We propose a truthful-in-expectation, (1 - 1/e)-approximation mechanism for a strategic variant of the generalized assignment problem (GAP). In GAP, a set of items has to be optimally assigned to a set of bins without...
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We propose a truthful-in-expectation, (1 - 1/e)-approximation mechanism for a strategic variant of the generalized assignment problem (GAP). In GAP, a set of items has to be optimally assigned to a set of bins without exceeding the capacity of any singular bin. In the strategic variant of the problem we study, values for assigning items to bins are the private information of bidders and the mechanism should provide bidders with incentives to truthfully report their values. The approximation ratio of the mechanism is a significant improvement over the approximation ratio of the existing truthful mechanism for GAP. The proposed mechanism comprises a novel convex optimization program as the allocation rule as well as an appropriate payment rule. To implement the convex program in polynomial time, we propose a fractional local search algorithm which approximates the optimal solution within an arbitrarily small error leading to an approximately truthful-in-expectation mechanism. The proposed algorithm improves upon the existing optimization algorithms for GAP in terms of simplicity and runtime while the approximation ratio closely matches the best approximation ratio known for GAP when all inputs are publicly known.
class of facet defining inequalities for the generalized assignment problem is derived. These inequalities are based upon multiple knapsack constraints and are derived from (1,k)-configuration inequalities.
class of facet defining inequalities for the generalized assignment problem is derived. These inequalities are based upon multiple knapsack constraints and are derived from (1,k)-configuration inequalities.
The generalized assignment problem (GAP) is an enlarged version of the classical assignmentproblem in which the assignment of several tasks to an agent is possible. The only restriction that can limit the assignment ...
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This paper presents a transportation branch and bound algorithm for solving the generalized assignment problem. This is a branch and bound technique in which the sub-problems are solved by the available efficient tran...
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This paper presents a transportation branch and bound algorithm for solving the generalized assignment problem. This is a branch and bound technique in which the sub-problems are solved by the available efficient transportation techniques rather than the usual simplex based approaches. A technique for selecting branching variables that minimize the number of sub-problems is also presented.
Three classes of valid inequalities based upon multiple knapsack constraints are derived for the generalized assignment problem. General properties of the facet defining inequalities are discussed and, for a special c...
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Three classes of valid inequalities based upon multiple knapsack constraints are derived for the generalized assignment problem. General properties of the facet defining inequalities are discussed and, for a special case, the convex hull is completely characterized. In addition, we prove that a basic fractional solution to the linear programming relaxation can be eliminated by a facet defining inequality associated with an individual knapsack constraint.
The emergence of GPU-CPU heterogeneous architecture has led to a significant paradigm shift in parallel programming. How to effectively implement Parallel Genetic Algorithm (GA) in these environments has become one of...
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The emergence of GPU-CPU heterogeneous architecture has led to a significant paradigm shift in parallel programming. How to effectively implement Parallel Genetic Algorithm (GA) in these environments has become one of the current hot issues. GA's calculation and operators are closely related to specific problems, thereby significantly affecting the acceleration method of GA algorithms. The generalized assignment problem (GAP) is a classic NP-hard combinatorial optimization problem. The more widely used genetic algorithms to solve the GAP in the CPU are difficult to be parallelized in a GPU environment due to severe data dependencies. To address this problem, two algorithms suitable for the implementation on the GPU are proposed, namely RPE algorithm and NNE algorithm, which obtain significant performance speedup by alleviating data dependencies and mutually exclusive synchronization overheads. At the same time, considering the new GPU architecture features and programming models, three different granular implementations of parallel genetic algorithms to solve the GAP are proposed, namely GPGA(thread), GPGA(warpsp) and GPGA(cgroup), by utilizing the warp-specialization technology and the cooperative group mechanism. GPGA series algorithms obtain better solution quality and very significant performance improvements compared with Serial GA, GTS (the GPU-CPU hybrid implementation of Scatter Search with Tabu lists) and Lagrange Relaxation algorithm on a CPU by solving 16 typical large-scale GAP instances.
The multilevel generalized assignment problem (MGAP) differs from the classical GAP in that agents can perform tasks at more than one efficiency level. Important manufacturing problems, such as lot sizing, can be form...
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The multilevel generalized assignment problem (MGAP) differs from the classical GAP in that agents can perform tasks at more than one efficiency level. Important manufacturing problems, such as lot sizing, can be formulated as MGAPs;however, the large number of variables in the related 0-1 integer program makes the use of commercial optimization packages impractical. In this paper, we present a heuristic approach to the solution of the MGAP, which consists of a novel application of tabu search (TS). Our TS method employs neighborhoods defined by ejection chains, that produce moves of greater power without significantly increasing the computational effort.
This paper discusses a heuristic for the generalized assignment problem (GAP). The objective of GAP is to minimize the costs of assigning J jobs to M capacity constrained machines, such that each job is assigned to ex...
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This paper discusses a heuristic for the generalized assignment problem (GAP). The objective of GAP is to minimize the costs of assigning J jobs to M capacity constrained machines, such that each job is assigned to exactly one machine. The problem is known to be NP-Hard, and it is hard from a computational point of view as well. The heuristic proposed here is based on column generation techniques, and yields both upper and lower bounds. On a set of relatively hard test problems the heuristic is able to find solutions that are on average within 0.13% from optimality.
The multi-resource generalized assignment problem is encountered when a set of tasks have to be assigned to a set of agents in a way that permits assignment of multiple tasks to an agent subject to the availability of...
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The multi-resource generalized assignment problem is encountered when a set of tasks have to be assigned to a set of agents in a way that permits assignment of multiple tasks to an agent subject to the availability of a set of multiple resources consumed by that agent. This problem differs from the generalized assignment problem in that an agent consumes not just one but a variety of resources in performing the tasks assigned to him. This paper develops effective solution procedures for the multi-resource generalized assignment problem. Various relaxations of the problem are studied and theoretical relations among these relaxations are pointed out. Rules for reducing problem size are discussed and are shown to be effective through computational experiments. Heuristic solution procedures and an efficient branch and bound procedure are developed. Results of computational experiments testing these procedures are reported.
Many real life optimization problems do not have accurate estimates of the problem parameters at the optimization phase. For this reason, the min-max regret criteria are widely used to obtain robust solutions. In this...
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ISBN:
(纸本)9781479964109
Many real life optimization problems do not have accurate estimates of the problem parameters at the optimization phase. For this reason, the min-max regret criteria are widely used to obtain robust solutions. In this paper we consider the generalized assignment problem (GAP) with min-max regret criterion under interval costs. We show that the decision version of this problem is Sigma(p)(2)-complete. We present two heuristic methods: a fixed-scenario approach and a dual substitution algorithm. For the fixed-scenario approach, we show that solving the classical GAP under a median-cost scenario leads to a solution of the min-max regret GAP whose objective function value is within twice the optimal value. We also propose exact algorithms, including a Benders' decomposition approach and branch-and-cut methods which incorporate various methodologies, including Lagrangian relaxation and variable fixing. The resulting Lagrangian-based branch-and-cut algorithm performs satisfactorily on benchmark instances.
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