Knowledge Management
INF5100 Autumn 2006
INF5100 Knowledge Management
-Outline
Background
Knowledge Management (KM)
What is knowledge
KM Processes
Knowledge Management Systems and Knowledge Bases
Ontologies
What is an ontology
Types of ontologies
Use of ontologies in KM
Ad-Hoc InfoWare (Example application)
Ad-Hoc InfoWare and Approach
Ontology Based Update
INF5100 Knowledge Management
-October 2006 3
Application Domain:
Rescue and Emergency Applications
Participants from different organizations
paramedics, police, fire,…
Rescue Site Leader, Team Leaders
Dynamic environment
movement and activity on site
personnel arriving and leaving
Sparse Mobile Adhoc Networks
minimal infrastructure, few nodes
heterogeneity, limited resources (battery, bandwidth)
a lot of movement; frequent disconnections;
delay tolerance
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Knowledge Management (KM) in Sparse
MANETs
Definition for KM:
”…the tools, techniques and processes for the most
effective management of an organization’s
intellectual assets”
(Davies et al 2003).
Adapted to information sharing in Sparse
MANETs:
… effective management of the intellectual
assets (information resources) available for
sharing in a Sparse MANET
INF5100 Knowledge Management
-Knowledge Management (KM) in Sparse
MANETs
Information sharing and content integration not
solved sufficiently in middleware for SMANETs
today.
KM offer solutions, but these do not consider
challenges posed by SMANETs
Beneficial for dynamic environments (e.g. rescue
operations) to combine middleware infrastructure
provided by SMANET with KM solutions
KM solutions may be valuable contribution to
INF5100 Knowledge Management
-October 2006 7
Problem Statement
Network wide information sharing in rescue
operations
Avoid information overflow
Cross organizational administration Information not static, frequent updates Only partial view of available information
Three main tasks
Establish who needs what information Enable vocabulary sharing & mapping Efficient metadata management
Outline
Background
Knowledge Management (KM)
What is knowledge KM Processes
Knowledge Management Systems and Knowledge Bases
Ontologies
What is an ontology
Types of ontologies
Use of ontologies in KM
Ad-Hoc InfoWare (Example application)
Ad-Hoc InfoWare and Approach
Ontology Based Update
INF5100 Knowledge Management
-October 2006 9
What is Knowledge Management?
Started in the 80s, Management Theory
with the notion that all knowledge can be formalized
the goal was to automatize production processes
Multidisciplinary: political science, communication
studies, IT, management sciences,…
Knowledge central – seen as part of an organization's
competence
Central questions in KM:
what is knowledge in the production process
how can the knowledge flow be improved
INF5100 Knowledge Management
-What is Knowledge Management?
”…the tools, techniques and processes for
the most effective management of an
organization’s intellectual assets
” (Davies et
al 2003)
“… a dynamic, continuous organizational
phenomenon of interdependent processes
with varying scopes and changing
INF5100 Knowledge Management -October 2006 11
Outline
Background
Knowledge Management (KM)
What is knowledge KM Processes Knowledge Management Systems and Knowledge Bases
Ontologies
What is an ontology Types of ontologies Use of ontologies in KM
Ad-Hoc InfoWare (Example application)
Ad-Hoc InfoWare and Approach Ontology Based Update
Rescue Ontology Example
Knowledge - Complementary Definition
(Gardner95):
KNOWING
what
information is needed
how
information must be processed
why
which information is needed
where
information can be found
to achieve a specific result
INF5100 Knowledge Management
-October 2006 13
Perspectives on Knowledge
Source: Alavi/Leidner 2001, p.111
INF5100 Knowledge Management
-Hierarchical View of Knowledge –
Common in IT
Data:
raw numbers and facts - symbols not yet interpreted
Information:
interpreted data - data which has been assigned a meaning Always linked to specific situation, has only limited validity
Knowledge:
personalized information
enables people to act and to deal intelligently with all the
available information sources. (action component)
Whole set of insights, experiences and procedures considered
correct and true, guide people’s thoughts, behavior and communication.
Always applicable in several situations, valid over a relatively
INF5100 Knowledge Management
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Types of Knowledge –
The most common taxonomy
Explicit: facts, in documents, models, pictures
articulated, codified, and communicated in symbolic form and/or natural language
Tacit: implicit, a mental model, skills
rooted in action, experience and involvement in a specific context
cognitive elements: mental models: mental maps, beliefs,
paradigms, view-points
technical elements: concrete know-how, crafts, skills – apply to
specific context, e.g. knowledge of the best way to approach a customer.
Individual: is created by and exists in the individual
Social/Collective: is created by and inherent in the collective actions of a group
Outline
Background
Knowledge Management (KM)
What is knowledge KM Processes Knowledge Management Systems and Knowledge Bases
Ontologies
What is an ontology Types of ontologies Use of ontologies in KM
Ad-Hoc InfoWare (Example application)
Ad-Hoc InfoWare and Approach Ontology Based Update
INF5100 Knowledge Management
-October 2006 17
Knowledge Management Processes
Creating knowledge
develop new - or replace existing - content within an organization’s knowledge
socialization, combination, externalization, internalization
Storing/retrieving knowledge
storage, organization, and retrieval of knowledge
Transferring and Sharing knowledge
communicating and sharing knowledge
Applying knowledge
integrate and make good use of knowledge in the organization
INF5100 Knowledge Management
-Knowledge Management Processes
- Role of IT
INF5100 Knowledge Management
-October 2006 19
Knowledge Storage/Retrieval –
Organizational Memory
Knowledge in various forms
e.g., documentation, structured information in databases, knowledge stored in expert systems, organizational procedures and processes
Semantic memory
: general, explicit and articulated
knowledge
e.g., organizational archives of annual reports
Episodic memory
: context-specific and situated
knowledge
e.g. specific circumstances of organizational decisions and their outcomes, place and time
Knowledge Storage/Retrieval –
Role of IT
Enhancement and expansion of semantic
and episodic organizational memory
Increase speed of access to organizational
memory
Effective tools: Query languages, multimedia
databases, DBMSs
Groupware: enable creation and sharing of
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Knowledge Sharing (KS) and Transfer
Sharing vs. Transfer:
Transfer: focus, a clear objective, unidirectional Sharing: can be unintentionally, multiple directionally,
without a specific objective
may occur
between and among individuals within and among teams
among organizational units among organizations
KM Systems for KS:
repositories – databases of knowledge (knowledge bases) networks –facilitate communications among team members
or groups of individuals
INF5100 Knowledge Management
-Knowledge Sharing (KS) and Transfer
Knowledge about where the knowledge is – often as
important as the original knowledge itself
Sharing this kind of metadata important
E.g. corporate directories: who knows what in
organization
Knowledge transfer is driven by communication
processes and information flows
Forms of knowledge transfer: informal/formal,
personal/impersonal
Knowledge transfer to locations where it is needed and
can be used is important
INF5100 Knowledge Management -October 2006 23
Outline
Background
Knowledge Management (KM)
What is knowledge KM Processes Knowledge Management Systems and Knowledge Bases
Ontologies
What is an ontology Types of ontologies Use of ontologies in KM
Ad-Hoc InfoWare (Example application)
Ad-Hoc InfoWare and Approach Ontology Based Update
Rescue Ontology Example
Knowledge Management Systems (KMS)
IT-based systems developed to support and
enhance all KM processes
Three common applications:
the coding and sharing of best practices
the creation of corporate knowledge directories the creation of knowledge networks
Requirements
must provide ontologies
must provide search capabilities
often provide filter capabilities (filters can be computer-based or human-computer-based)
provide opportunities for collaboration and use of expertise
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KMS and Knowledge Bases
Two main components of KMSs: knowledge
bases and ontologies
A knowledge base is a database
Usually domain dependent
Information may need to be abstracted,
synthesized, or integrated with other information
(e.g. in best practices databases)
Ontologies provide shared vocabulary and
facilitates reusability
INF5100 Knowledge Management
-Outline
Background
Knowledge Management (KM)
What is knowledge KM Processes
Knowledge Management Systems and Knowledge Bases
Ontologies
What is an ontology
Types of ontologies Use of ontologies in KM
Ad-Hoc InfoWare (Example application)
Ad-Hoc InfoWare and Approach
Ontology Based Update
INF5100 Knowledge Management
-October 2006 27
What is an Ontology
The term ontology can mean different things
glossaries & data dictionaries
thesauri & taxonomies
schemas & data models
formal ontologies & inference
Many definitions… the most commonly used:
“An ontology is an explicit specification
of a conceptualization.” (Gruber)
What is an Ontology
Basically a model of some part of the world
(Universe of Discourse)
Defines a common vocabulary for sharing
information in a domain
Specifies terms for classes/concepts and
relations between these
informal text or using formal language (e.g.
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Ontology Modelling & Implementation
Can be modelled using different knowledge
modelling techniques and implemented in various
kinds of languages
Heavyweight ontologies:
AI based languages (framebased, first order logic): e.g., Ontolingua, LOOM
Ontology mark-up languages: RDF(S), DAML + OIL, OWL
Only Lightweight ontologies :
Techniques from software engineering & databases: UML, ER, SQL-scripts
Not as expressive
INF5100 Knowledge Management
-Outline
Background
Knowledge Management (KM)
What is knowledge KM Processes
Knowledge Management Systems and Knowledge Bases
Ontologies
What is an ontology
Types of ontologies
Use of ontologies in KM
Ad-Hoc InfoWare (Example application)
Ad-Hoc InfoWare and Approach Ontology Based Update
INF5100 Knowledge Management
-October 2006 31
Types of Ontologies
We will look at two categorizations
These are based on
the richness of the internal structure
Lightweight ontologies Heavyweight ontologies (ontology proper)
the subject of their conceptualization
Lightweight Ontologies
Catalogs:
controlled vocabulary – a finite list of terms.
Glossary:
list of terms and meaning as natural language statements. Not
machine processable.
Thesaurus:
a networked collection of controlled vocabulary terms
synonym relationship. No explicit hierarchy.
Informal is-a hierarchies:
not strict subclass
INF5100 Knowledge Management
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Heavyweight Ontologies
Formal is-a
strict subclass hierarchies, necessary for exploiting inheritance
Formal instance relationships (formal is-a)
includes domain instances
Frames
ontology includes classes with property information. All subclasses inherit properties.
Value restrictions
More expressive ontologies, can place restrictions on values that can fill a property.
Expressing general logical constraints
the most expressive, first order logic.INF5100 Knowledge Management
-Lightweight vs. Heavyweight Ontologies
INF5100 Knowledge Management
-October 2006 35
Types of Ontologies Based on the Subject
of the Conceptualization
Top-level ontologies
aka Upper-level ontologies, general concepts, existing
ontologies link root terms to these (e.g. Cyc, SUMO)
Domain ontologies
Reusable in a specific domain (KM, medical, law,
engineering, chemistry etc. )
E.g., UMLS (medical)
Application ontologies
application dependent, often extend & specialize
vocabulary of a domain
Outline
Background
Knowledge Management (KM)
What is knowledge KM Processes Knowledge Management Systems and Knowledge Bases
Ontologies
What is an ontology Types of ontologies
Use of ontologies in KM
Ad-Hoc InfoWare (Example application)
Ad-Hoc InfoWare and Approach Ontology Based Update
INF5100 Knowledge Management
-October 2006 37
Use of Ontologies in KM
Knowledge representation
Offer a way to cope with heterogeneous
representations of resources
Give shared and common understanding of a
domain
Can be communicated between people and
application systems
INF5100 Knowledge Management
-Information Sharing and Integration
Interoperability problem
have to make the different systems and domains
understand each other
Structural heterogeneity
data structures, schema
solutions from domain of distributed databases
Semantic heterogeneity
meaning of content
INF5100 Knowledge Management
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Ontologies in Information Integration
As solution to semantic heterogeneity problem:
explicitly describe semantics of information sources language for translation
3 General approaches: (Wache et. al 2001)
Single: global ontology with shared semantics Multiple: need mapping between (each pair of) ontologies (inter-ontology mapping)
Hybrid: multiple ontologies are built on top of or linked to a shared vocabulary of basic terms (may function like a bridge or a translation)
Single, Multiple, and Hybrid
Ontology Approaches
single ontology approach hybrid ontology approach global ontology multiple ontology approach localontology ontologylocal local ontology local ontology local ontology local ontology shared vocabulary Or Top-level ontology
INF5100 Knowledge Management -October 2006 41
Outline
Background
Knowledge Management (KM)
What is knowledge KM Processes Knowledge Management Systems and Knowledge Bases
Ontologies
What is an ontology Types of ontologies Use of ontologies in KM
Ad-Hoc InfoWare (Example application)
Ad-Hoc InfoWare and Approach
Ontology Based Update Rescue Ontology Example
INF5100 Knowledge Management
-Ad-Hoc InfoWare
Simplify application development for Sparse MANETS
Configurable MW services
scalable protocols and services
Tradeoff
between abstraction and awareness of location, resources, context,... between non-functional requirements, e.g. performance vs. security and
availability
Separation of mechanisms and policies Coordination of knowledge management and resource management
Integration of information
Information, data, meta-data, resources Context awareness
Resource and QoS aware data placement
INF5100 Knowledge Management -October 2006 43
Ad-Hoc InfoWare
– Architecture Overview
Watchdogs Watchdogs Manager Watchdogs Execution Envir. Resource Manager Replic. Mgnt Proposal Unit Resource Monitor Adjac. Monitor Local Monitor Resource Avail. Distributed Event Notification Service Delivery State Mgnt Availability & Scaling Storage MgntSecurity and Privacy Manager
Authentication Access Control Key Management Encryption
Knowledge Manager
Semantic Meta-data & Ontology Framework Query Mgnt XML/RDF parser Profile & Context Mgnt LDD SDDD Data Dict. Manager
Knowledge Management (KM)
in Ad-Hoc InfoWare
Manage knowledge sharing and integration
in a Sparse MANET
Adds layer of knowledge
Services that allow relating metadata
descriptions to semantic context.
Only give tools (not decide usage & content)
Share information about where to find
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Related to KM Elements
Hierarchical view of knowledge
Explicit knowledge
Focused KM processes: Storage/Retrieval and
Transfer ( or Knowledge Sharing)
Not addressing learning aspect (knowledge creation)
Use of ontologies
Domain ontologies, e.g. medical, police, fire
Upper level ontology/ shared vocabulary (similar to Hybrid approach)
Ontology based update
Metadata enriched with terms/concepts from ontologies
Only ontology use (development etc not during rescue operation)
INF5100 Knowledge Management
-The Knowledge Manager
Distributed Event Notification System Watchdogs Resource Management
Security and Privacy Management
Data Dictionary Mgnt.
Semantic Metadata &
Ontology Framework XML Parser
Profile & Context Mgnt
Query Mgnt Knowledge Manager LDD SDDD UNDERSTANDING INFORMATION OVERLOAD EXCHANGE RETRIEVAL AVAILABILITY
INF5100 Knowledge Management
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Three Types of Metadata
Information structure and content description
metadata
Data Dictionary Management
Content, formats, data types etc
Semantic metadata
Semantic Metadata and Ontology Framework
Relations between concepts,
e.g. is-a, hasPart, hasResource, hasDeviceType
Profile and context metadata
Profile and Context Management User profile, device profile
Context: location, time, situation
Profiles and Context
Profiles
What, who
Device type, resources, groups etc (for device profile)
User preferences, roles, personalia etc (for user profile).
Fairly static information
Context
Where, when, why
location, time, situation (e.g. rescue operation)
Dynamic information (network nodes moving)
Used in different meanings (the term
context
)
time, location and situation for a device or userINF5100 Knowledge Management -October 2006 49 SDDD – linking level (Instance) (Link) LDD – metadata Semantic/ topical Context Information layer Conceptual Implementation Ontology layer
SDDD = Semantic Linked Distributed Data Dictionary. LDD = Local Data Dictionary.
Three-layered Approach
INF5100 Knowledge Management
-Outline
Background
Knowledge Management (KM)
What is knowledge KM Processes
Knowledge Management Systems and Knowledge Bases
Ontologies
What is an ontology Types of ontologies Use of ontologies in KM
Ad-Hoc InfoWare (Example application)
Ad-Hoc InfoWare and Approach
Ontology Based Update
INF5100 Knowledge Management
-October 2006 51
Approach to Ontology Based Update
Ontologies to represent
rescue operation context model
profiles for user, device and information
Update priorities
information types
rescue operation roles
Operational structure and organization
Issues of Dynamic Update
Dynamicity and limited resources
unstable availability
Frequent updates
increased communication needs
consistency issues
Need efficient metadata management to achieve
ontology based update in this environment
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Kinds of Dynamic Update
- Overview
Between Entities Metadata or Data Change or Append (Vertical) Local update Different level data dictionaries Metadata Both (Horizontal) Metadata Exchange SDDDs Metadata Append (Horizontal) Ontology BasedSDDDs & KBs Both Both
SDDD = Semantic Linked Distributed Data Dictionary. KB = Knowledge Base.
INF5100 Knowledge Management
-Outline
Background
Knowledge Management (KM)
What is knowledge KM Processes
Knowledge Management Systems and Knowledge Bases
Ontologies
What is an ontology Types of ontologies Use of ontologies in KM
Ad-Hoc InfoWare (Example application)
Ad-Hoc InfoWare and Approach Ontology Based Update
INF5100 Knowledge Management
-October 2006 55
Example of Organization and Structure in
Rescue Operations
INF5100 Knowledge Management
-October 2006 57
Upper Ontology for All Profiles
INF5100 Knowledge Management
-Information Profile
and
Example
INF5100 Knowledge Management -October 2006 59
User
Profile
Example of DB Schema
Information Profile:pr:InformationProfile(pr:IPId, pr:item)
pr:InformationItem(pr:IId, pr:subject, pr:priority)
pr:InformationPriority(pr:IPrId,...)
UserProfile:
pr:UserProfile(pr:UPId, pr:person, pr:role)
pr:RescueOperationRole(pr:RORId, pr:RORoleType, pr:reportsTo, pr:responsibility, pr:isMemberOf, pr:hasUpdatePriority)
pr:Responsibility(pr:PId,...)
pr:Team(pr:TId,...)
INF5100 Knowledge Management -October 2006 61
Example
of DB
Content
for
User
Profile
INF5100 Knowledge Management
-Rescue Scenario Timeline –
Populating the Knowledge Base
Phase 1: initial population of knowledge base
Phase 2: ontology individuals for current operation
Phase 4: adjustments: changes and new arrivals
INF5100 Knowledge Management
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Handling Profile Ontologies in our Architecture
Storage - who keeps what?
Based on user role in rescue operation
Each node keeps its own device profile and user profile
Components
Rescue ontology profiles
Profile and Context Management
Semantic Metadata and Ontology Framework
Sharing and dynamic update
Data Dictionary Manager