Ontology and Agent based
Approach for Knowledge
Management
Defense of PhD Thesis
Michal Laclav
í
k
Supervisor: Ing. Ladislav Hluch
ý
PhD.
Bratislava, 12th January 2006
2
Outline
Motivation
State of the Art
Objectives
Methodology and Tools
Agent Knowledge Model
–
Models,
Methodology, Library
Experience Management
Applications
Conclusion
Bratislava, 12th January 2006
3
Motivation and State of the Art
MAS is
powerful paradigm for distributed or heterogeneous
systems
MAS need Knowledge Support and Semantics
MAS need Connection with Existing Commercial Standards
Agent Technology Roadmap
: Current MAS Systems
–
lack of
Internal Agent Knowledge Model, lack of interconnection with
semantic web results (knowledge model representations) and
commercial standards
Focus on Agents and Knowledge representation (Ontologies)
Knowledge Management and Experience Management as
application domains
Bratislava, 12th January 2006
4
State of the Art
-
Agents
Agent Definition:
An agent is a computer
system capable of flexible autonomous action in
a dynamic, unpredictable and open environment.
(LUCK 2003)
MAS Standards:
FIPA, MASIF
Related to agent communication, agent platforms
No standards for internal agent knowledge model with
available implementations
Bratislava, 12th January 2006
5
State of the Art
-
Agents
Architectures:
Reactive Architecture
No specification of knowledge model, behavior of agent is based on
implemented responses to environment states
Belief Desire Intention Architecture
–
BDI
Belief
–
represents knowledge model, available some implementations
based on logic programming, not used in FIPA compliant MAS
Behavioral Architecture
FIPA compliant MAS are based on such architecture
No specification of Internal Agent Knowledge model
–
depend on agent
designer and developer
JADE Agent System
Support for ontologies based on FIPA
-
SL (Similar to First Order
Logic)
No Query engine
No Storage
No Inference
Bratislava, 12th January 2006
6
State of the Art
–
Ontologies, Knowledge
Ontologies
Knowledge Representation
OWL
-
DL compatible with Description
Logic
Query and Storage Engines available
RDF, OWL, RDQL based
Application domain
Knowledge Management
(KM) is the
process through which organizations
generate value from their intellectual and
knowledge
-
based assets
(Source: CIO Magazine)
Experience Management
is special
kind of KM
–
based on “lessons learned”
Characters
Data
Information
Knowledge
Actions
Syntax
Semantics
Pragmatics
Reasoning
(Bergman, 2002,
Experience Management)
Bratislava, 12th January 2006
7
Problem Specification
Multi Agent System
Agent 1
Agent 2
Agent 3
Graphical User Interface
External
System
Knowledge
Base
Directory
Facilitator
Knowledge Storage
Querying
XML, XML
-
RPC, SOAP
User requests
Displaying results
FIPA ACL,
KIF, FIPA
-
SL, FIPA
-
RDF
FIPA ACL,
RDF/OWL, RDQL
Knowledge
Model
KM
KM
IIOP,
HTTP,
SMTP
ACL
Bratislava, 12th January 2006
8
State of The Art Conclusion
Focus on
software
, intelligent and
FIPA
compliant
agents
Providing better
semantic infrastructure
(ontologies,
knowledge models
)
Apply basic principles of
software
and
knowledge engineering
Make stronger
connection
between MAS
and existing
commercial technologies
Bratislava, 12th January 2006
9
Thesis Objectives
Design of
Agent Architecture
using
Ontology
based
Knowledge Model
Design of
Software Development Methodology
for creation
of Agents with Ontology based Knowledge Model
Design of
Generic Ontology Model
for
Experience
Management
with extension to different application domains.
Design & Development of
Software Library
for building
Intelligent Agents with Ontology Knowledge Model with
possibility to plug agents to existing commercial technologies
Design and Development of user friendly
Knowledge
Presentation
.
Evaluation of Results
on real pilot operation.
Bratislava, 12th January 2006
10
Used Methods and Methodologies
Knowledge management, system design
Unified Modeling Language
–
UML
CommonKADS, MAScommonKADS
Protégé as Tool for CommonKADS
Formal methods for describing
ontology based models
Description Logic
Graph Ontology representation
Bratislava, 12th January 2006
11
Used Tools and Software
Protégé
Ontology Editor
Support for OWL ontology format
Can be used as modeling tool
JADE
(Java Agent DEvelopment
Framework)
Most developing MAS framework
Compliant with FIPA standards
Jena
–
Semantic Web Framework for Java
Support for OWL
–
best available OWL API
Support for RDQL model querying
Agent Knowledge Model
Objective:
Design of
Agent Architecture
using
Ontology
based
Knowledge Model
Bratislava, 12th January 2006
13
Agent Knowledge Model
Based on Events, Resources, Actions, Actors, Context
Formally Described using Sets, Description Logic
(compatible with OWL
-
DL), Graph Representation
Actor Context updating function/algorithm
(Actor Environment State)
C
A
new
= f
C
(e
a
,C
A
old
)
Resources updating function/algorithm
(result of fulfilled actor goals)
R
A
new
= f
R
(C
A
new
,R
A
old
)
Software Development
Methodology
Objective:
Design of
Software Development
Methodology
for creation of Agents
with Ontology based Knowledge Model
Bratislava, 12th January 2006
15
Development Methodology
(Knowledge Model)
Extending Model with Protégé Editor following
CommonKADS models
Organizational or Environment Model
Task Model
Agent or Actor Model
Includes implementation of algorithms for context and resource
updating
Results
Ontology developed in Protégé which can be exported in
OWL format.
Concrete Algorithms for each actor (often algorithms are
similar or same) which updates actors' context
C
A
new
and
resources
R
A
new
.
Bratislava, 12th January 2006
16
Development Methodology
(System Design)
UML Diagrams for concrete Application Domain
Use Case Diagram
for each agent
agent is taken as system
boundaries
Sequence Diagram
Communication among
agents
Class Diagram
Behaviors are described as methods
Agent Software Library
Objectives:
Design of
Agent Architecture
using
Ontology
based
Knowledge Model
Design & Development of
Software Library
for building
Intelligent Agents with Ontology Knowledge Model with
possibility to plug agents to existing commercial technologies
Bratislava, 12th January 2006
18
Agent Software Library
Support for OWL based Agent Knowledge Model
Support for XML
-
RPC connection to receive event and
send plain XML
Support for agent communication using FIPA ACL with
OWL and RDQL as content languages
Support for Presentation of Ontological Knowledge
(RDF/OWL => plain XML + XSL => HTML)
JADE and Jena Integration
Available on JADE official website
to MAS community
Bratislava, 12th January 2006
19
Agent Library Example
Support for Knowledge and
Experience Management
Objective:
Design of
Generic Ontology Model
for
Experience Management
with extension to
different application domains.
Bratislava, 12th January 2006
21
Extension of Model for
Experience Management
Extended Agent Memory
Model
Workflow Related
WfInstance, WfActivity
ActiveHint
Sub class of resource
Representation of
Experience
Employee
Bratislava, 12th January 2006
22
Algorithms for
EM Extension
Actor (Employee)
Context updating
algorithm
C
A
new
= f
C
(e
a
,C
A
old
)
Resources (Active Hint)
updating algorithm
R
A
new
= f
R
(C
A
new
,R
A
old
)
Bratislava, 12th January 2006
23
Complexity
of algorithms
All depends also on Active Hints
Templates count
–
this does not grow
too fast.
1
st
Case: Constant
–
final count of
context elements (1
-
6)
2
nd
Case: O(n)
–
based on
resource/event count in Memory
3
rd
Case: O(n
2
)
–
based on 2 loops:
events/resources, similar resources
experimental solution because algorithm
used other software e.g. Jena with RDQL
–
it was hard to prove complexity
different way.
Bratislava, 12th January 2006
24
Resource Similarity (3
rd
Case)
Similarity of Ontology
Individuals
Weighted matching of
properties
Similar to CBR
algorithm Weighted
Euclidian Distance
sim({res
1
,res
2
}) = fsim
(
"
{prop
i
}
property
i
.Resource({res
1
})
"
{prop
j
}
property
j
.Resource({res
2
})
{prop
i
}
{prop
j
}
{prop
i
}
DomainClass
DomainClass
Domain
$
{simWeight}
SimilarityWeight
domainClass.SimilarityWeight( DomainClass)
{simWeight}
{weight}
weight .SimilarityWeight( DomainClass)
{simWeight};
S
ij
{weight}/n
)
Presentation of Ontology
based Knowledge
Objective:
Design and Development of user
friendly
Knowledge Presentation
.
Bratislava, 12th January 2006
26
Presentation of Ontology
based Knowledge
Ontology Tree
Browse window
Graph
XSL Transformation
RDF/OWL => Plain XML +
XSL => HTML
Infrastructure to receive
plain XML using XML
-
RPC
Applications
Objective:
Evaluation of Results
on real
pilot operation.
Bratislava, 12th January 2006
28
Pellucid 5FP IST Project
Title:
Platform for Organizationally
Mobile Public Employees
Duration:
Sep 2002
-
Dec 2004
Knowledge Management to support
employees
Workflow based Administration
Processes
To support Employee Mobility in
organization
Agent Architecture based on
autonomous co
-
operating agents
Process Layer
Interaction Layer
Pellucid Architecture
Pellucid Agents
Bratislava, 12th January 2006
29
Pellucid Applications
CDG
, Genoa, Italy
Traffic Light Management
MMBG
, Sanlucar, Spain
Project Management
SADESI
, Seville, Spain
Telephone Incidence
Resolution
Bratislava, 12th January 2006
30
K
-
Wf Grid 6FP IST Project
Work on new
EMBET
architecture
Current state:
User Assistant Agent in K
-
Wf Grid uses model
presented in thesis.
Algorithms presented in chapter 5 were reused with same
improvements and modifications.
Architecture is not Agent based but users of system are
modeled as actors.
Knowledge Model
, its
implementation
and modified
algorithms
presented
in thesis are used
Title:
Knowledge
-
based Workflow System for Grid
Applications
Objectives:
To support workflow construction and
execution with Knowledge
Duration:
Sep 2004
-
Feb 2007
Conclusion and Future Work
Bratislava, 12th January 2006
32
Conclusion (1)
The most significant scientific achievements
Agent knowledge model
Applicable in any discrete environment where actors need to be
modeled
Can be expressed by ontology, sets or description logic
Such model was found useful for:
Simple goal oriented agents
Knowledge Management Solution based on Agents (Pellucid)
Experience Management Solution non agent based (EMBET
System)
Development Methodology
Speed up Knowledge based Agent development for concrete
application domains
Bratislava, 12th January 2006
33
Conclusion (2)
The most significant development achievements
Agent Library
Support for OWL based Agent Knowledge Model
Support for XML
-
RPC connection to receive event and send plain XML
Support for Presentation of Ontological Knowledge (RDF/OWL => plain
XML + XSL => HTML)
Support for agent communication using FIPA ACL with OWL and RDQL
as content languages
JADE and Jena Integration
Available on JADE official website to MAS community
(August
-
December 2005
–
314 downloads
)
Bratislava, 12th January 2006
34
Conclusion (3)
Extension of Work for
Experience Management
Model
Algorithms
Projects
Motivation for solving problems in real
Application
Evaluation of Thesis results
Bratislava, 12th January 2006
35
Future work
RAPORT
APVT project (01/2005
-
12/2007): Research and
development of a knowledge based system to support workflow
management in organizations with administrative processes
model and algorithms will be reused and extended
K
-
Wf Grid
EU 6FP RTD IST project (2004
-
2007)
evaluation on more applications, improvement of context detection
NAZOU
SPVV Project (09/2004
-
11/2007): Tools for acquisition,
organization and maintenance of knowledge in an environment of
heterogeneous information resources
OnTeA semantic annotation
–
not directly related but can be used for
context detection
Thank you !
Thank You for you attention
Many Thanks to my supervisor
Many Thanks to my colleagues
Many Thanks to the Reviewers for their helpful and
constructive comments and for reading my thesis
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