Recommending multimedia web services in a multi-device environment

In the last years, the Web community has shown a broad interest in Web services that handle multimedia contents. To improve the usability of these services different tools have been proposed in the literature, and in this context agent-based recommender systems appear to be a promising solution. However, the recommender systems presented in the past do not take into account, in their recommendation algorithms, the effect of the device exploited by the user, while it is clear that the same user shows a different behavior in the presence of different devices. This paper tries to give a contribution in this setting, in order to match more accurately user preferences and interests. In particular, a new agent-based system is proposed, whose architecture allows to compute recommendations of multimedia Web services, considering the effect of the currently exploited device. Some experimental results confirm the high quality of the recommendations generated by the proposed approach.     

Development of Web-Telecom based hybrid services orchestration and execution middleware over convergence networks

Influenced by the success of Web service technologies for development and deployment of IT services, Telecom R&D community starts to adapt and build similar service delivery platforms, trying to manage the hard constraints in Telecom domains, such as existence of heterogeneous protocols, extensive use of asynchronous communications and real-time delivery requirements, which will open a new paradigm for Web service based voice over IP communication and also can be easily integrated in end-to-end SOA solutions. In this paper, we study both the Web-Telecom based hybrid services orchestration and execution middleware for coordinating existing Telecom services and IT services. In particular, we focus on the design and implementation Web-Telecom based hybrid service bus (WTSB), event-driven Telecom service engine (EDLE) and also the integration layer for the messages dispatching and transformation between WTSB and EDLE, which can make the EDLE service engine seamlessly integrated into WTSB. More specifically, with multimedia conferencing scenarios, we demonstrate how our hybrid services orchestration and execution middleware orchestrate multimedia conferencing communication services together, and also make performance measurement and analysis. Finally, we give the conclusions and future work.     

基于匹配算法的服务发现本体模型*

针对服务发现领域存在的匹配问题,提出了基于匹配算法的服务发现本体模型。研究中,以本体技术为基础,分析服务发现模型所包含的主要元素,定义用户本体与服务本体之间最优匹配规划的命题。构建满足该命题的Web服务运行框架。针对运行框架中匹配规划和匹配模式,设计并实现MS算法和MP算法,获取候选匹配集及匹配规划的相关度。与现有服务发现方法相比,提出的服务发现本体模型具有较高的查全率与查准率,能够获得更多贴近用户服务请求的Web服务,具有较好的理论价值和应用前景。     

How to Use Web Services in Your Requirements Process

An effective solution for exploiting Web services to improve requirements must support specifying both requirements and services, discover services that match user requirements, and guide service integrators to exploit Web services to improve their specifications. The Service-Centric Systems Engineering (SeCSE) project provides solutions to these challenges.     

Self-adaptable media service architecture for guaranteeing reliable multimedia services

The main objective of this paper is to design and develop a Self-Adaptable Media Service Architecture (SAMSA) for providing reliable dynamic composite multimedia service through policy-based actions. The multimedia services such as media retrieval, transcoding, scaling and display services are combined based on the preferences of the user to create a dynamic composite multimedia service called as Video-on-Demand service. Such distributed multimedia services deployed using Service Oriented Architecture (SOA) can be accessed in heterogeneous environments that are prone to changes during run-time. To provide reliable and adaptive multimedia services, a powerful self-adaptable architecture with dynamic compositions of multimedia services is necessary to adapt during run-time and react to the environment. The adaptability in this proposed architecture is achieved by enabling the service providers to Monitor, Analyze and Act on the defined policies that support customization of compositions of multimedia services and guarantee the Quality of Service (QoS) provisioning. The Media Service Monitor (MSM) observes the business and quality metrics associated with the multimedia services during run-time. The monitored results are analyzed by Monitored Results Analyzer (MRA) which identifies the type and location of the fault. The Adaptive Media Service Manager (AMSM) takes corrective actions based on the monitored results, through the policies defined as an extension of WS-Policy (Web Service—Policy framework). The effectiveness of the proposed Self-Adaptable Media Service Architecture (SAMSA) has been evaluated on Dynamic Composite Real-time Video-on-Demand Web Service (DCRVoDWS) for a maximum of 200 simultaneous client’s requests. The analysis of results shows that the proposed architecture provides better improvement on reliability, response time and user satisfaction.     

基于语义的Web服务二次匹配算法

分析了传统的Web服务发现机制,发现利用关键字进行Web服务匹配的服务查全率和查准率不高。对服务发现中的服务匹配算法进行改进,提出了一种基于语义的Web服务二次匹配算法。结合关键字和概念层语义关系进行服务匹配,根据匹配度选择最优服务。该算法提高了服务匹配效率,实现了灵活的服务发现机制,其灵活性和扩展性能够实现复杂的Web服务发现。     

采用改进的本体相似的Web服务匹配

随着Internet上Web服务的快速增长,客户如何发现想要的Web服务,已经是Web服务技术中的难点和关键问题。鉴于UDDI注册中心的Web服务描述信息非常稀疏的特点,传统的基于关键字的服务匹配机制UDDI缺乏语义支持,搜索效率低;为了在UDDI注册中心提供的用WSDL描述的和未来用语义本体描述的Web服务信息的基础上提高Web服务匹配的查准率和查全率,提出了一种新的本体相似匹配方法,使Web服务匹配在查准率和查全率方面都有所提高。     

Building mobile multimedia services: a hybrid cloud computing approach

Mobile multimedia services are in high demand, but their development comes at high costs. The emergent computing paradigm cloud computing has great potential to embrace these issues. In fact, we are at the early stage of the coalescence of cloud computing, mobile multimedia and the Web. Motivated by the tremendous success story of the Web based on its simplicity principles, we argue for a comprehensive review on current practices of web and mobile multimedia cloud computing techniques for avoiding frictions. We draw on experience from the development of advanced collaborative multimedia web applications utilizing multimedia metadata standards like MPEG-7 and real-time communication protocols like XMPP. We propose our i5CLoud, a hybrid cloud architecture, which serves as a substrate for scalable and fast time-to-market mobile multimedia services. This paper demonstrates the applicability of emerging cloud computing concepts for mobile multimedia.     

基于事件驱动和QoS控制的Web服务器体系结构*

Web服务器在满足大量且不断上升的用户需求方面扮演着关键角色,但Web服务器也面临高并发的用户请求、不同的QoS需求和访问控制等众多挑战。针对这些挑战提出了一种采用事件驱动和QoS控制的新型Web服务器体系结构,并依此开发出命名为Epdds的原型服务器。通过对Epdds服务器的性能分析及与其他Web服务器性能对比,进一步验证了此种Web服务器体系结构的可行性和有效性。     

基于OWL共享本体的动态Web服务组合

在自动的动态Web服务组合中,如何提高匹配成功率是个很重要的课题。本文认为,通过结合语义Web服务本体语言OWL-S和Web本体语言OWL,将语义引入Web服务组合,可以提高服务发现和匹配的效率,并可以方便地实现Web服务组合的自动化。本文给出了一个基于Java的实现平台,并在服务匹配过程中实现了基于OWL共享本体的服务匹配。     

Searching for multimedia: analysis of audio,video and image Web queries

The development of digital libraries has enhanced the integration of textual and multimedia information in many document collections. The World Wide Web provides the connectivity for many digital library users. Studies exploring the searching characteristics of Web users are an important and a growing area of research. Most Web user studies have focused on general Web searching, regardless of subject matter or format. Little research has examined how Web users search for multimedia information. Our study examines users' multimedia searching on a major Web search service. The data set examined consisted of 1,025,908 queries from 211,058 users of Excite ®, a major Web search service. From this data set, we identified and analyzed queries for audio, image, and video queries. Our findings were compared to results from general Web searching studies. Implications for the design of Web searching services and interfaces are discussed.     

DaaS: Cloud-based mobile Web service discovery

The proliferation of smartphones and the recent advancement in ubiquitous wireless access have made mobile Web services more possible than ever before. However, finding relevant Web services that can match requests and fit user context remains a major concern. The challenges facing Web service discovery are further magnified by the stringent constraints of mobile devices and the inherit complexity of wireless heterogeneous networks. Cloud computing, with its flexible design and theoretically unlimited computing resources, is a viable approach to bootstrapping Web service discovery. The cloud can build bridges between mobile devices, as a convenient ubiquitous interface, and a backbone infrastructure with abundant computing resources. This paper introduces “Discovery as a service (Daas)”, a novel cloud-based discovery framework that addresses the core components of mobile Web service discovery. The DaaS framework lays the foundation of efficient mobile Web service discovery that takes into consideration user preferences and context. The experimental validation and performance evaluation demonstrate that DaaS can effectively rank relevant services according to the various user context and preferences, in addition to enhancing the precision of the discovered services. The prototype also shows that Web service clustering for discovery significantly improves the overall response time, while the cloud maintains scalability according to prespecified performance criteria.     

Optimizing download time of embedded multimedia objects for Web browsing

Notoriously high delays in accessing Web pages loaded with massive multimedia objects are highly undesirable. Inspired by the requirements of news agencies and other information providers to include multimedia content in their pages, this paper proposes a new solution to the problem of minimizing the Web response time. We consider an environment that consists of a central multimedia repository and various sites physically dispersed. Our approach is based on simultaneous downloading of some of the embedded multimedia objects from the repository, and the rest from the regional servers. We propose a cost model to formalize the relative benefits of the proposed scheme, and design an algorithm that replicates multimedia objects so as to take advantage of concurrency in data transferring. An extensive simulation study evaluates the performance of the proposed replication policy under storage and processing capacity constraints, as well as with various network transfer rates. Comparisons are carried out with alternative schemes.     

Standards for image annotation using Semantic Web

The impetus behind Semantic Web research remains the vision of supplementing availability with utility; that is, the World Wide Web provides availability of digital media, but the Semantic Web will allow presently available digital media to be used in unseen ways. An example of such an application is multimedia retrieval. At present, there are vast amounts of digital media available on the web. Once this media gets associated with machine-understandable metadata, the web can serve as a potentially unlimited supplier for multimedia web services, which could populate themselves by searching for keywords and subsequently retrieving images or articles, which is precisely the type of system that is proposed in this paper. Such a system requires solid interoperability, a central ontology, semantic agent search capabilities, and standards. Specifically, this paper explores this cross-section of image annotation and Semantic Web services, models the web service components that constitute such a system, discusses the sequential, cooperative execution of these Semantic Web services, and introduces intelligent storage of image semantics as part of a semantic link space.     

Web服务安全性测试技术研究

Web服务的应用越来越广泛,Web服务中的安全缺陷与漏洞也在不断增多,Web服务安全性问题日益突出。Web服务安全性测试是保证Web服务软件安全性、降低安全风险的重要手段。本文提出了一种Web服务安全性测试框架,论述了Web服务主要的安全功能需求、实现标准及实施安全功能测试的一般原理,并从攻击Web服务的角度对Web服务安全漏洞测试进行了系统介绍,分析了Web服务常见的安全漏洞及测试方法。     

Understanding user requirements and preferences for a digital library Web portal

This article reports the findings of a user study conducted in the context of the TELplus project to gain insights about user needs and preferences for the digital library services offered by The European Library Web portal. The user requirements collection for the Web portal was designed by adopting a comprehensive survey approach. This combined explicit user feedback with implicit usage data so as to provide a more in-depth analysis of user experience with the portal. The analysis conducted shed light on likely motivations for both participant usage and reluctance to use the services provided, leading to more informed decisions on how to refine, improve, and present Web portal services to their future users. The lessons learnt from this case study also contributed to the development of an integrated methodological framework which provided insights for the future design and evaluation of digital library Web portals and services.     

基于OWL-S的三层服务匹配模型

随着XML及语义技术的发展,Web服务已经在电子商务领域中得到了广泛应用.然而,如何有效地发现Web服务仍然是领域研究的难点.本文提出一种以OWL-S作为服务定义语言的服务查询匹配模型.该模型利用OWL-S支持Web服务的自动发现、调用、合成和运行监测的特点,提高了基于Web服务发现和匹配的效率.     

一种半自动化Web服务合成的算法

Web服务合成,即将现有的若干服务合成为一个新的服务以获得新的功能,对于B2B、B2C应用和企业应用集成等各个领域都是十分重要的。服务合成必须实现半自动化或自动化。半自动化是比较可行的,它在用户的参与下合成服务。本文提出了一个半自动化服务合成的原型。其要求对服务进行语义描述,合成算法根据服务的语义信息来完成服务的合成。本文提出了基于目标服务的合成算法。其关键问题是如何选择下一个服务,以产生合适的输出作为当前服务的输入参数;需要对待选服务进行语义匹配,提出了精确匹配、一般匹配和语义距离等概念来衡量匹配度,并且用户可以根据其它属性来过滤服务,选择最优的一个。最后开发了一个合成系统,进行实验测试。     

基于MVC设计模式的Web服务架构

Web服务以其良好的协同性和可扩展性，越来越受到企业的关注，但如何构建企业的Web服务是一个非常复杂的问题。MVC是一种架构松散耦合、高柔韧性软件的设计模式，它为架构Web服务提供一种很好的模型。本文描述了MVC设计模式，通过它和Web服务架构相关要素的类比，用MVC的设计模式描述了Web服务的体系结构，建立了基于MVC模式的Web服务架构。