• Title/Summary/Keyword: Branching Problem

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A new method for a multi-dimensional Knapsack problem (다차원(多次元) 배낭 문제의 새로운 해법(解法))

  • Park, Sun-Dal;Park, Yeong-Man
    • Journal of Korean Institute of Industrial Engineers
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    • v.9 no.1
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    • pp.3-6
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    • 1983
  • The objective of this paper is to present a new method for the multi-dimensional Knapsack problem. Toyoda method and Loulou and Michaelides method are well known for this problem. The new method introduces a new penalty factor for fast convergence and a branching technique for accurate solutions. The method is tested at IBM370 and shows that the method is slower than Toyoda method, but more accurate than other two methods.

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A Study on Optimal Allocation of Short Surface-to-Air Missile (단거리 지대공 미사일의 최적배치에 관한 연구)

  • 이영해;남상억
    • Journal of the military operations research society of Korea
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    • v.26 no.1
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    • pp.34-46
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    • 2000
  • The object of this study is to construct a model for an optimal allocation of short surface to air missile defending our targets most efficiently from hostile aircraft´s attack. For the purpose of this, we analyze and establish facility allocation concept of existing models, apply set covering theory appropriate to problem´s properties, present the process of calculating the probability of target being protected, apply Sherali-Kim´s branching variable selection strategy, and then construct the model. As constructed model apply the reducing problem with application, we confirm that we can apply the large scale, real problem.

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Dynamic Fracture Analysis with State-based Peridynamic Model: Crack Patterns on Stress Waves for Plane Stress Elastic Solid (상태 기반 페리다이나믹 모델에 의한 동적취성파괴 해석: 평면응력 탄성체의 응력 전파와 균열패턴 분석)

  • Ha, Youn Doh
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.3
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    • pp.309-316
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    • 2015
  • A state-based peridynamic model is able to describe a general constitutive model from the standard continuum theory. The response of a material at a point is dependent on the deformation of all bonds connected to the point within the nonlocal horizon region. Therefore, the state-based peridynamic model permits both the volume and shear changes of the material which is promising to reproduce the complicated dynamic brittle fracture phenomena, such as crack branching, secondary cracks, cascade cracks, crack coalescence, etc. In this paper, the two-dimensional state-based peridynamic model for a linear elastic plane stress solid is employed. The damage model incorporates the energy release rate and the peridynamic energy potential. For brittle glass materials, the impact of the crack-parallel compressive stress waves on the crack branching pattern is investigated. The peridynamic solution for this problem captures the main features, observed experimentally, of dynamic crack propagation and branching. Cascade cracks under strong tensile loading and secondary cracks are also well reproduced with the state-based peridynamic simulations.

Machine-part Grouping Algorithm Using a Branch and Bound Method (분지한계법을 이용한 기계-부품 그룹형성 최적해법)

  • 박수관;이근희
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.18 no.34
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    • pp.123-128
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    • 1995
  • The grouping of parts into families and machines into cells poses an important problem in the design and planning of the flexible manufacturing system(FMS). This paper proposes a new optimal algorithm of forming machine-part groups to maximize the similarity, based on branching from seed machine and bounding on a completed part. This algorithm is illustrated with numerical example. This algorithm could be applied to the generalized machine-part grouping problem.

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A Study on the Optimal Warehouse Location Problem by Using the Branch & Bound Algorithm (창고입지선정문제(倉庫立地選定問題)의 최적해법(最適解法)에 관한 연구(硏究))

  • Lee, Deuk-U;Lee, Sang-Yong
    • Journal of Korean Institute of Industrial Engineers
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    • v.12 no.1
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    • pp.73-80
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    • 1986
  • This paper deals with the problem of the optimal location of warehouses in the two stage distribution system, i.e., the distribution system where the product is transported from plants to customer areas via warehouses. The Problem is formulated with a zero-one mixed integer programming and an efficient branch and bound algorithm is then used to solve the problem. In order to obtain the solution of this problem, this paper shows the procedure of conversion of two stage distribution system into one stage distribution system. An improved method of solving the linear programming at the nodes and branching decision rule is also showed by this study.

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An Exact Algorithm for the Asymmetrical Vehicle Routing Problem (차량경로문제에 대한 최적해법)

  • 송성헌;박순달
    • Journal of the Korean Operations Research and Management Science Society
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    • v.12 no.1
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    • pp.34-44
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    • 1987
  • The general vehicle routing problem has been studied by many researchers such as Christofides, et al. and Laporte, et al., but only limited effort has been devoted to developing the optimal algorithms. The purpose of this paper is to develop a branch and bound algorithm which determines the optimal vechicle routes and the optimal number of vehicles concurrenetly for the asymmetrical vehicle routing problem. In order to enhance the efficiency, this algorithm emphasizes the followings ; First, an efficient primal-dual approach is developed to solve subproblems which are called the specialized transportation problem, formed by relaxing the illegal subtour constraints from the vehicle routing problem, second, an improved branching scheme is developed to reduce the number of candidate subproblems by adequate utilization of vehicle capacity restrictions.

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An Exact Algorithm for the vehicle scheduling problem with multiple depots and multiple vehicle types (복수차고 복수차중 차량 일정 문제의 최적 해법)

  • 김우제;박우제
    • Journal of the Korean Operations Research and Management Science Society
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    • v.13 no.2
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    • pp.9-17
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    • 1988
  • This vehicle scheduling problem with multiple depots and multiple vehicle types (VMM) is to determine the optimal vehicle routes to minimize the total travel costs. The object of this paper is to develope an exact algorithm for the VMM. In this paper the VMM is transformed into a mathematical model of the vehicle problem with multiple depots. Then an efficient branch and bound algorithm is developed to obtain an exact solution for this model. In order to enhance the efficiency, this algorithm emphasizes the follows; First, a heuristic algorithm is developed to get a good initial upper bound. Second, an primal-dual approach is used to solve subproblems which are called the quasi-assignment problem, formed by branching strategy is presented to reduce the number of the candidate subproblems.

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An Improved Best-First Branch and Bound Algorithm for Unconstrained Two-Dimensional Cutting Problems (무제한 2차원 절단문제에 대해 개선된 최적-우선 분지한계 해법)

  • Yoon Ki-Seop;Bang Sung-Kyu;Kang Maing-Kyu
    • Journal of the Korean Operations Research and Management Science Society
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    • v.30 no.4
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    • pp.61-70
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    • 2005
  • In this Paper, we develop an improved branch and bound algorithm for the (un)weighted unconstrained two-dimensional cutting problem. In the proposed algorithm, we improve the branching strategies of the existing exact algorithm and reduce the size of problem by removing the dominated pieces from the problem. We apply the newly Proposed definition of dominated cutting pattern and it can reduce the number of nodes that must be searched during the algorithm procedure. The efficiency of the proposed algorithm is presented through comparison with the exact algorithm known as the most efficient.

A Branch-and-Price Algorithm for the Bandwidth Packing Problem (대역폭 분할 문제를 위한 Branch-and-Price 알고리듬)

  • Kim Deokseong;Lee Kyungsik;Park Sungsoo
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2003.05a
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    • pp.381-385
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    • 2003
  • We consider the bandwidth parking problem arising from telecommunication networks The problem is to determine the set of calls to be routed and an assignment or them to the paths in arc capacitated network. The objective is to maximize profit. We formulate the problem as an integer programming and propose an algorithm to solve it. Column generation technique to solve the linear programming relxation is proposed with two types of columns in addition, to obtain an optimum integer solution, we consider a new branching strategy. Computational experiments show that the algorithm gives option at solutions within reasonably small time limits.

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Tree Structure Modeling and Genetic Algorithm-based Approach to Unequal-area Facility Layout Problem

  • Honiden, Terushige
    • Industrial Engineering and Management Systems
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    • v.3 no.2
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    • pp.123-128
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    • 2004
  • A tree structure model has been proposed for representing the unequal-area facility layout. Each facility has a different rectangular shape specified by its area and aspect ratio. In this layout problem, based on the assumption that the shop floor has enough space for laying out the facilities, no constraint is considered for a shop floor. Objectives are minimizing total part movement between facilities and total rectangular layout area where all facilities and dead spaces are enclosed. Using the genetic code corresponding to two kinds of information, facility sequence and branching positions in the tree structure model, a genetic algorithm has been applied for finding non-dominated solutions in the two-objective layout problem. We use three kinds of crossover (PMX, OX, CX) for the former part of the chromosome and one-point crossover for the latter part. Two kinds of layout problems have been tested by the proposed method. The results demonstrate that the presented algorithm is able to find good solutions in enough short time.