数字图书馆网络服务的监测   总被引：2，自引：0，他引：2  

庄纪林 《大学图书馆学报》2008,26(3):38-42,45

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。  相似文献   

Two-stage statistical language models for text database selection   总被引：2，自引：0，他引：2  

Hui Yang  Minjie Zhang 《Information Retrieval》2006,9(1):5-31

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.  相似文献   

构建基于J2EE规范的数字图书馆模型的探讨   总被引：2，自引：0，他引：2  

董慧  雷瑛  陈琮  杨宁 《中国图书馆学报》2004,30(3)

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。  相似文献   

数据移动技术的选择与实现     

卜鸥 《乐山师范学院学报》2003,18(4):111-113

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。  相似文献   

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

吴增德  饶卫雄  马范援 《浙江大学学报(A卷英文版)》2004,5(1):16-21

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.  相似文献   

CORBA、RMI与DCOM的对比研究   总被引：2，自引：0，他引：2  

廖继红 《南宁职业技术学院学报》2001,6(3):59-62

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。  相似文献   

Result merging methods in distributed information retrieval with overlapping databases   总被引：5，自引：0，他引：5  

Shengli Wu  Sally McClean 《Information Retrieval》2007,10(3):297-319

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.

Sally McCleanEmail:

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

《International Journal of Information Management》2020

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.  相似文献   

A pipelined architecture for distributed text query evaluation   总被引：1，自引：0，他引：1  

Alistair Moffat  William Webber  Justin Zobel  Ricardo Baeza-Yates 《Information Retrieval》2007,10(3):205-231

Two principal query-evaluation methodologies have been described for cluster-based implementation of distributed information retrieval systems: document partitioning and term partitioning. In a document-partitioned system, each of the processors hosts a subset of the documents in the collection, and executes every query against its local sub-collection. In a term-partitioned system, each of the processors hosts a subset of the inverted lists that make up the index of the collection, and serves them to a central machine as they are required for query evaluation. In this paper we introduce a pipelined query-evaluation methodology, based on a term-partitioned index, in which partially evaluated queries are passed amongst the set of processors that host the query terms. This arrangement retains the disk read benefits of term partitioning, but more effectively shares the computational load. We compare the three methodologies experimentally, and show that term distribution is inefficient and scales poorly. The new pipelined approach offers efficient memory utilization and efficient use of disk accesses, but suffers from problems with load balancing between nodes. Until these problems are resolved, document partitioning remains the preferred method. Alistair Moffat was supported by the Australian Research Council, the ARC Special Research Center for Perceptive and Intelligent Machines in Complex Environments, and the NICTA Victoria Laboratory. William Webber and Justin Zobel were supported by the Australian Research Council. Ricardo Baeza-Yates was supported by Grant P01-029-F from Millennium Initiative of Mideplan, Chile; and by the University of Melbourne as a visiting scholar at the time this project was undertaken.  相似文献   

改进的一致性哈希算法及应用     

方堃  武小年 《大众科技》2015,17(4)

针对分布式入侵检测中的数据分割问题,给出一种改进的一致性哈希算法。该算法针对采集的数据包,通过TCP流重组建立TCP数据链,保证数据流的完整性;再通过结点的分组对一致性哈希算法进行改进,并实现组间和组内的数据分配,减少虚拟结点数量;对结点的负载均衡检测和调整策略,改善了系统的负载均衡性。仿真测试结果表明该算法具有较好的负载均衡性。  相似文献