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Facility location models for distribution system design
, 2004
"... The design of the distribution system is a strategic issue for almost every company. The problem of locating facilities and allocating customers covers the core topics of distribution system design. Model formulations and solution algorithms which address the issue vary widely in terms of fundamenta ..."
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Cited by 33 (0 self)
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The design of the distribution system is a strategic issue for almost every company. The problem of locating facilities and allocating customers covers the core topics of distribution system design. Model formulations and solution algorithms which address the issue vary widely in terms of fundamental assumptions, mathematical complexity and computational performance. This paper reviews some of the contributions to the current stateoftheart. In particular, continuous location models, network location models, mixedinteger programming models, and applications are summarized.
Telecommunication and Location
, 2001
"... We review the models for telecommunication network design where there is a location problem involved. We classify the models into three classes as uncapacitated, capacitated and dynamic models. For each class, we discuss the core problem, its generalizations and the solution methods in the litera ..."
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Cited by 4 (1 self)
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We review the models for telecommunication network design where there is a location problem involved. We classify the models into three classes as uncapacitated, capacitated and dynamic models. For each class, we discuss the core problem, its generalizations and the solution methods in the literature.
A hybrid Benders’ decomposition method for solving stochastic constraint programs with linear recourse
 In Joint ERCIM/CoLogNET International Workshop on Constraint Solving and Constraint Logic Programming
, 2005
"... Abstract. We adopt Benders ’ decomposition algorithm to solve scenariobased Stochastic Constraint Programs (SCPs) with linear recourse. Rather than attempting to solve SCPs via a monolithic model, we show that one can iteratively solve a collection of smaller subproblems and arrive at a solution to ..."
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Abstract. We adopt Benders ’ decomposition algorithm to solve scenariobased Stochastic Constraint Programs (SCPs) with linear recourse. Rather than attempting to solve SCPs via a monolithic model, we show that one can iteratively solve a collection of smaller subproblems and arrive at a solution to the entire problem. In this approach, decision variables corresponding to the initial stage and linear recourse actions are grouped into two subproblems. The subproblem corresponding to the recourse action further decomposes into independent problems, each of which is a representation of a single scenario. Our computational experience on stochastic versions of the wellknown template design and warehouse location problems shows that, for linear recourse SCPs, Benders ’ decomposition algorithm provides a very efficient solution method. 1
Design Optimization of the Petaweb Architecture
 IEEE/ACM TRANSACTIONS ON NETWORKING
, 2006
"... This paper explores the design modeling issues of the Petaweb, an optical network architecture that provides fully meshed connectivity between electronic edge nodes. The Petaweb is simple to manage, simplifies key networking functions such as routing and addressing and can offer a total capacity of ..."
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This paper explores the design modeling issues of the Petaweb, an optical network architecture that provides fully meshed connectivity between electronic edge nodes. The Petaweb is simple to manage, simplifies key networking functions such as routing and addressing and can offer a total capacity of several Petabits per second. From the topology standpoint, it is an unusual structure as the backbone nodes are totally disconnected whereas the edge nodes are all attainable in onehop. The network design problem leads to a very hard combinatorial problem. We propose a model and a heuristic approach that is based on repeated matchings. Computational results concerning the modeling issues will be presented and thoroughly discussed.
Genetic Algorithms for the Single Source Capacitated Location Problem: A Computational Study
, 2001
"... In the Single Source Capacitated Location Problem (SSCLP) a set I = .., n} of possible plant locations, each with a maximum capacity a i , i I,andasetJ = .., m} of customers, each with a demand b j , j J,aregiven. It is required to choose a subset of plants and to fully assign each cu ..."
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In the Single Source Capacitated Location Problem (SSCLP) a set I = .., n} of possible plant locations, each with a maximum capacity a i , i I,andasetJ = .., m} of customers, each with a demand b j , j J,aregiven. It is required to choose a subset of plants and to fully assign each customer to one of the chosen plants, in such a way that the total cost is minimized, and the plant capacities are not exceeded. Total cost is composed by fixed costs, f i , i I, whenever plant i is open, and by the cost of assigning each customer to one plant, c ij , i I, j J . Considering x ij = 1, if customer j is assigned to plant i and y i = 1, if plant i is open 0, otherwise the SSCLP can be formulated as follows: min c ij x ij + f i y i (1) subject to x ij =1 j =1, .., m (2) b j x ij a i y i i =1, .., n (3) x ij 1} i =1, .., n, j =1, .., m (4) y i 1} i =1, .., n (5) Constraints (2) stipulate that each customer must be assign
Location of slaughterhouses under economies of scale
 EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
, 2005
"... The facility location problem described in this paper comes from an industrial application in the slaughterhouse industry of Norway. Investigations show that the slaughterhouse industry experiences economies of scale in the production facilities. We examine a locationallocation problem focusing on ..."
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The facility location problem described in this paper comes from an industrial application in the slaughterhouse industry of Norway. Investigations show that the slaughterhouse industry experiences economies of scale in the production facilities. We examine a locationallocation problem focusing on the location of slaughterhouses, their size and the allocation of animals in the different farming districts to these slaughterhouses. The model is general and has applications within other industries that experience economies of scale. We present an approach based on linearisation of the facility costs and Lagrangean relaxation. We also develop a greedy heuristic to find upper bounds. We use the method to solve a problem instance for the Norwegian Meat Cooperative and compare our results to previous results achieved using standard branchandbound in commercial software.
Stochastic Facility Location with General LongRun Costs and Convex ShortRun Costs
, 2006
"... ..."
Combining Lagrangian Decomposition with Very Large Scale Neighborhood Search for Capacitated Connected Facility Location
, 2009
"... We consider a generalized version of the rooted Connected Facility Location problem (ConFL) which occurs when extending existing communication networks in order to increase the available bandwidth for customers. In addition to choosing facilities to open and connecting them by a Steiner tree as in t ..."
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We consider a generalized version of the rooted Connected Facility Location problem (ConFL) which occurs when extending existing communication networks in order to increase the available bandwidth for customers. In addition to choosing facilities to open and connecting them by a Steiner tree as in the classic ConFL, we have to select a subset of all potential customers and assign them to open facilities respecting given capacity constraints in order to maximize profit. We present two exact mixed integer programming formulations and a Lagrangian decomposition (LD) based approach which uses the volume algorithm. Feasible solutions are derived using a Lagrangian heuristic. Furthermore, we present two hybrid variants combining LD with local search and a very large scale neighborhood search. By applying those improvement methods only to the most promising solutions, we are able to compute much better solutions without increasing the necessary runtime too much. As documented by our computational results, our hybrid approaches compute high quality solutions with tight optimality gaps in relatively short time.
Exactly solving a Twolevel Hierarchical Location Problem with modular node capacities
"... In many telecommunication networks a given set of client nodes must be served by different sets of facilities, providing different services and having different capabilities, which must be located and dimensioned in the design phase. Network topology must be designed as well, by assigning clients to ..."
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In many telecommunication networks a given set of client nodes must be served by different sets of facilities, providing different services and having different capabilities, which must be located and dimensioned in the design phase. Network topology must be designed as well, by assigning clients to facilities and facilities to higher level entities, when necessary. We tackle a particular location problem in which two sets of facilities have to be located, and in which different devices can be installed in each site, providing different capacities at different costs. We optimize simultaneously location and dimensioning of these facilities. We introduce a compact formulation for that problem, we exploit discretization and DantzigWolfe reformulation techniques to obtain better models, and we design an exact optimization algorithm. We test our approach on a set of instances derived from the facility location literature.
Preface
, 2008
"... February 2008, I investigated the possibilities to reduce the number of CPUs needed for several applications with supporting tasks in the KLM IT infrastructure. The research done during my internship was mainly concentrated on the matching of applications with different peak and valley times. Severa ..."
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February 2008, I investigated the possibilities to reduce the number of CPUs needed for several applications with supporting tasks in the KLM IT infrastructure. The research done during my internship was mainly concentrated on the matching of applications with different peak and valley times. Several algorithms were implemented and tested in order to find the best algorithm for the needs of KLM. Another substantial part concerns the automatic analysis of historical data of the CPU utilization of all applications. Only a small part of this thesis is dedicated to the latter, since this was mathematically less interesting. The internship resulted in a (hopefully) userfriendly application that (periodically) can be used by KLM in order to get insight in their current CPU use and the possibilities to improve their utilization grade. Since the application heavily depends on the KLM IT infrastructure and their data, no online package of the application was created. The internship was supervised by Tim van Loosbroek of KLM and Rob H. Bisseling of the Department of Mathematics of Utrecht University. Also involved from KLM was Rene Matla. I would like to express my thanks to all of them. Tim, for the opportunity to do my internship at KLM and his support and suggestions during my project. Rene, for the help in business