Weishi Zhang

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.

A Description Model to Support Knowledge Management

Knowledge management being implemented in organizations with low cost, less risk and less time is widely recognized to be one of the crucial problems. Using formal and informal methods we propose a description model to support knowledge management in an software organization with many projects and many people. The prototype system based on the model can help the organizations to capture, store and share knowledge produced by different people during different software development and avoid the repeated storage of the same knowledge package produced by different people or different project. The main ingredients of the model are: (1) meta-model and conceptual model of knowledge management, and (2) description of the knowledge management model. The model was implemented and evaluated empirically; the results suggest that knowledge management using requirements successfully promotes knowledge reuse

A Checking Mechanism of Software Component Adaptation

Software component adaptation is widely recognized to be a crucial problem in component-based software engineering. In this paper, we focus on the signature level component adaptation such as names, parameters and propose a checking mechanism to find the signature level mismatch. A component model is designed firstly in mathematical specification which can give more details to find and adapt the signatures that have a mismatch with the user need. Some notations and definitions are given to help the checking of signature level mismatch and then a checking mechanism of signature level mismatch with the use of context-free expressions is proposed. Our proposal is based on the more details provided by the user, and is supported by dedicated algorithms. At last future work and limitation of the checking mechanism are discussed

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.

Specification and Verification of Safe Web Service Behavior Adaptation

Behavior adaptation of Web service uses an adaptor to coordinate the interaction of Web services and solves behavior mismatch. An automatic and safe approach of Web service behavior adaptation is proposed. Firstly, the model and framework of Web service behavior adaptation is given. Then, the formal specification of service behavior and the definition of adaptor are given. The safety of service behavior adaptation is verified. The checking approach of behavior mismatch and the calculating approach of adaptor behavior are specified formally. At last, a case is studied to verify the validity of the approach proposed in this paper.

Researches on the novel methodology of traffic flow prediction based on similarity

Similarity is one of the important characteristics of traffic flow time series, it reflects the same property of every two time series, and it is very significant to traffic flow prediction and traffic guidance. There are many prediction models based on similarity, but they neglect the direct impacts of historical data more or less. So, based on similarity and referring the idea of battery discharge effects, a new prediction model is proposed, it fully takes into account the impacts of historical data on current traffic flow, its description and characteristic analysis are given in detail. Finally, its performances is analyzed and compared with other models.

Research on Behavior Adaptation of Software Component

Behavior adaptation of Software component is a crucial problem in component-based software engineering. A general approach is proposed to solve the behavior mismatch. Firstly, the synchronous vector between component behaviors according to the abstract specification of component behavior is calculated, and the specification of the adaptor is given. Then, in order to detect automatically deadlock mismatch, the synchronous product of Symbolic Transition Systems, which are the abstract specification of component behavior, is computed. The behavior of adaptor can be automatically calculated according to the synchronous vector. The adaptor can make component interaction correct. Finally, an example is presented to illustrate the proposed approach.