• Title/Summary/Keyword: Dynamic Heuristic

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Path Finding with Minimum Speed Dynamic Heuristic (최저 속력 동적 휴리스틱을 이용한 경로탐색)

  • Moon, Dae-Jin;Cho, Dae-Soo
    • Journal of Korea Spatial Information System Society
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    • v.10 no.2
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    • pp.35-48
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    • 2008
  • In this paper, we propose a Dynamic Heuristic to reduce the number of node accesses and improve quality of path in the client-based navigation service. The Dynamic Heuristic is to use heuristic data from server that is calculated with traffic data. The server-based navigation service provides a path searched on server and transmits it to client, but we propose that server only provide heuristic data to client. The proposed client searches a path with heuristic transmitted data from server. We present a new algorithm for using Dynamic Heuristic in the path-finding. The algorithm bases Grid Based Path-Finding, and has minimum speed data of edges in grid. It removes several grids whose minimum speed is less than limited speed.

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A Study on the Heuristic Search Algorithm on Graph (그라프에서의 휴리스틱 탐색에 관한 연구)

  • Kim, Myoung-Jae;Chung, Tae-Choong
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.10
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    • pp.2477-2484
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    • 1997
  • Best-first heuristic search algorithm, such as $A^{\ast}$ algorithm, are one of the most important techniques used to solve many problems in artificial intelligence. A common feature of heuristic search is its high computational complexity, which prevents the search from being applied to problems is practical domains such as route-finding in road map with significantly many nodes. In this paper, several heuristic search algorithms are concerned. A new dynamic weighting heuristic method called the pat-sensitive heuristic is proposed. It is based on a dynamic weighting heuristic, which is used to improve search effort in practical domain such as admissible heuristic is not available or heuristic accuracy is poor. It's distinctive feature compared with other dynamic weighting heuristic algorithms is path-sensitive, which means that ${\omega}$(weight) is adjusted dynamically during search process in state-space search domain. For finding an optimal path, randomly scattered road-map is used as an application area.

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Blackboard Scheduler Control Knowledge for Recursive Heuristic Classification

  • Park, Young-Tack
    • Journal of Intelligence and Information Systems
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    • v.1 no.1
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    • pp.61-72
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    • 1995
  • Dynamic and explicit ordering of strategies is a key process in modeling knowledge-level problem-solving behavior. This paper addressed the important problem of howl to make the scheduler more knowledge-intensive in a way that facilitates the acquisition, integration, and maintenance of the scheduler control knowledge. The solution a, pp.oach described in this paper involved formulating the scheduler task as a heuristic classification problem, and then implementing it as a classification expert system. By doing this, the wide spectrum of known methods of acquiring, refining, and maintaining the knowledge of a classification expert system are a, pp.icable to the scheduler control knowledge. One important innovation of this research is that of recursive heuristic classification : this paper demonstrates that it is possible to formulate and solve a key subcomponent of heuristic classification as heuristic classification problem. Another key innovation is the creation of a method of dynamic heuristic classification : the classification alternatives that are selected among are dynamically generated in real-time and then evidence is gathered for and aginst these alternatives. In contrast, the normal model of heuristic classification is that of structured selection between a set of preenumerated fixed alternatives.

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Meta-Heuristic Algorithms for a Multi-Product Dynamic Lot-Sizing Problem with a Freight Container Cost

  • Kim, Byung-Soo;Lee, Woon-Seek
    • Industrial Engineering and Management Systems
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    • v.11 no.3
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    • pp.288-298
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    • 2012
  • Lot sizing and shipment scheduling are two interrelated decisions made by a manufacturing plant and a third-party logistics distribution center. This paper analyzes a dynamic inbound ordering problem and shipment problem with a freight container cost, in which the order size of multiple products and single container type are simultaneously considered. In the problem, each ordered product placed in a period is immediately shipped by some freight containers in the period, and the total freight cost is proportional to the number of containers employed. It is assumed that the load size of each product is equal and backlogging is not allowed. The objective of this study is to simultaneously determine the lot-sizes and the shipment schedule that minimize the total costs, which consist of production cost, inventory holding cost, and freight cost. Because the problem is NP-hard, we propose three meta-heuristic algorithms: a simulated annealing algorithm, a genetic algorithm, and a new population-based evolutionary meta-heuristic called self-evolution algorithm. The performance of the meta-heuristic algorithms is compared with a local search heuristic proposed by the previous paper in terms of the average deviation from the optimal solution in small size problems and the average deviation from the best one among the replications of the meta-heuristic algorithms in large size problems.

A Tabu Search Approach for Resource Constrained Dynamic Multi-Projects Scheduling (자원제약하의 동적 다중 프로젝트 일정계획에 Tabu Search 적용)

  • 윤종준;이화기
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.22 no.52
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    • pp.297-309
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    • 1999
  • Resource Constrained Dynamic Multi-Projects Scheduling(RCDMPS) is intended to minimize the total processing time(makespan) of two or more projects sequentially arriving at the shop under restricted resources. The aim of this paper is to develop the new Tabu Search heuristic for RCDMPS to minimize makespan. We propose the insertion method to generate the neighborhood solutions in applying the Tabu Search for the RCDMPS and the diversification strategy to search the solution space diversely. The proposed diversification strategy apply the dynamic tabu list that the tabu list size is generated and renewed at each iteration by the complexity of the project, and change the proposed tabu attribute. In this paper, We use the dynamic tabu list for the diversification strategy and intensification strategy in the tabu search, and compare with other dispatching heuristic method to verify that the new heuristic method minimize the makespan of the problem.

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Batch Sizing Heuristic for Batch Processing Workstations in Semiconductor Manufacturing (반도체 생산 배취공정에서의 배취 크기의 결정)

  • Chun, Kil-Woong;Hong, Yu-Shin
    • Journal of Korean Institute of Industrial Engineers
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    • v.22 no.2
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    • pp.231-245
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    • 1996
  • Semiconductor manufacturing line includes several batch processes which are to be controlled effectively to enhance the productivity of the line. The key problem in batch processes is a dynamic batch sizing problem which determines number of lots processed simultaneously in a single botch. The batch sizing problem in semiconductor manufacturing has to consider delay of lots, setup cost of the process, machine utilization and so on. However, an optimal solution cannot be attainable due to dynamic arrival pattern of lots, and difficulties in forecasting future arrival times of lots of the process. This paper proposes an efficient batch sizing heuristic, which considers delay cost, setup cost, and effect of the forecast errors in determining the botch size dynamically. Extensive numerical experiments through simulation are carried out to investigate the effectiveness of the proposed heuristic in four key performance criteria: average delay, variance of delay, overage lot size and total cost. The results show that the proposed heuristic works effectively and efficiently.

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Algorithm for Search Space Reduction based on Dynamic Heuristic Value Change

  • Kim, Hyung-Soo;Moon, kyung-Seob
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.6
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    • pp.943-950
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    • 2002
  • Real time strategy game is a computer game genre of Playing with human or computer opponents in real time It differs from turn-type computer games in the game process method. Turn type games, such as chess, allow only one Player to move at a time. Real time strategy games allow two or more Players to move simultaneously. Therefore, in real time strategy computer games, the game components' movement plans must be calculated very quickly in order to not disturb other processes such as gathering resources, building structures, and combat activities. There are many approaches, which can reduce the amount of memory required for calculating path, search space, and reactive time of components. (or units). However, existing path finding algorithms tend to concentrate on achieving optimal Paths that are not as important or crucial in real time strategy game. This Paper introduces Dynamic Heuristic Af(DHA*) algorithm which is capable of reducing search space and reactive time of game units and compares with A* algorithm using static heuristic weighting.

Minimization of Cell-based Handoff Delays to Balance the Load in Fiber Optic Micro-cellular Systems (광마이크로셀 이동통신 시스템의 균등부하를 위한 셀단위 핸드오프 순서결정)

  • 이채영;장세헌
    • Journal of the Korean Operations Research and Management Science Society
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    • v.26 no.2
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    • pp.1-11
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    • 2001
  • This paper considers the scheduling of cell-based handoffs to balance the traffic in a fiber-optic microcelluar system. In the system depending on the order of cell based handoff, periodical balancing of the traffic among microcells can be achieved. The cell based handoff problem is formulated as a dynamic programming and the computational complexity is analyzed. Since the scheduling problem requires real time solution, heuristic algorithms are proposed and the computational results are discussed.

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Path Finding with Maximum Speed Dynamic Heuristic (최고 속력 동적 휴리스틱을 이용한 경로탐색)

  • Kim, Ji-Soo;Lee, Ji-Wan;Cho, Dae-Soo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.8
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    • pp.1615-1622
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    • 2009
  • Generally, the Terminal Based Navigation System(TBNS) used embedded road data searches a path that has less qualitative than The Center Based Navigation System(CBNS). TBNS has not used real time road data but it is recently able to use it with technique such as TPEG. However, it causes to increase a cost of exploring by using real time road data for improvement quality of a path, because of limited performance. In this paper, we propose a Dynamic Heuristic to improve quality of path in the TBNS. Dynamic Heuristic(DH) is not fixed data and is dynamically modified using transferred real time road data from server. In this paper, we propose path-lading algorithm with Maximum Speed Dynamic Heuristic (DH-MAX) and do an experiment. The DH-MAX is to be used the highest speed as DH, in real map divided by same size. And proposed algorithm searches path using the priority searching only of the fixed data, but also the highest speed with real time information. In the performance test, the quality of path is enhanced but the cost of searching is increased than A* algorithm.

Admission Control Policy Heuristic Algorithm for fairness of Call Blocking Probability in Differentiated Service Networks (차별화된 서비스를 갖는 인터넷 망에서 호 블로킹 확률의 공평성을 위한 수락 제어 정책 Heuristic 알고리즘 연구)

  • Min, Jun-Ki;Rhea, Woo-Seop;Chung, Jong-Soo
    • Journal of Internet Computing and Services
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    • v.6 no.3
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    • pp.121-128
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    • 2005
  • Recently, as the research of effective resource management for supporting of various next generation internet service, the admission control mechanisms using the dynamic provisioning methods in differentiated service networks are studied. However, even though admission control mechanism is applied to the network, there exits the unfairness of call blocking probability among the different bandwidth requested services. In this paper, we propose the new admission control policy heuristic algorithm that provides fairness of call blocking probability between the large bandwidth requested service and the small bandwidth requested service. The simulation results show that the proposed algorithm provides not only blocking probability fairness but also high bandwidth utilization.

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