Then it introduces small-world theory to the description and analysis of communication network, and uses the critical path length and clustering coefficient of small-world network to describe the frequency and centralization of communication.

Consequently, analyzing the industrial cluster by Small-world network model, and using the critical path length and clustering coefficient to describe the frequency of knowledge transfer and cluster degree, in order to supp.

Then it introduces the small-world theory to the description and analysis of communication networks, and uses the critical path length and clustering coefficient of small-world network to describe the frequency and cluster degree of interfirm innovation network.

This paper probes into two methods for calculating the character path length based on small world network, and inspects and verifies the actual results of the two methods under Chinese literature environment with examples.

The local area control of virus spreading is studied in the light of the path length in complex networks,and the efficiency of local area control for complex networks with different topologies is analyzed.

From the similarity relations of radiative transfer theory,a parameter,namely characteristic length,was introduced on the basis of P_1 and P_3 satisfying approximatly the first-order similarity and third-order similarity relations.

Based on the researching of the infrared decoy countermeasure to the target characteristic length and energy equivalent centre,the countermeasure to the point target image radiation characteristics are analyzed.

By the relationship between the theoretical roughness and fractal parameters,the fractal parameters were introduced into the calculation of trait of a bearing center,and the influences of fractal dimension and characteristic length on the position of bearing center were investigated.