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Knowledge Engineering and Agent Technology H-C Wu [email protected]

Knowledge Engineering and Agent Technology H-C Wu [email protected]

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Knowledge Engineering and Agent Technology

H-C [email protected]

Outline Study and Traveling in UK How to Research Knowledge Engineering Problem in Knowledge Transfer Ontology , Ontology Engineering Mature Methodology CommonKADS (KE+KM) Agent Definition Knowledge Level in Agent System Practical Reasoning Agent BDI Architecture Agent Tool Reference

Study in UK

IELS MA , Msc , MBA , Msc by Research M.Phil PhD , D. Phil New Route PhD , EngD Condition offer , Unconditional offer

Traveling in UK London Oxford, Cambridge Strafford Upon Avon York Newcastle upon Tyne Manchester Liverpool Edinburgh Glasgow

Research Process Motivation: Why this research is important Research Question: What are you going to study? Research sub-questions: Break down your

research question in several simpler questions Literature Review: What is the relevance of your

research question Research Methodology: How are you going to

answer your research question ? Scope: Which issues are you not going to study? Success Criteria: How are you going to evaluate

when you are down? Benchmark examples: Give some typical

examples of your research problem ?

Business Application Using Intelligent System Knowledge Base System Case Based Reasoning Intelligent Agent Fuzzy System Neural Network Genetic Algorithms Hybrid System

Knowledge Engineering It is the art of building complex computer

programs that represent and reason with knowledge of the world (Feigenbaum and McCorduck [1983])

Process of eliciting, structuring, formalizing, operational zing (Schreiber, Akkermans et al. 2000)

information and knowledge involved in a knowledge-intensive problem domain,

in order to construct a program that can perform a difficult task adequately

Errors in a knowledge-base can cause serious problems

Transfer View of KE Extracting knowledge from a human

expert“mining the jewels in the expert’s head”’

Transferring this knowledge into KS. expert is asked what rules are applicable translation of natural language into rule

format

Problems with transfer view

The knowledge providers, the knowledge engineer and the knowledge-system developer should share a common view on the problem solving

process and a common vocabulary

in order to make knowledge transfer a viable way of knowledge engineering

What Is An Ontology

An ontology is a specification of a conceptualization An ontology is an explicit description of a domain:

concepts properties and attributes of concepts Constraints on properties and attributes

An ontology defines a shared understanding a common vocabulary

It defines the formal vocabularies for representing knowledge about engineering artefacts and processes

What Is “Ontology Engineering”?Ontology Engineering: Defining terms in the domain and relations

among them Defining concepts in the domain (classes) Arranging the concepts in a hierarchy (subclass-superclass

hierarchy) Defining which attributes and properties (slots) classes can have

and constraints on their values Defining individuals and filling in slot values

The Protégé Ontology Editor and Knowledge Acquisition System

Protégé is an ontology editor and a knowledge-base editor.

Protégé is also an open-source, Java tool that provides an extensible architecture for the creation of customized knowledge-based applications.

A Short History of Knowledge Systems

1965 19851975 1995

general-purpose search engines

(GPS)

first-generation rule-based systems

(MYCIN, XCON)

emergence of structured methods

(early KADS)

mature methodologies

(CommonKADS)

=> from art to discipline =>

CommonKADS Model Set

OrganizationModel

TaskModel

AgentModel

KnowledgeModel

CommunicationModel

DesignModel

Context

Concept

Artefact

Agent Levels of Abstraction

Social Level1. Communication

2. Negotiation

Knowledge Level1. Symbol level (Information Processing)

2. Knowledge ,Goals, Actions and Principle of Rationality

Mechanism Level1. Circuit Level (Logical Behavior Computation)

2. Device Level ( Physical Behavior)

Agent

Agency ( 代辦 ) Delegation ( 委任 ) Proactive( 積極自發 ), Deliberative ( 三思而行 )

( 其他 AI 沒有的特性 ) Agent Intelligent Behavior (Practical Reasoning)

Intelligence is related to quantity and quality of knowledge

Agent Applications

“in 10 years time most new IT development will be affected, and many consumer products will contain embedded agent-based systems” (Guilfoyle 1995)

Agent Definition(Wooldridge and Jennings 1995) An Agent is a computer system situated in some

environment, and that is capable of autonomous action in this environment in order to meet its design objects.

Autonomy - Decision Control Reactivity - Interactive with environment Proactiveness - Exhibit goal-directed behaviour Social Ability -Interacting with other agents

Caglayan and Harrison (1997) Agent is a computing entity that performs

user delegated tasks Autonomously. An agent implies a personal assistant metaphor where the agent performs tasks on behalf of a user.

Agent Technology Factors

Mechinery

InferencingLearning validationrepresentation

Content

Rules, context,Application ontologies& grammars

Security

MutualPublic authenticationPrivacypayment

Access

To applicationsData & ServiceNetworkingMobility

Intelligence Agency

•The knowledge engineer attempts to understand how the subject matter expert reasons and solves problems and then encodes the acquired expertise into the agent's knowledge base.

•This modeling and representation of expert’s knowledge is long, painful and inefficient (known as the “knowledge acquisition bottleneck”).

Tecuci, G. (1998). Building Intelligent Agents : An Apprenticeship Multistrategy Learning Theroy, Methodology, Tool and Case Studies, ACADEMIC PRESS.

Tecuci, G., M. Boicu, et al. (2004). Development and use of Intelligent Decision Making Assistants:The Disciple Approach, Learning Agents Center

How are agents built and why it is hard

KnowledgeEngineer

DomainExpert

Knowledge Base

Inference Engine

Intelligent Agent

ProgrammingDialog

Results

Practical Reasoning

Decision Making Process Weighting Conflicting Consideration

Bratman, M. E., D. J. Israel, et al. (1988). "Plans and resource-bounded practical reasoning." Computational Intelligence 4: 349-355.

Practical Reasoning

Deliberation (What to Achieve)1. Option generation(= desires)2. Filtering

Mean-Ends Reasoning (How to Achieve)1. Computational Process2. Take Place Under Resource Bounds (Limit Size, Time

Constraint)3. Plan, Recipe

Implementing Practical Reasoning Agents

Agent Control Loop Version 11. while true2. observe the world;3. update internal world model;4. deliberate about what intention to achieve next;5. use means-ends reasoning to get a plan for the intention;6. execute the plan7. end while

Implementing Practical Reasoning Agents

State in Intelligent Agents

Beliefs What the world is like now

Desires (Goals) What we would like the world to be

Intentions (Plans) What we actually choose to carry out

Belief-Desire-Intention (BDI) Based upon practical reasoning.

Decide what goals to achieve and how to achieve them.

Belief Revision Function (brf)

Beliefs

Generate Options

Desires

Filter

Intentions

Action

SensorInput

ActionOutput

BDIArchitecture

BDI Architecture

An advantage is that BDI provides a reasoning capability similar to humans. IntuitiveProvides a clear functional decomposition

A disadvantage to BDI is determining the commitment level to intentions.Efficiently implementing the algorithms.

http://www.multiagent.com/arch/bdi/index.html

Agent Software

Product Company Language AgentBuilder Reticular Systems, Inc Java

JACK Intelligent Agents (BDI)

Agent Oriented

Software Pty. Ltd JACK Agent Language

MadKit Madkit Development Group

Java,Jess

Zeus (BDI) BT Java

JadeTelecom Italia Lab Open source Platfrom p2p, Java

JAM (BDI) Intelligent Reasoning Systems

Java

Reference

Bratman, M. E. (1987). Intention , Plan and Practical Reason, Harvard University Press.

Caglayan, A. and C. Harrison (1997). Agent Sourcebook, John Wiley & Sons.

Luck, M. (2003). "A Roadmap for Agent Based Computing." AgentLinkII: pp9-10.

Schreiber, G., H. Akkermans, et al. (2000). Knowledge Engineering and Management : The CommonKADS Methodology, MIT Press.

Wooldridge, M. (2002). An Introduction to MultiAgent Systems. John Wiley & Sons.

Wooldridge, M. and N. R. Jennings (1995). "Intelligent agents: Theory and practice." The Knowledge Engineering: p115-152.