• Title/Summary/Keyword: search algorithm

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Comparison of Estimating Parameters by Univariate Search and Genetic Algorithm using Tank Model (단일변이 탐색법과 유전 알고리즘에 의한 탱크모형 매개변수 결정 비교 연구)

  • Lee, Sung-Yong;Kim, Tae-Gon;Lee, Je-Myung;Lee, Eun-Jung;Kang, Moon-Seong;Park, Seung-Woo;Lee, Jeong-Jae
    • Journal of The Korean Society of Agricultural Engineers
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    • v.51 no.3
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    • pp.1-8
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    • 2009
  • The objectives of this study are to apply univariate search and genetic algorithm to tank model, and compare the two optimization methods. Hydrologic data of Baran watershed during 1996 and 1997 were used for correction the tank model, and the data of 1999 to 2000 were used for validation. RMSE and R2 were used for the tank model's optimization. Genetic algorithm showed better result than univariate search. Genetic algorithm converges to general optima, and more population of potential solution made better result. Univariate search was easy to apply and simple but had a problem of convergence to local optima, and the problem was not solved although search the solution more minutely. Therefore, this study recommend genetic algorithm to optimize tank model rather than univariate search.

Recent Development of Search Algorithm on Small Molecule Docking (소분자 도킹에서의 탐색알고리듬의 현황)

  • Chung, Hwan Won;Cho, Seung Joo
    • Journal of Integrative Natural Science
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    • v.2 no.2
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    • pp.55-58
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    • 2009
  • A ligand-receptor docking program is an indispensible tool in modern pharmaceutical design. An accurate prediction of small molecular docking pose to a receptor is essential in drug design as well as molecular recognition. An effective docking program requires the ability to locate a correct binding pose in a surprisingly complex conformational space. However, there is an inherent difficulty to predict correct binding pose. The odds are more demanding than finding a needle in a haystack. This mainly comes from the flexibility of both ligand and receptor. Because the searching space to consider is so vast, receptor rigidity has been often applied in docking programs. Even nowadays the receptor may not be considered to be fully flexible although there have been some progress in search algorithm. Improving the efficiency of searching algorithm is still in great demand to explore other applications areas with inherently flexible ligand and/or receptor. In addition to classical search algorithms such as molecular dynamics, Monte Carlo, genetic algorithm and simulated annealing, rather recent algorithms such as tabu search, stochastic tunneling, particle swarm optimizations were also found to be effective. A good search algorithm would require a good balance between exploration and exploitation. It would be a good strategy to combine algorithms already developed. This composite algorithms can be more effective than an individual search algorithms.

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Function Optimization Using Quadratically Convergent Algorithms With One Dimensional Search Schemes

  • Kim, Do-Il
    • Journal of Korean Institute of Industrial Engineers
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    • v.14 no.2
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    • pp.25-40
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    • 1988
  • In this paper, a unified method to construct a quadratically convergent algorithm with one dimensional search schemes is described. With this method, a generalized algorithm is derived. As it's particular cases, three quadratically convergent algorithms are performed. They are the rank-one algorithm (Algorithm I), projection algorithm (Algorithm II) and the Fletcher-Reeves algorithm (Algorithm III). As one-dimensional search schemes, the golden-ratio method and dichotomous search are used. Additionally, their computer programming is developed for actual application. The use of this program is provided with the explanation of how to use it, the illustrative examples that are both quadratic and nonquadratic problems and their output. Finally, from the computer output, each algorithm was analyzed from the standpoint of efficiency for performance.

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A New Block-based Gradient Descent Search Algorithm for a Fast Block Matching (고속 블록 정합을 위한 새로운 블록 기반 경사 하강 탐색 알고리즘)

  • 곽성근
    • Journal of the Korea Computer Industry Society
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    • v.4 no.10
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    • pp.731-740
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    • 2003
  • Since motion estimation remove the redundant data to employ the temporal correlations between adjacent frames in a video sequence, it plays an important role in digital video coding. And in the block matching algorithm, search patterns of different shapes or sizes and the distribution of motion vectors have a large impact on both the searching speed and the image quality. In this paper, we propose a new fast block matching algorithm using the small-cross search pattern and the block-based gradient descent search pattern. Our algorithm first finds the motion vectors that are close to the center of search window using the small-cross search pattern, and then quickly finds the other motion vectors that are not close to the center of search window using the block-based gradient descent search pattern. Through experiments, compared with the block-based gradient descent search algorithm(BBGDS), the proposed search algorithm improves as high as 26-40% in terms of average number of search point per motion vector estimation.

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A Fast Full Search Motion Estimation Algorithm using Partitioned Search Window (세분화된 탐색 영역을 이용한 고속 전영역 움직임 예측 알고리즘)

  • Park, Sang-Jun;Jin, Soon-Jong;Jeong, Je-Chang
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.1C
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    • pp.9-15
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    • 2007
  • We propose the fast full search algorithm that reduces the computation of the block matching algorithm which is used for motion estimation of the video coding. Since the conventional spiral search method starts searching at the center of the search window and then moves search point to estimate the motion vector pixel by pixel, it is good for the slow motion pictures. However the proposed method is good for the fast and slow motion because it estimates the motion in the new search order after partitioning the search window. Also, when finding the motion vector, this paper presents the method that reduces the complexity by computing the matching error in the order which is determined by local image complexity. The proposed algorithm reduces the computation up to 99% for block matching error compared with the conventional spiral full search algorithm without any loss of image quality.

Design of Efficient Data Search Function using the Excel VBA DAO (엑셀 VBA DAO 기능을 이용한 효율적인 데이타 검색 기능 설계)

  • Jang, Seung Ju;Ryu, Dae-Hyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.1
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    • pp.217-222
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    • 2014
  • In this paper, I propose an efficient data search system using data partitioning algorithm in Microsoft Excel. I propose searching algorithm to retrieve data quickly using VBA functioning in the Excel. This algorithm is to specify the sheet you are looking for. Once the sheet is specified, the algorithm searches the beginning and the end of the data in the sheet. The algorithm compares intermediate values and key words, from the starting position of the cell. In this way, it will search data to the end. This proposed algorithm was implemented and tested in the Excel system using VBA program. The experimental results showed that the performance was better than that of the conventional sequential search method.

An Approximate k-Nearest Neighbor Search Algorithm for Content- Based Multimedia Information Retrieval (내용 기반 멀티미디어 정보 검색을 위한 근사 k-최근접 데이타 탐색 알고리즘)

  • Song, Kwang-Taek;Chang, Jae-Woo
    • Journal of KIISE:Databases
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    • v.27 no.2
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    • pp.199-208
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    • 2000
  • The k-nearest neighbor search query based on similarity is very important for content-based multimedia information retrieval(MIR). The conventional exact k-nearest neighbor search algorithm is not efficient for the MIR application because multimedia data should be represented as high dimensional feature vectors. Thus, an approximate k-nearest neighbor search algorithm is required for the MIR applications because the performance increase may outweigh the drawback of receiving approximate results. For this, we propose a new approximate k-nearest neighbor search algorithm for high dimensional data. In addition, the comparison of the conventional algorithm with our approximate k-nearest neighbor search algorithm is performed in terms of retrieval performance. Results show that our algorithm is more efficient than the conventional ones.

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A Study on the Fast Search Algorithm for Vector Quantization (벡터 양자화를 위한 고속 탐색 알고리듬에 관한 연구)

  • 지상현;김용석;이남일;강상원
    • The Journal of the Acoustical Society of Korea
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    • v.22 no.4
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    • pp.293-298
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    • 2003
  • In this paper. we propose a fast search algorithm for nearest neighbor vector quantization (NNVQ). The proposed algorithm rejects those codewords which can not be the nearest codeword and reduces the search range of codebook. Hence it reduces computational time and complexity in encoding process, while it provides the same SD performance as the conventional full search algorithm. We apply the proposed algorithm to the adaptive multi-rate (AMR) speech coder and a general vector quantizer designed by LBG. algorithm. Simulation results show effectiveness of the proposed algorithm.

Efficient Computing Algorithm for Inter Prediction SAD of HEVC Encoder (HEVC 부호기의 Inter Prediction SAD 연산을 위한 효율적인 알고리즘)

  • Jeon, Sung-Hun;Ryoo, Kwangki
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.10a
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    • pp.397-400
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    • 2016
  • In this paper, we propose an efficient algorithm for computing architecture for high-performance Inter Prediction SAD HEVC encoder. HEVC Motion Estimation (ME) of the Inter Prediction is a process for searching for the currently high prediction block PU and the correlation in the interpolated reference picture in order to remove temporal redundancy. ME algorithm uses full search(FS) or fast search algorithm. Full search technique has the guaranteed optimal results but has many disadvantages which include high calculation and operational time due to the motion prediction with respect to all candidate blocks in a given search area. Therefore, this paper proposes a new algorithm which reduces the computational complexity by reusing the SAD operation in full search to reduce the amount of calculation and computational time of the Inter Prediction. The proposed algorithm is applied to an HEVC standard software HM16.12. There was an improved operational time of 61% compared to the traditional full search algorithm, BDBitrate was decreased by 11.81% and BDPSNR increased by about 0.5%.

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A 16:1 Subsampling Block-Matching Algorithm and Its Hardware Design (16:1 부분 표본 추출 블럭 정합 알고리즘과 이의 하드웨어 설계)

  • 김양훈;임종석;민병기
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.32B no.12
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    • pp.1624-1634
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    • 1995
  • Conventional full search block matching algorithm for motion estimation is computationally intensive and the resulting hardware cost is very high. In this paper, we present an efficient block matching algorithm using a 16:1 subsampling technique, and describe its hardware design. The algorithm reduces the number of pixels in calculating the mean absolute difference at each search location, instead of reducing the search locations.The algorithm is an extension of the block mating algorithm with 4:1 subsampling proposed by Liu and Zaccarin such that the amount of computation is reduced by a fact of 4(16 compared to the full search block matching algorithm) while producing similar performance.The algorithm can efficiently be designed into a hardware for real-time applications.

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