一种校园网反垃圾邮件系统设计方案

本文主要研究垃圾邮件防护理论与技术在校园网中的应用,应用垃圾邮件防护技术解决校园电子邮件系统中存在的安全问题,对提高经济欠发达地区、网络设备相对贫乏的校园网的安全性,具有重要的意义。     

电子邮件系统的安全性分析

电子邮件系统作为现代社会网络技术的一项重要应用,其所面临的安全风险日益严峻,现在电子邮件系统安全性的大多数的研究都集中在如何防范垃圾邮件上。本文就电子邮件系统的设计原理和操作流程进行阐述,对电子邮件系统所受到的安全威胁的漏洞原理进行分析,并针对电子邮件系统的功能特点分析了各种漏洞的利用方式和危害影响。     

基于电子邮件原理的垃圾邮件过滤策略

随着网络应用范围、领域的不断扩大,垃圾邮件也越来越多。为了防止垃圾邮件对网络和用户带来不必要的麻烦,从电子邮件系统的原理、结构出发,在电子邮件的发送、接收过程中研究如何对邮件的发送者进行身份认证。在电子邮件的发送服务器、接收服务器、接收者三个层次上分析垃圾邮件过滤方法。     

SPF技术在邮件服务系统中的应用

电子邮件是Internet应用最广的服务:通过网络电子邮件系统,您可以用非常低廉的价格,以非常快速的方式,与世界上任何一个角落的网络用户联络.但是,垃圾邮件也随着互联网的不断发展而大量增长,垃圾邮件的危害现在已经深入人心.本文主要介绍SPF技术在邮件服务系统中的应用,达到阻止垃圾邮件的目的.     

漏桶算法在反垃圾邮件系统中的应用

电子邮件是Internet应用最广的服务:通过网络电子邮件系统,您可以用非常低廉的价格,以非常快速的方式,与世界上任何一个角落的网络用户联络.但是,垃圾邮件也随着互联网的不断发展而大量增长,垃圾邮件的危害现在已经深入人心.本文主要介绍漏桶算法在反垃圾邮件系统中的应用,从而有效分析异常行为,以利于及时生成垃圾邮件过滤规则.     

反垃圾邮件技术

电子邮件作为目前在Internet上使用最广泛的服务，近年来日益受到垃圾邮件的威胁。众多的垃圾邮件最终将流向我们每一个电子邮件用户，极大地影响了电子邮件的使用效率。垃圾邮件之所以泛滥，原因在电子邮件系统本身在安全方面存在一些漏洞。当前已经有许多比较成熟的反垃圾邮件技术，其中的一些已经投入实用。本文将解释垃圾邮件的成因，并介绍一些主要的反垃圾邮件的技术，最后介绍一种新的类似于垃圾邮件的有害信息传播方式。     

金笛电子邮件系统（第四版）

由北京春笛信息技术有限公司推出的金笛电子邮件系统(第四版)是一款基于Java的大容量电子邮件系统产品，它支持多域管理、三级权限管理邮件杀毒、垃圾邮件过滤动态黑名单、邮件监控和报警等功能。在反垃圾邮件和反病毒邮件方面．它采用了独创的四层过滤技术(网络层，协议层、应用层及内容分析)，特别适合平时接收垃圾邮件和病毒邮件较多．对邮件过滤功能要求较高的企业使用。     

Internet邮件分组技术

该文对现有电子邮件系统中存在的安全性、垃圾邮件、邮件分类、信箱命名资源等问题进行了分析。在兼容现有邮件系统的基础上,提出了一种简单易行的邮件分组技术,并探讨了利用邮件分组技术解决现有邮件系统存在问题的方法。     

扼杀垃圾邮件

当垃圾邮件第一次作为一个问题出现在技术领域时,对于消费者和个人来说, 这是一个严重的问题,因为他们的个人数据(尤其是电子邮件地址)很容易被垃圾邮件的制造者得到,用于构建他们的数据库。这样不久公司的电子邮件系统也就被击跨了。根据公安部公布的全国信息网络安全状况暨计算机病毒疫情调查结果可以看出：因大规模垃圾邮件传播造成的安全事件已经高达36%。而整治垃圾邮件的工作已经进行了几年,效果并不明显,     

Foundir SpamWal反垃圾邮件解决方案

方标讯业在电子邮件系统和对抗有害信息方面积累了大量经验,紧密结合我国邮件服务单位和公安业务的特点,推出了反垃圾邮件系统Foundir pamWal和相关系统。在采集垃圾邮件特征方面具有明显技术突破,采用国际领先技术分析邮件,采取多样方式,各种手段相结合,提供网络层到应用层各种过滤和阻断方式,全面防止各种垃圾邮件的传播,防止各种人为和病毒的攻击。智能化、自动化、全面化,有效监控垃圾邮件。     

Online active multi-field learning for efficient email spam filtering

Email spam causes a serious waste of time and resources. This paper addresses the email spam filtering problem and proposes an online active multi-field learning approach, which is based on the following ideas: (1) Email spam filtering is an online application, which suggests an online learning idea; (2) Email document has a multi-field text structure, which suggests a multi-field learning idea; and (3) It is costly to obtain a label for a real-world email spam filter, which suggests an active learning idea. The online learner regards the email spam filtering as an incremental supervised binary streaming text classification. The multi-field learner combines multiple results predicted by field classifiers in a novel compound weight schema, and each field classifier calculates the arithmetical average of multiple conditional probabilities calculated from feature strings according to a data structure of string-frequency index. Comparing the current variance of field classifying results with the historical variance, the active learner evaluates the classifying confidence and takes the more uncertain email as the more informative sample for which to request a label. The experimental results show that the proposed approach can achieve the state-of-the-art performance with greatly reduced label requirements and very low space-time costs. The performance of our online active multi-field learning, the standard (1-ROCA)% measurement, even exceeds the full feedback performance of some advanced individual text classification algorithms.     

Expressing Location Information for Applications in the Internet

As part of the Spatial Location Protocol activity in the Internet Engineering Task Force (IETF), we have been working on how to express location information in an interoperable way in the Internet. The objective of this paper is to share our ideas on concepts for enabling interoperability and reuse of location information. These concepts can also be used in the area of ubiquitous computing. Correspondence to: Ms M. Korkea-aho, Department of Computer Science & Engineering, Helsinki University of Technology, Apollokatu 10 A 49, FIN-00100 Helsinki, Finland. Email: mari.korkea-aho@iki.fi     

发展军事卫星通信的一些看法

卫星通信在现代高技术战争中的作用越来越重要,各军事大国都在大力发展军事卫星通信。本文从网系、生存性及关键技术三个方面提出发展军事卫星通信的一些看法。     

Attribute‐Domain Matrix: A Reverse Engineering Method for Innovation

An innovative idea is a beautiful thing, but most innovative ideas do not become successful new products. For products that are successful, there is a variety of examples over more than 150 years of situations where customers used them in ways never planned by the designer. Only few companies are systematically exploiting non‐conventional use as a method to generate ideas for new product outcomes and problem solutions. TRIZ awareness of analogies systematizes the search for available alternate situations: the attribute‐domain matrix actively transfers product attributes to unexpected application domains, breaks the functional fixedness pattern and helps make aware the resources that are available in any product or system.     

局域网Email信息监控与过滤

电子邮件已成为广泛使用的通讯手段之一,对其实行合理有效的监控与过滤以保证网络安全,统计关键信息,杜绝不良信息的传播有重要作用。文章实现了一个基于Sniffer思想的电子邮件监控系统,对局域网中的电子邮件可进行有效的监控。并且基于Windows的实现方法,针对中文用户提出了一种改进的向量空间模型以达到信息有效过滤。     

Stability and traction control of an actively actuated micro-rover

This article addresses the issue of enhancing mobility of actively actuated vehicles by the use of optimal force distribution, and by actively controlling the location of the center of mass of the vehicle body. Force distribution in actively actuated vehicles is an underspecified problem, and optimal force distribution leads to improved contact conditions. Actively actuated vehicles also possess the ability to vary their configuration. This capability can be used to locate the center of mass of the system to further enhance mobility by providing sufficient traction, and ensuring vehicle stability, during difficult vehicle maneuvers. In this work, the general idea of control of the location of the center of mass, followed by optimal force distribution, is addressed first. This is followed by an application of these ideas to Gofor, a simple actively actuated wheeled micro-rover system, that has been designed and fabricated at the Jet Propulsion Laboratory. An algorithm to achieve desired traction and stability has been developed. Simulation studies were performed to investigate negotiation of a vertical surface. It was found that one set of wheels readily climbed the vertical surface with the use of active mass and force distribution. This is a significant improvement over traditional wheeled vehicle systems. © 1994 John Wiley & Sons, Inc.     

Randomization of data acquisition and ℓ<Subscript>1</Subscript>-optimization (recognition with compression)

A new paradigm for processing signals with sparse representation in some basis is actively developed for some time past. It relies largely on the ideas of measurement randomization and ℓ₁-optimization. The recent methods of acquisition and representation of the compressed data were christened compressive sensing.     

基于Web的客户端电子邮件系统的实现

该文阐述了在Ｉｎｔｅｒｎｅｔ／Ｉｎｔｒａｎｅｔ上发送和接收电子邮件的原理及由Ｍｉｃｒｏｓｏｆｔ Ｅｘｃｈａｎｇｅ Ｓｅｒｖｅｒ组成的电子邮件系统传输电子邮件的过程,提出了一种应用ＡＳＰ技术通过ＶＢＳｃｒｉｐｔ语言调用ＩＩＳ提供的ＣＤＯＮＴＳ类库实现在Ｗｅｂ上发送和接收电子邮件的方法。     

Decisional style and self-reported Email use in the workplace

Inefficient or inappropriate Email use within the workplace can lead to lowered productivity of an organisation. Technological predispositions, decisional style, and self-esteem may potentially influence the extent to which people use Email whilst at work. Higher levels of Email use in the workplace could be predicted by avoidant decisional styles such as procrastination and buck-passing. To understand how decisional style influences Email usage, 90 participants completed an Email Use Survey, the Melbourne Decision Making Questionnaire and the Coopersmith Self-Esteem Inventory. Procrastination, buck-passing, vigilance, hypervigilance and self-esteem were employed within separate multiple regressions to predict types of self-reported Email usage. Better-educated procrastinators reported higher levels of total Email usage. Older procrastinators reported more work-related Email usage. Young, better-educated individuals tended to report engaging in more personal Email usage in the workplace.     

一种电子邮件敏感信息检测算法

针对目前电子邮件安全网关不能很好地支持敏感信息检测问题,深入研究了Winnow算法和Markov模型,在N-Gram语言模型的基础上,提出了一种邮件特征选择方法--Markov-Gram,该方法以句子为单位进行特征项的选取,不仅保留了更多的语义信息,而且可以有效地减少特征项的数目,解决"维度灾难"问题;提出一种Winnow算法训练过程中初始权重生成方法,该方法融入了电子邮件结构特点以及