A STUDY ON APPLIED NETWORK EQUILIBRIUM MODELS

到目前为止，已经提出了许多模型来确定考虑到供应商和用户行为的最佳运输系统操作或战略计划。这些问题具有分层决策过程的共同结构：代表运输服务供应商或控制机构的单一决策单位试图就运输系统做出最佳决策，这可能会限制该运输系统用户的可行约束，并影响用户的行为或需求。在代数上，上述决策问题通常被描述为双层规划问题或Stackelberg问题。我们称这种广义运输问题为应用网络均衡分析，因为它总是认识到较低的问题由运输网络中的用户均衡模型组成。主要研究结果如下：(1)通过对日本铁路和客车行业成本结构的实证分析，可以看出大规模交通系统存在规模经济。这可能使拉姆齐定价规则在确定新引入的大众运输系统的价格和确定补贴方面有用。(2)传统的拉姆齐规则的应用是不现实和不充分的，因为它忽略了网络拥塞对定价的影响。(3)该规则非常简单，但在某些情况下，当运输系统供应商的固定成本负担非常高时，可能会提供令人望而却步的价格。政府补贴对于降低交通运输价格，实现福利最大化具有重要意义。(4)如果考虑网络拥塞效应，拉姆齐价格均衡模型可以表示为Stackelberg的领导-追随者问题。对于这一问题，用非线性灵敏度分析法对受限变分不等式问题进行分析是有效的。(5)在求解双层规划问题时，Nash均衡和Stackelbereg均衡概念都是可用的，但基于Stackelbereg均衡的算法给出了比Nash算法更高效的计算过程。少

Many models have been proposed so far to determine optimal transportation systems operations or strategic plans which take into account both supplier and user behavior. These problems have the common structure of a hierarchical decision-making process : A single decision-making unit which may represent a supplier of transportation services or controlling agency tries to make optimal decisions with respect to the transportation system, which may restrict the feasible constraints set for user of that transportation system and influence user behavior or demands. Algebraically, the decision making problem mentioned above is typically described as bilevel programming problem or Stackelberg problem. We call such a generalized transportation problem an applied network equilibrium analysis in a sense that it always recognizes that the lower problem consists of user equilibrium models in transportation networks.The main research results are summarized as follows :(1) It is evident from the empi … More rical analysis of cost structure for railway and bus industries in Japan that scale economy exists in mass transportation systems. This might make the Ramsey pricing rule useful for determining prices for newly introducing mass transportation systems and the determination of subsidy for them.(2) The applications of the conventional Ramsey rule is unrealistic and insufficient in that network congestion effects on pricing have been neglected.(3) That rule is very simple, but, possible to provide prohibitive prices in some cases when fixed costs burden for transit system providers are very high. The govemment subsidy is of importance to lower prices of transportation and achieve welfare maximization.(4) If network congestion effects are taken into account, Ramsey price equilibrium model can be formulated as a Stackelberg's leader-follower problem. For this problem, the nonlinear sensitivity analysis for the restricted variational inequality problem is effective.(5) In order to solve a bilevel programming problem, both of Nash equilibrium and Stackelbereg equilibrium concepts are available, however, the algorithm based on Stackelbereg equilibrium gives an efficient computation procedure than that of Nash. Less