机构地区: 长安大学经济与管理学院
出 处: 《交通运输工程学报》 2009年第4期56-60,共5页
摘 要: 为了定量描述中国公路货运枢纽体系结构现状,将公路货运量作为货运枢纽的规模参数,推导了分维数的计算公式,选取1997~2007年的货运量统计数据,计算了200个公路货运枢纽规模分布的分维数。数据拟合发现:1997~1999年公路货运枢纽的规模分布具有双分形特征,2000~2007年的规模分布呈单分形结构,且分维数介于1.464 6~1.570 1间,公路货运枢纽体系的规模分布与城镇体系基本一致。分析结果表明:中国公路货运枢纽体系规模分布从双分形到单分形的演化显示其发育较好,需加强大型公路货运枢纽建设,以进一步优化公路货运枢纽体系结构。 In order to quantitatively evaluate the system topology of Chinese truck transportation hubs in recent years,highway freight volume was regarded as a size index of truck transportation hub.A novel formula for exactly calculating the fractal dimension of size-distribution of the truck transportation hub was presented.The fractal dimensions of size-distributions of 200 largest truck transportation hubs during 1997~2007 were calculated by the formula based on the statistical data of highway freight volumes. Computation result shows that the size-distributions of true fractal of truc k transportation hubs duri dimensions are between 1 k transportation hub sys topology distribut ng 1997~1999 are bi-fractal, while that are single fractal and the 1. 464 6 and 1. 570 1 during 2000~2007, and the size-distribution tern is adapted to city system. The evolvement of the fractal from bi-fractal to single ions supported to of truck transportati optimize the structure