Search

We investigate the topological characteristics of complex networks as exemplified by the urban public traffic network (UPTN) in Chinese top-ten biggest cities. It is found that the UPTNs have small world behaviour, by the examination of their topological parameters. The quantitative analysis of the transport efficiency of the UPTNs reveals their higher local efficiency El and lower global efficiency Eg, which coincide well with the status quo of those Chinese cities still at their developing stage. Furthermore, the topological properties of efficiency in the UPTNs are also examined, and the findings indicate that, on the one hand, the UPTNs show robustness to random attacks and frangibility to malicious attacks on a global scale; on the other hand, the interrelation between UPTN efficiency and network motifs deserves our attention. The motifs which interrelate the UPTN efficiency are always triangular-formed patterns, e.g. motifs ID 238, ID 174 and ID 102, etc.

There are many types of non-periodic gradual analog signal with little sharp variation in practice and there is the conflict between high-speed sampling bringing lots of redundant information and the low-speed losing important information in monitoring them. In the paper, their characteristic are summarized, the relation between the slope and the bandwidth is analyzed according to the view that any complex waveform may be approximated with many straight broken lines, and the method that the signal’s local bandwidth is estimated with the slope is presented. The experimental simulation shows that the relation and the method are correct. Because the slope may be obtained very easily in the process of ADC, the real-time estimating signal’s local bandwidth is simply carried out. The conflict can be solved effectively with the strategy of high-speed sampling and alterable-speed storing in terms of local band-width.