具有未知参数的机器人-摄像机系统的自适应动态反馈跟踪控制

研究了不确定非完整移动机器人系统的跟踪问题.首先,基于视觉反馈和状态输入变换,展示了一种非完整移动机器人运动学系统的不确定链式模型.基于反步法思想和跟踪误差系统结构,给出了两个重要的新变换.然后运用李雅普诺夫直接方法和扩展巴巴拉引理设计了自适应控制律和动态反馈鲁棒控制器,以实现理想轨迹的跟踪控制.严格证明了闭环误差系统的渐近收敛性.最后,仿真结果证实了提出的控制策略有效.     

定位GSM用户的一种方法

利用GSM协议的一个缺陷,提出一个对GSM用户定位的方法.当用户使用GSM移动电话时,攻击者修改GSM移动电话和基站之间在空中接口传输的一些信令报文子域,诱使GSM移动电话向基站明文传输IMSI和IMEI身份标识符.这种攻击方法能让通信双方对攻击没有察觉,从而保证攻击的隐蔽性.攻击者根据截获的IMSI和IMEI,以及用户所属区域的LAI即可实现对用户的定位.     

新型智能远程控制系统的设计与研究

远程控制软件可以大大简化我们的网络管理工作,更加有效地保证网络和计算机操作系统的安全.本文采用服务器/客户机模式,以Java语言网络编程技术实现了远程控制系统.详细说明体系结构中各模块的主要功能;以流程图的方式详细说明系统软件的实现重点和过程.最后通过Java Socket网络编程,最终实现了新型智能远程担制系统的设计与开发.     

短信理财平台系统设计与实现方案

电子业务是银行中间业务的一个重要组成部分,直接关系到银行的信誉.本文根据银行业务部的短信理财系统的需求,结合现在移动梦网业务的发展,开发了短信理财系统,实现了短信理财的目标,并就系统的分析、设计和实现进行了详细的阐述.     

A verifiable privacy-preserving data collection scheme supporting multi-party computation in fog-based smart grid

Incorporation of fog computing with low latency,preprocession(e.g.,data aggregation)and location awareness,can facilitate fine-grained collection of smart metering data in smart grid and promotes the sustainability and efficiency of the grid.Recently,much attention has been paid to the research on smart grid,especially in protecting privacy and data aggregation.However,most previous works do not focus on privacy-preserving data aggregation and function computation query on enormous data simultaneously in smart grid based on fog computation.In this paper,we construct a novel verifiable privacy-preserving data collection scheme supporting multi-party computation(MPC),named VPDC-MPC,to achieve both functions simultaneously in smart grid based on fog computing.VPDC-MPC realizes verifiable secret sharing of users’data and data aggregation without revealing individual reports via practical cryptosystem and verifiable secret sharing scheme.Besides,we propose an efficient algorithm for batch verification of share consistency and detection of error reports if the external adversaries modify the SMs’report.Furthermore,VPDC-MPC allows both the control center and users with limited resources to obtain arbitrary arithmetic analysis(not only data aggregation)via secure multi-party computation between cloud servers in smart grid.Besides,VPDC-MPC tolerates fault of cloud servers and resists collusion.We also present security analysis and performance evaluation of our scheme,which indicates that even with tradeoff on computation and communication overhead,VPDC-MPC is practical with above features.     

从冲动到理性——浓缩中国网商成长史

2008年3月17日,浙江省永康市威仕达五金制造厂总经理杜美燕像往常一样打开电脑,开始查阅来自中国制造网(www.Made-in-China.com)的询盘.这个早在8年前就养成的习惯,为威仕达赢得了外贸销售额中90%的订单.不过最近几天,由于广交会的临近,询盘相对少了些,这让杜美燕忙里偷闲回忆起了往事:尽管公司从2000年的白手起家,到2007年通过电子商务拿到的订单已经超过了300万美元,但是回想这些年来网络外贸的经历,最令杜美燕难忘的还是2003年.     

Computer comparisons in the presence of performance variation

Performance variability,stemming from nondeterministic hardware and software behaviors or deterministic behaviors such as measurement bias,is a well-known phenomenon of computer systems which increases the difficulty of comparing computer performance metrics and is slated to become even more of a concern as interest in Big Data analytic increases.Conventional methods use various measures(such as geometric mean)to quantify the performance of different benchmarks to compare computers without considering this variability which may lead to wrong conclusions.In this paper,we propose three resampling methods for performance evaluation and comparison:a randomization test for a general performance comparison between two computers,bootstrapping confidence estimation,and an empirical distribution and five-number-summary for performance evaluation.The results show that for both PARSEC and highvariance BigDataBench benchmarks 1)the randomization test substantially improves our chance to identify the difference between performance comparisons when the difference is not large;2)bootstrapping confidence estimation provides an accurate confidence interval for the performance comparison measure(e.g.,ratio of geometric means);and 3)when the difference is very small,a single test is often not enough to reveal the nature of the computer performance due to the variability of computer systems.We further propose using empirical distribution to evaluate computer performance and a five-number-summary to summarize computer performance.We use published SPEC 2006 results to investigate the sources of performance variation by predicting performance and relative variation for 8,236 machines.We achieve a correlation of predicted performances of 0.992 and a correlation of predicted and measured relative variation of 0.5.Finally,we propose the utilization of a novel biplotting technique to visualize the effectiveness of benchmarks and cluster machines by behavior.We illustrate the results and conclusion through detailed Monte Carlo simulation studies and real examples.     

详解Dreamweaver的13个技巧

1.灵活运用样式 熟悉网页设计的网友都知道,调用Style的方法很多,我们可以单击鼠标右键选择Custon Style来调用Style,也可以在状态栏中的元素列表上单击右键来调用Style.虽然不同的方法达到的效果看似一样,但实际上产生的HTML代码则完全不同.比如用Custon Style来调用Style,在网页代码中就生成一个标签,这样的标签一多就会使文件十分臃肿而且影响浏览器的解析速度,所以我们应尽量使用状态栏中的元素列表来调用Stvle.     

抵御黑客攻击正版软件的良方

软件盗版仍然猖獗。根据商业软件协会和IDC的第二次年度全球软件盗版调查,在全世界个人电脑上安装的软件有35%是盗版软件,这意味着在2004年盗版造成了将近330亿美元的损失。为了确定对应用程序     

2007年计算机病毒/木马的特点分析及发展趋势预测

病毒"工业化"入侵凸显病毒经济病毒/木马背后所带来的巨大的经济利益催生了病毒"工业化"入侵的进程。2007年上半年,金山对外发布了病毒木马产业链的攻击特征,在此阶段,病毒木马的攻击通常是针对单个计算机的攻击行为。攻击的手法,一般利用社会工程欺骗的方式,发送经过伪装的木马以及通过网页挂马构造大