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The Exchange of Retrieval Knowledge about Services
between Agents
Mirjam MinorMike Wernicke
Can computer systems make experiences
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
Outline
• Brief introduction of Kühnel’s assistant agents
• The role of TCBR to improve this agents
• Merging of Case Retrieval Nets
• Implementation issues
• Contribution to Experience Management
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
Kühnel’s assistant agents
• Personal assistant agents that distribute how-to knowledge: – executing services on demand of user
(service: utility program like print a file)– planning with sub-services if necessary– collaborating with other agents by
• remote execution
• exchange of services
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
A service description
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
User requests
• How to find appropriate services to a user request?– Navigate? - only for a small service library– String matching? - bad recall– Textual Case-Based Reasoning!
• The service descriptions are the cases.• The retrieval is performed by means of a
Case Retrieval Net (CRN).
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
Textual CBR
• Case: AV pairs + textual sections, mapped on sets of information entities by means of dictionaries, e.g. print;prints;printing
• Similarity function: computes the best matching cases of the case base concerning a query, uses local similarity values, e.g.
Query Case
ji
e esimCaseQuerySIM
i j
ee ).,(),(
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
Retrieval of Texts in a CRN
Opens Yahoo in an Internet Explorer
Starting Yahoo with Netscape
__YAHOO__
__OPEN__
__START__
__BROWSER__
__IE__ __NETSCAPE__
Case
Information Entities
Query
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
Retrieval of Texts in a CRN
Opens Yahoo in an Internet Explorer
Starting Yahoo with Netscape
__YAHOO__
__OPEN__
__START__
__BROWSER__
__IE__ __NETSCAPE__
Case
Information Entities
Query
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
Retrieval of Texts in a CRN
Opens Yahoo in an Internet Explorer
Starting Yahoo with Netscape
__YAHOO__
__OPEN__
__START__
__BROWSER__
__IE__ __NETSCAPE__
Case
Information Entities
Query
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
Retrieval of Texts in a CRN
Opens Yahoo in an Internet Explorer
Starting Yahoo with Netscape
__YAHOO__
__OPEN__
__START__
__BROWSER__
__IE__ __NETSCAPE__
Case
Information Entities
Query
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
Retrieval of Texts in a CRN
Opens Yahoo in an Internet Explorer
Starting Yahoo with Netscape
__YAHOO__
__OPEN__
__START__
__BROWSER__
__IE__ __NETSCAPE__
Case
Information Entities
Query
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
Central vs. personal CRNs
• Central approach in the manner of yellow pages:– Easier to manage, e.g. by a central administrator
– Rather a client-server than an autonomous agent model
– Inconsistencies and ambiguities due to different sub-domains
• Personal approach with initially delivered and individually extendable dictionaries:– Individual service libraries with individual CRNs
– Communication of services and parts of the own CRN
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
Merging Case Retrieval Nets
__IEa__
__IEi=j’__
__IEy__
__IEz__
__IEx__
C1 C2C1‘
Merged set of case nodes
Merged set of Information Entities
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
Merging Case Retrieval Nets
Types of possible ‘syntactic’ conflicts:– Non-identical duplicates of information
entities:the new IE takes all strings of both originals
– Duplicates of similarity relationships with different weights: choose the maximum degree
– Differently assigned strings, e.g.__print__; print; printer__printer__; printer; print device
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
Merging Case Retrieval Nets
__IEa__
__IEi=j’__
__IEy__
__IEz__
__IEx__
C1 C2C1‘
Case nodes
Information Entities
new similarity arcs?
new relevance
arcs
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
Merging Case Retrieval Nets
New relevance arcs: rebuild the CRN
Missing similarity links, e.g.:
Still an open research issue!
__ALTAVISTA____GOOGLE__
__SEARCH ENGINE__
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
Implementation
• Java package ‘TCBR’ that implements a case-based retrieval for texts with a Case Retrieval Net and dictionaries
• Java package ‘AgentTCBRShell’ to extend the original description of a service with IEs and local similarity relationships
• The prototype is implemented and runs as a Java application.
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
System Architecture
RMI
Searching in
Planning
ExecutingAgent A
personal service library
personal dictionaries
CRN Searching in
Planning
ExecutingAgent B
personal service library
personal dictionaries
CRN
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
Contribution to Experience Management
• Agents that exchange how-to knowledge in form of services
• Transfer of background knowledge
• Integration of received knowledge with the own knowledge repository
• Individual ‘treasury of experiences’ that develops during the agent’s work history
Agents are able to make experiences and to share them!
Questions?
Long-Lived CBR SystemsLifecycle models and their impact on CBR systems
regarding usage, structure, and maintenance
ICCBR-03 Workshop in Trondheim, NorwayOrganizers: M. Nick, M. MinorImportant Dates:
April 9, 2003 submission deadlineJune 24, 2003 workshop
http://www.iccbr.org/2003/index-ws2.html
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
Applications of TCBR
• ExperienceBook: www.informatik.hu-berlin.de/~cbr-ws/EXP_BOOK
• Support of system administrators and common computer users during daily work
• Cases: problem description with solution, e.g. how to print an ASCII file with UNIX
• Lesson learnt by long-term use: knowledge management to keep it up to date
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
The Knowledge Creation Spiral of Nonaka/Takeuchi:
Socialisation Externalisation
Internalisation Combination
implicit
explicit
explicitimplicit
from
to
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
Experience Management (EM)
• deals with the management of experiential knowledge within an organization
• main problems:– How to make experiential knowledge explicit?– How to find (retrieve) it when it is needed? – Support of EM processes by tools, – Integration with the usual business processes
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
State-of-the-art EM Systems
• CBR systems: experiential knowledge in cases, user-triggered retrieval processes
• Ontology-based systems: Ontology = hierarchy of concepts, user browses through domain ontology
• Communities of practise: regular meetings of experts, user participates or deals with documentations of the meetings
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
EM Systems in Long-Term Use
• EM systems learn:– New experiential knowledge which is stored for
the users– Internal knowledge to execute or improve the
systems’ core tasks
• During usage, EM systems collect an own treasury of experiences!
M. Minor, M. Wernicke German Workshop on Experience Management, April 2003
Knowledge Sorts of the Treasury
• Knowledge contents (in CBR: the cases)• Own immanent experiences of the system:
– Work history of knowledge pieces– Indexing and other background knowledge– Valuating knowledge– Social knowledge– Knowledge about users