A Dynamic Analysis of Multiple-Center Formation in a City

本研究旨在对城市中多个商业中心的形成进行动态分析。假设在线性城市中预先指定了CBD和第二商务区（SBD）的中心，提出了一个优化模型，其中确定了新公司和家庭的位置，以便在规划范围内最大化净租金收入。SBD有两种不同的生长模式。在这两种模式中，企业都只在规划期的早期阶段位于CBD。这两种模式之间的差异发生在时间范围的后期，当一个城市的公司数量超过某个阈值水平时：即，CBD和SBD都在扩张（模式1），只有SBD在增长（模式2）。为了阐明每种模式产生的条件，进行了数值模拟分析。总体而言，其结果取决于交通成本、交通成本、区域中心的位置等因素的相对大小：交通成本越高，副中心的增长率越高；通信成本越高，CBD的扩展范围越广；离CBD越远，SBD的中心形成速度越慢。该模型可以通过比较建立子中心和不建立子中心两种情况下的总租金收益来评价建立子中心的效果。

This study intended to undetake a dynamic analysis of the formation of multiple business centers in a city. Provided the centers of the CBD and the second business district (SBD) are prespecified in a linear city, an optimizing model was presented where the locations of new firms and households are determined so as to maximize the net rental revenue over the planning horizon. There are two alternative patterns of growth of the SBD.In both patterns, firms are located only in the CBD at the early stages of planning period. The difference between the two patterns occurs in later stage of time horizon when the number of firms in a city exceeds some threshold level : i.e., the CBD as well as the SBD expands (pattern 1) and only SBD grows (pattern 2). For the purpose of clarifying the conditions for each pattern to emerge, a numerical simulation analysis was performed. The result, in general, depens on the relative sizes of communication cost, transport cost, the location of a center of the SBD and so on : the higher the transport cost, the higher the growth rate of the subcenter ; the higher the communication cost, the further the CBD expands ; the further from the CBD the center of the SBD, the slower the speed of the formation of the SBD.This model can be used to evaluate the effects of establishing a subcenter by comparing the total rental revenue between the two cases, when a subcenter is established and when it it not established.