一种隔水管涡激振动检测新算法

涡激振动(Vortex induced Vibration,VIV)是导致深水隔水管疲劳的主要诱因,振动位移或位移均方根是隔水管VIV监测的主要参数;针对VIV检测问题,提出了基于自相关矩阵分解的VIV频率和位移检测算法;给出了隔水管VIV检测模型,利用自相关矩阵分解算法检测出信号的频率以及相应的振幅,然后重构隔水管VIV响应位移的时间历程,得出位移或者均方根;仿真结果表明:与现有的Welch位移检测算法相比,基于自相关矩阵分解的VIV检测算法具有精度高,适用性广,实用性强等特点。     

Adaptive control for a class of nonlinear systems with time-varying delays in state and input

This paper is concerned with the adaptive stabilization problem of uncertain input delayed systems.A solution to this problem is given for a class of uncertain nonlinear systems with time-varying delays in both state and input.An adaptive asymptotically stabilizing controller,which can guarantee the stability of the closed-loop system and the convergence of the original system state,is designed by means of the Lyapunov-Krasovskii functional stability theory combined with linear matrix inequalities (LMIs) an...     

关联规则挖掘在教师成长中的应用

本文在对数据挖掘相关技术、关联规则挖掘算法进行深入研究的基础上,归纳总结了基于粗糙集理论的关联规则挖掘模型和属性约简算法,并将其应用于高校教师的成长中。     

一种抗合谋攻击的基于身份的门限签名方案

基于Paterson签名方案和分布式密钥生成协议,提出了一个新的基于身份的门限签名方案。该方案能有效抵抗合谋攻击和伪造签名攻击,并能实现签名成员的可追查性。无需可信中心参与,群签名成员共同生成群公钥和秘密分发群签名密钥。在标准模型下,该方案是健壮的和对适应性选择消息攻击是不可伪造的。     

Network coding-based reliable multicast in wireless networks

Reliable multicast, the lossless dissemination of data from one sender to a group of receivers, has a wide range of important applications. Recently, network coding has been applied to the reliable multicast in wireless networks, where multiple lost packets with distinct intended receivers are XOR-ed together as one packet and forwarded via single retransmission, resulting in a significant reduction of bandwidth consumption. However, the simple XOR operation cannot fully exploit the potential coding opportunities and finding the optimal set of lost packets for XOR-ing is a complex NP-complete optimization problem. In this work, we intend to move beyond the simple XOR to more general coding operations. Specifically, we propose two new schemes (a static scheme which repeatedly retransmits one coding packet until all intended receivers receive it and a dynamic scheme which updates the coding packet once one or more receivers receive it) to encode packets with more general coding operations, which not only can encode lost packets with common intended receivers together to fully exploit the potential coding opportunities but also have polynomial-time complexity. We demonstrate, through both analytical and simulation results, that the proposed schemes can more greatly reduce the bandwidth requirement than the available coding-based schemes, especially in the case of high packet loss probabilities and a larger number of receivers. This reduction can vary from a few percents to over 15% depending on the packet loss probabilities and the number of receivers.     

Research on the location of acoustic emission source of rock breaking point by using phase difference method and Geiger algorithm

Geiger iterative algorithm is very strict to the initial value. If the initial value is not selected suitably, it is difficult to enter the convergence range, thus increasing the number of iterations. The acoustic emission source location based on phase difference time delay estimation method reduces the error of acoustic emission location, but it has some shortcomings in accuracy. Based on the above problems, this paper presents a new algorithm for Geiger optimization based on source localization. Firstly, the initial value of Geiger is obtained by using the phase difference method. Then, the optimal solution is obtained by the iterative solution of Geiger algorithm and the least square method. The simulation results show that this method can effectively solve the problem of selecting the initial value of Geiger, so that it can quickly enter the convergence range, improving the convergence speed and positioning accuracy, comparing the positioning results of the United States PCI-2 type acoustic emission instrument, the average error reduced by about 5 mm.     

网站前端模块化开发策略研究

随着网站前端功能日渐增多且更新频繁,前端开发技术受到越来越多公司的重视。一种具有先进开发思想和良好设计模式的前端模块化技术正逐渐成熟。根据网站前端模块化的不同开发思想,详细分析了目前常见的三种模块化开发策略,阐述了每种开发策略的具体实现方法、常见的框架与工具存在的问题及优缺点,并提出了完善前端模块化开发策略的一些方法。     

Windows NT局域网网络安全初步

学校教学机房大多是采用服务器+有盘工作站架构的局域网,局域网络的安全对保障基于计算机的教学十分重要.本文介绍了保护Windows NT局域网网络安全的一些措施,通过我系局域网运行情况来看,较好的保证了网络的安全,为我系教学提供了良好的保证.     

基于IBL算法的CBR系统中索引与检索机制研究

文章介绍了基于示例学习算法IBL的概况,并对其加以改进,提出了一个新的算法IBL－Cluster。它主要由概念描述形成算法和概念描述修改算法构成。在此基础上建立了应用在基于事例的推理系统CBR中的基于IBL算法的索引与检索机制。实验表明新算法IBL－Cluster在存储空间及测试正确率方面均有改善。