基于L-Z方法的宏观交通运输系统复杂性测度

Complexity measure for macroscopical transportation system using Lempel-Ziv algorithm

为了测度宏观交通运输系统的复杂性,引入符号动力学中的L-Z方法,并针对趋势项导致的宏观数据非平稳性,改进了L-Z方法.从总量与分量、不同对象、不同时段等视角,以改进的L-Z方法分析30个交通运输时间序列的复杂度,结果表明:我国宏观交通运输系统的复杂度不高;一体化能够降低宏观交通运输系统的复杂度;旅客运输比货物运输的复杂度高;宏观交通运输系统的复杂度与时间序列的长度成反比.这说明,L-Z方法适用于宏观交通运输系统的复杂性测度,复杂性的测度结果可以作为宏观交通管理决策的重要依据.

The Lempel-Ziv algorithm of symbolic dynamics was introduced to measure the complexity of macroscopieal transportation system. It was improved aimed at the nonstationarity of macroscopical transportation data resulted from the trend term, and was then applied to the analysis on complexities of 30 transportation time series from three aspects, i. e. , total quantity and partial quantity, passenger and freight, and different periods of transportation. Results show that, the complexity of macroscopical transportation system in China is low, the transportation integration can reduce the complexity of macroscopical transportation system, the complexity of passenger transportation is higher than that of freight transportation, and the complexity of macroscopical transportation system is in inverse proportion to the length of time series. Therefore, it can be concluded that the improved Lempel-Ziv algorithm is suitable for the complexity measure of macroscopieal transportation system, and the measure results can be used as an important basis for decision - making in the management of maeroscopical transportation.