The structure of the formula is simple and easy to compute, the linear system method is superior to the former for handling the degeneracy problem.

Degeneracy phenomenon is a main disadvantage to particle filter application.

Degeneracy phenomenon is a main disadvantage to particle filter application,common re-sampling methods can resolve degeneracy phenomenon,but the sample impoverishment is deduced.

This paper discusses the cause of the theory of ecological security from the following four aspects: firstly, the ecological globalization is the real foundation of this theory; secondly, it is the innate defect of modern industrial civilization developing system that makes this theory come forth inevitably; thirdly, the theory of sustainable development is the ideological .

Researches on social and economic benefits and ecological problems aroused by water transfer projects in the USA;

Analysis of water resources vulnerability and ecological problems in Heihe river basin;

In view of the existence of the current meadow severely degradation,animal population density decrease,water flow reduction and other ecological problems,it presents we must draw up environmental protection regulations for this conserve as soon as possible,establish biodiversity conservation authority institutions,carry out condomin.