For a hybrid sensor network, the effective coverage rate can be optimized by adjusting the location of the mobile nodes. For many deployments by APF (artificial potential field), due to the common problem of barrier effect, it is difficult for mobile nodes to diffuse by the weaker attraction when the nodes initially distribute densely in some places. The proposed deployment algorithm PFPSO (Potential Field-Directed Particle Swarm Optimization) can overcome this problem and guide the mobile nodes to the optimal positions. Normally the requirement is different for the effective coverage rate between the hotspot area and the ordinary area. On the basis of PFPSO, NPFPSO (Nonuniform PFPSO) algorithm was also proposed to implement nonuniform coverage according to the importance degree of the monitoring area. Simulation result illustrates that PFPSO algorithm can effectively improve the effective coverage rate of the network, and NPFPSO algorithm can obtain a balanced result of effective coverage rate for both hotspot area and ordinary area.

The soil dynamic constitutive model has always been one of the frontier topics in soil dynamics. In the past few decades, the constitutive model of soil has been rapidly developed, and with computer technology and one-dimensional soil earthquakes. In the development of reaction analysis methods, many earthquake response models and calculation procedures for one-dimensional time domain nonlinear soil layers have emerged. In this paper, the deterministic method of theoretical analysis is used to summarize the development of soil constitutive model in soil-time seismic nonlinear method. The time-domain nonlinear soil used in different periods is introduced according to the development order of constitutive model. Layer seismic response procedures and their advantages and disadvantages, as well as the latest improvements made to them. Finally, the development direction of nonlinear method programs is prospected.