A survey of future broadband multimedia satellite systems, issuesand trends

The demand for advanced information services is growing in terms of both the number of users and the services to be supported. Voice and low-rate data services are insufficient for users in a world where high-speed World Wide Web access is taken for granted. The trend is toward global information networks offering flexible multimedia information services to users on demand, anywhere, anytime. Potential services include video on demand, interactive video, fast Internet access, telemedicine, tele-education, and large file transfer. The need to support bandwidth-intensive multimedia services places new and challenging demands on satellite systems and networks. Flexibility, efficiency, mobility, and the ability to guarantee end-to-end quality of service are at a premium     

一种支持科技信息资源共享的数据服务模型

提出一种用于科技信息资源共享的数据服务模型,支持以服务的形式发布并共享各类科技数据,特别是能在服务层面对数据的容量、冗余度、异常情况,以及完整性等数据本身的质量信息加以描述,并给出了这些质量信息的获取和更新方法.在服务层面为用户提供数据特征和数据质量的参考信息,有利于用户对科技信息资源的选择和使用,能够实现科技信息资源的有效共享,通过在全国科技信息服务网项目中的应用,初步验证了其效果.     

具有全局质量保障的Web服务组合研究

随着面向服务架构（SOA）的开发技术不断成熟,Internet上涌现出功能相同或相似的Web服务集合越来越大,如何从这些集合中选出满足用户质量（QoS）的组合Web服务是目前国内外学者研究的热点问题。针对保证组合服务的质量（QoS）全局最优问题,基于图的理论构建服务组合模型,并在此模型上提出相应的服务选择算法,保障选择的组合服务的质量（QoS）全局最优。     

RBAC在门户平台中的设计与实现

门户集成了网络中大量的信息和应用资源,它为用户提供统一的入口访问不同Web应用,并为每个用户提供个性化的服务。访问控制是门户的重要功能,如何建立一个高效的门户访问控制模块成为研究热点。在分析portal,RBAC访问控制模型、SAML和XACML后,提出一个扩展的RBAC访问控制模型并将其应用到门户中。该模型引入资源、动作分类概念,并结合上下文,能够更好地适应动态网络,具有更高的灵活性。     

基于定性多用户偏好的Web服务选择

随着Web服务数量逐渐增多,出现了许多服务提供者提供功能相同或相似服务的情况.如何在一些功能相似或相同的服务集合中,根据用户对服务质量的需求选出更符合用户要求的服务,是当前研究人员普遍关心的课题.本文提出一种定性的服务选择方法,用来解决涉及多个用户的Web服务选择问题.各用户对服务质量的需求被表示为偏好.提出的算法将能够综合考虑各个用户的偏好,使选出的服务尽可能满足大部分用户的偏好要求,并给出了一个实例说明该算法的应用.实验结果表明了算法的有效性.     

Research on user-aware QoS based Web services composition

To improve user experience of composite Web services, a user-aware quality of service (QoS) based Web services composition model is proposed. Under such model, a Web services selection method based on quantum genetic algorithm is proposed. This algorithm uses quantum bit encoding, dynamic step-length quantum gate angle adjustment, neighborhood service search and dynamic punishment strategy to expand search scope and speed up convergence. Simulation experiment shows that this algorithm is more efficient than other existing algorithms in Web services selection.     

一种实现无线数据网络差异化接入的方法

通过深层次分析无线网络资源控制过程和相关协议,以及吸取传统QoS业务模型和传统动态带宽分配方法 (DBA)的优点,发明了一种实现无线数据网络差异化接入的方法,可以实现在无线网络数据业务中结合不同用户等级与业务类型提供差异化服务。该发明专利申请已由国家知识产权局受理(申请号201110324444.7)。     

基于语义Web的电信服务组合研究

针对电信业务领域服务数量的不断增加,以及用户需求多样化的实际情况,通过研究语义Web服务、OWL-S等语义相关技术,提出一个基于语义Web的电信服务组合模型,设计了电信业务领域本体库,实现了电信业务领域知识的共享,在此基础上,提出电信服务组合流程,并在实际环境中进行例证。     

网络出口转换技术研究

随着网络利用的普及,企事业单位都多数建有自己的网络,为满足不同的需求,接入了多个网络出口。如何解决网络服务与网络接入的关系,提高网络服务系统接口带宽和访问速度,是多网接入用户需要解决的问题,文中结合作者的工作经验,以Web网站作为服务对象,对上述问题进行分析和研究,其成果对多网用户有较好的借鉴。     

基于语义Web服务的智能电信业务模型

该文针对电信业务领域用户需求多样化的实际情况,将互联网领域语义Web服务模型进行完善,提出了基于语义Web服务的智能电信业务模型。在模型中,设计了电信业务领域本体库,实现了电信业务领域知识的共享;提出了基于本体的用户个性数据库,利用本体的天然推理特性加强对用户个性的挖掘;引入了智能代理,将用户从浩淼的服务选择中解放出来。设计了语义转换XSLT代码生成模块提高了语义Web服务描述效率。该模型已经在实际的测试环境中得到验证,最后以流媒体业务为例,说明了该模型的工作原理。     

Building Grid Portal Applications From a Web Service Component Architecture

This work describes an approach to building Grid applications based on the premise that users who wish to access and run these applications prefer to do so without becoming experts on Grid technology. We describe an application architecture based on wrapping user applications and application workflows as Web services and Web service resources. These services are visible to the users and to resource providers through a family of Grid portal components that can be used to configure, launch, and monitor complex applications in the scientific language of the end user. The applications in this model are instantiated by an application factory service. The layered design of the architecture makes it possible for an expert to configure an application factory service with a custom user interface client that may be dynamically loaded into the portal.     

A performance evaluation approach for GSM-based information services

The ever increasing diffusion of mobile communications will lead to massive mobile access to the Internet. The paper focuses on the wireless application protocol (WAP) for providing mobile information services, as envisaged by the personalized access to local information and services for tourists (PALIO) project within the fifth research framework of the European Commission. In particular, we consider a global system for mobile communications (GSM) network where WAP traffic is transported by the short message service (SMS) on specific GSM signaling channels. We develop suitable traffic models for both the WAP downlink traffic and the signaling traffic. An analytical approach is described that allows evaluation of the mean transmission delay of a WAP page. Finally, a downlink traffic scheduling policy is proposed in order to reduce the delay variance so that users experience a more regular traffic behavior (service usability requirement). The theoretical derivations for the GSM-SMS scenario are general and can also be tailored for other mobile communication systems. The study allows dimensioning of both the service and the downlink signaling traffic capacity in order to fulfill quality-of-service requirements for users.     

ACDAS: Authenticated controlled data access and sharing scheme for cloud storage

Cloud storage services require cost‐effective, scalable, and self‐managed secure data management functionality. Public cloud storage always enforces users to adopt the restricted generic security consideration provided by the cloud service provider. On the contrary, private cloud storage gives users the opportunity to configure a self‐managed and controlled authenticated data security model to control the accessing and sharing of data in a private cloud. However, this introduces several new challenges to data security. One critical issue is how to enable a secure, authenticated data storage model for data access with controlled data accessibility. In this paper, we propose an authenticated controlled data access and sharing scheme called ACDAS to address this issue. In our proposed scheme, we employ a biometric‐based authentication model for secure access to data storage and sharing. To provide flexible data sharing under the control of a data owner, we propose a variant of a proxy reencryption scheme where the cloud server uses a proxy reencryption key and the data owner generates a credential token during decryption to control the accessibility of the users. The security analysis shows that our proposed scheme is resistant to various attacks, including a stolen verifier attack, a replay attack, a password guessing attack, and a stolen mobile device attack. Further, our proposed scheme satisfies the considered security requirements of a data storage and sharing system. The experimental results demonstrate that ACDAS can achieve the security goals together with the practical efficiency of storage, computation, and communication compared with other related schemes.     

Game theoretic modeling of security and trust relationship in cyberspace

Today, online network services have evolved as the highest‐emergent medium, enabling various online activities to be lucrative. However, these lucrative activities also bring new forms of privacy threats to the community. In a reliable e‐business service, users should be able to trust the providers of the service to protect their customers' privacy. The service providers should not risk the personal and private information about their customers in cyberspace. There is an economic gain for a business provider when users trust the service provider. Despite those benefits, cyber security concern is the main reason some large organization may go bankrupted. Unfortunately, attackers may attempt to breach a provider's database and expose customers' private information. Therefore, in this paper, we propose a game theoretic framework for security and trust relationship in cyberspace for users, service providers, and attackers. Mathematical proofs and evaluations support our model. Service providers may use the model to see how important and dissuasive against attackers is when investing in cybersecurity. Copyright © 2016 John Wiley & Sons, Ltd.     

Web服务技术-大数据抓取及存储的研究与实现

简述web服务的关键技术以及其发展的过程,并对一些关键技术进行阐述,web服务是有自己独特的体系,拥有自己的一套架构,并且在这套架构上,web服务拥有自己的核心技术,当单个的web服务难以满足需求的时候,这时候web服务组合就出现了,它能够很好的解决单个web所不能解决的问题,这个很好的满足了现代社会的需求,最后提出web服务技术的未来,其中重点是说明web服务的核心技术。随着网络的兴起,web服务技术被广泛应用于大数据的海洋抓取,比如代购网站中,就需要用到数据的海洋抓取和存储。     

Web服务组合分布式协调模型研究

Web服务环境下的B2B交互需要事务机制来保证其可靠性。尽管目前业界已存在许多Web服务组合模型和描述语言，但对事务处理的支持还不够。文章通过分析Web服务组合中的事务处理需求．扩展WSBPEL的事务处理能力以支持流程的分布式协调，并实现了Web服务组合分布式协调原型系统，最后通过一个应用场景提出基于WSBPEL的分布式协调模型并进行了分析．