Blue C. W. Lan

Composition and evaluation of trustworthy web services

Web service technology seamlessly enables integration of different software to fulfil dynamic business demands in a platform-neutral fashion. By means of standard interfaces, service requesters can obtain their desired functionalities through certain service discovery mechanism, and service providers can offer the functionality to service requesters without exposing details of provided services. However, the adoption of loosely coupled and distributed services will cause trustworthiness problems. In this paper, we use ontology to describe experience and we utilise statistical techniques along with Petri nets to conduct a trustworthy evaluation method for composite web services. The degree of trustworthiness of all involved services in an aggregated composite service will be evaluated by analysing past experiences so that the trustworthiness of the composite service could be estimated.

A new approach for context aware SOA

In this paper, a context aware service-oriented architecture is proposed to facilitate service discovery, composition, and verification. There are three main building blocks in this proposed architecture: service verifier, semantic matchmaker, and agent platform. service verifier utilizes Petri nets mechanism to analyze the validity of service description and process model so that no invalid services is published. Semantic matchmaker is designed with the consideration of requesters context to enhance the precision of request-service matchmaking. Agent platform consists of three agents, request agent, broker agent, and service agent to collaborate and execute the entire context aware SOA on behalf of the requesters, matchmaker, and service providers.

Service Level Agreement-Based QoS Analysis for Web Services Discovery and Composition

Quality-of-Service (QoS) in Web services considers a services non- functional characteristics during service specification, discovery, and composition. In order to encourage the development of QoS-aware Web services, we first develop a QoS-aware model, which contains a common set of QoS attributes including response time, throughput, reliability, availability and price etc. Then, based on the attributes, two alternative service selection methods, namely absolute and relative matchmaking, are presented. Finally, according to the formal semantics of different workflow patterns, we utilize the aggregative effects of QoS attributes to help service consumers perform QoS-aware service composition.

An ontology based content model for Web services description

Correctly described Web service facilitates automatically discovery of Web service in semantic Web. In this paper, we present a content model for a better ontological metadata representation to facilitate Web service description. The proposed content model has two parts: content profile and process model. The content profile consists of three metadata, a core metadata, a structural metadata, and a semantic metadata, by which we can use to describe a Web services basic properties, content structure and semantic meaning, respectively. The process model provide control construct to design complex service. We also provide a mechanism to transform a content model to a DAML-S Web service.

A trustworthy Web services framework for business processes integration

Web services can help business processes integration (BPI) in both flexible and efficient manner to fulfill dynamic business demands and trustworthiness becomes the critical concern for realizing the vision of such service-oriented enterprises. In this paper, we propose a trustworthy Web services framework for BPI to discuss various trustworthy issues from three different perspectives: structure, service and management. From structure perspective, we consider that the dependability of underlying data, applications and organizational policies are the basis of the trustworthiness of Web services based BPI. From service perspective, each involved actor in the business process model should be described by both functional and trustworthy capabilities so that business analysts could aggregate qualified Web services to fulfill the business goal. From management perspective, enterprises can perform the evaluation of quantifiable attributes of executed Web services to manage trust relationships among partners and customers. The proposed framework does not only assist enterprises perform Web services based BPI in a trustworthy way but also facilitate enterprises to develop trustworthy Web services.

Trustworthy Web Services: An Experience-Based Model for Trustworthiness Evaluation

Web service technology enables seamless integration of different software to fulfill dynamic business demands in a platform-neutral fashion. However, the adoption of loosely-coupled and distributed services will cause trustworthiness problems. In this article, we present an experience-based evaluation of service’s trustworthiness based on trust experience (understanding) and trust requirements (policy). We utilize ontology to specify past experiences of services and trustworthy requirements of the requester. Before invoking found services, the addressed method can help the requester evaluate the trustworthiness of the services based on his or her trustworthy requirements and past experiences of the services. Furthermore, we also present an evaluation method for composite services by taking the structure of the composite services into account. The main contribution of the paper is providing evaluation methods for Web services such that the service requester can make better decisions in selecting found services in terms of service’s trustworthiness.

Ubiquitous Collaborative Learning in Knowledge-Aware Virtual Communities

In this paper, we applied peer-to-peer (P2P) and instant messenger (IM) approaches to provide a seamless integration of learning resources. The learning resources contain three categories, namely learning collaborators, content, and services. This seamless learning environment aimed for knowledge sharing in collaboration supported virtual learning communities. Content found by peer-to-peer network refers to the sources of explicit knowledge; while the discussion and interaction details recorded in instant messenger network is the source of tacit knowledge. Interaction occurred in social network can be bi-parties communication, message exchange, file sharing, and knowledge sharing. Results of this study demonstrate that the applied knowledge sharing mechanism helps learning collaborators find right content and related knowledgeable collaborators who are willing to share their knowledge

Trustworthy service-oriented Business Processes Integration

Service-oriented technology enables software to be invoked with universal interface. Enterprises can employ this technology to assist business process integration in enhancing adaptability and flexibility. However, adoption of service-oriented technology could result in trustworthiness problems, for example, how to ensure the dependability of services? How to ensure that all found services will work as expected? How to manage trust relationships among partners and customers? In this paper, we analyse trustworthiness from three perspectives namely structure, service and management. For each identified issue, we have addressed corresponding guidelines to help enterprises perform trustworthy service-oriented business process integration.