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Artificial intelligence project. CYC. CONTENTS. OBJECTIVE +WHAT IS CYC ? +WHAT DOES DO ? CYC Architecture Knowledge Base +Constants +Individuals +Collection +Truth Function +Functions - PowerPoint PPT Presentation
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Artificial intelligence project
CONTENTS
OBJECTIVE
+WHAT IS CYC ?
+WHAT DOES DO ? CYC Architecture Knowledge Base
+Constants
+Individuals
+Collection
+Truth Function
+Functions Inference Engine
+How it works Natural Language System CYCL-Representation Language Mapping Ontology into CYCL
OBJECTIVE
CYC attempts to assemble an comprehensive ontology and
Knowledge Base of common sense knowledge.
This Helps AI projects to do human like reasoning
The objective was to codify, in machine-usable form, millions of
pieces of knowledge that comprise human common sense.
Example: “Every Tree is a Plant” && “Plants eventually die” from
which we can infer “All trees Die”.
(note: the first two phrases are the things present in the normal
database)
CYC ARCHITECTURE
CYC Said!!!
CYC Foundation: “Imagine a world in which every single person is given free access
to programs that reason with the sum of all human knowledge. That's what we're doing.”
KNOWLEDGE BASE
KNOWLEDGE BASE cont…
The Knowledge Base (KB) is a collection of over one million human-defined assertions, rules or common sense ideas.
The concept names in CYC are known as constants. Individuals: Individual items known as individuals, such as #$BillClinton or
#$France. Collections, such as #$Tree-ThePlant (containing all trees) or
#$EquivalenceRelation (containing all equivalence relations). A member of a collection is called an instance of that collection.
Truth Functions which can be applied to one or more other concepts and return
either true or false.
KNOWLEDGE BASE cont.. EXAMPLE: #$siblings is the sibling relationship, true if the two arguments are
siblings. By convention, truth function constants start with a lower-case letter.
Functions, This produce new terms from given ones. EXAMPLE:
#$FruitFn, when provided with an argument describing a type (or collection) of plants, will return the collection of its fruits. By convention, function constants start with an upper-case letter and end with the string "Fn".
The Cyc KB is divided into many (currently thousands of) "microtheories", each of which is essentially a bundle of assertions that share a common set of assumptions
Expert System
INFERENCE ENGINE
An Inference engine is a computer program that tries to derive answers from a knowledge base.
The CYC inference engine performs general logical deduction (including modus ponens, modus tollens, and universal and existential quantification)
NATURAL LANGUAGE SYSTEM
The CYC-NL system can be described in terms of its three primary components, although in truth there are many other utilities that contribute to its success.
The three main components are the Lexicon:
The lexicon is the backbone of the NL system. It contains syntactic and semantic information about English words.
Each word is represented as a Cyc constant.
Example:
the constant#$Light-TheWord is used to represent the English word "light".
NLP cont..
The syntactic parser
--The syntactic parser utilizes a phrase-structure grammar loosely based on Government and Binding principles.
--Using a number of context-free rules, the parser builds tree-structures, bottom-up, over the input string.
--The parser outputs all trees allowed by the rule system, so multiple parses are possible in cases of syntactic ambiguity.
NLP cont..
The semantic interpreter.
Cyc-NL's semantic component transforms syntactic parser into CycL formulas.
The output of the semantic component is "pure" CycL: a parsed sentence can immediately be asserted into the KB,
for example, or a parsed question can be presented to the SQL generator in order to pose a database query.
Populating CYC from web
CycCycCyc
Ontology &Knowledge
Base
CycOntology &Knowledge
Base
ReasoningModules
ReasoningModules
Interface to External Data Sources
Interface to External Data Sources
Cyc
API
Cyc
API
Know
led
ge
Entr
y T
ools
Know
led
ge
Entr
y T
ools
User Interface(with Natural Language Dialog)
User Interface(with Natural Language Dialog)
DataBases
WebPages
Text Sources
Other KBs
KnowledgeUsers
KnowledgeUsers
ExternalData
Sources
ExternalData
Sources
KnowledgeAuthors
KnowledgeAuthors
Populating CYC from web
Choosing a query: Because the number of concepts in the KB is so large, the number of possible CycL queries is enormous; choosing interesting, productive queries auto-matically is a necessary step in automating the knowledge acquisition process. An example of such a query might be:
Searching: Once a query is selected, it is translated into one or more English
search strings. The query above might be rendered into strings such as: 3. Parsing results: The relevant components of sentences are identified by their
location relative to the search string. The terms are then parsed into CycL via the natural lan-guage parsing process described in section 3.3, resulting in one or more GAFs such as:
KB consistency checking: Some of the results retrieved during the search
process are disprovable, because they are inconsistent with knowledge already present in the knowl-edge base; others are already known or trivially provable, and therefore redundant. Any GAF found via inference to be inconsistent or redundant is discarded.
Open CYC and Research CYC
Open CYC is a open source part of the original CYC Knowledge base The original Knowledge base is Proprietary.
But later an upgraded version of the Open CYC was released with the entire Knowledge base.
More recently, CYC has been made available to AI researchers under a research-purposes license as Research CYC
Recent Application
Terrorism Knowledge Base
The comprehensive Terrorism Knowledge Base is an application of cyc in development that will try to ultimately contain all relevant knowledge about terrorist groups, their members, leaders, ideology, founders, sponsors, affiliations, facilities, locations, finances, capabilities, intentions, behaviors, tactics, and full descriptions of specific terrorist events. The knowledge is stored as statements in mathematical logic, suitable for computer understanding and reasoning.
Cyclopedia
Cyclopedia is being developed that superimposes cyc keywords on pages taken from Wikipedia pages.
Reference
http://www.cyc.com http://en.wikipedia.org
Searching for Common Sense: Populating Cyc™ from the Web
Thank You
- Regards
HariHaran