Generalized network flow problems generalize normal network flow problems by specifying a flow multiplier ยต v w for each arc v w . For every unit of flow entering the arc, ยต v w units of flow exit. We present a strongly polynomial algorithm for a single-source generalized shortest paths problem, usi
Combinatorial algorithms for inverse network flow problems
โ Scribed by Ravindra K. Ahuja; James B. Orlin
- Publisher
- John Wiley and Sons
- Year
- 2002
- Tongue
- English
- Weight
- 122 KB
- Volume
- 40
- Category
- Article
- ISSN
- 0028-3045
No coin nor oath required. For personal study only.
โฆ Synopsis
An inverse optimization problem is defined as follows: Let S denote the set of feasible solutions of an optimization problem P, let c be a specified cost vector, and x 0 สฆ S. We want to perturb the cost vector c to d so that x 0 is an optimal solution of P with respect to the cost vector d, and wสd ุ cส p is minimum, where ส โ ส p denotes some selected l p norm and w is a vector of weights. In this paper, we consider inverse minimum-cut and minimumcost flow problems under the l 1 normal (where the objective is to minimize ยฅ jสฆJ w j อฆd j ุ c j อฆ for some index set J of variables) and under the l ุ norm (where the objective is to minimize max{w j อฆd j ุ c j อฆ: j สฆ J}). We show that the unit weight (i.e., w j โซุโฌ 1 for all j สฆ J) inverse minimum-cut problem under the l 1 norm reduces to solving a maximum-flow problem, and under the l ุ norm, it requires solving a polynomial sequence of minimum-cut problems. The unit weight inverse minimum-cost flow problem under the l 1 norm reduces to solving a unit capacity minimum-cost circulation problem, and under the l ุ norm, it reduces to solving a minimum mean cycle problem. We also consider the nonunit weight versions of inverse minimum-cut and minimum-cost flow problems under the l ุ norm.
๐ SIMILAR VOLUMES
different from the one considered in [MES94] and [SME95]. We consider the case where the nonlinear flow equations are diagonally monotone nondecreasing and offdiagonally monotone nonincreasing. This case is more general than M-functions. We also concentrate on a different class of mappings. We study