• 전자공학회논문지S
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• 제34S권9호
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• pp.77-83
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• 1997

We present a fast adaptive block matching algorithm using variable search area and subsampling to estimate motion vector more exactly. In the presented method, the block is classified into one of three motion categories: zero motion vector block, medium-motion bolck or high-motion block according to mean absolute difference of the block. By the simulation, the computation amount of the presented methoe comparable to three step search algorithm and new three step search algorithm. In the fast image sequence, the PSNR of our algorithm increased more than TSS and NTSS, because our algorithm estimated motion vector more accurately.

• 한국음향학회지
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• 제22권4호
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• pp.293-298
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• 2003

본 논문에서는 NNVQ (nearest neighbor vector quantization)를 위한 고속탐색 알고리듬을 제안하였다. 제안된 알고리듬은 입력 벡터 내 지정된 요소의 부호화 왜곡을 임계값과 비교해서 최적 코드워드가 될 가능성이 없는 코드워드를 탐색 대상 코드워드에서 제외함으로써 코드북 탐색의 범위를 줄인다. 이를 통해 기존의 풀서치(full-search) 알고리듬과 동일한 SD(spectral distortion) 성능을 얻으면서 부호화 과정에서의 처리시간과 복잡도를 감소시킨다. 제안된 알고리듬을 Gauss-Markov 소스에 대해 설계된 일반적인 벡터 양자화기와 3GPP에서 표준화된 AMR (adaptive multi-rate) 음성 코덱의 LSP 양자화기에 각각 적용하여 실험하였다. 실험결과 제안된 알고리듬은 SD 성능감쇄 없이 탐색 대상 범위를 감소시킴으로써 부호화시 복잡도를 50%이상 줄일 수 있었다.

• 제어로봇시스템학회논문지
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• 제13권7호
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• pp.631-636
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• 2007

An efficient obstacle avoidance algorithm is proposed in this paper to avoid dynamic obstacles using a collision vector while a tele-operated mobile robot is moving. For the verification of the algorithm, an operator watches through a monitor and controls the mobile robot with a force-reflection joystick. The force-reflection joystick transmits a virtual force to the operator through the Inter-net, which is generated by an adaptive impedance algorithm. To keep the mobile robot safe from collisions in an uncertain environment, the adaptive impedance algorithm generates the virtual force which changes the command of the operator by pushing the operator's hand to a direction to avoid the obstacle. In the conventional virtual force algorithm, the avoidance of moving obstacles was not solved since the operator cannot recognize the environment realistically by the limited communication bandwidth and the narrow view-angle of the camera. To achieve the dynamic obstacle avoidance, the adaptive virtual force algorithm is proposed based on the collision vector that is a normal vector from the obstacle to the mobile robot. To verify the effectiveness of the proposed algorithm, mobile robot navigation experiments with multiple moving obstacles have been performed, and the results are demonstrated.

• 응용통계연구
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• 제17권1호
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• pp.75-88
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• 2004

서포트 벡터 기계(Support Vector Machines, SVMs) 알고리즘은 표본 점들과 분리 초평면 사이의 최소 거리를 최대화하는 것에 관심을 가져왔다. 본 논문은 모든 데이터 점들과 분리 초평면 사이의 거리들을 고려하는 total margin을 제안한다. 본 논문에서 제안하는 방법은 기존의 서포트 벡터 기계 알고리즘을 확장하고, 일반화 오차 경계를 개선하게 된다. 새롭게 제안하는 total margin알고리즘이 기존 방법들과의 비교를 통하여 더욱 우수한 수행능력을 가지고 있음을 수치 예제들을 통하여 확인할 수 있다.

• 전자공학회논문지S
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• 제34S권9호
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• pp.91-98
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• 1997

In this paper, a new pixel decimation algorithm for the estimation of motion vector is proposed. In traditional methods, the computational cost can be reduced since only part of the pixels are used for motion vector calculation. But these methods limits the accuracy ofmotion vector because of the same reason. We derive a selection criteria of subsampled pixels that can reduce the probablity of false motion vector detection based on stochastic point of view. By using this criteria, a new pixel decimation algorithm that can reduce the prediction error with similar computational cost is presented. The simulation results applied to standard images haveshown that the proposed algorithm has less mean absolute prediction error than conventional pixel decimation algorithm.

• 한국통신학회논문지
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• 제28권2C호
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• pp.141-146
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• 2003

본 논문은 동영상 압축 방식에서 사용되는 움직임 벡터 추정의 탐색 영역을 적응적으로 결정하는 방식에 대해 제안한다. 일반적인 동영상 압축 방식에서 사용되는 움직임 벡터 예측 방식의 성능은 압축 효율을 결정하는 움직임 벡터 예측을 위한 전처리 과정의 역할을 하는 제안된 동적 탐색 영역 방식은 인접 블록의 움직임 벡터의 통계적 특성에 따라 효율적으로 탐색 영역을 결정하여 영상 화질의 저하 없이 평균 60(%) 이상의 계산량을 절감하게 된다. 제안된 방식의 성능은 실험을 통해서 확인할 수 있었다.

• Journal of Information Processing Systems
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• 제15권6호
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• pp.1503-1516
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• 2019

In this paper, to improve the accuracy of long sentence similarity calculation, we proposed a sentence similarity calculation method based on a system similarity function. The algorithm uses word2vector as the system elements to calculate the sentence similarity. The higher accuracy of our algorithm is derived from two characteristics: one is the negative effect of penalty item, and the other is that sentence similar function (SSF) based on word2vector similar elements doesn't satisfy the exchange rule. In later studies, we found the time complexity of our algorithm depends on the process of calculating similar elements, so we build an index of potentially similar elements when training the word vector process. Finally, the experimental results show that our algorithm has higher accuracy than the word mover's distance (WMD), and has the least query time of three calculation methods of SSF.

• 한국IT서비스학회지
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• 제8권4호
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• pp.129-140
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• 2009

The accurate estimation of software reliability is important to a successful development in software engineering. Until recent days, the models using regression analysis based on statistical algorithm and machine learning method have been used. However, this paper estimates the software reliability using support vector regression, a sort of machine learning technique. Also, it finds the best set of optimized parameters applying immune algorithm, changing the number of generations, memory cells, and allele. The proposed IA-SVR model outperforms some recent results reported in the literature.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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• pp.1457-1460
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• 1987

2-D shape matching algorithm is proposed which uses pivot vector and componentwise adaptive convergence factor. It is proved that proposed algorithm has better result than any other algorithm. It is to be expected that this algorithm will work effectively in 3-D shape matching.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1998년도 추계학술대회논문집:21세기에 대비한 지능형 통합항만관리
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• pp.211-221
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• 1998

A digital image processing technique which is able to get the velocity vector distribution of a surface of the spilled oil in the ocean without contacting the flow itself. This technique is based upon the PIV(Particle Imaging Velocimetry) technique and its system mainly consists of a high sensitive camera, a CCD camera, an image grabber, and a host computer in which an image processing algorithm is adopted for velocity vector acquisition. For the acquisition of the advective velocity vector of floating matters on the ocean, a new multi-frame tracking algorithm is proposed, and for the acquisition of the diffusion velocity vector distribution of the spilt oil onto the water surface, a high sensitive gray-level cross-correlation algorithm is proposed.