• 제목/요약/키워드: Inverse Combinatorial Optimization

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Inverse Bin-Packing Number Problems: Polynomially Solvable Cases

  • Chung, Yerim
    • Management Science and Financial Engineering
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    • 제19권1호
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    • pp.25-28
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    • 2013
  • Consider the inverse bin-packing number problem. Given a set of items and a prescribed number K of bins, the inverse bin-packing number problem, IBPN for short, is concerned with determining the minimum perturbation to the item-size vector so that all the items can be packed into K bins or less. It is known that this problem is NP-hard (Chung, 2012). In this paper, we investigate some special cases of IBPN that can be solved in polynomial time. We propose an optimal algorithm for solving the IBPN instances with two distinct item sizes and the instances with large items.

Note on the Inverse Metric Traveling Salesman Problem Against the Minimum Spanning Tree Algorithm

  • Chung, Yerim
    • Management Science and Financial Engineering
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    • 제20권1호
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    • pp.17-19
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    • 2014
  • In this paper, we consider an interesting variant of the inverse minimum traveling salesman problem. Given an instance (G, w) of the minimum traveling salesman problem defined on a metric space, we fix a specified Hamiltonian cycle $HC_0$. The task is then to adjust the edge cost vector w to w' so that the new cost vector w' satisfies the triangle inequality condition and $HC_0$ can be returned by the minimum spanning tree algorithm in the TSP-instance defined with w'. The objective is to minimize the total deviation between the original and the new cost vectors with respect to the $L_1$-norm. We call this problem the inverse metric traveling salesman problem against the minimum spanning tree algorithm and show that it is closely related to the inverse metric spanning tree problem.

Inverse Bin-packing Number Problems: NP-Hardness and Approximation Algorithms

  • Chung, Yerim
    • Management Science and Financial Engineering
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    • 제18권2호
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    • pp.19-22
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    • 2012
  • In the bin-packing problem, we deal with how to pack the items by using a minimum number of bins. In the inverse bin-packing number problem, IBPN for short, we are given a list of items and a fixed number of bins. The objective is to perturb at the minimum cost the item-size vector so that all items can be packed into the prescribed number of bins. We show that IBPN is NP-hard and provide an approximation algorithm. We also consider a variant of IBPN where the prescribed solution value should be returned by a pre-selected specific approximation algorithm.