摘要:

AbstractA finitemetric(or more properly semimetric) onnpoints is a nonnegative vectord=(dij)1 ⩽i

ISSN:0028-3045    

DOI:10.1002/net.3230210602

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThe scenario aggregation algorithm is specialized for stochastic networks. The algorithm determines a solution that does not depend on hindsight and accounts for the uncertain environment depicted by a number of appropriately weighted scenarios. The solution procedure decomposes the stochastic program to its constituent scenario subproblems, thus preserving the network structure. Computational results are reported demonstrating the algorithm's convergence behavior. Acceleration schemes are discussed along with termination criteria. The algorithm's potential for execution on parallel multiprocessors is discussed.

ISSN:0028-3045    

DOI:10.1002/net.3230210603

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThe reliability of capacitated networks subject to random arc failures is evaluated by the expected value of maximum flow. It is known that calculating the expected value of maximum flow is NP‐hard, but a lower bound can be efficiently computed by the method of Carey and Hendrickson. This bound sometimes gives the exact value, e.g., if graphs are bipartite. In this article, for directed and undirected networks, respectively, we give necessary and sufficient conditions for the above lower bound to provide the exact valu

ISSN:0028-3045    

DOI:10.1002/net.3230210604

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThis work addresses spanning forests and trees in which the number of nodes in component subtrees is balanced. The solution procedure developed makes use of Lagrangean relaxation and heuristics. Dual‐ascent procedures in conjunction with heuristics are used to yield lower and upper bounds. Computational experience indicates that optimal or suboptimal solutions with very tight bounds can be obtained in 180 to 300 iterations on the average for 100‐node balanced tree problems and 700 to 1400 iterations for 100‐node balanced forest pro

ISSN:0028-3045    

DOI:10.1002/net.3230210605

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThis article proposes two approximate methods to solve capacitated, single‐commodity and fixed‐charge network flow problems. First, relaxed problems obtained by the Lagrange relaxation method are shown to form a minimum spanning tree problem, yielding a lower bound to the original problem. The subgradient optimization technique can be then applied to improve this bound by updating the Lagrange multipliers. The second part of the article presents a new, simple, and efficient heuristic to find a feasible and approximate solution that is also an upper bound to the original prob

ISSN:0028-3045    

DOI:10.1002/net.3230210606

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

ISSN:0028-3045    

DOI:10.1002/net.3230210601

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY