Browsing by Author "Peter R. Wurman, Committee Member"

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A Community-Based Rating System for Selecting Among Web Services
(2003-03-31) Sreenath, Raghuram Masti; Michael R. Young, Committee Member; Peter R. Wurman, Committee Member; Munindar P. Singh, Committee Chair
The current infrastructure for Web services has a static approach to discover a service. It is based on a common repository that has a simple search interface that lets the user query and find a provider for the desired service. More often than not, the repository produces a long list of service providers along with typical interfaces to talk to them. There is no support to evaluate service providers. Such evaluations are important to make a selection among competing service providers. This thesis develops a community-based approach for evaluating service providers. In this approach, agents cooperate with each other to evaluate different providers. Importantly, the agents rate each other, to decide how to weigh each other's recommendations. The reasoning of each agent is enabled by a concept lattice, which supports a mechanism to rate the agents.
Semantic Web Services Query and Manipulation Language for Quality Attributes of Web Services
(2003-08-21) Bilgin, Ahmet Soydan; Peng Ning, Committee Member; Munindar P. Singh, Committee Chair; Peter R. Wurman, Committee Member
The Web is moving toward a collection of interoperating Web services. Achieving this interoperability requires dynamic discovery of Web services on the bases of their capability. The capability of a service can be best determined by its functional description attributes, which describe the service interface such as input and output of the service, and quality attributes, which provide additional information to evaluate the service. This thesis defines an approach where these quality attributes can be advertised and queried by using DAML as the query, ontology, and service description language. As a core part of this system, we modify and extend an existing DAML query language. We develop this system as an extension of current Web service registries so our system will be fully synchronized with any available Web service registry.
Specifying and Resolving Temporal Commitments
(2002-12-18) Mallya, Ashok Ullal; Dennis R. Bahler, Committee Member; Peter R. Wurman, Committee Member; Munindar P. Singh, Committee Chair
Commitments are a powerful representation for modeling multiagent protocols, especially for applications such as electronic commerce, where contracts are a natural component of the desired interactions. Previous approaches have considered the semantics of commitments and how to check compliance with them. However, these approaches, although valuable, do not capture some of the subtleties that arise in applications of commitments in real-life settings. In particular, practical contracts and institutions have subtle temporal properties. The present thesis develops a rich representation for the temporal content of commitments. This enables us to capture realistic contracts and institutions rigorously, and avoid subtle ambiguities. Consequently, this approach enables us to reason about questions of great practical import, for example, whether and when exactly a commitment is satisfied or breached and whether it is or ever becomes unenforceable.
Toward Autonomic Web Services Trust and Selection
(2005-03-08) Maximilien, Eugene Michael; Laurie A. Williams, Committee Member; Mladen A. Vouk, Committee Member; Peter R. Wurman, Committee Member; Munindar P. Singh, Committee Chair
Emerging standards in Web services enable the development of large-scale applications in open environments. In particular, they enable services to be dynamically bound. However, current techniques fail to address the critical problem of selecting the right service instances to bind. The right service instances would be determined based on user preferences and business policies in a manner that considers their trustworthiness. We propose a multiagent approach that naturally provides a solution to the selection problem. This approach is based on an architecture and programming model in which agents represent applications and services. The agents support considerations of semantics and quality of service (QoS). They interact and share information, in essence creating an ecosystem of collaborative service providers and consumers. Consequently, our approach enables applications to be dynamically configured at runtime in a manner that continually adapts to the preferences of the participants. Our agents are designed using decision theory and make use of Semantic Web knowledge representation techniques for shared conceptualizations (ontologies). We evaluate our approach conceptually and through simulation experiments.
Verifying Commitment Based Business Protocols and their Compositions: Model Checking using Promela and Spin
(2006-08-22) Cheng, Zhengang; Laurie Williams, Committee Member; Peter R. Wurman, Committee Member; Munindar P. Singh, Committee Co-Chair; Mladen A. Vouk, Committee Co-Chair
A protocol-oriented approach of modeling and enacting business processes and workflows has been developed recently that offers advantages in terms of supporting the autonomy and heterogeneity of business partners and the reconfigurability of their process. Importantly, protocols are described using commitments, map to the individual computation of the participating roles, and can be composed to yield more complex protocols. However, verifying that the protocols, especially composed protocols, fully satisfy appropriate correctness properties remains an open problem. This dissertation presents a novel way to model business protocols in terms of commitments involved and the constraints for protocol composition. The correct composition of a business process can be expressed via individual protocol definitions and their composition constraints,thereby enabling the verification of large processes. Importantly, as part of the verification process, protocols are translated into the language Promela, which makes them amenable to analysis and verification using the model checker Spin. As a result many important properties of business protocols and their compositions into partial and full workflows can be verified, and improved protocols can be produced. The contribution of this dissertation is in providing a generalized mechanism for modeling commitments, formulating and verifying properties related to commitments. In fact, the results are applicable to a wide range of processes and related protocols, such as scientific discovery processes and workflows.