This article not only focuses on data cleaning methods to ensure data quality of the safety of marketed drugs,such as triage strategies and duplicate detection,but also compares the classical signal detection methods in practice,including the conformity of these methods.

Multiple flow direction algorithm with flow partition scheme based on downslope gradient;

Improvement of four-step commutation strategy for matrix converter based on two line voltage synthesis;

Improvement of commutation strategy of matrix converter;

Aiming at safe commutation and improving quality of output waveforms,the paper presents a new varying-step safe commutation strategy of matrix converter by analyzing the character of traditional four-step commutation and improved four-step commutation strategy.

This paper is going to analyze transnational corporation s logistics tactics in China,especially including the enlightenment on the native corporations.