Personal service areas for mobile Web applications

Location-based mobile services let wireless mobile users access Web-based information about resources in their immediate vicinities. The authors describe an algorithm that draws on context mobility elements, such as the user's travel direction and speed, to form personal service areas. Their experimental context-aware tourist information system (CATIS) leverages XML technologies and Web services to provide tourist information to mobile users based on these personal service areas and the users' preferences. Because Web service performance depends on the underlying databases, the authors also developed a layered caching scheme for storing environmental data to improve response time.     

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.     

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。     

Toward Quality-Driven Web Service Discovery

Service-oriented architectures follow the find-bind-execute paradigm, in which service providers register their services in public or private registries, which clients use to locate Web services. If a service registry has information on a service that matches a client's criteria, it provides a contract and an access point. Web service discovery is a key component in service-oriented computing. However, without Web service quality standards and quality-based discovery mechanisms, the trustworthiness of business-to-business interactions can't be guaranteed.     

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.     

基于Agent的移动Web服务集成方案

结合Aglets平台和J2EE servlet技术,提出一种基于Agent的J2ME移动Web服务3层集成方案。在终端层,使用轻量级代理接入方式减少移动设备资源受限系统的负载需求。在Web接入层,采用Web服务标准接入方式确保异构移动平台的统一接入。在移动Agent层,通过多Agent协同工作保证系统高效性与灵活性。在此基础上,设计并实现一个移动进货比价系统。应用结果表明,该方案能提高无线环境下J2ME设备发现、访问Web服务的效率与健壮性。     

Enhancing Web accessibility via the Vox Portal and a Web-hosted dynamic HTMLVoxML converter

Interactive voice browsers offer an alternative paradigm that enables both sighted and visually impaired users to access the World Wide Web. In addition to the desktop PC, voice browsers afford ubiquitous mobile access to the World Wide Web using a wide range of consumer devices. This technology can facilitate a safe, ‘hands-free' browsing environment which is of importance both to car drivers and various mobile and technical professionals. By providing voice-mediated access, information providers can reach a wider audience and leverage existing investment in their World Wide Web content. In this paper we describe the Vox Portal, a scaleable VoxML client, and a World Wide Web Server-hosted dynamic HTMLVoxML converter.     

A trustworthy QoS-based collaborative filtering approach for web service discovery

Many network services which process a large quantity of data and knowledge are available in the distributed network environment, and provide applications to users based on Service-Oriented Architecture (SOA) and Web services technology. Therefore, a useful web service discovery approach for data and knowledge discovery process in the complex network environment is a very significant issue. Using the traditional keyword-based search method, users find it difficult to choose the best web services from those with similar functionalities. In addition, in an untrustworthy real world environment, the QoS-based service discovery approach cannot verify the correctness of the web services’ Quality of Service (QoS) values, since such values guaranteed by a service provider are different from the real ones. This work proposes a trustworthy two-phase web service discovery mechanism based on QoS and collaborative filtering, which discovers and recommends the needed web services effectively for users in the distributed environment, and also solves the problem of services with incorrect QoS information. In the experiment, the theoretical analysis and simulation experiment results show that the proposed method can accurately recommend the needed services to users, and improve the recommendation quality.     

A JESS-enabled context elicitation system for providing context-aware Web services

Providing context-aware Web services is an adaptive process of delivering contextually matched Web services to meet service requesters’ needs. We define the term “context” from two perspectives: one from service requesters; and the other from Web services. From the former perspective, context is defined as the surrounding environment affecting requesters’ services discovery and access, such as requesters’ preferences, locations, activities, and accessible network and devices. From the latter perspective, context is defined as the surrounding environment affecting Web services delivery and execution, such as networks and protocols for service binding, devices and platforms for service execution, and so on. This paper presents a Java Expert System Shell (JESS)-enabled context elicitation system featuring an ontology-based context model that formally describes and acquires contextual information pertaining to service requesters and Web services. Based on the context elicitation system, we present a context-aware services-oriented architecture for providing context-aware Web service request, publication, and discovery. Implementation details of the context elicitation system and the evaluation results of context-aware service provision are also reported.     

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.     

METEOR-S WSDI: A Scalable P2P Infrastructure of Registries for Semantic Publication and Discovery of Web Services

Web services are the new paradigm for distributed computing. They have much to offer towards interoperability of applications and integration of large scale distributed systems. To make Web services accessible to users, service providers use Web service registries to publish them. Current infrastructure of registries requires replication of all Web service publications in all Universal Business Registries. Large growth in number of Web services as well as the growth in the number of registries would make this replication impractical. In addition, the current Web service discovery mechanism is inefficient, as it does not support discovery based on the capabilities of the services, leading to a lot of irrelevant matches. Semantic discovery or matching of services is a promising approach to address this challenge. In this paper, we present a scalable, high performance environment for Web service publication and discovery among multiple registries. This work uses an ontology-based approach to organize registries into domains, enabling domain based classification of all Web services. Each of these registries supports semantic publication and discovery of Web services. We believe that the semantic approach suggested in this paper will significantly improve Web service publication and discovery involving a large number of registries. This paper describes the implementation and architecture of the METEOR-S Web Service Discovery Infrastructure, which leverages peer-to-peer computing as a scalable solution.     

Mobile access to real-time information—the case of autonomous stock brokering

When services providing real-time information are accessible from mobile devices, functionality is often restricted and no adaptation of the user interface to the mobile device is attempted. Mobile access to real-time information requires designs for multi-device access and automated facilities for the adaptation of user interfaces. We present TapBroker, a push update service that provides mobile and stationary access to information on autonomous agents trading stocks. TapBroker is developed for the Ubiquitous Interactor system and is accessible from Java Swing user interfaces and Web user interfaces on desktop computers, and from a Java Awt user interface on mobile phones. New user interfaces can easily be added without changes in the service logic.     

A synergetic mechanism for digital library service in mobile and cloud computing environment

Digital library services in the mobile computing have come into our daily life with the development of wireless communication and the manufacture of mobile devices. Digital libraries have collected large-scaled data for providing information service. However, there are still many problems such as limitations of computing on mobile devices and data transmission problems in the wireless network. This paper proposes a synergetic mechanism for digital library to provide information service in the mobile and cloud computing environment, which combines the digital library servers, mobile hosts and personal cloud space into a synergetic work group seamlessly. The proposed mechanism integrates the strong computing and large-scaled storage ability of cloud computing together with the convenience of mobile computing. It could help promoting knowledge sharing and improve work efficiency of users in the mobile and cloud computing environment.     

MicroMAIS: executing and orchestrating Web services on constrained mobile devices

Mobile devices with their more and more powerful resources allow the development of mobile information systems in which services are not only provided by traditional systems but also autonomously executed and controlled in the mobile devices themselves. Services distributed on autonomous mobile devices allow both the development of cooperative applications without a back‐end infrastructure and the development of applications blending distributed and centralized services. In this paper, we propose MicroMAIS: an integrated platform for supporting the execution of Web service‐based applications natively on a mobile device. The MicroMAIS platform is composed of mAS and μ‐BPEL. The former allows the execution of a single Web service, whereas the latter permits the orchestration of several Web services according to the WS‐BPEL standard. Copyright © 2011 John Wiley & Sons, Ltd.     

A social approach to context-aware retrieval

We present a general purpose solution to Web content and services perusal by means of mobile devices, named Social Context-Aware Browser. This is a novel approach for information access based on users’ context, that exploits social and collaborative models to overtake the limits of the existing solutions. Instead of relying on a pool of experts and on a rigid categorization, as it is usually done in the context-aware field, our solution allows the crowd of users to model, control, and manage the contextual knowledge through collaboration and participation. To have a dynamic and user-tailored context representation, and to enhance the process of retrieval based on users’ actual situation, the community of users is encouraged to define the contexts of interest, to share, use, and discuss them, and to associate context to content and resources (Web pages, services, applications, etc.). This paper provides an overall presentation of our solution, describing the idea, the implementation, and the evaluation through a benchmark based methodology.     

An Ontology-Based Approach to Personalized Situation-Aware Mobile Service Supply

Mobile devices such as personal digital assistants (PDAs) and mobile phones are in widespread use already today and converging to mobile smart phones. They enable users to access a wide range of services and information without guidance through their actual demands. Especially during mass events like the Olympic Games 2008 in Beijing—which was initially the context of our work—a large service space is expected to support all mobile visitors, being athletes, journalists, or spectators. Current approaches tackling such problems are location based, meaning that a user's location is central to service provision, and even context-aware, meaning that, beyond location, characteristics of a user's environment are taken into account. Such information obviously helps to deliver relevant information at the right time to the mobile users. Going one step further, a situation-aware system abstracts from the context dimensions by translating specific contexts into logical situations. Knowing the situation end users are in allows the system to better identify the information to be delivered to them and to choose the appropriate services with regard to their scope, which is referred to as service roaming. Even though many context frameworks have been introduced in the past few years, what is usually missing is the notion of characteristic features of contexts that are invariant during certain time intervals. This paper presents these concepts in the context of a platform development, namely FLAME2008, which is able to support its mobile users with personalized situation-aware services in push and pull mode.     

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.