校园网“毒瘤”ARP病毒防治

ARP攻击是指黑客利用ARP协议缺陷的基本原理,通过在区域内一台终端或服务器上发布欺骗ARP广播包以达到进行盗取用户帐号、篡改网站内容、嵌入恶意代码、发布不良信息、监听传输数据等非法活动的目的。     

基于802．Ix协议的准入控制技术

本文首先分析了网路准入控制原理以及网路准入控制技术的实现方式进行了探讨,运用802．1x协议的网路准入方式的工作和应用进行探讨,并对网路准入控制技术结合安全管理系统对网路安全模式进行了再一次规整。     

计算机网络信息系统安全稳定运行的解决方案研究简

内网信息系统主要为企业内部提供信息的传递合和分享,意义十分重大,在网络技术促进信息交流的同时,也出现了一些安全隐患对系统的安全构成威胁,极易造成内部信息失真或被篡改窃取,因此,必须采取相应的防护措施保证系统安全运行。     

计算机网络的安全问题及预防措施浅探简

导致的计算机硬件、软件数据而遭到的破坏、更改和泄露就是计算机网络安全问题,而其影响因素则比较复杂,因而,这就需要在加强法制管理,提高防范意识的同时,不断提高防范技术,而且,不仅要被动防御,更要强化主动防护、动态地对网络安全进行防护。     

电力系统维修的关键要点研究

采用先进的检测手段和分析诊断技术来检测设备状态,在任何时候都能使设备的运行状况将得到体现,这取决于设备的维修项目及维修时间合理安排,最大限度地降低维护成本,提高设备的可靠性,延长使用寿命.本文将探讨以上等问题.     

语音识别中小波分析的应用

语音信号是一种时变、非平稳的随机信号。现有语音识别系统的适应性比较差,尤其在高噪声环境下的语音识别非常困难,若将语音识别系统商品化,还有识别速度、拒识问题以及关键词／句检测技术等细节问题需要解决。如何把语言学、生理学、心理学方面的研究成果量化、建模并用于语音识别,还需深入研究。本文介绍了语音识别中小波分析的研究现状及几种常见的技术方法,并且分析探讨了语音识别中小波分析的应用和发展前景。     

孤立词语音识别技术及其应用前景分析

孤立词语音识别技术,采用的是模式匹配法,是语音识别技术的核心之一。首先,用户将词汇表中的每一词依次说一遍,并且将其特征矢量作为模板存入棋板库。然后,将输入语音的特征矢量依次与模板库中的每个模板进行相似度比较,将相似度最高者作为识别结果输出。本文介绍了孤立词语音识别技术的研究现状及几种常见的技术方法,并且分析探讨了孤立词语音识别技术的应用和发展前景。     

CGA560增强助磨剂在水泥粉磨中的应用研究

研究了CGA560增强助磨剂在水泥粉磨中对台时产量和水泥质量的影响。试验结果表明:在磨机状况不改变的条件下,CGA560增强助磨剂的加入可提高磨机产量10%-30%;同时可有效减少过粉磨现象,优化水泥颗粒级配,提高了水泥粉磨细度及比表面积;因而使水泥强度等性能得到了明显改善和提高。     

On adaptive sliding mode control without switching gain overestimation

This paper presents some further results on adaptive sliding mode control (ASMC) for a class of nonlinear systems with bounded uncertain parameters. Given a large initial tracking error, current ASMC design generally produces an unnecessarily large switching gain, consequently leading to a serious chattering problem or a large‐amplitude control jump for the continuous counterpart. To solve such an overadaptation problem, the switching gain adaptation mechanism is first analyzed in this paper, and the adaptation induced by the initial tracking error is suggested to be removed. Then, by exploiting the global sliding mode feature of time‐varying sliding mode control and integral sliding mode control, we present two effective methodologies for ASMC design. The proposed ASMC algorithms ensure that there is no overestimation of the switching gain and the system response is not slowed down when a small switching gain is generated. The validity of the proposed methods is verified by both theoretical analysis and simulation results. Copyright © 2012 John Wiley & Sons, Ltd.     

Containment control of multi‐agent systems by exploiting the control inputs of neighbors

This paper studies the containment control problem for multi‐agent systems consisting of multiple leaders and followers connected as a network. The objective is to design control protocols so that the leaders will converge to a certain desired formation while the followers converge to the convex hull of the leaders. A novel protocol is proposed by exploiting the control input information of neighbors. Both continuous‐time and discrete‐time systems are considered. For continuous‐time systems, it is proved that the protocol is robust to any constant delays of the neighbors' control inputs. For discrete‐time systems, a sufficient condition on the feedback gain for the containment control is given in terms of the time delay and graph information. Some numerical examples are given to demonstrate the results. Copyright © 2013 John Wiley & Sons, Ltd.