Jorge Lobo

Associate Professor

Education:

Doctor of Philosophy, Computer Science, December 1990

The University of Maryland at College Park

Master of Science, Computer Science June 1985.

Universidad Simon Bolivar, Caracas, Venezuela

Bachelor of Science, Computer Engineering, June 1983

Universidad Simon Bolivar, Caracas, Venezuela

Research Interests:

My recent projects center on the use of the rule programming paradigm and the formal properties of rule computational models to define and develop efficient policy based management systems. Rule systems have been successfully applied in many expert systems and database applications, from consistency maintenance to the general encoding of business rules process to diagnosis systems. However, the applicability of the paradigm goes beyond data management or expert systems. Rules can be used in network management and monitoring, electronic commerce, computer security and access management, resource allocation in distributed systems and other application areas to express policies -- collections of general principles specifying the desired behavior of a system. Currently, most implementations of such policy based systems are done ad hoc in a case by case bases. Policy enforcement is embedded in the application and switching applications requires the re-implementation of the policy module. Using the Event/Condition/Action rule paradigm to express policies has proven to be a fairly general abstraction (both in expressive power and computational efficiency) to model and implement application independent policy servers. My most recent project is a policy server for the availability management of a Presence Server. The server has been successfully tested inside two cellular phone networks in Europe. Other projects include a policy server for management and monitoring networks of softswitches and a language to program network routers.

Publications:

Books and Book Chapters:

Foundations of Disjunctive Logic Programming. With Jack Minker and Arcot Rajasekar. MIT Press (1992).

A Resolution-based Procedure for Default Theories with Extensions. With M. Barback. In J. Dix, L.M. Pereira and T.C. Przymusinski, editors, Non-Monotonic Extensions of Logic Programming. Springer-Verlag, Lecture Notes in Artificial Intelligence, No 927, 1995. Refereed.

Circumscription and Disjunctive Logic Programming. With J. Minker and A. Rajasekar. In V. Lifschitz, editor, Artificial Intelligence and Mathematical Theory of Computation. Academic Press. (Invited 1991).

Theory of Disjunctive Logic Programs. With J. Minker and A. Rajasekar. In J. Lassez, editor, Computational Logic: Essays in honor of Alan Robinson. MIT Press. Refereed. (1991).

On General Disjunctive Logic Programs. With Jack Minker and Arcot Rajasekar. In M. Zemankova and Z. Ras, editors, INTELLIGENT SYSTEMS: State of the art and future directions, 1990. Ellis Horwood. Refereed.

Journal papers:

Realizing network control policies using distributed action plans. With M. Kohli. Journal of Network and Systems Management, September 2003.

Conflict Resolution Using Logic Programing. With J. Chomicki, S. Naqvi: IEEE Transaction on Knowledge and Data Engineering 10(15) (2003)

Formalizing and Reasoning about the Requirements Specifications of Workflow Systems. With G. Trajcevski, C. Baral: International Journal of Intelligent Information Systems 10(4): 483-507 (2001)

Knowledge and the Action Description Language A. With Gisela Mendez, Stuart R. Taylor: TPLP 1(2): 129-184 (2001)

Qualifying Answers According to User Needs and Preference. With T. Gaasterland. Fundamenta Informaticae 32(2): 121-137, 1997. Short version appeared in VLDB94 (see below).

Minimal and Consistent Evolution of Knowledge Bases. With G. Trajcevski. Journal of Applied Non-classical Logics, 7 (1-2), 117-146, 1997.

Abductive Consequence Relations. With C. Uzcategui. Artificial Intelligence, 89 (1997), 149-171. For a short version of this paper see conference papers below.

Abductive Change Operators. With C. Uzcategui. Fundamenta Informaticae. 27(4), 319-418, 1996.

Fixpoint and stable model semantics for update rule programs and implementation in a relational database management system. With L. Rachid. ACM Transactions on Database Systems, 21(4):526-517, 1996.

Computation of Best Bounds of Probabilities from Uncertain Data. With C. Luo, C. Yu, G. Wang and T. Phan. Computational Intelligence, 12(4),541-566,1996.

A High-level Petri Net Model for a Declarative Semantics of Concurrent Logic Languages. With T. Jeffrey and T. Murata. To appear in IEEE Transactions on Knowledge and Data Engineering., 8(2):241--259, 1996.

Dynamic Maintenance of the Transitive Closure in Disjunctive Graphs. With Q. Yang, C. Yu, G. Wang and T. Phan. Annals of Mathematics and Artificial Intelligence, 14,151-176,1995.

An Extended Petri-net model for normal logic programs. With T. Shimura and T. Murata. IEEE Transactions on Knowledge and Data Engineering. 7(1):150-162, 1995.

A semantics for a class of non-deterministic and causal production system programs. With L. Rachid. Journal of Automated Reasoning, 12:305--349, 1994.

View updates in stratified disjunctive databases. With J. Grant, J. Horty, and J. Minker. Journal of Automated Reasoning, 11:249-267, 1993.

Processing negation and disjunction in logic programs through integrity constraints. With T. Gaasterland. Journal of Intelligent Information Systems, Vol. 2, No. 3, 1993.

Disjunctive LP + Integrity Constraints = Stable Model Semantics. With J.A.Fernandez, J. Minker, V.S. Subrahmanian. Annals of Mathematics and Artificial Intelligence, Vol. 8, No. 3-4, 1993.

Relating minimal models and pre-requisite-free normal defaults. With V.S. Subrahmanian. Information Processing Letters, 44:129-133,1992.

Generalized disjunctive well-founded semantics for logic programs. With C. Baral and J. Minker. Annals of Mathematics and Artificial Intelligence, 5:89-132,1992.

Semantics for Horn and Disjunctive Logic Programs. With J. Minker, and A. Rajasekar. Journal of Theoretical Computer Science, 86:93-106,1991.

Weak Generalized Closed World Assumption. With J. Minker and A. Rajasekar. Journal of Automated Reasoning, 5:293-307, 1989.

Conference & Workshop papers:

Monitors for History-based Policies. J. Chomicki and J. Lobo. In Proc. International Workshop of Polices for Distributed Systems and Networks, POLICY 2001. LNCS 1995. January, 2001,

Reasoning about Policies using Logic Programs. T.C. Son and J. Lobo. In Working notes of the 2001 AAAI Spring Symposium on Answer Set Programming. March, 2001.

Distributed Action Plans in and Agent based Network Management System. M. Kohli and J. Lobo. In Proc. Fourth International Conference on Autonomous Agents. June, 2000.

Extended version of A Logic Programming Approach to Conflict Resolution in Policy Management. J. Chomicki, J. Lobo and S. Naqvi. Proc. 7th International Conference on Principles of Knowledge Representation and Reasoning (KR'2000), April 2000, Breckenridge, Colorado, Morgan Kaufman, pp.121-132

Netmon Network management for the SARAS softswitch. A. Virmani, J. Lobo and M. Kohli. In Proc. IEEE/IFIP Network Operations and Management Symposium. April, 2000.

Policy Evaluation for Network Management. R. Bhatia, J. Lobo and M. Kohli. in INFOCOM. March, 2000.

A Policy Description Language. J. Lobo, R. Bhatia and S. Naqvi. In Proc. AAAI. July, 1999.

COPLAS: a COnditional PLAnner with Sensing actions. In Working Notes of the AAAI98 Fall Symposium on Cognitive Robotics. AAAI Press TR FS-98-02, pp. 109-116. Oct., 1998.

Formal characterization of active databases: Part II. With C. Baral and G. Trajcevski. To appear in Proc. of Fifth International Conference on Deductive and Object-Oriented Databases, Switzerland, Dec. 1997.

Defeasible Specification in Action Theories. With C. Baral. Proc. of IJCAI. August , 1997.

Adding knowledge to the Action Description Language "A". With G. Mendez and S. Taylor. Proc. of AAAI. July, 1997.

Abductive Consequence Relations. With C. Uzcategui. In working notes of the 1996 Common Sense Reasoning Workshop. Extended version will appear in Artificial Intelligence. See journal papers above.

Formal Characterization of Active Databases. With C. Baral. Logic In Databases 96, LNCS 1154, 175-196, 1996.

Abduction and Change. With C. Uzcategui. In Proc. of the 1996 Non-monotonic reasoning workshop.

An Experimental Distributed Deductive Database System. With C. Robles and T. Gaasterland. Proc. of Fourth International Conference on Deductive and Object-Oriented Databases, Singapore, December, 1995.

Qualified Answers That Reflect User Needs and Preferences. With T. Gaasterland. Proc. of 20th International Conference on Very Large Databases, Santiago, Chile, 1994.

Assigning Function to CDS Through Qualified Query Answering. with T. Gaasterland, N. Maltsev and G. Chen. Proceedings of the Second International Conference on Intelligent Systems for Molecular Biology, Stanford, CA, August 1994.

Using Semantic Information for Processing Negation and Disjunction in Logic Programs. With T. Gaasterland. Proc. of seventh International Symposium on Methodologies for Intelligent Systems, Trondheim, Norway, 1993.

The Non-monotonic Nature of a Class of Incomplete Information. With M.D. Barback and J.J Lu. Proc. of International Conference on Database Theory, Berlin, Germany, (October 1992).

A Petri Net Semantics for Logic Programs with Negation. With T. Shimura and T. Murata. Fourth International Conference on Software Engineering and Knowledge Engineering, Italy, (June 1992).

View updates in stratified disjunctive databases. With J. Grant, J. Horty, and J. Minker. Proc. of second International Symposium on Artificial Intelligence and Mathematics, Fort Lauderdel, FL, 1992.

WF^3: A semantics for negation in normal disjunctive logic programs. With C. Baral and J. Minker. Proc. of International Symposium on Methodologies for Intelligent Systems, Charlotte, NC, 1991.

On Constructive Negation for Disjunctive Logic Programs. In S. Debray and M. Hermenegildo, editors, Proc. North American Conference on Logic Programming, pages 704-718, Austin, Texas, 1990. MIT Press.

Generalized disjunctive well-founded semantics for logic programs: Declarative semantics. With C. Baral and J. Minker. In M. Zemankova Z. W. Ras and M. L. Emrich, editors, Proc. of Fifth International Symposium on Methodologies for Intelligent Systems, pages 465-473, Knoxville, Tennessee, 1990. North-Holland.

Generalized disjunctive well-founded semantics for logic programs: Procedural semantics. With C. Baral and J. Minker. In M. Zemankova Z. W. Ras and M. L. Emrich, editors, Proc. of Fifth International Symposium on Methodologies for Intelligent Systems, pages 456-464, Knoxville, Tennessee, 1990. North-Holland.

Generalized Well-Founded Semantics for Logic Programs. With C. Baral and J. Minker. In M. E. Stickel, editor, Proc. of Tenth International Conference on Automated Deduction, Kaiserslautern, FRG, July, 1990. Springer-Verlag.

Extending the Semantics of Logic Programs to Disjunctive Logic Programs. With J. Minker, and A. Rajasekar. In G. Levi and M. Martelli, editors, Proc. International Conference on Logic Programming, Lisbon, Portugal, June 19-23 1989. MIT Press.

Skeptical Reasoning and Disjunctive Programs. With A. Rajasekar and J. Minker. In Proceedings of First International Conference on Knowledge Representation and Reasoning, pages 349-357. Morgan-Kaufmann, 1989.

Weak Completion Theory for Non-Horn Programs. With A. Rajasekar, and J. Minker. In R.A. Kowalski and K.A. Bowen, editors, Proc. International Conference and Symposium on Logic Programming, pages 828-842, Seattle, Washington, August 15-19 1988. MIT Press.

A Metaprogramming Approach to Semantically Optimize Queries in Deductive databases. With J. Minker. In L. Kerschberg, editor, Proceedings of The Second International Conference on Expert Database Systems, pages 387-420, Tysons Corner, Virginia, April 1988.

Research in progress and other reports:

Temporal and Distributed Revision Programs. With S. Zabala.

Temporal Logic and Reasoning about Actions. With G. Mendez, J. Llopis and C. Baral.

Characterizing Production Systems using Logic Programming and the Situation Calculus. With C. Baral.

Formalizing workflows as collections of condition-action rules. With C. Baral and G. Trajcevski.

jorge@cs.uic.edu