Research Overview

The success of the world wide web can be attributed to the network effect: The absence of central control on content and organization of the web allows thousands of independent actors to contribute resources (web pages) that are interlinked to constitute the web. Recent efforts to extend the web into a semantic web are aimed at enriching the web with machine interpretable content and interoperable resources and services. Realizing the full potential of the semantic web requires the large-scale adoption and use of ontology based approaches to sharing of information and resources. In such a setting, instead of a single, centralized ontology, it is much more natural to have multiple distributed ontologies that cover different, perhaps partially overlapping, domains (e.g., biology, medicine, pharmacology). Such ontologies represent the local knowledge of the ontology designers, that is, knowledge that is applicable within a specific context. Hence, there is an urgent need for theoretically sound yet practical approaches that support user, context, or application-specific adaptation and reuse of knowledge from multiple autonomously developed ontologies in specific applications. Ontologies on the semantic web need to satisfy apparently conflicting objectives: Selective sharing or reuse of knowledge across autonomously developed ontologies on the one hand and accommodation of the local points of view or contextuality of knowledge on the other. Our research on modular ontologies has led to:

• The development of Package-Based Description Logics (P-DL) and Federated Description Logics (F-DL) which are modular variants of description logics that provide mechanisms for semantic importing of names (including concept, role and nominal names) across ontology modules and contextualized interpretation of imported knowledge. A natural consequence of contextualized interpretation is that inferences that are drawn are always from the point of view of a witness module. Thus, different modules might infer different consequences, based on the knowledge that they import from other modules.
• The development of distributed tableaux-based reasoning algorithms for P-DL which provide support for inference from the point of view of an ontology module, using knowledge that is imported from other modules, without the need for complete integration of multiple ontology modules. The algorithm has been implemented in the simplified setting wherein the DL used in each module is restricted to ALC.
• The development of a general framework for answering queries against a knowledgebase using secret or private knowledge, whenever it is posssible to do so without compromising secret or private knowledge.

Work in progress is aimed at:

• Design and implementation of P-DL or closely related federated knowledge base technologies for distributed semantics-driven applications, including in particular, biomedical informatics, comparative genomics, and security informatics.
• The development of a framework for strategies for answering queries against knowledge bases using private knowledge whenever it is possible to do so without compromising private knowledge, in settings where multiple querying agents interact with the knowledge base and with each other.
• Incorporation of epistemic operators into description logics for applications that involve reasoning about knowledge or beliefs of multiple agents for distributed knowledgebase applications.

A long-term goal of our research on modular ontologies is to transform distributed data and knowledge base applications in the same way that the World-Wide Web has transformed the construction, sharing and use of hyperlinked documents and Wiki has transformed encyclopedia construction.

Funding

This research has been funded in part by:

• IIS-0639230 SGER: Exploratory Investigation of Modular Ontologies. Vasant Honavar (PI), Giora Slutzki (Co-PI). National Science Foundation. 2006-2008. $112,000.
• A Collaborative Building Environment for Animal Trait Ontologies, Vasant Honavar (PI), James Reecy, (Co-PI), Center for Integrative Animal Genomics and Center for Computational Intelligence, Learning, and Discovery, Iowa State University. 2006. $25,0000.
• Privacy-preserving reasoning. Vasant Honavar (PI), Giora Slutzki (Co-PI). NSF Industry-University Collaborative Research Center For Information Protection. 2008. $25,000.
• Secrecy-preserving reasoning. Vasant Honavar (PI), Giora Slutzki (Co-PI). NSF Industry-University Collaborative Research Center For Information Protection. 2009. $25,000.

Personnel

• Dr. Vasant Honavar, Professor of Computer Science and of Bioinformatics and Computational Biology, Iowa State University.

• Dr. Giora Slutzki, Professor of Computer Science, Iowa State University.

• Dr. George Voutsadakis, Assistant Professor of Mathematics and Computer Science, Lake Superior State University.

• Dr. Jie Bao, Collaborator, Rensselaer Polytechnic.

• Jia Tao, Ph.D. Student, Computer Science, Iowa State University.

• Harris Lin, Ph.D. Student, Computer Science, Iowa State University.

Publications

1. Bao, J., Slutzki, G., and Honavar, V. (2009). P-DL: A Semantic Importing Approach to Selective Knowledge Reuse in Modular Ontologies. In: Ontology Modularization. Parent, C., Spaccapietra, S., and Stuckenschmidt, H. (Ed). Berlin: Springer. In press.

2. Voutsadakis, G., Bao, J., Slutzki, G., and Honavar, V. (2008). F-ALCI: A Preliminary Report. Fully Contextualized, Federated Logic for the Semantic Web. Proceedings of the ACM/IEEE/WIC Conference on Web Intelligence, Sydney, Australia. pp. 575-578. http://doi.ieeecomputersociety.org/10.1109/WIIAT.2008.296. Extended version: F-ALCI: A Fully Contextualized, Federated Logic for the Semantic Web..

3. Bao, J., Voutsadakis, G., Slutzki, G., and Honavar, V. (2008). On the Decidability of Role Mappings between Modular Ontologies. In: Proceedings of the 23nd Conference on Artificial Intelligence (AAAI-2008), Menlo Park, CA: AAAI Press, pp. 400-405
   

4. Hughes, LaRon, Bao, J., Honavar, V., and Reecy, J. (2008). Animal Trait Ontology (ATO): the importance and usefulness of a unified trait vocabulary for animal species. Journal of Animal Science, 86: 1485-1491.

5. Bao, J., Slutzki, G., and Honavar, V. (2007). A Semantic Importing Approach to Knowledge Reuse from Multiple Ontologies.. In: Proceedings of the 22nd Conference on Artificial Intelligence (AAAI-2007). Vancouver, Canada. Semantic Importing Approach to Knowledge Reuse from Multiple Ontologies. pp. 1304-1309. AAAI Press.

6. Bao, J., Slutzki, G., and Honavar, V. (2007). Privacy-Preserving Reasoning on the Semantic Web. IEEE/WIC/ACM Conference on Web Intelligence. IEEE. pp. 791-797
   

7. Bao, J., Caragea, D., and Honavar, V. A Tableau Based Federated Reasoning Algorithm for Modular Ontologies. In: Proceedings of the ACM/IEEE/WIC Conference on Web Intelligence. IEEE Press. pp. 404-410.

8. Bao, J., Caragea, D., and Honavar, V. On the Semantics of Linking and Importing in Modular Ontologies.In: Proceedings of the International Semantic Web Conference (ISWC 2006), Lecture Notes in Computer Science, Vol. 4273. pp. 72-86. Berlin: Springer.

9. Bao, J., Hu, Z., Caragea, D., Reecy, J., and Honavar, V. A Tool for Collaborative Construction of Large Biological Ontologies. Fourth International Workshop on Biological Data Management (BIDM 2006), Krakov, Poland, DEXA Workshops. IEEE Press. pp. 191-195. 2006.

10. Bao, J., Caragea, D., and Honavar, V. A Distributed Tableau Algorithm for Package-based Description Logics. Proceedings of the Second International Workshop on Context Representation and Reasoning (CRR 2006), Riva del Garda, Italy, CEUR. Vol. 2006.

11. Bao, J., Caragea, D., and Honavar, V. Modular Ontologies - A Formal Investigation of Semantics and Expressivity. In Proceedings of the First Asian Semantic Web Conference, Beijing, China, Springer-Verlag. Vol. Vol. 4185, pp. 616-631, 2006. Best Paper Award

12. Bao, J., Caragea, D., and Honavar, V. Towards Collaborative Environments for Ontology Construction and Sharing. Proceedings of the International Symposium on Collaborative Technologies and Systems., Las Vegas, 2006. Slides

Software

In progress.