摘要:

AbstractIt is observed that sample cost functions for the pipeline problem [1] are discretely convex, i.e., their graphs are discrete subsets of graphs of convex functions. As a result, it is shown that the pipeline problem may be attacked by using either a minimum cost flow approach, or a combination of dynamic programming and sorting. Problems with concave cost functions are shown to be relatively easy. Even for problems which are neither convex nor concave, it is shown that in certain instances, only a subset of the data for each cost function is relevant. Error bounds are presented when approximations to the original cost functions are used. Results obtained in [4]for a related problem are summarized.

ISSN:0028-3045    

DOI:10.1002/net.3230030102

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

年代:1973

数据来源: WILEY

摘要:

AbstractThrough the intermediary of state‐variable equations, realization of an N‐path filter from a prescribed transfer function is obtained. An equivalence is found which shows how passive RC circuits incorporating time‐variable gyrators can be used to realize N‐path filters. It is also proved possible to realize any stable transfer function as an N‐path filter structure and that the system is insensitive to the frequency of the multiplying signals or the frequency of the gyration conductance.„Listen again to this. I have seen moonlight Sometimes the statues leaning over like reeds In the middle of living fruit, – the statu

ISSN:0028-3045    

DOI:10.1002/net.3230030103

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

年代:1973

数据来源: WILEY

摘要:

AbstractIn the usual approach to network equilibrium models, the flow variables are modeled as continuous. When the problem under study involves discrete decision makers each controlling an indivisible unit of flow, another approach is called for. We treat the problem as an n‐person noncooperative game with pure strategies corresponding to feasible paths through the network. It is shown that pure‐strategy Nash equilibria exist and that any solution to an integer‐variable analogue of the usual network equilibrium model is such a Nash equilibrium. It is also shown that when individuals can control more than a single unit of flow and want to minimize the sum of their costs, pure‐strategy Nash equilibria do not necessaril

ISSN:0028-3045    

DOI:10.1002/net.3230030104

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

年代:1973

数据来源: WILEY

摘要:

AbstractThe problem of finding a shortest route in a network with unrestricted costs is approached through solving an assignment problem associated to the network.The upper bound on the number of elementary calculations required for the solution is 0(m3). However, in most cases, the actual number of computations is considerably less and depends on different network characteristics than Dynamic Programming algorithms do. In examples of networks generated stochastically, this number was below 0(m2.5).A parametric analysis is presented. It is shown that if after a shortest route is determined, the costs on all arcs incident into or out of a node are modified in any form, at most 0(m2) elementary calculations will determine a new optimal solution. This feature, shared by Dynamic Programming algorithms only for cases where all cost decrease, can be applied to problems such as the determination of the K‐shortest routes and the K‐smallest assignments, leading to upper bounds of 0(Km3) in both ca

ISSN:0028-3045    

DOI:10.1002/net.3230030105

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

年代:1973

数据来源: WILEY

摘要:

AbstractIn this article a problem teaching situation is described and studied with the help of a mathematical model of problem presentation. Two psychological hypotheses and a difficulty function lead to an operational definition of optimal problem presentation according to the order and difficulties involved in each step. Certain properties of this model then show natural behavior and support the basic hypotheses.

ISSN:0028-3045    

DOI:10.1002/net.3230030106

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

年代:1973

数据来源: WILEY

ISSN:0028-3045    

DOI:10.1002/net.3230030107

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

年代:1973

数据来源: WILEY

ISSN:0028-3045    

DOI:10.1002/net.3230030108

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

年代:1973

数据来源: WILEY

ISSN:0028-3045    

DOI:10.1002/net.3230030101

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

年代:1973

数据来源: WILEY