A note on attraction and stability of neutral stochastic delay differential equations with Markovian switching

This paper is concerned with neutral stochastic delay differential equations with Markovian switching (NSDDEs-MS). A kind of ψ ??function is introduced and some criteria on the attractor for the product of the ψ ??function are obtained. By the new criteria, the almost sure stability with the general decay rate of NSDDEs-MS could be examined, including the exponential stability and the polynomial stability. Finally, an example is provided to illustrate the applications of our results clearly.     

基于高斯混合模型的遥感影像连续型朴素贝叶斯网络分类器

提出了一种新的嵌入高斯混合模型(GMM,Gaussian Mixture Model)遥感影像朴素贝叶斯网络模型GMM-NBC(GMMbased Na ve Bayesian Classifier)。针对连续型朴素贝叶斯网络分类器中假设地物服从单一高斯分布的缺点,该方法将地物在特征空间的分布用高斯混合模型来模拟,用改进EM算法自动获取高斯混合模型的参数;高斯混合模型整体作为一个子节点嵌入朴素贝叶斯网络中,将其输出作为节点(特征)的中间类后验概率,在朴素贝叶斯网络的框架下进行融合获得最终的类后验概率。对多光谱和高光谱数据的分类实验结果表明,该方法较传统贝叶斯分类器分类效果要好,且有较强的鲁棒性。     

煤矿35/6kV变电站综合自动化改造

以葛泉矿为例,提出了煤矿35/6 kV变电站自动化改造的方案。通过综合自动化改造实现了变电站继电保护和控制、远动、计量、故障录波、数据处理、五防操作和闭锁、在线监测等功能,满足了变电站后期扩容和线路改造的需要。     

基于单片机的电机软起动器设计

分析晶闸管三相交流调压的工作原理。介绍电机软起动器的硬件组成和软件程序设计。     

校园网中无线局域网的安全策略探讨

随着无线局域网在校园网中的普及应用,其安全问题也日益突出,无线局域网面临着信息泄露、完整性破坏、业务拒绝和非法使用等安全威胁,本文从校园无线局域网的安全技术和安全管理两个方面,探讨了校园无线局域网的安全策略。     

南堡油田注多元热流体吞吐水平井加热效果评价

以南堡35-2油田稠油油藏为研究对象,针对多元热流体吞吐水平井加热半径沿程分布计算问题,通过两相渗流理论,利用保角变换方法,建立了加热半径沿程分布计算模型.研究了水平段井筒温度、加热半径沿程分布规律和不同注汽参数对加热效果的影响.研究表明,井筒温度和加热半径沿程分布呈"U"型;利用渗流力学方法计算的加热半径较油藏工程方法计算结果更符合实际.B31H井注汽参数优化表明,加热半径随非凝结气含量增加先增加后降低;随注汽速度增加基本不变;随周期注汽量增加先迅速增加后增加缓慢.该模型对准确评价注汽后加热效果及后期预测产能具有重要意义.     

Controlled bidirectional grammars

We investigate context-free grammars the rules of which can be used in a productive and in a reductive fashion, while the application of these rules is controlled by a regular language. We distinguish several modes of derivation for this kind of grammar. The resulting language families (properly) extend the family of context-free languages. We establish some closure properties of these language families and some grammatical transformations which yield a few normal forms for this type of grammar. Finally, we consider some special cases (viz. the context-free grammar is linear or left-linear), and generalizations, in particular, the use of arbitrary rather than regular control languages.