Low-Cost Web Service Discovery Based on Distributed Decision Tree in P2P Environments

Peer to Peer (P2P) techniques were widely applied into Web service discovery fields, but most existing schemes only focused on matching the functional attributes of Web services and ignored the non-functional attributes, i.e. quality of services (QoS). In this paper, we present a QoS-aware Web service discovery approach. The approach maps each Web service into virtual space to distribute all QoS attributes among P2P nodes, and then designs a distributed decision tree to support range service query with QoS requirements. Finally, a load balance algorithm is used to reduce range query cost. Experimental results based on synthetic and real datasets show our proposed approach can perform effective service discovery with low cost in P2P environments.     

Composable Mediation for Security-Aware Mobile Services

This article shows how service mediation can be used to add security features to services in a mobile service platform. This base platform takes care of security, charging, and other basic functions, which are then configured for services at runtime using a pluggable mediator framework. Service providers can focus on content, and thus leverage the signaling and mediation capabilities of the core platform. Mediators add specific functionality to a service, and are a specific form of service composition and selection. We examine how security technologies for authentication and authorization are integrated by mediators into a single policy infrastructure with a homogeneous interface for services. We consider here the Web services SAML and the 3GPP GBA security bootstrapping standard in the context of mobile services. We give an example using a video on demand service, and discuss how and when security concerns of services can be transferred from the services to mediators.     

基于社会网络面向个性化需求的可信服务推荐

在当前服务计算和社会计算背景下,针对难以获取满足用户个性化需求的可信Web服务问题,给出基于社会网络面向个性化需求的可信Web服务推荐模型;设计用户个性化功能需求分解与匹配算法,并利用语义词典提高功能需求语义匹配的准确性;基于个性化功能需求、社会网络节点信任度及服务信任度,设计了一种满足用户个性化需求的可信服务推荐算法,通过对社会网络节点之间、节点与服务之间的信任相关性进行分析,提高服务协同可信推荐性能。算法分析及实验结果表明该方法是有效和可行的。     

面向领域标签辅助的服务聚类方法

Web服务数量的激增对服务发现提出了更高的要求,服务聚类是促进服务发现的一种重要技术.但是,现有服务聚类方法只对单一类型的服务文档进行聚类,缺乏考虑服务的领域特性和服务标签的应用.针对这些问题,本文首先使用本体辅助的支持向量机和面向领域的服务特征降维技术建立服务的特征内容向量,然后使用一种标签辅助的主题服务聚类方法T-LDA建立融合标签信息之后的隐含主题表示,并利用归一化方法消除通用主题的影响,综合上述方法建立一个面向领域标签辅助的Web服务聚类方法DTWSC.实验结果表明,该框架能够提高针对不同类型的服务文档的聚类效果.与LDA、K-Means等方法相比,该方法在聚类纯度、熵和F-Measure指标上均具有更好的效果.     

多策略QoS感知的服务选择与排序模型

随着网络中具有相同功能、不同QoS服务的增多,在用户请求服务时,为了确保能找到满足用户功能与质量要求的服务,并对找到的可用候选服务集按一定的策略进行选优,提出了一种多策略QoS感知的服务选择与排序模型。在该模型中,综合考虑服务的性能与运营维护成本等属性,提出了一个扩展的服务QoS模型,在此基础上引入用户、运营商对服务满意度的计算方法,通过改变用户满意度与运营商满意度在排序选优过程中所占的不同比重,灵活设置服务选优策略,有效的解决了服务排序选优问题。搭建了服务选择与排序原型系统,并通过应用实例对上述模型进行了验证。     

一种支持迁移的Web服务安全防护机制

SOA是一种标准化接口的分布式计算模型,基于Web服务平台无关性的特点允许服务功能通过动态组合支撑不同种类的应用业务,但是服务运行的动态性、复杂性和跨组织的松耦合性使服务系统面临严重的攻击威胁。针对分布式环境中服务全生命周期安全防护的应用需求,提出了一种可迁移的Web服务安全防护方法,不仅能够在服务节点正常运行过程中通过安全防护模块支撑服务的认证、访问控制和攻击检测,而且能够对服务迁移的全过程进行安全增强,实现无缝的安全防护能力,为安全服务环境的设计完善提供了一种可行思路。     

Web service discovery utilizing logical reasoning and semantic similarity

Web service discovery facilitates the implementation of complex and reconfigurable applications in service‐oriented architecture, such as service selection, composition, and provision. This paper presents an approach for semantic and automated Web service discovery. Our approach to semantic Web service discovery consists of ontology‐based service preprocessor, reasoning‐based service filter, and parameter‐based service matcher. An important feature of this approach is that the relationship among concepts in ontology is quantified and considered as an important factor in the matching process, which results in high precision and recall. Additionally, we propose a filtering method based on logical reasoning to preprocess the large amount of Web services. Through the filtering method, Web services which are feasible in logic are selected to be matched with user requests. So there is a great improvement in the run‐time performance of service discovery approach. Experiments show that our approach is feasible and effective to discover the required Web services.     

全维可定义网络能力

针对现有网络能力提供形式单一、动态性差、效能低、运维僵化以及难以适应未来复杂场景下专业化、个性化业务需求的问题,提出了全维可定义网络能力。基于“以网络为核心”的设计理念,开放网络各层能力,实现通信主体、网络功能、网络资源、安全等全维度网络能力可定义,支持动态加载和演进发展。通过业务需求自映射和网络能力自组织灵活适配业务发展需求,以多种接口形式主动向终端业务输出多样化网络内生能力,自然适应未来业务的复杂不确定演进。     

基于QoS的语义Web服务组合优化算法

在面向服务的环境下,存在众多可满足服务请求者要求的服务组合方案,如何从中选出最优或近似最优方案是Web服务组合优化要解决的问题.设计出一个不必探索整个解空间的优化算法——SBG算法,为服务请求者提供最优选择方案.实验结果表明,这种方法可有效提高选择方案的求解效率.     

Service-oriented Access to Next Generation Networks—from Service Creation to Execution

Existing telecommunication networks and classical roles of operators are subject to fundamental change. Many network operators are currently seeking for new sources to generate revenue by exposing network capabilities to 3rd party service providers. At the same time we can observe that services on the World Wide Web (WWW) are becoming mature in terms of the definition of APIs that are offered towards other services. The combinations of those services are commonly referred to as Web 2.0 mash-ups. Rapid service design and creation becomes therefore important to meet the requirements in a changing technology and competitive market environment. This report describes our approach to include Next Generation Networks (NGN)-based telecommunications application enabler into complex services by defining a service broker that mediates between 3rd party applications and NGN service enablers. It provides policy-driven orchestration mechanisms for service enablers, a service authorization functionality, and a service discovery interface for Service Creation Environments. The work has been implemented as part of the Open SOA Telco Playground testbed at Fraunhofer FOKUS.     

基于UML模型的NGN业务安全分析

相比传统的电信网，NGN面临着众多的安全威胁，NGN的业务安全也面临着巨大的挑战。业务的开发和部署需要考虑到更多的安全特性和安全功能。利用UML安全扩展UMLsec对NGN中的业务安全需求进行分析建模，提出了一种细粒度的安全需求分析方法，通过抽象出安全功能抽象类说明NGN业务的安全特性需求。并通过用例讨论了基于安全应用接口的安全需求实现，使得各种安全特性能够更方便、更灵活地集成到业务中。     

基于组合上下文的服务替换方法

随着用户需求的多样性和网络环境的日益复杂性,组合服务的复杂程度越来越高,在对失效服务进行替换时,为了减少被替换服务的冗余信息和提高替换方法的准确性,提出以待替换服务的组合上下文为研究对象,通过以下2个步骤完成替换:第一,基于已有的着色petri网服务工作流建模方法,提出服务的组合上下文信息采集算法(CCICA,composition context information collection algorithm),以服务的组合上下文为服务信息采集源;第二,提出基于编辑距离的服务替换方法(LDBSSM,levenshtein distance-based service substitution method),并将服务接口的依赖关系加入到了算法中.仿真实验表明,该方法不仅较好地减少了被替换服务的信息冗余,而且有效提高了服务替换的准确性,具有更好的实用价值.     

基于OWL-S的Web服务匹配的研究

服务匹配是Web服务发现中一个很重要的部分。针对目前服务发现方法的描述缺少灵活性和表示性的不足，文章提出了一种基于OWL-S的Web服务匹配算法，其核心思想是用OWL-S进行服务描述并将其发布后．通过对服务描述中的输入输出和用户需求中功能的测度来判断服务与用户需求的匹配程度．将UDDI和功能匹配结合起来，使得用户能够更好地进行服务查询。     

An architectural approach to minimizing feature interactions intelecommunications

Feature interaction, in the context of telecommunications, is the phenomenon where a user (end-user or system operator) observes services failing to perform as expected, and where the failures are due to the presence of other services (or multiple instances of a single service) in the network. We propose an architectural approach to minimize the problem of feature interaction while increasing the reusability of software for services. Our approach recognizes that currently many assumptions about service operations and system capabilities are implicitly built into the service software architecture. We claim that many nontrivial feature interactions arise when services or technologies with new capabilities, based on conflicting assumptions, are introduced. We propose an architecture based on software agents and separation of concerns. A processing model for service-independent interaction management within the agent architecture is discussed. This architecture effectively removes many common assumptions about roles and technology from the service software architecture, thus reducing the need to provide ad hoc solutions to particular feature interactions. We demonstrate the power of such an architecture by showing how it deals with examples of interactions among existing services, interactions introduced by Universal Personal Telecommunications (UPT), and its applicability to emerging broadband and multimedia service requirements. We also consider the architecture in the context of the intelligent network     

Navigation modeling from a user services oriented perspective

Traditional methodologies for Web Information Systems (WIS) development, usually propose to obtain the navigation model from the conceptual data model. Our proposal address the problem of navigation model construction under a user services oriented perspective, unlike the traditional methodologies which follow a structural approach to build it. Our method is based on the identification of the conceptual user services, which are specific services required by the user. The obtained models are user services oriented. So, the final navigation model is focused on the services required by the user. One specific route is also identified for each conceptual user service, that guides the navigation of the user through the WIS. In this paper the method is proposed and it is showed through a case study, which shows how the navigation model conceived from a user services oriented approach, is intuitive and user friendly.     

异构环境下语义Web服务发现算法研究

随着网络上越来越多种类各异的Web服务,如何对其进行有效发现是实现动态Web服务组合的关键.本文研究了异构环境下服务发现语义信息的匹配问题,利用领域本体解决了异构数据的综合利用与共享,并通过实验表明了本文提出方法的有效性.     

基于Chord的带有QoS的语义Web服务发现方法研究

服务的描述语言,元数据的存储方式以及服务的匹配算法是影响服务发现效率和质量的3个主要问题。该文从这3个问题出发,提出了基于Chord的带有QoS的语义Web服务发现系统。将服务质量(QoS)信息加入到OWL-S中来描述服务,并称之为OWL-QoS;采用基于Chord的分布式方式存储元数据;通过基于OWL-QoS的服务匹配算法来查询服务。实验表明,这种方法有效地提高了服务发现的查询效率与查准率。     

Analysis of end-to-end QoS for networked virtual reality services in UMTS

Virtual reality services may be considered a good representative of advanced services in the new-generation network. The focus of this article is to address quality of service support for VR services in the context of the UMTS QoS framework specified by the 3G standardization forum, the Third Generation Partnership Project. We propose a classification of VR services based on delivery requirements (real-time or non-real-time) and degree of interactivity that maps to existing UMTS QoS classes and service attributes. The mapping is based on matching VR service requirements to performance parameters and target values defined for UMTS applications. Test cases involving heterogeneous VR applications are defined, using as a reference a general model for VR service design and delivery. Measurements of network parameters serve to determine the end-to-end QoS requirements of the considered applications, which are in turn mapped to proposed VR service classes.