看了许多USB协议，感觉有些概念讲得比较模糊，这里是我对USB协议理解而做出的部分总结，希望对初学者有帮助。-Saw many USB protocol, I feel some concepts stood out fuzzy, here is my understanding of the USB protocol and made part of the summary of hope for beginners.

基于AHP分析SAW算法和TOPSIS算法在异构切换环境下的性能-AHP analysis algorithms SAW and TOPSIS algorithm performance in heterogeneous environments based switching