We review how to solve the all-pairs shortest-path problem in a nonnegatively Ε½ 2 . weighted digraph with n vertices in expected time O n log n . This bound is shown to hold with high probability for a wide class of probability distributions on nonnegatively weighted Ε½ . digraphs. We also prove that
The time-dependent shortest pair of disjoint paths problem: Complexity, models, and algorithms
β Scribed by Sherali, Hanif D.; Ozbay, Kaan; Subramanian, Shivaram
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 160 KB
- Volume
- 31
- Category
- Article
- ISSN
- 0028-3045
No coin nor oath required. For personal study only.
β¦ Synopsis
In this paper, we examine complexity issues, models, and algorithms for the problem of finding a shortest pair of disjoint paths between two nodes of a network such that the total travel delay is minimized, given that the individual arc delays are time-dependent. Such disjoint paths address the issue of network vulnerability by prescribing alternate routes for traffic flows. Applications include the dispatching of duplicate packets of data to improve the reliability in communication networks and the diverting of traffic during congestion to reduce the chances of bottlenecks in transportation networks, in the presence of time-dependent variations in travel delays in the network. We prove that this problem, and many variations of it, are NP-hard and we develop a 0-1 linear programming model that can be used to solve this problem. This model can accommodate various degrees of disjointedness of the pair of paths, from complete to partial with respect to specific arcs. We also present some computational results obtained by solving the above models using CPLEX-MIP.
π SIMILAR VOLUMES
We study the average-case complexity of shortest-paths problems in the vertexpotential model. The vertex-potential model is a family of probability distributions on complete directed graphs with arbitrary real edge lengths, but without negative cycles. We show that on a graph with n vertices and wit
This paper presents an optimal dynamic programming algorithm, the first such algorithm in the literature to solve the shortest path problem with time windows and additional linear costs on the node service start times. To optimally solve this problem, we propose a new dynamic programming algorithm w