对“总串分并”四层反垃圾邮件过滤系统设置分析与研究

反垃圾邮件过滤器众多,但没有一种过滤器可以单独使用,目前垃圾邮件过滤系统一般是将多种过滤器进行简单的级联形成分层过滤系统。分层过滤可以达到较高的召回率,但FP(False Positive)率却并没有因为多种过滤方案的整合而得到提升,时间性能反而因为系统采用多种过滤器而大大降低。设计"总串分并"的四层反垃圾邮件过滤系统,系统采用四个模块进行总体级联,实现较好的时间性能,同时每一个模块又采用"贝叶斯"算法将多种过滤器进行并联,更加严格的控制垃圾邮件的评定。     

基于贝叶斯的垃圾邮件过滤技术

大量垃圾邮件的出现给用户收发电子邮件带来极大困扰。贝叶斯算法由于在垃圾邮件过滤处理上表现出很高的准确度,因此受到广泛应用。因此,分析常用贝叶斯算法的优缺点,并对贝叶斯算法进行改进,应用最小风险贝叶斯方法与多项式(MM)模型相结合,构成邮件分类器的基本结构,降低垃圾邮件过滤系统分类错误率,提高分类准确率。最后对反垃圾邮件技术进行总结和展望。     

浅谈反垃圾邮件技术

如今,电子邮件的应用已经非常广泛,但是垃圾邮件的泛滥也给合法的电子邮件用户带来了许多不便,特别是病毒类的垃圾邮件,已经严重威胁到了用户信息的安全。反垃圾邮件技术的研究具有现实意义,通过介绍常见的垃圾邮件发送技巧和垃圾邮件发展的新趋势,浅谈几种常见的反垃圾邮件技术并提出新的反垃圾邮件的解决途径。     

垃圾邮件过滤的贝叶斯算法研究

介绍垃圾邮件的定义和危害,简要论述垃圾邮件过滤技术的发展.详细阐述基于内容过滤的贝叶斯算法的原理和过滤的步骤,分析贝叶斯过滤的优点.     

垃圾邮件及反垃圾邮件技术研究

当前,垃圾邮件日益泛滥,严重损害了互联网服务提供商、企业和消费者的利益.介绍垃圾邮件的危害,并探讨分别在邮件系统服务器端及客户端部署实施的各种反垃圾邮件技术和手段.     

基于J2ME的Push Mail实现

利用现有的GPRS网络并在功J2ME平台上实现便携式终端到邮件服务器上的双向全新移动Email解决方案.     

浅析计算机办公网络信息安全解决方案

本文对于计算机办公网络信息安全相关问题进行分析，具体来说就病毒防治方案设计，建立垃圾邮件过滤系统方案设计，防火墙方案设计和数据备份方案设计进行相关分析。     

企业网络故障小故事（一）

故事发生某日,A公司的员工告知该公司的网管人员邮件无法发送,但可以接收。故障解决遇到此类问题,网管人员通常都会采用猜、排查,实在不行重装系统或更换硬件的方式解决故障。在这个例子中,网管员首先怀疑是邮件服务器出了故障,经检查竟有700万个邮件服务器访问请求,     

基于内容的网络异常信息过滤

虽然网络促进社会经济的发展与进步,但是在互联网规模的不断扩大下,恶意邮件和不良网络,以及不健康网络内容的传播等都将严重影响网络健康运行。因此,对内容的网络异常信息过滤的安全保护成为人们关注的焦点。通过简要介绍网络异常信息过滤,对网络异常信息过滤模型进行分析,并设计基于内容的网络异常信息过滤系统,同时通过试验与分析证明其实用的价值。     

物联网远程电梯监控系统关键技术研究与实现

为提高电梯管理水平,有效避免电梯安全事故的发生,设计和开发物联网(IOT)远程电梯监控系统。该系统将电梯工作现场采集的电梯运行状态信息封装成数据包,通过中继器上传到数据中心进行处理,利用富客户端技术(Silverlight)实现监控客户端浏览器与服务器的双向交互。提出物联网远程电梯监控系统的拓扑结构,研究物联网电梯监控系统中客户端浏览器和服务器信息交互、数据中心管理以及终端硬件设计等关键技术及其实现。实践证明:系统能够实现对电梯进行全面智能化监控和管理,具有良好的应用前景和实用价值。     

智能终端接收广播数字电视的设计与实现

介绍了基于嵌入式Linux的数字电视流媒体转发系统实现免流量接收转发地面广播数字电视信号的方法.该系统采用内置的电视棒调谐接收射频信号,并解调成含有多路节目的 TS流,通过服务器进行分发成为多个单路节目TS流,传输给流媒体服务器,在WIFI热点所建的局域网内,基于TCP/IP和RTSP协议,采用IP多播技术,免流量传输给智能手机终端.这套系统突破已有技术局限接收广泛覆盖的数字电视信号,拥有便携、免流量接收、节省网络带宽等优点.     

Insight into weak enforcement of intellectual property rights in China

Based on the combination of institutional theory and a literature review, the paper contemplates the weak enforcement of intellectual property rights (IPRs) in China by legal, economic, political, social, and cultural institutions. It indicates that the legal system cannot be solely responsible for weak enforcement of IPRs. Only by changing the whole IP institutional environment over time will IPRs be well enforced. IP environment analysis and corresponding proactive actions are suggested for foreign companies to overcome institutional barriers in the environment. The paper also puts forward advice to Chinese policymakers on improving the whole IP environment.     

智能DNS在校园网多链路控制的应用

为了解决校内外用户高速访问高校校园网的内部资源服务器的问题,提出了校园网智能DNS解决方案.智能DNS利用Bind9视图技术,结合F5负载均衡器的虚拟服务器和链路控制原理,能根据网络用户IP的来源,将校内资源服务器的域名动态解析成用户IP对应网络的IP地址,从而提高用户访问校内资源的速度和可靠性.测试结果表明,教科网、电信网和联通网等公网用户和内网用户都能获得最佳的链路以访问校内资源,校内用户访问其他公网资源也能获得更好的体验.     

E-mail Spam Classification Using Grasshopper Optimization Algorithm and Neural Networks

Spam has turned into a big predicament these days, due to the increase in the number of spam emails, as the recipient regularly receives piles of emails. Not only is spam wasting users’ time and bandwidth. In addition, it limits the storage space of the email box as well as the disk space. Thus, spam detection is a challenge for individuals and organizations alike. To advance spam email detection, this work proposes a new spam detection approach, using the grasshopper optimization algorithm (GOA) in training a multilayer perceptron (MLP) classifier for categorizing emails as ham and spam. Hence, MLP and GOA produce an artificial neural network (ANN) model, referred to (GOAMLP). Two corpora are applied Spam Base and UK-2011 Web spam for this approach. Finally, the finding represents evidence that the proposed spam detection approach has achieved a better level in spam detection than the status of the art.     

The effect of overloading sequences on landing gear fatigue damage

In service, landing gear can be subject to unexpected hard landing load, which is beyond the design domain. The consequences due to overload can affect the design life of a landing gear to some extent. In this paper, the effect of overload and different loading sequences in random spectra on fatigue damage are investigated, using strain–life based fatigue analysis methods. The discussions are emphasised on the effect of loading sequences on residual stress and mean stress, especially the effect of overload on the fatigue damage of subsequent cycles. In addition, different fatigue analysis techniques in commercial fatigue analysis packages are reviewed and compared. The analysis indicates that the overload effect is stress state dependent and dominated by local residual and mean stress. A ‘Begin’ overload in a load spectrum would cause more damage in the local compressive yield area and an ‘End’ overload within a spectrum will worsen the tensile yielding area. It is suggested that the load sequence effect should be considered in common fatigue analysis if local yielding would exist before or after overloading.     

IMS实时计费系统集群的负载均衡研究

对IP多媒体子系统(IMS)中的实时计费系统(OCS)集群进行了研究,针对其高集群异构性和高请求负载异构性特征,提出了一种最小公倍数能力(LCMC)负载均衡算法.此算法考虑了各个服务器处理能力的差异和各个服务器当前的负载,并特别考虑了不同请求产生的负载差异,采用概率的方式进行请求分发.实验结果表明,在高集群异构性和高请求负载异构性的系统中,LCMC算法明显优于一些传统的负载均衡算法,能很好地满足IMS中OCS集群独有的特征.     

Preventing Cloud Network from Spamming Attacks Using Cloudflare and KNN

Cloud computing is one of the most attractive and cost-saving models, which provides online services to end-users. Cloud computing allows the user to access data directly from any node. But nowadays, cloud security is one of the biggest issues that arise. Different types of malware are wreaking havoc on the clouds. Attacks on the cloud server are happening from both internal and external sides. This paper has developed a tool to prevent the cloud server from spamming attacks. When an attacker attempts to use different spamming techniques on a cloud server, the attacker will be intercepted through two effective techniques: Cloudflare and K-nearest neighbors (KNN) classification. Cloudflare will block those IP addresses that the attacker will use and prevent spamming attacks. However, the KNN classifiers will determine which area the spammer belongs to. At the end of the article, various prevention techniques for securing cloud servers will be discussed, a comparison will be made with different papers, a conclusion will be drawn based on different results.     

Detecting spam web pages using content and link-based techniques

Web spam is a technique through which the irrelevant pages get higher rank than relevant pages in the search engine’s results. Spam pages are generally insufficient and inappropriate results for user. Many researchers are working in this area to detect the spam pages. However, there is no universal efficient technique developed so far which can detect all spam pages. This paper is an effort in that direction, where we propose a combined approach of content and link-based techniques to identify the spam pages. The content-based approach uses term density and Part of Speech (POS) ratio test and in the link-based approach, we explore the collaborative detection using personalized page ranking to classify the Web page as spam or non-spam. For experimental purpose, WEBSPAM-UK2006 dataset has been used. The results have been compared with some of the existing approaches. A good and promising F-measure of 75.2% demonstrates the applicability and efficiency of our approach.     

Secure Internet access to gateway using secure socket layer

The Internet is the most widely used medium to access remote sites. Data sent and received using transmission control protocol/Internet Protocol (TCP/IP) is in plain text format and can be accessed and tampered with quite easily and, hence, provides no data security. This is the case especially if the data are confidential and access to the gateway server has to be strictly controlled, although there are several protocols and mechanisms that have been thoroughly scrutinized to tackle these problems. This paper also intends to provide a model that uses secure socket layer (SSL) to provide a secure channel between client and gateway server. A smart card will be used for client authentication and encryption/decryption of the data.     

基于STM32的煤质化验仪器数据传输系统设计

针对火力发电厂煤质化验设备数据上传的问题,本文设计了一款基于STM32微处理器的数据传输系统。系统使用了虚拟仪器技术、RS232、RS485和TCP/IP协议等通信技术,实现了将多种化验仪器的不同协议不同格式的数据进行逐级封装上传到云端服务器的功能。经过测试表明,系统在全负荷工作时的稳定性、实时性和准确性较高,满足设计要求。