• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.7
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• pp.129-140
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• 1994

In this paper we investigate the hardware implementation of block matching algorithms (BMAs) for moving sequences. Using systolic arrays we propose a hardware architecture of a two-stage BMA using integral projections which reduces greatly computational complexity with its performance comparable to that of the full search (FS). Proposed hardware architecture is faster than hardware architecture of the FS by 2~15 times. For realization of the FS and two stage BMA modeling and simulation results using SPW and VHDL are also shown.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.403-403
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• 2006

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.40 no.3
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• pp.171-180
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• 2003

A content-based image retrieval(CBIR) system builds the image database using low-level features such as color, shape and texture and provides similar images that user wants to retrieve when the retrieval request occurs. What the user is interest in is a response time in consideration of the building time to build the index database and the response time to obtain the retrieval results from the query image. In a content-based image retrieval system, the similarity computing time comparing a query with images in database takes the most time in whole response time. In this paper, we propose the two-phase search method with the clustering technique of feature vector in order to minimize the similarity computing time. Experimental results show that this two-phase search method is 2-times faster than the conventional full-search method using original features of ail images in image database, while maintaining the same retrieval relevance as the conventional full-search method. And the proposed method is more effective as the number of images increases.

• Journal of Microbiology and Biotechnology
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• v.6 no.1
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• pp.54-59
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• 1996

In the research and development of bioactive compounds, determining whether a compound is novel is necessary at almost every stage. Fast and efficient determination can save money, time and effort, and thereby increase efficiency. Analysis and investigation of empirical results for previously determined compounds is also important in such research. The need to communicate research findings between workers is necessary. In effect, a systematic, centralized communication medium is required. Therefore, we have developed and constructed our own database and search systems. We have developed a search system on DOS and constructed a source file for our own database. To support multiple users, we have developed another specific and comprehensive search system, including powerful searching and output management features. The system has been developed to be simple and user-friendly, using the curses library of UNIX, while still allowing complicated queries to be performed easily with simple full-screen facilities. This UNIX version will be available for use by researchers on a computer network and is expected to make numerous contributions to basic research in universities. It will also have direct applications for institutes and industry.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.836-839
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• 2016

In this paper, we propose a motion estimation method that is important in performance of video encoding. Conventional motion estimation methods have serious problems of low prediction quality and problems of much computation increase. In the paper, we propose a method that reduces unnecessary computations only using optimal candidate points, while keeping prediction quality almost similar to that of the full search. The proposed method takes only 3~5% in computational amount and has decreased prediction quality about 0~0.01dB compared with the fast full search algorithm.

• Journal of the Institute of Convergence Signal Processing
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• v.5 no.2
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• pp.126-131
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• 2004

Full search algorithm(FA) provides the best performance but this is usually impractical because of the large number of computations required for large search region. Fast search and conventional Boolean matching algorithms reduce computational complexity and data processing time but this algorithms have disadvantages that is difficult of implementation of hardware because of high control overhead and that is less performance than FA. This paper presents new Boolean matching algorithm, called BCBM(Bit Converted Boolean Matching). Proposed algorithm has performance closed to the FA by Boolean only block matching that may be very efficiently implemented in hardware for real time video communication. Simulation results show that the PSNR of the proposed algorithm is about 0.08㏈ loss than FA but is about 0.96∼2.02㏈ gain than fast search algorithm and conventional Boolean matching algorithm.

• Journal of Radiation Protection and Research
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• v.20 no.4
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• pp.227-236
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• 1995

Using beam data and accurate 3D dose model, a study of the spatial dose distribution for various arcs was carried out. The dose dirstibution generated by the accurate dose model could be represented by a simple approximate analytic form which is convenient and very efficient for calculating dose distribution iteratively in the optimization procedure. We developed an empirical cylindrical dose model to compute dose for one full rotational arc or partial rotational arc. After a tedious search for fits to a collection of 200 points of accurate dose data, we found simple formular with 7 parameters search. As a consequence, the programs required approximately less than 1 second to compute dose for one single arc on a 20 by 20 matrix (400 points) using fast approximate dose model. In conclusion the fast approximate dose model give dose distributions similar to the accurate dose model, which makes this fast dose model an attractive alternative to the accurate 3D dose model.

• Journal of Broadcast Engineering
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• v.8 no.3
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• pp.288-296
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• 2003

ATSC (Advanced Television System Committee) has specified 18 video formats for DTV (Digital Television), e.g., scan format, size format, and frame rate format conversion. Effective MPEG-2 video transcoders should support any conversion between the above-mentioned formats. Scan format conversion Is hard to Implement because it may often induce frame rate and size format conversion together. Especially. because of picture type conversion caused by scan format conversion, the computational burden of motion estimation (ME) in transcoding becomes serious. This paper proposes a fast ME algorithm for MPEG-2 video transcoding supporting scan format conversion. Firstly, we extract and compose a set of candidate motion vectors (MVs) from the input bit-stream to comply with the re-encoding format. Secondly, the best MV is chosen among several candidate MVs by using a weighted median selector. Simulation results show that the proposed ME algorithm provides outstanding PSNR performance close to full search ME, while reducing the transcoding complexity significantly.

• Journal of Broadcast Engineering
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• v.12 no.4
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• pp.303-310
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• 2007

Motion Estimation (ME) is a core part of most Video compression systems since it affects directly the output video quality and the encoding time. The most basic method of ME, Full Search (FS) gives the highest visual quality but also has the problem of significant computational load. To solve this problem, many fast algorithm has been proposed. Among them, MVFAST and PMVFAST show impressive results in video quality and the computational load by using the correlation between motion vectors of adjacent blocks. In particular, PMVFAST reduces search points dramatically and also gives very high video quality by using the median predictor. In this paper, we propose a new algorithm that uses the redefined median predictor which reduces the number of search points and yields a high visual quality by reducing the number of thresholds and early termination conditions.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.11a
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• pp.229-232
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• 2010

비디오 압축 기법에서 움직임 추정(Motion Estimation)은 매우 중요한 부분을 차지하는데, 그것은 움직임 추정이 화질과 인코딩 시간에 직접적으로 영향을 미치기 때문이다. 가장 기본적인 움직임 추정 기법은 전역 탐색 기법(Full Search)인데, 이는 가장 좋은 화질을 보여주긴 하지만 매우 많은 계산량이 필요하다는 단점이 있다. 따라서 좋은 화질을 유지하면서도 계산량을 낮추기 위한 많은 고속 탐색 알고리즘들이 제안되었다. 이 논문에서는 현재 프레임의 매크로블록과 이전프레임의 매크로블록간의 Sum of Absolute Difference를 이용하여 탐색영역을 변경하는 새로운 예측 방법을 제시한다. 실험결과에 따르면 우리가 제안한 알고리듬은 FS와 비슷한 PSNR을 유지하면서 속도가 크게 향상된 것을 볼 수 있었다.