数字图书馆网络服务的监测

数字图书馆通常是一个分布式的松散耦合的多系统构成的庞大的应用服务体系,采用"安装代理"和"远程登录"的商业化网络服务监测软件并不适用于数字图书馆网络服务的监测。在分析数字图书馆网络服务特点的基础上提出了"基于内容"的数字图书馆网络服务监测方案,解决了数字图书馆网络服务体系中只有"访问权限"而没有"管理权限"的网络服务的监测问题。     

Two-stage statistical language models for text database selection

As the number and diversity of distributed Web databases on the Internet exponentially increase, it is difficult for user to know which databases are appropriate to search. Given database language models that describe the content of each database, database selection services can provide assistance in locating databases relevant to the information needs of users. In this paper, we propose a database selection approach based on statistical language modeling. The basic idea behind the approach is that, for databases that are categorized into a topic hierarchy, individual language models are estimated at different search stages, and then the databases are ranked by the similarity to the query according to the estimated language model. Two-stage smoothed language models are presented to circumvent inaccuracy due to word sparseness. Experimental results demonstrate that such a language modeling approach is competitive with current state-of-the-art database selection approaches.     

构建基于J2EE规范的数字图书馆模型的探讨

从软件工程的角度分析,数字图书馆实质是一个分布式管理信息系统。构建数字图书馆,就是构建一个分布式管理信息系统。J2EE的多层次的分布式应用模型和一系列开发技术规范,为构建数字图书馆平台提供了可靠保证。图1。参考文献11。     

数据移动技术的选择与实现

数据移动技术是分布式数据库中非常重要的技术之一。本归纳总结了分布式数据库中的数据移动技术，从本质上将现有的数据移动技术分为在线、同步、复制三类技术。在线技术系统可以达到绝对的一致性，但该技术对网络要求很高，且在节点较少时才比较有效。同步技术可以支持大量节点，异构和级联环境，要求有效的网络连接，存在一定的一致性延时。复制技术比较灵活，支持大量节点，异构和级联环境；可以在较好的网络环境，也可以在无直接或网络环境恶劣的情况下使用；存在一定的一致性延时，也可达到准实时的一致性。这三类数据移动技术的应用和选择，主要取决于业务需求和可用的技术架构以及系统对一致性和延时的要求。     

Super-proximity routing in structured peer-to-peer overlay networks

Peer-to-Peer systems are emerging as one of the most popular Internet applications. Structured Peer-to-Peer overlay networks use identifier based routing algorithms to allow robustness, load balancing, and distributed lookup needed in this environment. However, identifier based routing that is independent of Internet topology tends to be of low efficiency. Aimed at improving the routing efficiency, the super-proximity routing algorithms presented in this paper combine Internet topology and overlay routing table in choosing the next hop. Experimental results showed that the algorithms greatly improve the efficiency of Peer-to-Peer routing.     

CORBA、RMI与DCOM的对比研究

文章介绍了当今最流行的三种分布式结构 CORBA、RMI和 DCOM的基本结构模型 ,分析和比较了它们的相关特性和开发易难程度。     

Result merging methods in distributed information retrieval with overlapping databases

In distributed information retrieval systems, document overlaps occur frequently among different component databases. This paper presents an experimental investigation and evaluation of a group of result merging methods including the shadow document method and the multi-evidence method in the environment of overlapping databases. We assume, with the exception of resultant document lists (either with rankings or scores), no extra information about retrieval servers and text databases is available, which is the usual case for many applications on the Internet and the Web. The experimental results show that the shadow document method and the multi-evidence method are the two best methods when overlap is high, while Round-robin is the best for low overlap. The experiments also show that [0,1] linear normalization is a better option than linear regression normalization for result merging in a heterogeneous environment.

A framework for analysing blockchain technology adoption: Integrating institutional,market and technical factors

The adoption of blockchain technologies require the consideration of a broad range of factors, over and above the predominantly technology focus of most current work. Whilst scholarly literature on blockchain technology is only beginning to emerge, majority are focused on the technicalities of the technology and tend to ignore the organizational complexities of adopting the technology. Drawing from a focused review of literature, this paper proposed a conceptual framework for adoption of blockchain technology capturing the complex relationships between institutional, market and technical factors. The framework highlights that varying outcomes are possible, and the change process is focal as this shapes the form blockchain applications take. Factors presented in the framework (institutional, market and technical) interact and mutually influence each other. The proposed framework can be used by organisations as a reference point for adopting blockchain applications and by scholars to expand, refine and evaluate research into blockchain technology.     

基于分布式数据库的房地产管理信息系统的设计与实现

本文对房地产管理信息系统设计方案中的分布式数据库技术进行了详细阐述,包括分布式数据库的设计原则、系统结构、分布式查询与数据更新等内容.     

基于合同网协议的异地分布式敏捷开发多团队间任务分配分析

异地分布式协同开发是大型复杂产品开发策略的一部分,而任务分配是异地分布式敏捷协同开发项目计划阶段的关键决策。结合相关理论以及前期研究,构建基于合同网协议的产品开发异地分布式团队间的任务分配模型,将任务重要程度优先权引入任务分配模型中,通过实例进行仿真计算,验证所提方法的可行性。实证表明所提方法更适用于异地分布式敏捷开发项目,可提高异地分布式开发敏捷性项目的效率。