基于VQ的说话人识别系统

该文介绍了一种基于矢量量化(VQ)方法的一个说话人识别算法。基于矢量量化的说话人识别,因其运算过程简单等特点,在说话人识别领域有着广泛的应用。用不同语音参数进行实验,实验表明应用矢量量化的方法用在说话人识别中是一种有效方法。     

基于网络型中央控制器的多媒体教室远程管理

网络中控系统通过人性化的人机界面、开放式的可编程控制平台、交互式的控制结构,实现了设备的互连操作和集中控制,它集成了电源管理、视音频切换矩阵、红外遥控、VGA切换矩阵、全数码声音控制、可编程串行通讯、设备IP网络连接等功能,应用到多媒体教学中,不仅有效解决了对设备的管理与信息的切换,也使实现多媒体教室的远程管理成为可能。该文以创捷HT1800中控系统为例,就实现这一技术的原理和方法进行了阐述,便于大家更好地对网络中控系统有一个全面的认识。     

A distributed expansible authentication model based on Kerberos

There is a potential server bottleneck problem when the Kerberos model is applied in large-scale networks because the model uses centralized management. To enlarge its application scope, researchers must consider how to build a trust relation among those Kerberos servers located on different isolated domains, but have not provided a way to prevent the potential bottleneck that can occur with Kerberos servers. With the development of across-domain authentication techniques, the local server bottleneck problem has not been alleviated; in fact, it has become more serious.Adopting the rigorous binary tree code algorithm, we present an authentication model based on Kerberos. Compared with similar models, our model has several advantages. First, it overcomes the potential server bottleneck problem and can balance the load automatically. Second, it can process across-domain authentication and enlarge the authentication boundary. Finally, its authentication path is short, with no more than two Kerberos servers being involved when authenticating a user.     

Achieving evenhandedness in certified email system for contract signing

Certified email is a system which enables a sender to prove a receiver’s receipt of email. Such a system can be used for applications related to electronic commerce on the Internet. This paper considers a situation where a sender or a receiver wants to change his/her mind due to the change of mail content value (e.g., stock, auction, gambling) during the transaction. We point out that no traditional certified email systems have been designed for such a case, thus one of the participants can be at a disadvantage. To avoid this problem, we propose an evenhanded certified email system in which each participant can change his/her choice, either cancel or finish the transaction, at any time during the transaction.

Quantum programming languages

After giving a bird’s view of some existing quantum programming languages, this paper reports the recent results made by the quantum computation group of the State Key Laboratory for Novel Software Technology and the Department of Computer Science and Technology at Nanjing University, i.e., the quantum programming languages NDQJava, NDQFP and their processing systems.     

Freeman链码压缩算法的研究

文中提出一种新的链码编码方法。在链码中的每个码是根据它与其前一个码之间的前进方向角度差来进行编码的。统计结果表明,这样编码的每个码值的出现概率是很不同的。角度差小的码值出现概率较大,而角度差大的码值出现概率较小。这样结合霍夫曼（Huffman)编码方法就可实现链码的压缩。新链码与现有链码进行了比较。比较结果显示新链码具有最小的平均码长1．97位／码。     

Towards a Mobile Code Management Environment for Complex,Real-Time,Distributed Systems

We present a novel mobile code management environment,currently under design and development. Our design employs anopen architecture, suitable for ``plug-and-play' with COTS andother groups' tools. While we have studied new algorithms, costand objective functions, and other fundamental issues, the maincontribution of this experimental research work is in the environmentitself. It should be noted that networked platforms, such asthe World Wide Web, are inherently not suitable for traditional,predictable real-time applications. Thus, real-time concernsnecessarily need to be blended with others concerns, and thetarget applications, making use of our environment, will toobe a blend of partially hard real-time and partially (or mostly)soft-real- time ones. The prototype environment will thereforesupport performance-based analysis and management focusing notonly on predictability but also on compilation, efficiency, safetyand other tradeoffs. We have selected the Java language and itsbytecode format as a representation for mobile code as well asa language for our implementation.     

Java移动代码的授权访问研究

Java移动代码是一种可以通过网络从一台计算机传珐另一台计算机上运行的Ｊava程序,在现代网络计算及电子商务中具有广泛应用,Ｊava的这一显著特性也蕴藏着授权管理上的不足,未授权者可以很容易地非法使用这些程序,针对Ｊava移动代码的这些不足之处,分别对Ｊava Applet及Ｊava Applet及Ｊava Servlet提出了基于数字签名算法的授权与访问控制方案,安全,有效地解决了这种新兴的授权与访问控制问题。     

Formal Analysis of Multiparty Contract Signing

We analyze the multiparty contract-signing protocols of Garay and MacKenzie (GM) and of Baum and Waidner (BW). We use a finite-state tool, Mocha, which allows specification of protocol properties in a branching-time temporal logic with game semantics. While our analysis does not reveal any errors in the BW protocol, in the GM protocol we discover serious problems with fairness for four signers and an oversight regarding abuse-freeness for three signers. We propose a complete revision of the GM subprotocols in order to restore fairness.     

利用分级建库技术建造汉语语义词典

文章介绍了立足于机读文本资源——机读《现代汉语词典》和机读《同义词词林》,分级建造以统一管理、共享数据资源为特征的汉语语义词典的研究工作。