390 likes | 538 Views
Knowledge Representation and Reasoning. Stuart C. Shapiro Professor, CSE Director, SNePS Research Group Member, Center for Cognitive Science Faculty Member, Interdisciplinary MS in Computational Linguistics. Introduction. Long-Term Goal. Theory and Implementation of
E N D
Knowledge Representation and Reasoning Stuart C. Shapiro Professor, CSE Director, SNePS Research Group Member, Center for Cognitive Science Faculty Member, Interdisciplinary MS in Computational Linguistics S.C. Shapiro
Introduction S.C. Shapiro
Long-Term Goal • Theory and Implementation of Natural-Language-Competent Computerized Cognitive Agent/Robot • and Supporting Research in Artificial Intelligence Cognitive Science Computational Linguistics. S.C. Shapiro
Research Areas • Knowledge Representation and Reasoning • Cognitive Robotics • Natural-Language Understanding • Natural-Language Generation. S.C. Shapiro
Goal • A computational cognitive agent that can: • Understand and communicate in English; • Discuss specific, generic, and “rule-like” information; • Reason; • Discuss acts and plans; • Sense; • Act; • Maintain a model of itself; • Remember and report what it has sensed and done. S.C. Shapiro
Cassie • A computational cognitive agent • Embodied in hardware • or Software-Simulated • Based on SNePS and GLAIR. S.C. Shapiro
GLAIR Architecture Grounded Layered Architecture with Integrated Reasoning Knowledge Level SNePS Perceptuo-Motor Level NL Sensory-Actuator Level Vision Sonar Proprioception Motion S.C. Shapiro
SNePS • Knowledge Representation and Reasoning • Propositions as Terms • SNIP: SNePS Inference Package • Specialized connectives and quantifiers • SNeBR: SNePS Belief Revision • SNeRE: SNePS Rational Engine • Interface Languages • SNePSUL: Lisp-Like • SNePSLOG: Logic-Like • GATN for Fragments of English. S.C. Shapiro
Example Cassies& Worlds S.C. Shapiro
BlocksWorld S.C. Shapiro
FEVAHR S.C. Shapiro
FEVAHRWorld Simulation S.C. Shapiro
UXO Remediation Corner flag Field Drop-off zone UXO NonUXO object Battery meter Corner flag Corner flag Recharging Station Cassie Safe zone S.C. Shapiro
Crystal Space Environment S.C. Shapiro
Princess from “The Trial, The Trail” A VR drama by Josephine Anstey S.C. Shapiro
Vacuum Cleaner Cassie Using Byron Weber Becker’s Java Karel S.C. Shapiro
Magellan ProTM Mobile RobotfromiRobot S.C. Shapiro
Sample Research Issues:Indexicals S.C. Shapiro
Representation and Use of Indexicals • Words whose meanings are determined by occasion of use • E.g. I, you, now, then, here, there • Deictic Center <*I, *YOU, *NOW> • *I: SNePS term representing Cassie • *YOU: person Cassie is talking with • *NOW: current time. S.C. Shapiro
Analysis of Indexicals(in input) • First person pronouns: *YOU • Second person pronouns: *I • “here”: location of *YOU • Present/Past relative to *NOW. S.C. Shapiro
Generation of Indexicals • *I: First person pronouns • *YOU: Second person pronouns • *NOW: used to determine tense and aspect. S.C. Shapiro
Use of Indexicals 1 Come here. S.C. Shapiro
Use of Indexicals 2 Come here. I came to you, Stu. I am near you. S.C. Shapiro
Use of Indexicals 3 Whoam I? Your name is ‘Stu’ and you are a person. Whohaveyoutalkedto? I am talking to you. TalktoBill. I am talking to you, Bill. Comehere. S.C. Shapiro
Use of Indexicals 4 Comehere. I found you. I am looking at you. S.C. Shapiro
Use of Indexicals 5 Comehere. I found you. I am looking at you. I came to you. I am near you. S.C. Shapiro
Use of Indexicals 6 WhoamI? Your name is ‘Bill’ and you are a person. Whoareyou? I am the FEVAHR and my name is ‘Cassie’. Whohaveyoutalkedto? I talked to Stu and I am talking to you. S.C. Shapiro
Current Research Issues: Distinguishing Perceptually Indistinguishable ObjectsPh.D. Dissertation, John F. Santore S.C. Shapiro
Some robots in a suite of rooms. S.C. Shapiro
Are these the same two robots? • Why do you think so/not? S.C. Shapiro
Next Steps • How do people do this? • Currently analyzing protocol experiments • Getting Cassie to do it. S.C. Shapiro
Current Research Issues: Representation & Reasoningwith Arbitrary ObjectsStuart C. Shapiroin conjunction with Development of SNePS 3 S.C. Shapiro
Classical Representation • Clyde is gray. • Gray(Clyde) • All elephants are gray. • x(Elephant(x) Gray(x)) • Some elephants are albino. • x(Elephant(x) & Albino(x)) • Why the difference? S.C. Shapiro
Representation Using Arbitrary & Indefinite Objects • Clyde is gray. • Gray(Clyde) • Elephants are gray. • Gray(any x Elephant(x)) • Some elephants are albino. • Albino(some x Elephant(x)) S.C. Shapiro
Structural Subsumption Among Arbitrary & Indefinite Objects (any x Elephant(x)) (any x Albino(x) & Elephant(x)) (some x Albino(x) & Elephant(x)) (some x Elephant(x)) If x subsumes y, then P(x) P(y) S.C. Shapiro
Example (Runs in SNePS 3) Hungry(any x Elephant(x) & Eats(x, any y Tall(y) & Grass(y) & On(y, Savanna))) Hungry(any u Albino(u) & Elephant(u) & Eats(u, any v Grass(v) & On(v, Savanna))) S.C. Shapiro
Axiomatic Subsumption(Runs in SNePS 3) Animal(any x Mammal(x)) Hairy(any x Mammal(x)) Mammal(any x Dog(x)) Dog(Fido) Hairy(any x Dog(x)) Hairy(Fido) Animal(Fido) S.C. Shapiro
Next Steps • Finish theory and implementation of arbitrary and indefinite objects. • Extend to other generalized quantifiers • Such as most, many, few, no, both, 3 of, … S.C. Shapiro
For More Information • Shapiro:http://www.cse.buffalo.edu/~shapiro/ • SNePS Research Group:http://www.cse.buffalo.edu/sneps/ • Meets Fridays 9-11, 242 Bell Hall • Join us! S.C. Shapiro