Study On The Influence Of Non-square Block For Transportation On Grid Network

The grid network in which the number of square or non-square blocks is subsistent is the typical network of China. With those blocks close and surrounded by walls for long traditional close life and work, travelers cann't cross the block via the road in it which don't belong to city network. So those blocks influence the transportation operation efficiency. Having discussed the influences of square block for transportation convenience capability on grid network from the change of the number of the shortest path, the previous didn't consider the change of the length of the shortest path and lacked the related research of non-square block. Based on the above, this thesis analyzes different number of non-square blocks'influence to the network from the change of both the number and length of the shortest path. One aim is to make up for the previous research shortage; the other aim is to give some suggestions for policy-makers to plan the block and the road. According to the results of this thesis, policy-makers can measure the impact of one or more non-square blocks on the grid network.The main creative results of the research are as follows:1. Aiming at the situation that there is a non-square block on grid network, the thesis studying from the changes of both the number and length of the shortest path, gives the definition of inflection point for arbitrary couple of vertices, proposes indexes of inflection point coefficient of non-square block for transportation on grid network for arbitrary couple of vertices or the entire network. And with a produkte type block as an example, it analyzes the properties of the location of the inflection point, designs the algorithm of the indexes. Finally, it, shows an example from the real map of Xi'an.2. Aiming at the situation that there is more than one non-square block on grid network in the real life, the thesis studying from the change of both the number and length of the shortest path, discusses the influences of 2 or some special cases of N non-square blocks for the transportation on grid network. Respectively, it gives the properties of the location of inflection point, designs the algorithm of inflection point coefficient arbitrary couple of vertices or the entire network, shows an example to validate the properties and the algorithm.