Delphi+ActiveX+DCOM→多层数据库

Internet可谓是计算机网络的网络，它特指目前全球范围内的计算机互联网络，通过它可以实现全球范围内的信息共享。WorldWideWeb（WWW，简称Web）是实现这种共享的一种方式，任何人借助一定的软硬件设备与Internet连接后，都能以Web页（WebPage）的方式在网上发布信息，为他的客户提供信息，而他又可以作为客户使用Web测览器访问别人发布在Web页上的信息。采用与Internet相同的通信协议（TIP／IP），遵循客户机／服务器原则，使用Web形式而建立信息系统的局域网称为Intranet。Inhanet是采用Internet技术的企业内部网，它基于多层…     

基于Web的数据采集

在本文中，将讨论使用标准Web技术——HTML、XML和Java——开发的一种基于Web的数据采集方法。万维网是到目前为止世界上最丰富和最密集的信息来源，但其结构使它很难用系统的方法来利用信息。本文描述的方法主要是通过设定目标锚并利用XALAN技术在源信息里获取目标数据，最后生成XML文档。这种方法可使那些熟悉Web最常用技术的开发人员能快速而便捷地获取他们所需的以Web方式发布的信息。     

在网上做自测题——用Authorware制作Web页面在线答题自测系统

本文利用Authorware的知识对象。给出一种制作Web页面的在线答题自测系统，并在教学局域网上发布的方法。     

一种基于PC的H.261视频广播系统

阐述了一种利用Delphi5开发的实时视频广播系统，可以图像采集卡采集的图像信息进行H．261压缩编码，并且在局域网内以广播式、交互式传输，在此系统的基础上，可方便地构建视频会议系统及视频监控系统。     

基于Internet的Web Services收集方法

Web Services作为一种部署在Internet上的新型的可复用软件资源,得到广泛的重视和应用。但是,现有通用搜索引擎并不能很好地支持Web Services的发现,这使得软件开发人员需要花费很大的代价寻找合适的Web Services。鉴于此,提出了一种基于Internet的Web Services获取方法,采用通用搜索引擎和特定Web Services信息发布网站相结合的方法,从Internet上收集Web Services,并从Web Services的相关网页中抽取相关描述信息。利用收集到的Web Services数据,对当前互联网上的WebServices现状进行了统计分析。这些统计结果一定程度上反映了WebServices的发展现状。     

怎样才可以把内网服务发布到公网

很多用户在自己的机器中架设起网站、FTP服务，甚至是小型邮件服务器，但这些网络服务由于防火墙或处于内网的缘故，只能供自己或同一局域网内的用户使用。如果你想让这些网络服务被更多的人分享，其实可以利用防火墙将这些服务发布到互联网中，如何发布呢？     

Web网站安全技术研究

信息安全是网络应用中的一个重要问题。网站是信息的发布中心,其数据库中存放有大量的供用户共享的重要信息,因此,网站的安全是网站建设和运行过程中应该充分考虑的重要问题。针对微软的因特网信息服务器(IIS)系统,该文从网站上运行的操作系统、信息发布平台(Web服务器)及信息之源(数据库)等几个方面研究了基于IIS的Web网站的安全问题,并结合目前的技术手段,阐述了构建Web网站应该采取的一些安全措施。在构建Web网站的实践中证明,这些安全措施是行之有效的。     

基于DOM树的可适应性多信息块Web信息抽取

Web信息抽取通常采用的是一种归纳学习方法,从指定的模版网页中归纳到抽取规则,这种方法虽然能够准确地抽取出信息,当网站的模版发生改变后,必须重新获得抽取规则,因而这种抽取器的维护成本比较高,可适应性差。本文针对这一难题,提出一种基于DOM树的可适应性多信息块Web信息抽取,该方法首先通过NekoHtml将网页解析成DOM树,然后确定包含关键词组的信息块,从而实现Web信息抽取。经过大量网站的实验证明该方法适用于不同站点的信息抽取,并且能对多信息块的Web页面进行信息抽取。     

Web网站安全技术研究

信息安全是网络应用中的一个重要问题.网站是信息的发布中心,其数据库中存放有大量的供用户共享的重要信息,因此,网站的安全是网站建设和运行过程中应该充分考虑的重要问题.针对微软的因特网信息服务器(ⅡS)系统,该文从网站上运行的操作系统、信息发布平台(Web服务器)及信息之源(数据库)等几个方面研究了基于IIS的Web网站的安全问题,并结合目前的技术手段,阐述了构建Web网站应该采取的一些安全措施.在构建Web网站的实践中证明,这些安全措施是行之有效的.     

一种基于Visual C＋＋6.0的实时图象传输系统

阐述了一种在Visual 6.0平台上开发的实时图象传输系统,在局域网内可对图象采集卡采集的图象信息进行广播式和交互式传输,既可直接传输位图,也可先先进压缩后传输。在此系统的基础上,可方便地构建视频会议系统及视频监控系统。     

一种新的移动Agent间通信算法

在分析已有广播通信机制的基础上,提出了一种新的移动Agent间通信算法。通过可靠扩散来实现广播,保证接收者至少接收一次消息;通过接收者主动请求消息,保证接收者只能接收一次消息。新算法保证可靠地完成消息发送以及消息传递的exactly—once语义,并在效率上有了进一步的提高。除了基本的算法,还讨论了一些改进的算法以及实现中遇到的一些问题。     

Systems of recall broadcast

In a system of recall broadcast, each message contains a set of message identifiers called its recall set. The recall set of a message identifies all previously received messages upon which the message is based. When a message is received by a process and displayed to an external user, all messages in its recall set are also displayed to the user. Our recall broadcast system is efficient in three ways. First, each message is broadcasted only once. Second, each process stores a small number of previously received messages because these messages may be recalled in future messages. Third, processes exchange additional messages to delete previously received messages that can no longer be recalled. The additional messages have the same format as regular messages, and are handled exactly as regular messages.     

基于属性的广播加密认证方案

在前人研究的基础上,提出一种适合于Ad Hoc网络的新的广播机制,即基于属性的广播加密认证机制。在该机制中,设计一个与广播节点属性相关的访问控制策略,基于此策略对所要广播的信息进行加密,使得只有属性集符合访问控制策略的节点才能解密获得明文。同时采用基于身份的签名方案实现对广播节点的认证。     

Broadcast protocols for distributed systems

An innovative approach is presented to the design of fault-tolerant distributed systems that avoids the several rounds of message exchange required by current protocols for consensus agreement. The approach is based on broadcast communication over a local area network, such as an Ethernet or a token ring, and on two novel protocols, the Trans protocol, which provides efficient reliable broadcast communication, and the Total protocol, which with high probability promptly places a total order on messages and achieves distributed agreement even in the presence of fail-stop, omission, timing, and communication faults. Reliable distributed operations, such as locking, update, and commitment, typically require only a single broadcast message rather than the several tens of messages required by current algorithms     

A fault-tolerant protocol for atomic broadcast

A general protocol for atomic broadcast in networks is presented. The protocol tolerates loss, duplication, reordering, delay of messages, and network partitioning in an arbitrary network of fail-stop sites (i.e. no Byzantine site behavior is tolerated). The protocol is based on majority-concensus decisions to commit on unique ordering of received broadcast messages. Under normal operating conditions, the protocol requires three phases to complete and approximately 4N/V messages where N is the number of sites. This overhead is distributed among the messages of which the delivery decision is made and the heavier the broadcast message traffic, the lower the overhead per broadcast message becomes. Under abnormal operating conditions, a decentralized termination protocol (also presented) is invoked. A performance analysis of this protocol is presented, showing that this protocol commits with high probability under realistic operating conditions without invoking termination protocol if N is sufficiently large. The protocol retains its efficiency in wide-area networks where broadcast communication media are unavailable     

基于CAN 网的模糊优先级配置策略

利用CAN网的广播特性,提出一种新的闭环模糊优先级配置策略.各节点数据优先级的设定既与其QoS需求有关,又与其节点标识位及前一个传输数据的优先级有关.该策略尽管使用较少的优先级,但仍能保证实时数据较高的可调度性和非实时数据的服务公平性.较少的优先级只占用较少的bit位,这样不仅扩大了CAN网的服务能力,而且提高了CAN网的带宽利用率.     

无线传感器网络低功耗多跳广播时钟同步算法

为满足无线传感器网络低功耗的要求,提出一种双广播域同步的低功耗多跳广播时钟同步算法。该算法基于接收端-接收端同步机制,通过一对已同步节点间对等广播消息,只需多发送一次消息,即可将该对节点的同步范围扩大为两广播域的并集,并采用双根节点的层级结构将算法扩展到全网络范围。OMNeT++仿真结果表明,与MBS算法相比,该算法能有效降低全网络同步需要传输的报文个数。     

Privacy-preserving identity-based broadcast encryption

Broadcast encryption enables a broadcaster to encrypt messages and transmit them to some subset S of authorized users. In identity-based broadcast encryption schemes, a broadcasting sender typically encrypts a message by combining public identities of receivers in S and system parameters. However, previous identity-based broadcast encryption schemes have not been concerned about preserving the privacy of receivers. Consequently, all of the identities of broadcast receivers in S are exposed to the public in the previous schemes, which may be subject to attacks on user privacy in lots of pragmatic applications. We propose a novel privacy-preserving identity-based broadcast encryption scheme against an active attacker. The proposed scheme protects the privacy of receivers of broadcasted messages by hiding the identities of receivers in S. Additionally, it achieves less storage and computation costs required to encrypt and decrypt the broadcast message, compared to the previous identity-based broadcast encryption schemes that do not provide user privacy.     

Restricted usage of anonymous credentials in vehicular ad hoc networks for misbehavior detection

The automobile industry is entering a new era of digitalization with major impact on human mobility and transportation infrastructures. A result of such a convergence between the automobile and information technologies is vehicular ad hoc network (VANET), a type of mobile ad hoc networks that has recently enjoyed a lot of attention from the industry, the research community, lawmakers and privacy activists. In VANET, vehicles frequently broadcast various types of messages, including location data. This enables innovative applications and improvements in safety and driving experience. As messages broadcasted in the VANET are digitally signed and the receiver must be able to verify the sender’s authentication and message integrity, there is a need to ensure broadcast authentication and protect driver’s anonymity. However, communication in VANETs takes place with high frequency, and malicious vehicles can hide behind anonymity in order to duplicate packets and get advantage over other vehicles in the network. Indeed, state-of-the-art approaches to privacy-preserving messages broadcast in the VANET typically ensure that each vehicle has a number of pseudonymous certificates that are changed regularly in order to thwart an automated tracing of its activities. However, the possibility of uncontrolled simultaneous use of pseudonyms by misbehaving vehicles remain unaddressed. This paper proposes a set of anonymous credential system based protocols for VANET that enables the detection and limitation of pseudonym/credential overspending. The revocation of the misbehaving vehicle can be also achieved through the proposed solutions. With the prototypical implementation of the proposed protocols, it has been shown that the successful detection of fraud, i.e., pseudonyms overspending and the subsequent revocation of credentials are possible in VANET.     

MESSAGE AUTHENTICATION USING QUADRATIC RESIDUES

This paper shows a method for authenticating messages based on quadratic residues. The method will detect accidental or deliberate changes to a message, and will verify the sender of the message, both with near certainty. It does not require any preliminary exchange of messages, and does not require publishing any additional data besides each user's public key.