Objective: This paper concerns the design and analysis of phase IV clinical trial under non-null hypothesis.

Objective:The matched-pair design is generalized to the situation with non-null hypothesis and stratification.

In this article, the author analyzes some aspects of false centers in construction of sunk shaft foundations such as formation, reasons and hazards, and states matters need attention in construction and prevention and correction measures.

On the basis of introducing its structure and functional modules,the paper detailedly discusses two technical problems of memory management and virtual interrupt handling in virtual machine design and gives a specific method,which excellently solves the problem of programmable d.