CYC: The Common Sense Knowledge Base

CYC: The Common Sense Knowledge Base By: Jeremy Berman Alok Sahgal Dr. Reed CSC 550

Intro • History • What is Cyc? • How does it work? • Applications • OpenCyc • CycSecure

History of CYC • Douglas B. Lenat and MCC (1984) • GOFAI at a massive scale • Construct “Common Sense” knowledge • 3 million rules of thumb (2002) • 300,000 terms

The First 10 Years • Initial Goals (1984) • representation language • Interface for browsing and editing • "cadre of lightly trained knowledge enterers" could easily use • hooks to other AI programs. • Midpoint Report (1990) • CycL developed

Current State • Now, anyone can be knowledge-enterer • Web allows acceleration of knowledge entry • Lenat claims human-level capacity in 5 years

How CYC Works Knowledge Server • Knowledge Base • Inference Engine • CycL • Cyc-NL • Semantic Integration Bus

Knowledge Base • Contains facts about everyday life (common sense) • Terms written in CycL • Assertions about terms • Entered by humans • Created by Cyc • Microtheories

Inference Engine • General logical deduction • Best-first search • Due to size, ordinary expert system methods of accessing data do not work. • Cyc team developed new methods of retrieving data (secret)

CycL • CycL • Cyc representation language • variation of first-order predicate calculus

CycL • Constant - #$OrganicStuff • NAT - (#$FruitFn #$AppleTree) • Variable - • (#$colorOfObject #$Grass ?someColor) • Expression – • (#$colorOfObject #$Grass #$Green)

CycL • Assertions “Animals sleep at home.” (ForAll ?x (ForAll ?S (ForAll ?PLACE(implies (and(isa ?x Animal)(isa ?S SleepingEvent)(performer ?S ?x)(location ?S ?PLACE))(home ?x ?PLACE))))) if x is an animal and the performer of a sleeping event then the place where that event takes place is the home of x.

Cyc-NL • Used to translate between English and CycL The man saw the light with the telescope. {:SENTENCE {:NP {:DETP {#$Determiner [the]}} {:N-BAR {#$SimpleNoun [man]}}} {:VP {#$Verb [saw]} {:NP {:DETP {#$Determiner [the]}} {:N-BAR {#$SimpleNoun [light]}} {:PP {#$Preposition [with]} {:NP {:DETP {#$Determiner [the]}} {:N-BAR {#$SimpleNoun [telescope]}}}}}}}}

Cyc-NL Fred saw the plane flying over Zurich. Fred saw the mountains flying over Zurich. • Cyc “knows” that: • planes fly. • people fly in planes. • mountains do not fly. • Zurich is a city.

Semantic Integration Bus • Makes data from a variety of sources usable to the Inference Engine.

Applications OpenCyc • Uses • Goals of Project • Demonstration CycSecure

OpenCyc Uses Allows user to create applications that access and use data in CycKB Starting point for: • Speech understanding • Database integration • Email prioritizing • Game engines • Letting people develop their own “worlds”

OpenCyc Goals of Project • Growth of Knowledge Base • Establish CycKB as the standard for: • knowledge representation/management • database integration • intelligent software applications

OpenCyc Goals cont. • Raise awareness for symbolic knowledge • Help to combine symbolic systems with emergent ones (neural nets, genetic algorithms, etc)

OpenCyc Demonstration http://www.opencyc.org/images/opencyc-kb-browser.gif

CycSecure • Automated network auditing service that simulates network attacks • First real commercial application • Complements other network security apps

Anatomy Of CycSecure • Network Configuration Simulator • Inputs the data for security assessment • CycSecure Knowledge Base • Contains knowledge of vulnerabilities and patterns of attacks • AttackPlan Analyzer • Simulates a planned attack

How CycSecure Works • Uses virtual network from NCS • Finds vulnerabilities of network security • DoD’s Information Assurance Vulnerability Assessment

More about CycSecure • Evolved Scanner • Costs • Still in beta-testing

Future of Cyc • Online brokering of goods and services • "Smart" interfaces • Advancement gaming AI • Improved speech recognition • Sophisticated user modeling • Local consistency

Conclusion • KB is already enormous and broad • Large corporate support • Largest GOFAI attempt

References • www.cyc.com • www.opencyc.org • Anthes, Gary H. Computerizing Common Sense, Computerworld April 8, 2002.

CYC: The Common Sense Knowledge Base