Research Areas:Software Modeling, Testing, Verification, Web Services. Also interested in Statistics and Bioinformatics
Active Projects: WebStrar, Pi4SOA
Past Projects: Microsoft Phoenix

This is the architecture of WebStrar.

Step 1: Raw Web Services Repository and Raw Test cases Repository
When the service provider registers their services, the webstrar will put the service into the raw service repository for testing.
Webstrar is an open architecture, in the meantime, anybody can submit the test cases, the test cases will be put into the raw test case repository.

After this step, we have many test cases and many services, we need to do blackbox testing, this is done by the WS group testing.

Step 2: Web Service Group Testing (WSGT)
This step is actually the core part of WebStrar. It involves various analysis method, including statistics, stochastic process, bayesian methods, etc.

In ws testing, for some test cases, we may not know the correct output. In this case, we need to use a voting mechanism to find a correct output. The voting result is called an oracle. However, sometimes, we may vote a wrong oracle, so we have a confidence for each oracle. In some cases, the oracle cannot be established, the human intervention is needed.

In addition to rank the services, we can also rank the test cases, and put the test cases into the ranked test cases repository for further testing.

Step 3: Web Service Ranking and Test Case Ranking
After the Web service group testing, the bad services can be eliminated, and only those good services will be put into the trustworthy service repository. The client can use the services directly, or use the service with dynamic verification mechanism (Pi4SOA).

PSML-P is the model-based Policy Specification Language

The model of PSML-P is PSML which has two sub-models: PSML-S and PSML-C.

PSML-P follows the Event-Condition-Assertion-Action model.

Event is the event that triggers the policy enforcement procedure.
Condition gives the constraints that have to be met in order to enforcement the policy.
Assertionis is an instance of the template: predicate<subject, object>, which asserts the relationship between the subject and the object.
Action is the compensation action that has to do once the assertion is compromised.

The following diagram shows the relationship between PSML-P, PSML-S and PSML-C.

The following diagram shows the layered architecture of PSML-S, PSML-C and PSML-P for Service-Oriented Architectures.

Pi4SOA is the Policy Infrastructure for Service Oriented Architecture

The following diagram shows Pi4SOA, which is the enforcement infrastructure of PSML-P in Service-Oriented Architectures.

The following diagram shows how policy is registered, triggered and enforced on a global PEP (usually is on the UDDI server).