Personal mobile services

Ubiquitous information access through mobile devices has become a typical practice in everyday life. The mobile service paradigm shifts the role of mobile devices from consumers to providers, opening up new opportunities for a multitude of collaborative services and applications ranging from sharing personal information to collaborative participatory sensing. Although many basic principles of the standard Web service approach continue to apply, the inherent constraints of mobile devices and broadband wireless access render the deployment of the standard architecture in mobile environments inefficient. This paper introduced personal services, a user-centric paradigm that enables service-oriented interactions among mobile devices that are controlled via user-specified authorization policies. Personal services exploit the user’s contact list (ranging from phonebook to social lists) in order to publish and discover Web services while placing users in full control of their own personal data and privacy. Experimental validation demonstrates the ability of personal services to foster a new generation of collaborative mobile services. Performance evaluation results show that the publication and discovery through contact lists are efficient and that service announcements and discovery requests can reach a huge number of users in a few seconds. Results also support a conclusion that resources-constrained devices can collaborate to carry out functionalities beyond the ability of their resources limitations.     

移动终端应用的个性化混搭方法

随着移动互联网的发展,Mashup混搭技术逐渐延伸到移动终端领域。然而目前的移动端Mashup研究主要关注于如何调用后台Web API,却没有将移动端数量庞大的移动应用作为主要的混搭对象进行研究。论文目标是将移动应用、Android框架层API、Web API等各种服务统一视为混搭的基本组件,研究移动端的应用混搭与整合机制,实现APP间的通信,控制APP的执行顺序及相互间的交互与协作,从而满足用户个性化需求。为了消除异构服务间的差异性,提取服务的功能信息构造抽象服务层,封装和屏蔽异构服务调用方式以及输入输出数据类型的差异。定义了描述移动终端应用间混搭的描述型语言,移动终端用户可以DIY式创建满足个性化需求的移动终端Mashup方案。通过一个具体案例展示和验证了方法的有效性。     

基于语义Web技术的上下文感知的智能移动服务

语义Web技术应用于上下文感知的智能移动服务，通过构建上下文信息本体，使得移动服务的实体之间可以进行上下文信息共享和语义互操作，并进行上下文信息推理，实现智能服务。本文首先介绍了语义Web及本体技术，其次阐述了语义Web技术应用于上下文感知的移动服务，然后详细分析了智能移动服务中的上下文信息本体构建，包括通用的上下文信息本体、用户概况本体、情境本体以及服务本体等，接着介绍了相关的研究项目，最后进行展望和总结。     

User needs for location-aware mobile services

Mobile contexts of use vary a lot, and may even be continuously changing during use. The context is much more than location, but its other elements are still difficult to identify or measure. Location information is becoming an integral part of different mobile devices. Current mobile services can be enhanced with location-aware features, thus providing the user with a smooth transition towards context-aware services. Potential application fields can be found in areas such as travel information, shopping, entertainment, event information and different mobile professions. This paper studies location-aware mobile services from the user's point of view. The paper draws conclusions about key issues related to user needs, based on user interviews, laboratory and field evaluations with users, and expert evaluations of location-aware services. The user needs are presented under five main themes: topical and comprehensive contents, smooth user interaction, personal and user-generated contents, seamless service entities and privacy issues.     

基于上下文感知的移动Web服务

移动Web服务的目的是随时、随地为资源有限的任何移动设备提供信息服务。该文以一个移动旅游者娱乐系统为例,阐述移动Web应用服务系统的体系结构、主要组件对象之间的交互及用户个性化服务的实现。讨论上下文管理机制的功能、模型和相关实现技术,介绍其接口与WSDL的实现。     

危急呼救定位及路径跟踪系统的设计

开发了一套基于GPRS和GPS的危急呼救定位及路径跟踪系统,包括移动式呼叫装置,服务中心接收器和软件。该系统是能够随时随地发送呼救信息的移动式呼叫装置,可以实现"一键式"呼救,能够立即将用户的位置信息以短信及互联网的形式发送到服务中心,服务中心即时显示呼救者的个人信息并进行路径跟踪以备及时展开救援。     

Development and validation of an instrument to measure user perceived service quality of information presenting Web portals

Increasing numbers of organizations have set up material on their Web portals as a way of providing users with information about their products or services. This study developed and validated an instrument to measure user perceived service quality of such portals. Based upon conceptual models in the areas of IS and technology adoption, and using responses from 1992 users, we validated a five-dimension service quality instrument involving: usability, usefulness of content, adequacy of information, accessibility, and interaction. This scale provides a useful instrument for researchers who wish to measure the service quality of Web portals and for portal managers who want to improve their service performance.     

Integrating implicit feedbacks for time-aware web service recommendations

An increasing number of Web services have been published on the Internet over the past decade due to the rapid development and adoption of the SOA (Services Oriented Architecture) standard. However, in the current state of the Web, recommending suitable Web services to users becomes a challenge due to the huge divergence in published content. Existing Web services recommendation approaches based on collaborative filtering are mainly aiming to QoS (Quality of Service) prediction. Recommending services based on users’ ratings on services are seldomly reported due to the difficulty of collecting such explicit feedback. In this paper, we report a data set of implicit feedback on real-world Web services, which consist of more than 280,000 user-service interaction records, 65,000 service users and 15,000 Web services or mashups. Temporal information is becoming an increasingly important factor in service recommendation since time effects may influence users’ preferences on services to a large extent. Based on the collected data set, we propose a time-aware service recommendation approach. Temporal information is sufficiently considered in our approach, where three time effects are analyzed and modeled including user bias shifting, Web service bias shifting, and user preference shifting. Experimental results show that the proposed approach outperforms seven existing collaborative filtering approaches on the prediction accuracy.     

Efficient access to Web services

For Web services to expand across the Internet, users need to be able to efficiently access and share Web services. The authors present a query infrastructure that treats Web services as first-class objects. It evaluates queries through the invocations of different Web service operations. Because efficiency plays a central role in such evaluations, the authors propose a query optimization model based on aggregating the quality of Web service (QoWS) parameters of different Web services. The model adjusts QoWS through a dynamic rating scheme and multilevel matching in which the rating provides an assessment of Web services' behavior. Multilevel matching allows the expansion of the solution space by enabling similar and partial answers.     

移动计算环境下的个人化服务发布和组装

随着移动计算技术的发展,移动设备用户可以服务的方式共享移动设备及其周围设备的计算能力和计算资源.然而,移动设备的私有性、资源受限性以及移动性等特征使得这种基于移动设备提供的个人化服务在发布和组装方面存在着一些特殊问题,例如用户隐私、移动设备资源消耗、网络环境变化引起的失效问题等.针对以上这些问题,提出一种移动计算环境下的个人化服务发布和组装方法.该方法在个人化服务发布过程中引入了服务意愿的概念,并在服务选择过程中综合考虑了服务意愿和服务效用.此外,还提出了资源感知的心跳机制来定期更新服务选择所依赖的设备及服务状态信息,从而解决由于网络环境变化等引起的服务失效问题.基于该方法,提出了一个基于JADE和OSGi的实现框架.通过一个案例分析,验证了所提出的实现框架的有效性以及在移动计算环境下考虑服务意愿的合理性.     

On Composite Web Services Provisioning in an Environment of Fixed and Mobile Computing Resources

We present a framework for Web services provisioning in a hybrid environment of fixed and mobile computing resources. Several obstacles still hinder the seamless provisioning of Web services in mobile environments. Examples of such obstacles are: throughput and connectivity of wireless networks, limited computing resources of mobile devices, and risks of communication channel disconnections. In the proposed framework, software agents represent users, providers of services, and providers of resources. The business logic of composite services is expressed as a process model using statecharts formalism. Among other things, the use of agents provides an infrastructure that has the ability to handle disconnections during service preparation for execution. The framework also integrates a service execution planning approach to optimally select computing resources (fixed or mobile) on top of which services will be executed.     

基于协同过滤的可信Web服务推荐方法

为了实现对可信Web服务的推荐,在分析了Web服务推荐技术与电子商务推荐技术的不同的基础上,提出了一种基于协同过滤的可信Web服务推荐方法。首先,根据已有成果对待组装应用的可信需求进行评估,根据此需求对相似用户进行首次筛选;然后在首次筛选的用户中,根据用户使用服务后的评分数据和用户信息来对相似用户进行二次筛选,经过两次筛选得到最终推荐用户。在根据用户对服务的评分数据计算用户之间的相似性时,考虑了不同服务对于用户间相似性的贡献值;在根据用户信息计算用户之间的相似性时,考虑到用户信息之间非线性的特点,引入了欧几里得距离公式来计算其相似值;在产生推荐的过程中还考虑了不诚实用户和用户数不足的问题。模拟实验结果表明该方法能够有效地对可信Web服务进行推荐。     

The Seven Flaws of Identity Management: Usability and Security Challenges

Web identity management systems are complex systems with powerful features - and many potential vulnerabilities. They aim to facilitate the management of identifiers, credentials, personal information, and the presentation of this information to other parties. In many schemes, an identity provider (IdP) issues identities or credentials to users, while a relying party (RP) depends on the IdP to check the user credentials before it allows users access to Web site services. By separating the role of and IdP from the RP, identity management systems let users leverage one identifier across multiple Web services.     

Towards ubiquitous tourist service coordination and process integration: A collaborative travel agent system architecture with semantic web services

With the recent advances in Internet and mobile technologies, there are increasing demands for ubiquitous access to tourist information systems for service coordination and process integration. However, due to disparate tourist information and service resources such as airlines, hotels, tour operators, it is still difficult for tourists to use them effectively during their trips or even in the planning stage. Neither can current tourist portals assist tourists proactively. To overcome this problem, we propose a Collaborative Travel Agent System (CTAS) based on a scalable, flexible, and intelligent Multi-Agent Information System (MAIS) architecture for proactive aids to Internet and mobile users. We also employ Semantic Web technologies for effective organization of information resources and service processes. We formulate our MAIS architecture for CTAS further with agent clusters based on a case study of a large service-oriented travel agency. Agent clusters may comprise several types of agents to achieve the goals involved in the major processes of a tourist’s trip. We show how agents can make use of ontology from the Semantic Web to help tourists better plan, understand, and specify their requirements collaboratively with the CTAS. We further illustrate how this can be successfully implemented with Web service technologies to integrate disparate Internet tourist resources. To conclude, we discuss and evaluate our approach from different stakeholders’ perspectives.

移动互联时代下的社区服务信息化模式探究

目前社区服务信息化平台多为依托于个人电脑和桌面互联网,但这种平台对于用户的使用和体验都有着诸多条件的限制。而随着宽带无线接入技术和移动终端技术的迅速发展,社区服务信息化的建设模式具备了从单一的桌面互联网转变至结合移动互联网的跨平台模式的可能性。在探寻面向主导型社区居民的真实需求及社区中特殊人群的需求差异的同时,我们需要依托移动终端为社区服务信息化提供更加定制化的信息设计,以帮助实现社区内部、社区与社会之间更好的交流互动;并将碎片化的内容整合为对公众更加有效的信息服务!     

Look, Ma, My homepage is Mobile!

Much of the ongoing research in ubiquitous computing has concentrated on providing context information, e.g. location information, to the level of services and applications. Typically, mobile clients obtain location information from their environment which is used to provide “locally optimal” services. In contrast, it may be of interest to obtain information about the current context a mobile user or device is in, from a client somewhere on the Web, i.e. to use the mobile device as an information provider for Internet clients. As an instance of such services we propose the metaphor of a “location-aware” Web homepage of mobile users providing information about, e.g. the current location a mobile user is at. Requesting this homepage can be as easy as typing a URL containing the mobile user's phone number such ashttp://mhp.net/+49123456789 in an off-the-shelf browser. The homepage is dynamically constructed as Web users access it and it can be configured in various ways that are controlled by the mobile user. We present the architecture and implementation and discuss issues around this example of “inverse” ubiquitous computing.