes a direction applied cross diamond search method that adaptively change search pattern according to moving direction of search point. Proposed method predict motion vectors from neighbor macro blocks, and define initial motion direction by using predicted motion vectors. It improve search efficiency by using alternately proposed search pattern according to motion direction of BMP in search process. The simulation results show that proposed method is able to fast motion estimation compared with conventional cross diamond search, according as it reduce computational complexity that is required of motion estimation with $0.43%{\sim}1.76%$.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.38 no.11
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• pp.1-8
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• 2001

Adaptive and Strict Packet Dropping mechanism we proposed in this paper drops adaptively packets for the congestion control, as predicting traffic pattern between each cycle. Therefore the proposed mechanism makes up for the drawback of RIO mechanism and minimizes the wastes of the bandwidth being capable of predicting in Dynamic and Strict Packet Dropping (DSPD) mechanism. And we executed a simulation and analyzed the throughput and packet drop rate based on the Sending Drop Precedence changing dynamically depending on the network traffic and compared RIO and the DSPD. The results show that the proposed mechanism provides better performance on drop precedence levels and stricter drop precedence policy for AF class than RIO and the DSPD mechanism.

• 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.

• Journal of the Institute of Convergence Signal Processing
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• v.7 no.2
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• pp.53-59
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• 2006

Dynamic neural networks have been applied to diverse fields requiring temporal signal processing such as system identification and signal prediction. This paper proposes the gamma neural network(GAM), which uses gamma memory kernel in the hidden layer of feedforward multilayered network, to improve dynamics of networks and then describes nonlinear adaptive prediction using the proposed network as an adaptive filter. The proposed network is evaluated in nonlinear signal prediction and compared with feedforword(FNN) and recurrent neural networks(RNN) for the relative comparison of prediction performance. Simulation results show that the GAM network performs better with respect to the convergence speed and prediction accuracy, indicating that it can be a more effective prediction model than conventional multilayered networks in nonlinear prediction for nonstationary signals.

• Journal of the Institute of Convergence Signal Processing
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• v.16 no.4
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• pp.129-133
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• 2015

In this paper, we propose a fast motion estimation algorithm which is important in the performance of video encoding. Conventional fast motion estimation algorithms have serious problems of low prediction quality in some frames and still much computation. In the paper, we propose an algorithm that reduces unnecessary computations only, while keeping prediction quality almost similar to that of the full search. The proposed algorithm uses distribution of probability of motion vectors, divides search range into several groups according to its importance, and applies adaptive block matching criteria for each group of search range. The proposed algorithm takes only 3~5% in computational amount and has decreased prediction quality about 0~0.01dB compared with the fast full search algorithm.