• 한국기계연구소 소보
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• 통권20호
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• pp.13-20
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• 1990

An algorithm is presented for 3-dimensional contour lines with a hidden line removal ~technique developed by T.L. Janssen(l). Contour line algorithm on any 3-dimensional plane cutting solid body is also shown. NUFIG(2) algorithm is adopted for searching contour lines. Test problems show well-established contour lines on the surface and also on the cutting plane of the structure.

• 한국통신학회논문지
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• 제38A권6호
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• pp.465-470
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• 2013

본 연구에서는 이차원 인접 심볼간 간섭(2D ISI) 및 인접 페이지간 간섭 (IPI)을 줄이며, 고립된 픽셀이 발생하지 않는 홀로그래픽 저장장치를 위한 이차원 변조부호를 선택하는 문제를 고려한다. 본 연구에서 고려하는 2D ISI 및 IPI를 줄이기 위한 변조부호 선택문제에서는 코드 내부에서 인접 셀간 심볼값의 차이를 최소화하고, 사용된 심볼의 분포가 균등하고, 선택된 코드워드가 임의로 이차원에 배열될 때, 고립된 픽셀이 발생할 수 없는 코드워드를 선택한다. 코드워드 선택 문제와 선택된 코드워드에서 고립된 픽셀의 발생여부를 검색하는 모형은 정수계획법 모형으로 형성되고, 두 모형을 결합하는 절단평면(cutting plane) 알고리즘을 개발하였다. 제안된 알고리즘을 사용하여 $4{\times}2$ 6/8 변조부호에서 고립된 픽셀이 발생하지 않으면서, 2D ISI와 IPI를 줄일 수 있는 코드워드를 계산하였다.

• Management Science and Financial Engineering
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• 제11권1호
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• pp.49-61
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• 2005

We consider the graph disconnection problem, which is to find a set of edges such that the total cost of destroying the edges is no more than a given budget and the weight of nodes disconnected from a designated source by destroying the edges is maximized. The problem is known to be NP-hard. We present an integer programming formulation for the problem and develop an algorithm that includes a preprocessing procedure for reducing the problem size, a heuristic for providing a lower bound, and a cutting plane algorithm for obtaining an upper bound. Computational results for evaluating the performance of the proposed algorithm are also presented.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1993년도 춘계공동학술대회 발표논문 및 초록집; 계명대학교, 대구; 30 Apr.-1 May 1993
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• pp.3-3
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• 1993

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 1997년도 추계학술대회발표논문집; 홍익대학교, 서울; 1 Nov. 1997
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• pp.57-57
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• 1997

• 한국경영과학회지
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• 제25권3호
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• pp.17-33
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• 2000

We consider the Steiner tree packing problem. For a given undirected graph G =(V, E) with positive integer capacities and non-negative weights on its edges, and a list of node sets(nets), the problem is to find a connection of nets which satisfies the edge capacity limits and minimizes the total weights. We focus on the switchbox routing problem in knock-knee model and formulate this problem as an integer programming using Steiner tree variables. The model contains exponential number of variables, but the problem can be solved using a polynomial time column generation procedure. We test the algorithm on some standard test instances and compare the performances with the results using cutting plane approach. Computational results show that our algorithm is competitive to the cutting plane algorithm presented by Grotschel et al. and can be used to solve practically sized problems.

• 한국경영과학회지
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• 제22권3호
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• pp.59-80
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• 1997

Designing highly survivable interoffice telecommunication networks is considered. The problem is formulated as a minimum-cost network design problem with three node connectivity constraints. These valid and facet-defining inequalities for the convex hull of the solution are presented. A branch and cut algorithm is proposed based on the inequalities to obtain the optimal solution. With the lower bound by the cutting plane algorithm, a delete-ink heuristic is proposed to otain a good upper bound in the branch and bound procedure. The effeciveness of the branch and cut algorithm is demonstrated with computational results for a variety of problem sets : different lower bounds, two types of link costs and large number of links. The cutting plane procedure based on the three inequalities provides excellent lower bounds to the optimal solutions.

• 산업공학
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• 제8권2호
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• pp.151-159
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• 1995

Two-dimensional cutting stock problem is to find a waste-minimizing method of cutting a single rectangular plane into a number of smaller pieces of known dimensions. In practice, besides wastes, setup cost taken during adjusting is of an important concern. We suggest 2-phased guillotine cutting method as a solution to the problem which minimize wastes and setup costs. Also, in order to reduce the computing time we apply techniques of discretization, cutoff, median. Experimental results show good performance of our algorithm.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1994년도 춘계공동학술대회논문집; 창원대학교; 08월 09일 Apr. 1994
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• pp.691-700
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• 1994

Voronoi diagram of a set of geometric entities on a plane such as points, line segments, or arcs is a collection of Voronoi polygons associated with each entity, where Voronoi polygon of an entity is a locus of point which is closer to the associated entity than any other entity. Voronoi diagram is one of the most fundamental geometrical construct and well-known for its theoretical elegance and the wealth of applications. Various geometric problems can be solved with the aid of Voronoi diagram. For example, the maximum tool diameter of a milling cutter for rough cutting in a pocket can be easily found, and the pocketing tool path can be efficiently generated from Voronoi diagram. In PCB design, the design rule checking can be easily done via Voronoi diagram, too. This paper discusses an algorithm to construct Voronoi diagram of a simple polygon which consists of simple curves such as line segments as well as arcs in a plane with O(nlogn) time complexity by employing the divide and conquer scheme.

• Management Science and Financial Engineering
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• 제10권1호
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• pp.97-106
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• 2004

In this paper, we propose an effective cut generation method based on the Chvatal-Gomory procedure for a variable-capacity (0,l)-Knapsack problem with two general integer variables. We first derive a class of valid inequalities for the problem using Chvatal-Gomory procedure, then analyze the associated separation problem. Based on the results, we show that there exists a pseudo-polynomial time algorithm to solve the separation problem. By analyzing the theoretical strength of the inequalities which can be generated by the proposed cut generation method, we show that generated inequalties define facets under mild conditions. We also extend the result to the case in which a nontrivial upper bound is imposed on a general integer variable.