From the principle of geometrical optics,the mode that electromagnetic wave promulgate in pyramid absorber is analyzed,which include electromagnetic wave promulgate inside the pyramid and reflect between pyramids nearby.

From the angle of the mathematical and geometrical bases,this paper makes brief discussion on the compensation of the lining and measuring system in D09―32 continuous tamping machine,emphatically introduces the compensation principles of the "three points" lining operation and "four points" lining operation,and probes into the lining compensation control of the traveling bogie.

An efficient and practical stochastic gradient algorithm for calculating structural reliability index is presented in this paper on basis of geometrical principle of reliability index.

Based on the geometrical principle of reliability index,a new optimization model is produced.

The two methods are developed based on geometrical principles.

In consideration of the deficiencies of quadratic-function-response-surface method in structural reliability analysis,an improved response surface method is presented based on high-order-response-surface function and iterative rule with the geometry principle of JC method to decide center point.