• 대한수학교육학회지:학교수학
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• 제7권2호
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• pp.123-137
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• 2005

순열 조합의 문제는 내재된 의미 구조에 의해 선택, 분배, 분할의 세 가지의 유형으로 분류될 수 있다. 본 연구에서는 순열 조합의 연산과 문제 유형의 변인이 문제의 난이도에 미치는 영향을 분석하였다 그리고 문제 이해과정에서의 오류를 순서, 중복, 대상의 구별, 같은 것이 있는 순열, 상자의 구별, 분할의 조건, 기타로 분류하고 이해 단계의 장애를 구체적으로 분석하였다. 연구 결과, 순열 조합 연산과 문제의 유형은 난이도에 유의미한 영향을 미치는 것으로 나타났다. 특히 학생들에게 선택, 분할, 분배 문제간의 변환은 쉽지 않으며 순열 조합의 문제에서 학생들이 겪는 어려움 중 하나는 바로 문제 유형의 차이에서 비롯된다는 것을 알 수 있었다. 또한 현 교과서에서는 선택, 분배, 분할을 고려한 다양한 문제 유형이 부족한 것으로 나타났다. 따라서 순열 조합의 지도에 있어 문제 유형을 활용하여 다양한 의미 구조의 문제를 제시하고, 공식위주가 아닌 문제 상황을 충분히 이해하고 이에 대한 해법을 변형, 확장하는 경험을 강조하는 것이 필요하다고 하겠다.

• Journal of applied mathematics & informatics
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• 제26권1_2호
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• pp.283-290
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• 2008

This paper is motivated by the problem of fitting a group of cuboids into a simplified rotating vessel of the artificial satellite. Here we introduce a combinatorial optimization model which reduces the three-dimensional layout problem with behavioral constraints to a finite enumeration scheme. Moreover, a global combinatorial optimization algorithm is described in detail, which is an improved graph-theoretic heuristic.

• Journal of Computational Design and Engineering
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• 제3권4호
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• pp.295-311
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• 2016

This paper addresses to the flowshop scheduling problem with blocking constraints. The objective is to minimize the makespan criterion. We propose a hybrid combinatorial particle swarm optimization algorithm (HCPSO) as a resolution technique for solving this problem. At the initialization, different priority rules are exploited. Experimental study and statistical analysis were performed to select the most adapted one for this problem. Then, the swarm behavior is tested for solving a combinatorial optimization problem such as a sequencing problem under constraints. Finally, an iterated local search algorithm based on probabilistic perturbation is sequentially introduced to the particle swarm optimization algorithm for improving the quality of solution. The computational results show that our approach is able to improve several best known solutions of the literature. In fact, 76 solutions among 120 were improved. Moreover, HCPSO outperforms the compared methods in terms of quality of solutions in short time requirements. Also, the performance of the proposed approach is evaluated according to a real-world industrial problem.

• Management Science and Financial Engineering
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• 제3권1호
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• pp.75-88
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• 1997

Tabu search (TS) has been successfully applied for solving many complex combinatorial optimization problems in the areas of operations research and production control. However, TS is for single-objective problems in its present form. In this article, a TS-based heuristic is developed to determine Pareto-efficient solutions to a multi-objective combinatorial optimization problem. The developed algorithm is then applied to the discrete optimal design problem in statistics to demonstrate its usefulness.

• Management Science and Financial Engineering
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• 제13권1호
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• pp.115-119
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• 2007

In [1], robust combinatorial optimization problem is introduced, where a positive integer $\Gamma$ is used to control the degree of robustness. The proposed algorithm needs solutions of n+1 nominal problems. In this paper, we show that the number of problems needed reduces to $n+1-\Gamma$.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2001년도 제34회 추계학술대회 개최
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• pp.166-171
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• 2001

In order to improve the efficiency of the design process and the quality of the resulting design for the application-based exclusive rolling element bearings, this study propose design methodologies by using a genetic-based combinatorial optimization. By the presence of discrete variables such as the number of rolling element (standard component) and by the engineering point of views, the design problem of the rolling element bearing can be characterized by the combinatorial optimization problem as a fully discrete optimization. A genetic algorithm is used to efficiently find a set of the optimum discrete design values from the pre-defined variable sets. To effectively deal with the design constraints and the multi-objective problem, a ranking penalty method is suggested for constructing a fitness function in the genetic-based combinatorial optimization. To evaluate the proposed design method, a robust performance analyzer of ball bearing based on quasi-static analysis is developed and the computer program is applied to some design problems, 1) maximize fatigue life, 2) maximize stiffness, 3) maximize fatigue life and stiffness, of a angular contact ball bearing. Optimum design results are demonstrate the effectiveness of the design method suggested in this study. It believed that the proposed methodologies can be effectively applied to other multi-objective discrete optimization problems.

• 한국경영과학회지
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• 제21권2호
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• pp.125-140
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• 1996

Simulated annealing (SA) is a very promising general purpose algorithm which can be conveniently utilized for various complicated combinatorial optimization problems. But its slowness has been pointed as a major drawback. In this paper, we propose an accelerated SA and test its performance experimentally by applying it for two standard combinatorial optimization problems (TSP(Travelling Salesman Problem) and GPP(Graph Partitioning Problem) of various sizes. It turns out that performance of the proposed method is consistently better both in convergenge speed and the quality of solution than the conventional SA or SE (Stochastic Evolution). In the second part of the paper we apply the accelerated SA to solve the virtual path management problem encountered in ATM netowrks. The problem is modeled as a combinatorial optimization problem to optimize the utilizy of links and an efficient SA implementation scheme is proposed. Two application examples are given to demonstrate the validity of the proposed algorithm.

• 대한산업공학회지
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• 제35권1호
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• pp.87-91
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• 2009

In the server disconnection problem, a network with m servers and their users is given and an attacker is to destroy a set of edges to maximize his net gain defined as the total disconnected utilities of the users minus the total edge-destruction cost. The problem is known to be NP-hard. In this paper, we study the server disconnection problem restricted to a ring network. We present an efficient combinatorial algorithm that generates an optimal solution in polynomial time.

• Journal of applied mathematics & informatics
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• 제17권1_2_3호
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• pp.391-399
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• 2005

In this paper we present an algorithm based on network flow techniques which provides a solution for a combinatorial problem. Then, in order to provide all the solutions of this problem, we make use of an algorithm that given the bipartite graph $G=(V_1 {\cup}{V_2},\;E,\;{\omega})$ outputs the enumeration of all bipartite matchings of given cardinality v and cost c.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.143-146
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• 1996

In this paper, we propose a hopfield model for solving the part-matching which is the number of parts and positions are changed. The goal of this paper is to minimize part-connection in pairs and net total path of part-connection. Therefore, this kind of problem is referred to as a combinatorial optimization problem. First of all, we review the theoretical basis for hopfield model to optimization and present two method of part-matching; Traveling Salesman Problem (TSP) and Weighted Matching Problem (WMP). Finally, we show demonstration through computer simulation and analyzes the stability and feasibility of the generated solutions for the proposed connection methods.