摘要:

AbstractThis paper presents new procedures for obtaining upper and lower bounds in the cost minimization of multistage dynamic networks with random link capacities and contrasts them to existing methods. These methods include adaptation of Jensen's inequality to the problem, Monte‐Carlo simulations and an analytical approximation procedure. The new bounding procedures involve a backward pass in the network coupled with a linear approximation at each stage. Some numerical results are presented for networks of substantial size. ©1993 by John Wiley&Sons, I

ISSN:0028-3045    

DOI:10.1002/net.3230230702

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

年代:1993

数据来源: WILEY

摘要:

AbstractIn this article, we study the problem of locating a server on a tree network that operates as a FIFO M/G/1 queue. The goal is to identify sets of efficient facility locations with respect to moments of the response time. The results are illustrated via an example. ©1993 by John Wiley&Sons, Inc

ISSN:0028-3045    

DOI:10.1002/net.3230230703

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

年代:1993

数据来源: WILEY

摘要:

AbstractConsider a flow network whose nodes do not restrict flow transmission and arcs have random, discrete, and independent capacities. Letsandtbe a pair of selected nodes, let δ denote the value of a maximums—tflow, and let Γ denote a set ofs–tcuts. Also, let ℱ denote a set of independent joint capacity distributions with common state space. For fixedl

ISSN:0028-3045    

DOI:10.1002/net.3230230704

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

年代:1993

数据来源: WILEY

摘要:

AbstractThis paper demonstrates that when the backordering of demand is permitted in a Multiperiod Transshipment Problem it is necessary to include additional side constraints that restrict the number of backorders a node can have in a time period. Computer experience on a small set of test problems is presented to validate this problem formulation. Two stricter backorder constraint sets are also presented, both of which are piecewise linear. For these piecewise linear constraint cases, a method is outlined whereby the original network problem is transformed into a mixed integer linear network flow problem that is very difficult to solve. Some highlights of work by other authors in solving mixed integer linear network flow problems are given. ©1993 by John Wiley&Sons, Inc

ISSN:0028-3045    

DOI:10.1002/net.3230230705

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

年代:1993

数据来源: WILEY

摘要:

AbstractWe present a new two‐commodity flow formulation for the traveling salesman problem. Each commodity corresponds to a resource that is either distributed or picked up along the tour of all nodes. This formulation is partcularly well suited to handling time window constraints; the resource used is then the time. This formulation can be extended to the makespan problem. For an‐node problem, the linear relaxation of the formulation involves onlyO(n)constraints andO(n2) variables. Implementation issues are discussed and numerical experimentations have been realized for problems of up to 60 nodes. ©1993 by John Wiley&Sons,

ISSN:0028-3045    

DOI:10.1002/net.3230230706

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

年代:1993

数据来源: WILEY

摘要:

AbstractMotivated by the study of large graphs with given degree and diameter, and the recent interest in the design of highly symmetric interconnection networks (e.g., the study of Cayley digraphs), we are led to the search for large vertex symmetric digraphs with given degree and diameter. The main result of this paper is the construction of a new class of vertex symmetric directed graphs, Γδ(D)(δ ≥D) that have degree δ, diameterD, and (δ + 1)δ … (δ –D+ 2) vertices. The graphs Γδ(D)are first found in the notation of Cayley coset digraphs. Then, we discover that they have a very simple representation in terms of sequences like the commonly studied networks such as the hypercube, de Bruijn graphs, and Kautz graphs. Based on the sequence representation, we give a simple shortest‐path routing scheme. We also show that the average distance in our digraph Γδ(D)is very close to its diameterD. As a consequence, it follows that the natural routing scheme, which is even simpler than the shortest‐path routing, is nearly optimal on an average basis. ©1993 by

ISSN:0028-3045    

DOI:10.1002/net.3230230707

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

年代:1993

数据来源: WILEY

ISSN:0028-3045    

DOI:10.1002/net.3230230701

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

年代:1993

数据来源: WILEY