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arXiv 1201.3148math.OC
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可分凹Optimization近似等于分段线性最优化

Separable Concave Optimization Approximately Equals Piecewise-Linear Optimization

Thomas L. Magnanti, Dan Stratila

摘要:

研究了紧可行集上非负可分凹函数的极小化问题。我们近似这个问题的一个因素内的1+ 1/2的分段线性最小化问题在同一可行集。我们的主要结果是,当可行集是一个多面体,结果块的数量是多项式的输入大小的多面体和线性的1/1。对于许多实际的凹成本问题,所得到的分段线性成本问题可以被表述为一个研究充分的离散最优化问题。因此,各种多项式时间精确算法,近似算法,和多项式时间算法的离散最优化问题立即产生完全多项式时间近似计划,近似算法,和多项式时间算法的相应凹成本问题。我们在两个问题上说明我们的方法。针对凹成本多商品流问题,设计了一种新的启发式算法,并通过计算实验研究了其性能。我们能够近似解决比以前可能的更大的测试实例,并获得平均4.27%的最优解。对于凹费用设施点定位问题,我们得到了一个新的1.4991+ λ的近似算法.

英文摘要:

We study the problem of minimizing a nonnegative separable concave function over a compact feasible set. We approximate this problem to within a factor of 1+epsilon by a piecewise-linear minimization problem over the same feasible set. Our main result is that when the feasible set is a polyhedron, the number of resulting pieces is polynomial in the input size of the polyhedron and linear in 1/epsilon. For many practical concave cost problems, the resulting piecewise-linear cost problem can be formulated as a well-studied discrete optimization problem. As a result, a variety of polynomial-time exact algorithms, approximation algorithms, and polynomial-time heuristics for discrete optimization problems immediately yield fully polynomial-time approximation schemes, approximation algorithms, and polynomial-time heuristics for the corresponding concave cost problems. We illustrate our approach on two problems. For the concave cost multicommodity flow problem, we devise a new heuristic and study its performance using computational experiments. We are able to approximately solve significantly larger test instances than previously possible, and obtain solutions on average within 4.27% of optimality. For the concave cost facility location problem, we obtain a new 1.4991+epsilon approximation algorithm.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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