变阈性

Proceed from the principle of neural networks, the mechanism of mapping between input and output of neural networks was analyzed, and the BP algorithm for training the thresholds of neurons was derived. Based on the study to the distinguishability of input of networks, the effect of neural networks to distinguish-ability of characteristics was studied, and the optimizations of the structure of networks, learning rate, impulse factor, thresholds of neurons and initial weight of networks were completed. Through the experiments under fixed cutting regime and alternative cutting regime, the methods based on neural networks for tool wear monitoring were studied.

本文从神经网络的基本原理出发，研究了神经网络输入输出的映射机理，探讨了神经网络处理方法具有自适应性的原因；推导了神经元阈值学习BP算法；在研究网络输入特征可分性准则和特征敏感性准则的基础上，探讨了神经网络对特征可分性的作用；完成对网络结构参数、网络学习率和冲量因子、神经元阈值以及网络初始权值等参数的优化；并在固定切削用量和变切削用量条件下，对基于神经网络的刀具磨损检测方法进行了实验研究。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。