Integrating Diagnostic and Repair to Ensure the Quality of a Composition of Web Services

Service-Oriented Computing is based on dynamic composition of web services to meet the demand of a user. A major challenge in conditioning actual use of web services is to monitor their performance and enable them to react to unexpected malfunctioning. This can be done using the mechanisms of exception handling. But they do react in a predefined manner and local issues have to be planned at the services design time. However, in dynamic environments like the Internet, web services may be subject to unexpected malfunctioning which may not be handled with repair mechanisms defined at design time. In addition, local management ignores errors during the interactions between services, which limit their effectiveness. Such failures may also propagate through the services before being detected, and the key is to find the problem at the source of the malfunction and repair the service. In this context, this work is dedicated to study a distributed but coordinated and dynamic management of repair mechanisms. The difficulty is that repairs are carried out locally, but a global approach must be ensured to take into account interactions between different services. Our objective is to propose a diagnostic-repair architecture and mechanisms for this feature in detail

A Relational Approach for Efficient Service Selection

Web services are gaining momentum as a major vehicle to deliver business functionalities on the Web. More and more business organizations have begun to use Web services to facilitate user interactions and the collaboration among themselves. This essentially forms a large service space, which still keeps growing. Meanwhile, there may be functionality overlaps among different service providers. The concept of Quality of Web Serivce (QoWS) is emerging as a key feature in distinguishing between competing service providers. We present in this paper a systematic approach for efficient service selection by using QoWS as the major criterion. In particular, we adopt a relational approach that enables to store QoWS information in a relational DBMS and leverage standard relational operators for efficient service selection. We perform a preliminary set of experiments to evaluate the proposed service selection algorithms

Attention-based High-order Feature Interactions to Enhance the Recommender System for Web-based Knowledge-Sharing Servic

Providing personalized online learning services has become a hot research topic. Online knowledge-sharing services represents a popular approach to enable learners to use fragmented spare time. User asks and answers questions in the platform, and the platform also recommends relevant questions to users based on their learning interested and context. However, in the big data era, information overload is a challenge, as both online learners and learning resources are embedded in data rich environment. Offering such web services requires an intelligent recommender system to automatically filter out irrelevant information, mine underling user preference, and distil latent information. Such a recommender system needs to be able to mine complex latent information, distinguish differences between users efficiently. In this study, we refine a recommender system of a prior work for web-based knowledge sharing. The system utilizes attention-based mechanisms and involves high-order feature interactions. Our experimental results show that the system outperforms known benchmarks and has great potential to be used for the web-based learning service

Time-Sensitive User Profile for Optimizing Search Personlization

International audienceThanks to social Web services, Web search engines have the opportunity to afford personalized search results that better fit the user’s information needs and interests. To achieve this goal, many personalized search approaches explore user’s social Web interactions to extract his preferences and interests, and use them to model his profile. In our approach, the user profile is implicitly represented as a vector of weighted terms which correspond to the user’s interests extracted from his online social activities. As the user interests may change over time, we propose to weight profiles terms not only according to the content of these activities but also by considering the freshness. More precisely, the weights are adjusted with a temporal feature. In order to evaluate our approach, we model the user profile according to data collected from Twitter. Then, we rerank initial search results accurately to the user profile. Moreover, we proved the significance of adding a temporal feature by comparing our method with baselines models that does not consider the user profile dynamics

Linked Data and Spatial Data Infrastructures

Spatial Data Infrastructures (SDIs) such as AuScope Grid and INSPIRE are being planned and built using discovery, access and processing components based on a services model. While the principle of distribution and delegation using the internet is a major step forward from traditional data warehouses and private collections, the query-oriented interaction paradigm is merely evolutionary, compared with traditional access systems designed for expert users. In contrast, the success and scalability of the world wide web has been based on hypertext, in which browsing is the key mode of interaction, supported by Universal Resource Identifiers (URIs). Linked Data has been proposed as the bridge from the browseable web to the deep web of technical data. Linked Data is still based on web-pages (usually HTML) for user interactions, but supported by Resource Description Framework (RDF) for richer link semantics. Links can resolve to datasets in legacy file formats which thus serve as leaf-nodes, but can also be part of the web of resources. Key standards used in SDI were designed on Linked Data principles, even before the name was coined. For instance, Geography Markup Language (GML) is essentially an RDF/XML application. Thus, in principle, SDIs should integrate seamlessly into the web of linked data. There are, however, a number of issues to consider or resolve in order to bring this about. These include: the definition of 'resource' in the context of databases that are accessed as projected subsets by query, accessed through web-service interfaces; multiple representations of the same feature from different services to support different applications; semantics embedded in structured representations expressed in non-RDF XML forms; standard vocabulary and identifier services.JRC.H.6-Digital Earth and Reference Dat

A Programming Language for Web Service Development

There is now widespread acceptance of Web services and service-oriented architectures. But despite the agreement on key Web services standards there remain many challenges. Programming environments based on WSDL support go some way to facilitating Web service development. However Web services fundamentally rely on XML and Schema, not on contemporary programming language type systems such as those of Java or .NET. Moreover, Web services are based on a messaging paradigm and hence bring forward the traditional problems of messaging systems including concurrency control and message correlation. It is easy to write simple synchronous Web services using traditional programming languages; however more realistic scenarios are surprisingly difficult to implement. To alleviate these issues we propose a programming language which directly supports Web service development. The language leverages XQuery for native XML processing, supports implicit message correlation and has high level join calculus-style concurrency control. We illustrate the features of the language through a motivating example