1. © 2008 The MITRE Corporation. All rights reserved 26 June 2008 Semantic Web Ontologies and Rules With Efficient Runtime Reasoning Using Logic Programming Ontolog Panel Session: Rules in Semantic Web Applications June 26, 2008 Based on the paper given at the VORTE Workshop EDOC 2007, October 15, 2007, Annapolis, MD [1] Leo Obrst lobrst@mitre.orgMITRE Information Semantics Group Information Discovery & Understanding Dept. Command and Control Center

2. © 2008 The MITRE Corporation. All rights reserved 26 June 2008 2 Objectives Demonstrate Semantic Web ontology, rule, efficient automated reasoning environment Rules separated from executable code Rules separated from executable code Rules integrated with ontologies to leverage logic Rules integrated with ontologies to leverage logic Demonstrate a dynamic Service-Oriented Architecture using rules that allow adaptive change in standard operating procedures Rules supporting situation awareness Rules supporting situation awareness Rules adjusting in response to real-time events Rules adjusting in response to real-time events Optimization of the Logic Programming environment that integrates and reasons over rules and ontologies

3. © 2008 The MITRE Corporation. All rights reserved 26 June 2008 3 Mission Use Case Key Concepts

4. © 2008 The MITRE Corporation. All rights reserved 26 June 2008 4 Scenario Ontology Overview

5. © 2008 The MITRE Corporation. All rights reserved 26 June 2008 5 Applications of Rules Support intelligent processing of real-time events Synthesize information from multiple sources Synthesize information from multiple sources Apply data integrity constraints Apply data integrity constraints (Future work) Mediate between conflicting sources, and (Future work) Mediate between conflicting sources, and Derive new knowledge based on source type and reliability Derive new knowledge based on source type and reliability Construct conceptualization of the battlespace for enhanced situational awareness Transfer attribute values from ObservationArtifacts to TheaterObjects Transfer attribute values from ObservationArtifacts to TheaterObjects Establish ‘safety zones’ and ‘threat areas’ (ROIs) for objects Establish ‘safety zones’ and ‘threat areas’ (ROIs) for objects Detect and report threats to friendly forces Detect and report threats to friendly forces Assist decision makers in applying Rules of Engagement to developing situations

6. © 2008 The MITRE Corporation. All rights reserved 26 June 2008 6 Sample Rules (High Visibility)‏ an unknown mover is within the convoy’s ‘safety zone’ alert the commander that there is a nearby unknown mover IF THEN an unknown mover is within the convoy’s ‘safety zone’ recommend that the convoy deploy UAV reconnaissance IF THEN

7. © 2008 The MITRE Corporation. All rights reserved 26 June 2008 7 Ontology Extended to Space A pilot entering an area impacted by degraded satellite communication The region of interest in red shows the projection of the satellite coverage area onto the earth

8. © 2008 The MITRE Corporation. All rights reserved 26 June 2008 8 Modified Ontology: Extend to Space, Maritime By simply adding a few new classes, we were able to leverage the overall situational awareness framework

9. © 2008 The MITRE Corporation. All rights reserved 26 June 2008 9 Logic Programming Environment Developed SWORIER (Semantic Web Ontologies & Rules for Interoperability with Efficient Reasoning) Reasons over ontologies and rules and answers queries with Logic Programming Reasons over ontologies and rules and answers queries with Logic Programming Designed general Prolog predicates to implement the semantics of OWL (e.g., hasPropertyWith, disjointClasses, logicNot)‏ Addressed major challenges Prolog and OWL define negation differently Prolog and OWL define negation differently Prolog assumes closed world, while OWL assumes open world Prolog assumes closed world, while OWL assumes open world Disjoint and complementary classes Disjoint and complementary classes Previous work claimed this was not possible [Volz et al., 2003] Simpler approach for equivalence Simpler approach for equivalence Initial performance of SWORIER slow; improvements gained with extensionalization, avoiding reanalysis, and code minimization

10. © 2008 The MITRE Corporation. All rights reserved 26 June 2008 10 Knowledge Base Design

11. © 2008 The MITRE Corporation. All rights reserved 26 June 2008 11 Architecture of the Semantic Environment for Enterprise Reasoning (SEER) and SWORIER SWORIER

12. © 2008 The MITRE Corporation. All rights reserved 26 June 2008 12 Conclusions OWL (a Description Logic) is expressive and meets the majority of identified requirements Ontologies & rules are inseparable: need both Ontologies can be applied for rapid enterprise integration We were able to deliver new capabilities in hours, instead of weeks or months We were able to deliver new capabilities in hours, instead of weeks or months Rules are useful in aggregation of events in a battlespace Semantic Web + Logic Progamming Combining semantics of OWL (DL) & LP is difficult Combining semantics of OWL (DL) & LP is difficult Translation of rule languages fairly straightforward: usually based on Horn Rules Translation of rule languages fairly straightforward: usually based on Horn Rules We are engaged in the W3C RIF: some extensions to SWRL desired, etc.

13. © 2008 The MITRE Corporation. All rights reserved 26 June 2008 13 Future Work Develop meta-rules to select rule set Completion of SWORIER Consider hybrid logic, constraint logic, answer set programming Storage of instances in a database Extend to new domains

14. © 2008 The MITRE Corporation. All rights reserved 26 June 2008 14 References 1.Stoutenburg, Suzette; Leo Obrst; Deborah Nichols; Paul Franklin; Ken Samuel; Michael Prausa. 2007. Ontologies and Rules for Rapid Enterprise Integration and Event Aggregation. Vocabularies, Ontologies and Rules for the Enterprise (VORTE 07), EDOC 2007, Annapolis, MD, Oct. 15-19, 2007. 2.Obrst, Leo; Dru McCandless; Suzette Stoutenburg; Karen Fox; Deborah Nichols; Mike Prausa; Rick Sward. 2007. Evolving Use of Distributed Semantics to Achieve Net-centricity. Regarding the “Intelligence” in Distributed Intelligent Systems, AAAI Fall Symposium, Arlington VA, Nov. 8-11, 2007. 3.Samuel, Ken; Leo Obrst; Suzette Stoutenberg; Karen Fox; Paul Franklin; Adrian Johnson; Ken Laskey; Deborah Nichols; Steve Lopez; and Jason Peterson. 2008. Applying Prolog to Semantic Web Ontologies & Rules: Moving Toward Description Logic Programs. The Journal of the Theory and Practice of Logic Programming (TPLP), Massimo Marchiori, ed., Cambridge University Press, forthcoming. 4.Stoutenburg, Suzette; Leo Obrst; and Deborah Nichols. 2007. Ontologies in OWL for Rapid Enterprise Integration. OWL: Experiences and Directions Third International Workshop (OWLED 2007), 6-7 June 2007, Innsbruck, Austria. 5.Stoutenburg, Suzette; Obrst, Leo; Nichols, Deborah; Samuel, Kenneth; and Franklin, Paul. 2007. Toward a Standard Rule Language for Enterprise Application Integration, Year 2 Results, MITRE Technical Report MTR070025, February, 2007. 6.Stoutenburg, Suzette, Leo Obrst, Deborah Nichols, Ken Samuel, and Paul Franklin. 2006. Applying Semantic Rules to Achieve Dynamic Service Oriented Architectures. RuleML 2006: Rules and Rule Markup Languages for the Semantic Web, co-located with ISWC 2006, Athens, GA, November 10-11, 2006. In: Service-Oriented Computing – ICSOC 2006, Lecture Notes in Computer Science Volume 4294, 2006, pp. 581-590. Heidelberg: Springer-Verlag, Also: MITRE Technical Report MTR 06B0000014, March 2006. http://www.mitre.org/work/tech_papers/tech_papers_06/06_0904/index.html.