• Title/Summary/Keyword: $A^*$ 알고리즘

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Units' Path-finding Method Proposal for A* Algorithm in the Tilemap (타일맵에서 A* 알고리즘을 이용한 유닛들의 길찾기 방법 제안)

  • Lee Se-Il
    • Journal of the Korea Society of Computer and Information
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    • v.9 no.3
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    • pp.71-77
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    • 2004
  • While doing games, units have to find goal And according to algorism, there is great difference in time and distance. In this paper the researcher compared and described characteristics of each of the improved algorism and A* algorism by giving depth-first search, breadth-first search and distance value and then argued algorism. In addition. by actually calculating the presumed value in A* a1gorism, the researcher finds the most improved value. Finally, by means of comparison between A* algorism and other one, the researcher verified its excellence and did simple path-finding using A* algorism.

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PBUG: Bug Algorithms for a Pair of Mobile Robots (PBUG: 모바일 로봇 쌍을 위한 버그 알고리즘)

  • Cho, Chang-Kwon;Woo, Gyun
    • Proceedings of the Korea Information Processing Society Conference
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    • 2012.04a
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    • pp.312-315
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    • 2012
  • 이 논문은 한 대의 모바일 로봇의 모션 계획 알고리즘인 Bug1과 Bug2를 개선한 알고리즘을 제안한다. 장애물이 있는 환경에서 목표지점까지 도달하기 위한 경로 계획 알고리즘으로 Bug1과 Bug2가 제안되었지만, 이 두 알고리즘은 모두 장애물 형태에 따라 탐사 시간이 오래 걸릴 수 있다는 단점이 있다. Bug2 알고리즘은 Bug1 알고리즘을 개선한 형태로 제안되었지만 심지어 극적적인 경우에는 무한 루프에 빠진다는 단점이 있다. 이 논문에서는 이러한 단점을 해결하기 위해 한 쌍의 모바일 로봇을 이용한 병렬 탐색 PBug1, PBug2 알고리즘을 제안한다. 제안된 PBug1과 PBug2 알고리즘은 각각 Bug1과 Bug2의 속도를 보장하며 일반적으로 빠른 탐사시간을 보인다. 측히 PBug2 알고리즘은 Bug2와 달리 무한루프에 빠지는 경우가 없다. 제안된 알고리즘의 성능을 평가하기 위해 PBug1, PBug2 알고리즘을 구현하여 Bug1, Bug2 알고리즘과 비교하였다. 실험결과 PBug1 알고리즘은 Bug1 알고리즘보다 탐사 시간이 64.9%로 감소하였고 PBug2 알고리즘은 Bug1 알고리즘과 비슷한 탐사 시간을 보였다.

Performance Improvement of LZ77 Algorithm using a Strategy Table and a Genetic Algorithm (전략 테이블과 유전 알고리즘을 이용한 LZ77 알고리즘의 성능 개선)

  • Jung Soonchul;Seo Dong-Il;Moon Byung-Ro
    • Journal of KIISE:Software and Applications
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    • v.31 no.12
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    • pp.1628-1636
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    • 2004
  • Data compression techniques have been studied for decades because they saved space and time to reduce costs. The Lempel-Ziv 77 (LZ77) is a dictionary-based, lossless compression algorithm. The dictionary size of the LZ77 algorithm is fixed, and the performance of the algorithm is highly dependent on its dictionary size. In this paper, we suggest a dynamic LZ77 algorithm that changes its dictionary size during compression, and also we suggest a genetic algorithm to evolve the dictionary-resizing strategies. The suggested algorithm outperformed the original version up to about 16%.

A DFS-ALOHA Algorithm with Slot Congestion Rates in a RFID System (RFID시스템에서 슬롯의 혼잡도를 이용한 DFS-ALOHA 알고리즘)

  • Lee, Jae-Ku;Choi, Seung-Sik
    • The KIPS Transactions:PartC
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    • v.16C no.2
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    • pp.267-274
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    • 2009
  • For the implementation of a RFID system, an anti-collision algorithm is required to identify multiple tags within the range of a RFID Reader. There are two methods of anti-collision algorithms for the identification of multiple tags, conclusive algorithms based on tree and stochastic algorithms based on slotted ALOHA. In this paper, we propose a Dynamic Framed Slotted ALOHA-Slot Congestion(DFSA-SC) Algorithm. The proposed algorithm improves the efficiency of collision resolution. The performance of the proposed DFSA-SC algorithm is showed by simulation. The identification time of the proposed algorithm is shorter than that of the existing DFSA algorithm. Furthermore, when the bit duplication of the tagID is higher, the proposed algorithm is more efficient than Query Tree algorithm.

Fast and Scalable Path Re-routing Algorithm Using A Genetic Algorithm (유전자 알고리즘을 이용한 확장성 있고 빠른 경로 재탐색 알고리즘)

  • Lee, Jung-Kyu;Kim, Seon-Ho;Yang, Ji-Hoon
    • The KIPS Transactions:PartB
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    • v.18B no.3
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    • pp.157-164
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    • 2011
  • This paper presents a fast and scalable re-routing algorithm that adapts to dynamically changing networks. The proposed algorithm integrates Dijkstra's shortest path algorithm with the genetic algorithm. Dijkstra's algorithm is used to define the predecessor array that facilitates the initialization process of the genetic algorithm. After that, the genetic algorithm re-searches the optimal path through appropriate genetic operators under dynamic traffic situations. Experimental results demonstrate that the proposed algorithm produces routes with less traveling time and computational overhead than pure genetic algorithm-based approaches as well as the standard Dijkstra's algorithm for large-scale networks.

A Hybrid Search Method of A* and Dijkstra Algorithms to Find Minimal Path Lengths for Navigation Route Planning (내비게이션 경로설정에서 최단거리경로 탐색을 위한 A*와 Dijkstra 알고리즘의 하이브리드 검색법)

  • Lee, Yong-Hu;Kim, Sang-Woon
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.10
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    • pp.109-117
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    • 2014
  • In navigation route planning systems using A* algorithms, the cardinality of an Open list, which is a list of candidate nodes through which a terminal node can be accessed, increases as the path length increases. In this paper, a method of alternately utilizing the Dijkstra's algorithm and the A* algorithm to reduce the cardinality of the Open list is investigated. In particular, by employing a depth parameter, named Level, the two algorithms are alternately performed depending on the Level's value. Using the hybrid searching approach, the Open list constructed in the Dijkstra's algorithm is transferred into the Open list of the A* algorithm, and consequently, the unconstricted increase of the cardinality of the Open list of the former algorithm can be avoided and controlled appropriately. In addition, an optimal or nearly optimal path similar to the Dijkstra's route, but not available in the A* algorithm, can be found. The experimental results, obtained with synthetic and real-life benchmark data, demonstrate that the computational cost, measured with the number of nodes to be compared, was remarkably reduced compared to the traditional searching algorithms, while maintaining the similar distance to those of the latter algorithms. Here, the values of Level were empirically selected. Thus, a study on finding the optimal Level values, while taking into consideration the actual road conditions remains open.

A study on the direction of teaching algorithms with analysis of algorithms (알고리즘 분석을 통한 컴퓨터교육에서의 알고리즘 교육의 방향)

  • Hong, Soon-Jo;Han, Sun-Kwan
    • 한국정보교육학회:학술대회논문집
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    • 2004.08a
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    • pp.236-241
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    • 2004
  • Algorithms is defined "step-by-step procedure for accomplishing a task that we wish to complete." Algorithms has much educational values. Already many scholar is making researches about paper-and-pencil algorithms in mathematic education. The purpose of this paper is to propose a study on the direction of teaching algorithms with analysis of algorithms

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A Study of Adapted Genetic Algorithm for Circuit Partitioning (회로 분할을 위한 어댑티드 유전자 알고리즘 연구)

  • Song, Ho-Jeong;Kim, Hyun-Gi
    • The Journal of the Korea Contents Association
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    • v.21 no.7
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    • pp.164-170
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    • 2021
  • In VLSI design, partitioning is a task of clustering objects into groups so that a given objective circuit is optimized. It is used at the layout level to find strongly connected components that can be placed together in order to minimize the layout area and propagation delay. The most popular algorithms for partitioning include the Kernighan-Lin algorithm, Fiduccia-Mattheyses heuristic and simulated annealing. In this paper, we propose a adapted genetic algorithm searching solution space for the circuit partitioning problem, and then compare it with simulated annealing and genetic algorithm by analyzing the results of implementation. As a result, it was found that an adaptive genetic algorithm approaches the optimal solution more effectively than the simulated annealing and genetic algorithm.

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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The Cubically Filtered Gradient Algorithm and Structure for Efficient Adaptive Filter Design (효율적인 적응 필터 설계를 위한 제 3 차 필터화 경사도 알고리즘과 구조)

  • 김해정;이두수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.18 no.11
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    • pp.1714-1725
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    • 1993
  • This paper analyzes the properties of such algorithm that corresponds to the nonlinear adaptive algorithm with additional update terms, parameterized by the scalar factors a1, a2, a3 and Presents its structure. The analysis of convergence leads to eigenvalues of the transition matrix for the mean weight vector. Regions in which the algorithm becomes stable are demonstrated. The time constant is derived and the computational complexities of MLMS algorithms are compared with those of the conventional LMS, sign, LFG, and QFG algorithms. The properties of convergence in the mean square are analyzed and the expressions of the mean square recursion and the excess mean square error are derived. The necessary condition for the CFG algorithm to be stable is attained. In the computer simulation applied to the system identification the CFG algorithm has the more computation complexities but the faster convergence speed than LMS, LFG and QFG algorithms.

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