Xiuguo Zhang

A Context-Aware Adaptive Web Service Composition Framework

It is a challenge for Web service composition to perceive dynamic changes of external environment and adapt to the changes of business process rapidly. In this paper, a context-aware adaptive Web service composition framework is presented and the functions of main modules are also described in detail. In this framework, BPEL is used to describe Web service composition process and a kind of special Web service called context service is defined to support context-awareness. Agent technology is introduced to enable context service to actively perceive and process contexts of Web service and Web service composition.

A KPN based cooperative composition model of services

KPN (Kahn Process Network) is a model of computation based on dataflow and commonly used for describing a set of cooperative processes that communicate with each other by means of dataflow. In this paper, we propose a KPN based cooperative composition model of services called CCM. The corresponding mapping mechanism of KPN to CCM is presented. CCM model aims at reducing unanticipated circumstances and uncooperative cases of services in service composition and improving chances of composition success. The data description and service description techniques adopted in CCM model is introduced in detail. Based on CCM model, a cooperative composition framework of services is designed. Finally a case study is presented to show how to describe cooperative service processes in CCM model.

Modeling and application of data correlations among heterogeneous data sources

Data correlations are relationships among heterogeneous data. They reflect the correlations among the heterogeneous data sources on business logics, and are very significant to data exchange, data integration and so on. Traditional methods of data exchange neglect the direct-correlations among data, and meanwhile, existing data models have limitations on expressiveness. In order to solve these problems, referring to the ideas of the hyperlinks and data correlations of web services, the concept of data correlations among heterogeneous data is proposed, which expresses data correlations as static explicit declarations. The abstract model of data correlations and its XML implementation is given, and the application of this model is discussed in detail, Finally the performance is analyzed and compared through experiments.

Safety Verification of Software Component Behavior Adaptation

The behavior adaptation of Software component is a crucial problem in component-based software engineering. Software component adaptation aims at generating, as automatically as possible, adaptors to compensate behavior mismatch during components interaction, and ensure the deadlock-freedom of components interaction at the architectural level. A general and safe approach is proposed to solve the behavior mismatch. Firstly, the model of component behavior adaptation and the definition of adaptor are given. Then, the formal specification of component behavior protocol is given and the safety of component behavior adaptation is verified formally. The adaptor can make the correctness of the component interaction with data exchange, and realize the reordering of message. Finally, an example is presented to illustrate the validity of the approach proposed in this paper.

Research on Safe Behavior Adaptation of Software Component

The behavior adaptation of Software component is a crucial problem in component-based software engineering. Software Adaptation aims at generating, as automatically as possible, adaptors to compensate mismatch between component interfaces, and ensure the deadlock-freedom of component interaction at the architectural level. A general and safe approach is proposed to solve the behavior mismatch. Firstly, the model of component behavior adaptation is given. Then, the formal specification of component behavior protocol and the definition of adaptor are given. The deadlock is used to check the mismatch of component behavior. The behavior of adaptor can be calculated automatically from the adapted components and the adaptor specification. The adaptor can make the correctness of the component interaction with data exchange, and realize the reordering of message. Finally, an example is presented to illustrate the approach proposed.

Research on Design and Its Key Technologies of Web Service Platform in P2P Environment

P2P technology is a new kind of architecture based on peer network. P2P implements the sharing of resources and services using the effective communication among the peers. Web service is a new technology used to develop distributed application. This paper introduces the concepts and technologies of P2P and Web service. Using JXTA protocol as the implementation technology of P2P and using JUDDI AXIS as the server of Web service, we design a Web service Platform in P2P environment and present a prototype system which is applied to publish, inquire and invoke Web services. JXTA peer services are deployed on UDDI peers so that this platform can implement the backup and self-organization of UDDI; The JXTA group services are built in order that the client peer can transparently visit all the UDDI registries; The same service is deployed on many client peers so that service requestor can invoke the service to execute parallel computing. The Web service platform in P2P environment given in this paper is appropriate for the Intranet UDDI registry.

Context-awareness in CCML based web service composition

With the rapid development of computer technology, programming methods have changed a lot. Nowadays, software developing based on SOA (Service Oriented Architecture) is more and more popular due to its autonomous, distributed and reusable. And at the same time, user requirements are also changing, they are anxious for the information they want from the vast data, regardless of the time and space. Thus, using the context that can be used to characterize the situation of an entity in the service composition is a significant and promising method. In fact, the usage of context is widespread in pervasive computing raised by Weiser in 1990s. But in service composition, the usage is less relatively, and researches in this field also have some common problems. For example, in these researches, the contexts are fixed to a few predefined contexts. In this paper, a web service composition modeling language (CCML) supporting context-awareness was proposed, and we also gave an composition Interpreter for this language. Finally we introduced an application case to show how to describe context-awareness using this language.

A context-aware web service composition model for dynamic E-commerce applications

In web service based dynamic E-commerce applications, inclusion of context-aware features in the delivered services is an important approach to improve the efficiency of the dialogues between users and systems. In this paper, we explore a novel context-aware web service composition model for dynamic E-commerce applications, aims to effectively process and take advantage of contexts and facilitate the development of context-aware E-commerce applications. We present a context-aware composition model of web services for E-commerce applications based on a formal model, Context-aware Process Network (CAPN), which is a dataflow and channel based model of cooperative computation. We extend the Context-aware Process Network to a context-aware web service composition model named ECModel by adding a kind of sensor processes which is used to catch contextual data from external environment. Through modeling the register links behaviors, we present how a web service can respond to its context changes dynamically. We describe formal behavior semantics of ECModel and realize context-awareness in this model. We also present a composition framework of dynamic E-commerce based on ECModel‥

Research on Interpreter of Context-Aware Cooperative Composition Modeling Language

In recent years, context-awareness technology is introduced to Web Service Composition to solve the personalization problem in Web Service Composition, which makes the composition results more suitable to the user’s environment. The context-aware web service composition language called CA-CCML (Context-aware Cooperative Composition Modeling Language) is designed. This paper focuses on the research of CA-CCML interpreter, which is composed of CA-CCML Editor, Context Manager and Web Service Manager. Finally, an application case of a study hall searching system is presented to show the usability and validity of CA-CCML interpreter.

Research on Visual Editor of Web Services Composition Language

Based on the research of cooperative composition model (CCM) and Cooperative Composition Modeling Language (CCML) for Web services, a visual editor for CCML based Web services composition is designed and implemented. The editor is based on the Eclipse RCP platform, combined with the Graphical Editing Framework, similar to the Eclipse IDE user interface, provided graphics editing, and convenient graphical operating such as the generation of graphics, copy, paste, scaling, etc.; graphics editor is a graphical representation of the CCM model, can provide different functions for different graphics. Meanwhile, the editor can provide binary, graphics, XML document for the user to select memory editing results. And with air ticket reservation system as an example, the use of editor for Web services combination is validated.