QingPing Tan

Verifying web services composition based on hierarchical colored petri nets

Current Web services composition proposals, such as BPML, BPEL, WSCI, and OWL-S, provide notations for describing the control and data flows in Web service collaborations. However, such proposals remain at the descriptive level, without providing any kind of mechanisms or tool support for verifying the composition specified in the proposed notations. In this paper, we present to verify Web services composition by using CP-nets. CP-nets combine the strengths of Petri nets with the expressive power of high-level programming and have sound mathematical semantics. These services composition proposals can be transformed by transformation rules into CP-nets, which can be used to analyze the performance and to investigate behavioral properties such as deadlock or livelock by CP-nets tools.

Exploiting hierarchical CP-nets to increase the reliability of Web services workflow

Individual Web services can be composed together to form value-added composite Web services represented as business process workflow. However, the value of such composite Web services is directly influenced by the reliability of the composite services. Composing Web services is not an easy task and is error-prone, so there is a growing interest for the verification techniques which enable designers to find and repair design errors even before actual running of the service, or allow designers to detect erroneous properties such as deadlocks or livelocks and formally verify whether the service process design does have certain desired properties (such as consistency with the conversation protocols of partner service). In this paper, we present to analyze and verify Web services composition by using some kind of colored Petri nets (CP-nets) called hierarchical CP-nets, which combine the strengths of Petri nets with the expressive power of high-level programming and have sound mathematical semantics. Services composition proposals can be transformed by transformation rules into CP-nets, which can be simulated to analyze the performance and verified to investigate behavioral properties by exploiting existing CP-nets specialized tools

Transform BPEL workflow into hierarchical CP-Nets to make tool support for verification

Availability of a wide variety of Web services over the Internet offers opportunities of providing new value added services by composing existing ones. Service composition poses a number of challenges. A composite service can be very complex in structure, containing many temporal and data-flow dependencies between the component services. It is highly desirable therefore to be able to validate that a given composite service is well formed: proving that it will not deadlock or livelock and that it respects the sequencing constraints of the constituent services. In this paper, we propose an approach of composition analysis and verification based on Colored Petri nets (CP-nets), which is an extended version of Petri Nets, which have a sound mathematical semantics and a number of existing analysis tools. We provide translation rules of web composition language into CP-nets and a technique to analyze and verify effectively the net to investigate several behavioral properties. Our translation technique is essentially independent of which language we describe composition. As an example, to show the effectiveness of our technique, we pick up BPEL and translate the BPEL specification into CP-nets in a constructive way. These nets are analyzed and verified as prototypes of the specification.

The Use of UML Sequence Diagram for System-on-Chip System Level Transaction-based Functional Verification

An important problem faced by system-on-chip transaction-based verification is how to design the complex transaction test sequence. Scenario-based sequence diagram is a good way to capture the system level functional specification. In the paper, we propose a method to support transaction level verification of SoC based on UML sequence diagram. We use UML sequence diagram to capture the communication and collaboration behaviour among IP cores in system-on-chip and build high level specification for transaction level verification. Then these sequence diagrams will be used to guide the generation of transaction test sequence. We develop a component-based transaction verification environment named SoC-CBTVE. In the SoC-CBTVE, based on the method, we verify a typical SoC design. Experimental results show that UML sequence diagram can capture the complex communication behaviour among IP cores in SoC design, and efficiently supports SoC system level functional verification

Verifying web services composition

Current Web services composition proposals, such as BPEL, BPSS or WSCI, provide notations for describing the control and message flows in service collaborations. However, they remain at the descriptive level, without providing any kind of mechanisms or tool support for verifying the composition specified in them. In this paper, we present an approach based on CP-net formalism to analyze and verify Web services composition. We provide translation scheme from composition language into CP-nets and the techniques to analyze and verify effectively the CP-nets to investigate several behavioral properties. Our approach is essentially independent of the language describing composition. As an example, to show the effectiveness of our technique, in this paper, we present the transformation of WSCI to CP-nets, which can be analyzed, verified and simulated as prototypes of WSCI models by the CP-net tools.

Setup algorithm of web service composition

A number of web services are now available and it therefore seems natural to reuse existing web services to create composite web services. The pivotal problems of web services composition are how to model the input and output data dependency of candidate web services and how to satisfy that of a service request by composition efficiently. In this paper we present the concept of “invocation layer” based on data dependency between web services invocation and design the algorithms to get the least invocation layers of candidate web services satisfying the given service request.

Verifying Web Services Composition: A Transformation-Based Approach

Web services composition is an emerging paradigm for enabling application integration. BPEL is a promising language describing composition in form of business processes, but is lack of sound formal semantic. This paper presents the transformation of BPEL to CP-nets in a constructive way. Therefore we can translate composition specified in BPEL into CPnets, which can be analyzed and verified by many specialized tools. So we make tool support available for verifying BPEL composition.

Model transformation based verification of web services composition

Current Web services composition proposals, such as BPEL, BPSS, BPMN and WSCI, provide notations for describing the control and message flows in Web service collaborations. However, such proposals remain at the descriptive level, without providing any kind of mechanisms or tool support for verifying the composition specified in the proposed notations. In this paper, we present to analyze and verify Web services composition by using CP-nets. CP-nets combine the strengths of Petri nets with the expressive power of high-level programming and have sound mathematical semantics. These services composition proposals can be transformed by model transformation rules into CP-nets, which can be used to analyze the performance and to investigate behavioral properties by CP-nets specialized tools.

Transformation-Driven development of composite web services

The numerous Web services in existence and complex service requests make it natural to compose simple Web services to get value-added composite ones. In this paper, we present an approach driven by Model Driven Architecture (MDA) to develop composite Web services: using UML Class diagram to model structure PIMs (Platform Independent Models) and UML Activity diagram to model behavior PIMs; then converting the PIMs to specific Web services specification platforms and execution platform to get the corresponding PSMs (Platform Specific Models) by model transformation.

Equivalence checking of scheduling in high-level synthesis

By adopting high level synthesis tools, electronic system level designs provide a promising solution to fill the growing design-productivity gap of high-quality hardware system. Unfortunately, the synthesis process is very complex and error prone. In this paper, we present a novel approach on equivalence checking of scheduling in high-level synthesis. Our approach combines the translation validation, cut-point and shared-value graphs techniques, and provides a unified framework to deal with various scheduling optimizations efficiently. We have implemented our approach and some empirical experimental results are provided. The promising results show the effectiveness and efficiency of the proposed method.