• Title/Summary/Keyword: $A^*$ Search 알고리즘

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Subband PRI analysis algorithm (Subband PRI 분석 알고리즘)

  • 윤원식
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.6
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    • pp.1425-1429
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    • 1996
  • A conventional sequence search algorithm for PRI analysis occurs the harmonic problem under missing pulses. An improved PRI analysis algorithm is proposedto remedy the harmonic problem. After dividing an overall PRI range into subbands withoug harmonic, a sequence search is done into forward and backward in time. The proposed algorithm increases the preformance compared with that of conventional sequence search algorithm.

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Efficient Bidirectional Search Algorithm for Optimal Route (최적 경로를 보장하는 효율적인 양방향 탐색 알고리즘)

  • 황보택근
    • Journal of Korea Multimedia Society
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    • v.5 no.6
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    • pp.745-752
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    • 2002
  • A* algorithm is widely used in optimal car route search which is a kind of informed search, since the locations of starting and ending points are known a priori. Unidirectional A* algorithm requires considerable search time but guarantees a optimal path, bidirectional A* algorithm does not guarantee a optimal path and takes even longer search time than unidirectional search to guarantee a optimal path. In this paper, a new bidirectional A* algorithm which requites less search time and guarantees a optimal path is proposed. To evaluate the efficiency of the proposed algorithm, several experiments are conducted in real road map and the results show that the algorithm is very effective in terms of finding a optimal path and search time.

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An Efficient Center-Biased Hybrid Search Algorithm (효율적인 Center-Biased Hybrid 탐색 알고리즘)

  • Su-Bong Hong;Soo-Mok Jung
    • Journal of the Korea Computer Industry Society
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    • v.4 no.12
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    • pp.1075-1082
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    • 2003
  • In this paper, we propose an Efficient Center-Biased Hybrid Seearch (ECBHS) for motion estimation based on Center-Biased Hybrid Search(CBHS). This proposed algorithm employ hybrid of a compact plus shaped search, X shaped search, and diamond search to reduce the search point for motion vectors which distributed within 3pels radius of center of search window. ECBHS reduces the computations for motion estimation of CBHS with similar accuracy The efficiency of the proposed algorithm was verified by experimental results.

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Optimum Allocation of Pipe Support Using Combined Optimization Algorithm by Genetic Algorithm and Random Tabu Search Method (유전알고리즘과 Random Tabu 탐색법을 조합한 최적화 알고리즘에 의한 배관지지대의 최적배치)

  • 양보석;최병근;전상범;김동조
    • Journal of the Korean Institute of Intelligent Systems
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    • v.8 no.3
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    • pp.71-79
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    • 1998
  • This paper introduces a new optimization algorithm which is combined with genetic algorithm and random tabu search method. Genetic algorithm is a random search algorithm which can find the global optimum without converging local optimum. And tabu search method is a very fast search method in convergent speed. The optimizing ability and convergent characteristics of a new combined optimization algorithm is identified by using a test function which have many local optimums and an optimum allocation of pipe support. The caculation results are compared with the existing genetic algorithm.

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An Iterative Local Search Algorithm for Rural Postman Problems (Rural Postman Problem 해법을 위한 Iterative Local Search 알고리즘)

  • 강명주
    • Journal of the Korea Society of Computer and Information
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    • v.7 no.1
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    • pp.48-53
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    • 2002
  • This paper Proposes an iterative Local Search (ILS) algorithm for Rural Postman Problems (RPPs). LS searches neighbors from an initial solution in solution space and obtains a nearoptimal solution which can be a local-minima. As an extension of LS, the ILS algorithm is a method that uses various initial solutions for LS. Hence. ILS can overcome the defect of LS. This paper proposes LS and ILS methods for 18 RPPs and analyzes the results of LS and ILS. In the simulation results, the ILS method obtained the better results than the LS method.

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A Fast Block Matching Algorithm by using the Cross Pattern and Flat-Hexagonal Search Pattern (크로스 패턴과 납작한 육각 탐색패턴을 이용한 고속 블록 정합 알고리즘)

  • 남현우;김종경
    • Journal of the Korea Computer Industry Society
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    • v.4 no.12
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    • pp.953-964
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    • 2003
  • 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 cross pattern and the flat-hexagon search pattern. Our algorithm first finds the motion vectors that are close to the center of search window using the cross pattern, and then lastly finds the other motion vectors that are not close to the center of search window using the flat-hexagon search pattern. Through experiments, compared with the hexagon-based search algorithm(HEXBS), the proposed cross pattern and flat-hexagonal pattern search algorithm(CFHPS ) improves about 0.2-6.2% in terms of average number of search point per motion vector estimation and improves about 0.02-0.31dB in terms of PSNR(Peak Signal to Noise Ratio).

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Hybrid Genetic Algorithms for Feature Selection and Classification Performance Comparisons (특징 선택을 위한 혼합형 유전 알고리즘과 분류 성능 비교)

  • 오일석;이진선;문병로
    • Journal of KIISE:Software and Applications
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    • v.31 no.8
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    • pp.1113-1120
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    • 2004
  • This paper proposes a novel hybrid genetic algorithm for the feature selection. Local search operations are devised and embedded in hybrid GAs to fine-tune the search. The operations are parameterized in terms of the fine-tuning power, and their effectiveness and timing requirement are analyzed and compared. Experimentations performed with various standard datasets revealed that the proposed hybrid GA is superior to a simple GA and sequential search algorithms.

A Fast Block Matching Algorithm using Unit-Diamond and Flat-Hexagonal Search Patterns (단위 다이아몬드와 납작한 육각패턴을 이용한 고속 블록 정합 알고리즘)

  • 남현우;위영철;김하진
    • Journal of KIISE:Computing Practices and Letters
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    • v.10 no.1
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    • pp.57-65
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    • 2004
  • 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 unit-diamond search pattern and the flat-hexagon search pattern. Our algorithm first finds the motion vectors that are close to the center of search window using the unit-diamond search pattern, and then fastly finds the other motion vectors that are not close to the center of search window using the flat-hexagon search pattern. Through experiments, compared with the hexagon-based search algorithm(HEXBS), the proposed unit-diamond and flat-hexagonal pattern search algorithm(UDFHS) improves as high as 11∼51% in terms of average number of search point per motion vector estimation and improves about 0.05∼0.74㏈ in terms of PSNR(Peak Signal to Noise Ratio).

A Flat Hexagon-based Search Algorithm for Fast Block Matching Motion Estimation (고속 블록 정합 움직임 예측을 위한 납작한 육각 패턴 기반 탐색 알고리즘)

  • Nam, Hyeon-Woo
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.1 s.45
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    • pp.57-65
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    • 2007
  • In the fast 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 qualify. In this paper, we propose a new fast block matching algorithm using the flat-hexagon search pattern that ate solved disadvantages of the diamond pattern search algorithm(DS) and the hexagon-based search algorithm(HEXBS). Our proposed algorithm finds mainly the motion vectors that not close to the center of search window using the flat-hexagon search pattern. Through experiments, compared with the DS and HEXBS, the proposed f)at-hexagon search algorithm(FHS) improves about $0.4{\sim}21.3%$ in terms of average number of search point per motion vector estimation and improves about $0.009{\sim}0.531dB$ in terms of PSNR(Peak Signal to Noise Ratio).

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High Speed Motion Match Utilizing A Multi-Resolution Algorithm (다중해상도 알고리즘을 이용한 고속 움직임 정합)

  • Joo, Heon-Sik
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.2 s.46
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    • pp.131-139
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    • 2007
  • This paper proposed a multi-resolution algorithm. Its search point and complexity were compared with those of block match algorithm. Also the speed up comparison was made with the block match algorithm. The proposed multi-resolution NTSS-3 Level algorithm was compared again with its targets, TSS-3 Level algorithm and NTSS algorithm. The comparison results showed that the NTSS-3 Level algorithm was superior in search point and speed up. Accordingly, the proposed NTSS-3 Level algorithm was two to three times better in search point and two to four times better in complexity calculation than those of the compared object, the block match algorithm. In speed up, the proposed NTSS-3 Level algorithm was two times better. Accordingly, the proposed multi-resolution NTSS-3 Level algorithm showed PSNR ration portion excellency in search point and speed up.

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