TSPN: Term-Based Semantic Peer-to-Peer Networks

In this paper,we propose Term-based Semantic Peerto-Peer Networks (TSPN) to achieve semantic search.For each peer,TSPN builds a full text index of its documents.Through the analysis of resources,TSPN o...     

Brown Dwarf: A fully-distributed, fault-tolerant data warehousing system

In this paper we present the Brown Dwarf, a distributed data analytics system designed to efficiently store, query and update multidimensional data over commodity network nodes, without the use of any proprietary tool. Brown Dwarf distributes a centralized indexing structure among peers on-the-fly, reducing cube creation and querying times by enforcing parallelization. Analytical queries are naturally performed on-line through cooperating nodes that form an unstructured Peer-to-Peer overlay. Updates are also performed on-line, eliminating the usually costly over-night process. Moreover, the system employs an adaptive replication scheme that adjusts to the workload skew as well as the network churn by expanding or shrinking the units of the distributed data structure. Our system has been thoroughly evaluated on an actual testbed: it manages to accelerate cube creation up and querying up to several tens of times compared to the centralized solution by exploiting the capabilities of the available network nodes working in parallel. It also manages to quickly adapt even after sudden bursts in load and remains unaffected with a considerable fraction of frequent node failures. These advantages are even more apparent for dense and skewed data cubes and workloads.     

Self-scaling cooperative discovery of service compositions in unstructured P2P networks

We propose an efficient technique for improving the performance of automatic and cooperative compositions in unstructured Peer-to-Peer networks during service discovery. The technique exploits a probabilistic forwarding algorithm that uses different sources of knowledge, such as network density and service grouping, to reduce the amount of messages exchanged in the network. The technique, analysed in several network configurations by using a simulator to observe resolution time, recall and message overhead, presents good performance especially in dense and large-scale service networks.     

非结构化P2P网络中基于节点的MQR算法设计与实现

在非结构化P2P搜索中,由于缺少全局性的管理机制,网络节点无法获得整个网络的拓扑结构及目标数据的定位信息,因此查询消息的路由过程具有较高的随机性,不仅查询性能低,而且宽带消耗大。为在有效控制网络冗余消息规模的同时提高数据的搜索范围,在分析现有2类典型非结构化P2P路由算法的基础上,提出一种基于节点的MQR算法。利用网络节点的状态信息及搜索过程中查询消息的TTL值状态信息,从数据的搜索范围与网络使用情况2个方面来提高非结构化P2P网络搜索性能。仿真实验结果表明,与传统的P2P路由算法APS和Random Walk相比,该算法在搜索准确率、网络利用率及召回率方面有更好的表现。     

P2P流媒体网络中基于博弈理论的带宽请求分配策略

基于对等网(P2P)技术的视频流媒体系统以其较低的服务器开销和良好的可扩展性被广泛应用。但由于在这类系统中普遍存在节点的资源及视频播放位置的异构性,使得节点负载不均衡的问题极易发生,进而严重影响到节点的视频播放质量。该文重点研究面向节点负载均衡的节点带宽请求分配策略,将服务请求节点竞争服务提供节点带宽的行为建模为一个非协作博弈,通过寻求该博弈问题的 Nash 均衡解的方法确定优化的带宽请求分配(GBRA)策略。通过和典型的带宽请求分配策略进行实验对比,数值结果表明该文提出的GBRA 策略能有效改善P2P流媒体网络节点负载不均的问题并降低节点获取所需视频数据的平均延迟。     

Segment Storage System:基于P2P的网络存储服务

Segment Storage System(S3)是一种基于P2P模型的网络存储服务,它具有高可用性、可靠性和持久性的特点。S3继承了P2P网络的优点并且摒弃了诸如文件时效性和不稳定性等缺点。S3的目标是提供一种高质量的网络存储服务。文章是对S3的设计架构的一个概览。     

一种基于PKI的P2P计算平台设计与实现*

分布式P2P计算不同于传统的客户/服务器模式.通过分析P2P系统的安全需求,讨论了如何将PKI技术应用到P2P分布式计算中的问题.设计并实现了一种基于PKI技术的P2P安全计算平台.该平台结合了Web Services中的XML,SOAP等技术以及JXTA架构,在一定程度上实现了P2P环境中的安全认证与资源的访问控制,保证了P2P计算的安全性.     

计算机支持的技术支援:概念与网络体系结构

首次提出了计算机支持的技术支援（CSTA）概念。计算机支持的技术支援是信息社会中技术支援的主要形式。分析了技术支援的过程、CSTA的技术特点和优点．总结了CSTA的基本研究内容和常用形式。针对技术支援的新需求、介绍了基于P2P的CSTA网络体系结构。     

An efficient composition of Web services with active network support

Composition of Web services enables collaboration among autonomous business organisations such that they can integrate their services to perform collaborative business activities. It facilitates the development of new services using pre-existing Web services thus reducing development and operational costs. However, the highly distributed, dynamic, and autonomous nature of component Web services gives rise to various issues such as service matchmaking, reliability, availability, security and efficiency. This paper presents a new protocol in order to improve the efficiency of Web services composition. The proposed protocol is based on the peer-to-peer paradigm which exploits the capabilities of underlying networks such that part of the processing is carried out at the network nodes. Efficiency of the proposed protocol is tested through various experiments. Experimental results show that the proposed protocol significantly improves performance by reducing the system response time in the composition of Web services.     

跨越NAT的P2P应用UDP通讯

随着基于Internet的P2P网络技术的广泛应用，更多的内网主机需要参与到P2P中来。NAT之后的主机IP地址在Internet上是不可见的．Internet上的主机不能主动访问这些NAT之后的主机，但P2P网络要求任何主机之间都能够直接对等交换信息，这就使得P2P网络应用必须解决穿越NAT实现双向对等通讯的问题。本文在介绍了NAT基本原理和NAT对P2P应用的影响基础上，分析了客户端位于同一个NAT的后面、客户端位于不同的NAT的后面和客户瑞位于多级NAT的后面这三种情况下．P2P软件跨越NAT的UDP通讯问题。