• Title/Summary/Keyword: Heuristics

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볼트의 자동공정계획수립을 위한 CBR시스템의 개발 (Developing CBR System for Bolt's CAPP)

  • 김진백
    • Asia pacific journal of information systems
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    • 제9권2호
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    • pp.19-37
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    • 1999
  • Computer aided process planning(CAPP) is a key for implementing CIM. It is bridge between CAD and CAM and translates the design information into manufacturing instructions. Generally, manufacturing is an area where intelligent systems will not be able to rely on methods requiring formalized knowledge. Manufacturing lacks a body of knowledge that is specific, formalized, and rigorous, and which can be coded as rules or procedures. Thus expertise in manufacturing is developed over a period of many years. Case-based reasoning(CBR) offers a new approach for developing intelligent system. In the case-based approach the problem solving experience of the experts is encoded in the form of cases. CBR's retrieval process can be divided to two step. The first step is matching step, and the second step is selection step. For selecting base case, new preference heuristics were introduced using similarity concept. Similarity concept has three has three dimensions, i.e. entity similarity, structural similarity, and goal similarity. In this paper, bolt's process planning was selected an application domain. Following the test result, the new preference heuristics were approved as a useful procedure in CAPP.

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경도장애 학생들의 수학적 문제해결을 위한 폴리아의 전략 효과 연구 (The Effect of Polya's Heuristics in Mathematical Problem Solving of Mild Disability Students)

  • 한경화;김영옥
    • East Asian mathematical journal
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    • 제32권2호
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    • pp.253-289
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    • 2016
  • This study attempted to figure out new teaching method of mathematics teaching-learning by applying Polya's 4-level strategy to mild disability students at the H Special-education high school where the research works for. In particular, epilogue and suggestion, which Polya stressed were selected and reconstructed for mild disability students. Prior test and post test were carried by putting the Polya's problem solving strategy as independent variable, and problem solving ability as dependent variable. As a result, by continual use of Polya's program in mathematics teaching course, it suggested necessary strategies to solve mathematics problems for mild disability students and was proven that Polya's heuristic training was of help to improve problem solving in mathematics.

원료공장 잎담배 창고의 저장방법 (The Storage Method of a Leaf Tobacco Warehouse in Leaf Tobacco Factory)

  • Han-Joo Chung;Byong-Kwon Jeh;Yong-Ok Kim
    • 한국연초학회지
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    • 제25권1호
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    • pp.53-58
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    • 2003
  • This study deals with the leaf tobacco assignment problem of a leaf tobacco warehouse with multiple input points and single output point. Also, the number of storage frequences is not necessary the same as that of retrieval for each leaf tobacco. A mathematical model is developed with the objective of minimizing the total travel distance associated with storage and retrieval operations. We also develop several heuristics based on the retrieval order frequency, retrieval/storage frequency ratio of leaf tobacco, and ABC curve. It is observed that the ABC curve based heuristic gives the best solution which is near optimal. Based on the test results from real world data, the ABC curve based heuristic is found to give a best performance. Comparing to current assignment method, the ABC curve based heuristic reduced total travel distance about 17.2%.

개선형 탐색법에 의한 기계공장 배치안 작성시 고려요소별 가중치의 크기에 관한 연구 (A Study on Weight of Consideration Factors in Layout Development for Machinery Industries using Improvemant-type Heuristics)

  • 문기주
    • 한국경영과학회지
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    • 제20권2호
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    • pp.109-123
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    • 1995
  • Weight of the factors to be considered in layout development with improvement-type heuristics is discussed in this paper. Determination of weight is especially important if it is designed to be used with an improvement-type heuristic. It is same as the value of variable coefficients in a multi-objective function as well as indices for departmental switching orders in the heuristic. Various weights are examined through computer simulation to verify whether the numerical values collected from machinery industries can be used as weights. And then a method to be used for searching an optimum or optimum-tending layout for machinery industries is presented using the weight.

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다수준 시스템의 중복 할당 최적화 문제 (Multi-Level Redundancy Allocation Optimization Problems)

  • 윤원영;정일한;김종운
    • 대한산업공학회지
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    • 제43권2호
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    • pp.135-146
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    • 2017
  • This paper considers redundancy optimization problems of multi-level systems and reviews existing papers which proposed various optimization models and used different algorithms in this research area. Three different mathematical models are studied: Multi-level redundancy allocation (MRAP), multiple multi-level redundancy allocation, and availability-based MRAP models. Many meta-heuristics are applied to find optimal solutions in the several optimization problems. We summarized key idea of meta-heuristics applied to the existing MARP problems. Two extended models (MRAP with interval reliability of units and an integrated optimization problem of MRAP and preventive maintenance) are studied and further research ideas are discussed.

Distributed Database Design using Evolutionary Algorithms

  • Tosun, Umut
    • Journal of Communications and Networks
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    • 제16권4호
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    • pp.430-435
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    • 2014
  • The performance of a distributed database system depends particularly on the site-allocation of the fragments. Queries access different fragments among the sites, and an originating site exists for each query. A data allocation algorithm should distribute the fragments to minimize the transfer and settlement costs of executing the query plans. The primary cost for a data allocation algorithm is the cost of the data transmission across the network. The data allocation problem in a distributed database is NP-complete, and scalable evolutionary algorithms were developed to minimize the execution costs of the query plans. In this paper, quadratic assignment problem heuristics were designed and implemented for the data allocation problem. The proposed algorithms find near-optimal solutions for the data allocation problem. In addition to the fast ant colony, robust tabu search, and genetic algorithm solutions to this problem, we propose a fast and scalable hybrid genetic multi-start tabu search algorithm that outperforms the other well-known heuristics in terms of execution time and solution quality.

드론 배달 경로를 위한 효율적인 휴리스틱 알고리즘 (Efficient Heuristic Algorithms for Drone Package Delivery Route)

  • 요나탄;테메스겐;김재훈
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2016년도 춘계학술발표대회
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    • pp.168-170
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    • 2016
  • Drone package delivery routing problem is realistic problem used to find efficient route of drone package delivery service. In this paper, we present an approach for solving drone routing problem for package delivery service using two different heuristics algorithms, genetic and nearest neighbor. We implement and analyze both heuristics algorithms for solving the problem efficiently with respect to cost and time. The respective experimental results show that for the range of customers 10 to 50 nearest neighbor and genetic algorithms can reduce the tour length on average by 34% and 40% respectively comparing to FIFO algorithm.

효율적인 휴리스틱들을 가지는 선로 자동화 전문가 시스템 (An Expert System for Feeder Automation with Efficient Heuristics)

  • 고윤석;김호용;장정태;하복남
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1995년도 하계학술대회 논문집 B
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    • pp.482-484
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    • 1995
  • This paper proposes an expert system with improved heuristics in order to enhence convergence rate to the optimal solution when an emergence problem occurrs in the automated large scale distribution system. These heurictics, which a re obtained from the line loss and load balancing change after a line section transferred, are newly adopted for the emergence problem.

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A Method for Caption Segmentation using Minimum Spanning Tree

  • Chun, Byung-Tae;Kim, Kyuheon;Lee, Jae-Yeon
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 ITC-CSCC -2
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    • pp.906-909
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    • 2000
  • Conventional caption extraction methods use the difference between frames or color segmentation methods from the whole image. Because these methods depend heavily on heuristics, we should have a priori knowledge of the captions to be extracted. Also they are difficult to implement. In this paper, we propose a method that uses little heuristics and simplified algorithm. We use topographical features of characters to extract the character points and use KMST(Kruskal minimum spanning tree) to extract the candidate regions for captions. Character regions are determined by testing several conditions and verifying those candidate regions. Experimental results show that the candidate region extraction rate is 100%, and the character region extraction rate is 98.2%. And then we can see the results that caption area in complex images is well extracted.

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A High Quality Solution Constructive Heuristic for No-Wait Flow Shop Scheduling Problem

  • Nagano, Marcelo Seido;Miyata, Hugo Hissashi
    • Industrial Engineering and Management Systems
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    • 제15권3호
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    • pp.206-214
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    • 2016
  • This paper deals with the no-wait flow shop scheduling problem in order to minimize the total time to complete the schedule or makespan. It is introduced a constructive heuristic which builds the production schedule from job partial sequences by using an appropriate mechanism of insertion. An extensive computational experiment has been performed to evaluate the performance of proposed heuristic. Experimental results have clearly shown that the presented heuristic provides better solutions than those from the best heuristics existing.