A Generic Architecture Multimedia Service and Management

A multimedia service architecture is constructedby using a generic component model. In order to derivespecific components, a generic service agent and genericservice component architectures are developed. Using generic agent and the service components,a TINA-C conformant object-oriented hierarchical genericservice component is developed and presented. As anexample, a multimedia QoS service and management architecture is presented.     

基于位置的社交网络用户轨迹相似性算法研究

针对位置社交网络的用户轨迹相似性分析,先对签到点分层聚类,然后计算各分层的用户轨迹相似性,加权得到用户总体相似性,提出了一种基于自适应密度聚类的用户轨迹相似性双重加权模型。首先根据签到点的分布,提出基于聚类区域半径的自适应密度聚类算法,对签到点进行聚类,得到符合一定区域半径的自适应分层聚类区域。然后针对用户相似性的计算,提出用户轨迹相似性双重加权模型：基于不同层次上权重不同及同一层次上不同签到区域权重不同两个原则。基于分层聚类区域,计算用户访问各分层的轨迹相似性;由于不同签到区域对相似度的表征能力不同,通过不同权重来计算具体层次上的相似性。进而进行层次上的加权,获得用户总体的相似性。通过仿真,该方法能有效的分析出用户轨迹相似性,具备较高的准确性。     

SOAP协议在远程控制中的应用

本文对soap协议作了一个简单的介绍，并且对该协议在远程控制系统中的应用作了分析。     

A Flexible and Robust Peer-to-Peer Architecture with XML-Based Open Communication for Laboratory Automation

Traditional lab automation systems are highly centralized: dispatch and coordination of activities are mediated by a system controller, usually via a single, monolithic control procedure. This approach, while conceptually simple, makes changes to the system difficult; adding or removing instruments and functionality can be a daunting task. In addition, most automated systems are tied to particular development languages and protocols, making operation in heterogeneous environments (i.e., the real world) problematic, since instrument software comes in many different implementations.We present a peer-to-peer architecture for lab automation, using an XML-based communication protocol. The architecture consists of peer instrument servers, an XML communication layer, and an open control center. Each instrument peer can control, be controlled by, and communicate information to other instrument peers to fulfill the automation task. Our protocol is based on XML-RPC, a lightweight communication standard built atop HTTP.This provides an open and flexible means of peer-to-peer interfacing. The control center serves as a convenient, Web-based interface to manage the instruments. The automated procedure can be distributed across all available instrument peers (each instrument assigned a set of responsibilities); the controller implements a limited set of high-level instructions. The software components included in our prototype system are implemented in various programming languages, including Java, C/C++, Visual Basic, and LabVIEW. Our approach facilitates rapid development of laboratory automation systems.     

Temporal Network Management Information Model and Services

The paper addresses the issue of time as anattribute of the network management information. Thetemporal dimension is incorporated in the managementinformation model proposed by the Internet Engineering Task Force (IETF), as it is described by theStructure of Management Information (SMI). The core ofthe proposed network management information model is theTemporal Management Information Base (TMIB), a conceptual representation of the diachronicbehavior of network resources. The temporal networkmodel also includes the definition of a specificarchitecture and a number of temporal services. Theexistence of such services facilitates the development oftime-reference applications in different functionalareas.     

Using the Concept of Intelligent Agents in Fault Management of Distributed Services

This paper proposes the application of conceptsfrom the area of intelligent agents to overcomedeficiencies of existing management architecturesregarding distribution of functionality and flexibility. Its main contribution is the proposal of amethodology for a flexible, distributed realization ofcomplex management tasks. The main application areas aredistributed services which are complex pieces of software, distributed across variousheterogeneous end systems in a network. Mostly, theyrely on the provision of other services as well. Theapproach relies on well-known concepts, such ascooperative distributed problem solving and intelligentagents, and offers a framework to combine these twoconcepts, providing a step on the roadmap to a flexible,distributed management architecture. The assessment of the approach is displayed throughout thepaper by scenarios from the area of nontime criticalfault management.     

Synchronization Architecture for Multimedia Services in Mobile Radio Environments

The management of multimedia teleservices inthird-generation mobile radio environments is achallenging task due to the multicomposite andmultirequirement nature of this kind of traffic.Following the choice of carrying multimedia information onmultiple bearers over the air interface of a wirelesspersonal communication system, and after the selectionof a TDMA-like multiple access protocol based on the bandwidth reservation, the system isrequired to provide for an interstream synchronizationamong components of the multimedia service. This paperpresents an architecture for guaranteeing that temporal relationships among components at thetransmitter side can be maintained, after crossing theair interface, at the receiver side, regardless ofdifferent bearers' delay constraints and delays sufferedin the buffer of the base station. The attentionis focused on a kind of roughsynchronization to be performed on the system MAC leveland refined by higher protocol layers. Static anddynamic priorities concepts are exploited to achieve the targetsynchronization degree among components. Simulationresults, carried out in a case of a video-audioconnection, confirm the effectiveness of the proposedmechanism.     

A Novel Multiaccess Strategy for Multimedia Wireless LANs

The main focus of the research presented in thispaper is to evaluate how efficiently a commoncommunication medium such as broadcast radio can beshared by a large number of network devices in anin-building environment. The goal is to recommend anoptimal method to fulfil the demanding requirementsdictated by broadband multimedia applications operatingin wireless local area networks. To this end, apractical and efficient multiaccess scheme calledreserved polling is proposed and analyzed.It is shown that the new method is able to handle anintegrated mix of multimedia traffic and operaterobustly in an unreliable wireless transport medium. Ananalytical approach based on queueing theory is employedto gain some insight into the complex behavior of theprotocol. This approach appears to be accurate in predicting its performance for both bursty andperiodic traffic types. The analytical results areverified by network simulation.