Semantic Web Applications for Modeling and Simulation

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Semantic Web Applications for Modeling and
Simulation
Lee W. Lacy Dynamics Research Corporation
Captain Joel Pawloski U.S. Army TRAC-M

• July 11, 2001
• DMSO Technical Exchange Meeting

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Agenda

• Web Technology Evolution
• XML MS Applications
• U.S. Army TRAC-M XML Research
• Semantic Web Background
• DARPA Semantic Web Research
• Potential Semantic Web MS and C4I Applications

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The Evolving Web
Web of Knowledge
Proof, Logic and Ontology Languages (e.g.,
DAMLOIL)
Shared terms/terminology Machine-Machine
communication
2010
Resource Description Framework (RDF) eXtensible
Markup Language (XML)
Self-Describing Documents
2000
HyperText Markup Language (HTML) HyperText
Transfer Protocol (HTTP)
Formatted Documents Foundation of the Current Web
1990
Based on Berners-Lee, Hendler Nature, 2001
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Hypertext Markup Language (HTML)

• Enabled standard communication of content
  combined with format
• Loosely defined specific (limited) grammar
  specified using SGML (specific language)
• Started by Tim Berners-Lee
• Standardized by World-Wide Web Consortium (W3C)
• Ubiquitous method of presenting and communicating
  data
• Used throughout DoD on both public internet and
  SIPRNET and other classified networks
• Not useful for machine search

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eXtensible Markup Language (XML)

• Separates content from format (standard syntax)
• Simplified version of SGML (metalanguage) for
  defining eXtensible tag sets
• Started by Tim Bray et al based on conversations
  with Tim Berners-Lee
• Standardized by W3C
• Used to define updated HTML grammar (XHTML)
• Used in Modeling and Simulation community
  primarily for Data Interchange Formats (DIFs)
  that support data sharing

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XML DIF Method
ModSAF
XML-based Data Interchange File (DIF)
Janus
CCTT
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MS and C4I use of XML

• HLA Data Interchange Formats (DIFs)
• JSIMS Common Component Workstation Battlespace
  Schema
• Combat XXI Scenario Files
• OneSAF Objective System
• Land Warrior User Interface Specifications
• Joint C4ISR Integration Facility (JCIF) Joint
  Battlespace Infosphere (JBI) XML Assessment

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Specific U.S. Army MS XML Research Initiatives

• Military Scenario Definition Language (MSDL)
• Computer Generated Forces (CGF) Behaviors
• Equipment Characteristics and Performance (CP)

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MSDL Objectives

• Support Scenario Developers
• Improve Scenario Quality
• Reduce Time to Develop Scenarios
• Reduce Costs of Developing Scenarios
• Support Scenario Generation Tool Developers
• Reduce Tool Development Costs
• Improve Tool Interoperability

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Scenario Content Analysis

• Metadata
• Environment
• Organization
• Simulation Object
• Information Item
• Events
• Unassigned

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MSDL Standard

• Initial work reviewed by Combat XXI
• Combat XXI enhancements merged into Army Modeling
  and Simulation Office (AMSO) Standards Nomination
  and Approval Process (SNAP) submission
• SNAP submission serving as starting point for
  OneSAF Objective System (OOS)

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MSDL Schema

• Defined using XML DTD and XML Schema
• Sample scenarios marked up

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CGF Behaviors

• Computer Generated Forces (CGF) systems simulate
  units and platforms
• CGF systems operate at a variety of fidelity and
  resolution levels
• Behaviors historically hard coded
• Newer systems represent behaviors in data
• Considerable resources required to develop CGF
  systems and their associated behaviors

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Current CGF Systems
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Perfect World Behavior Sharing
System 1
System 2
Behaviors Represented in Common Language Using
XML
System 3
System 4
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CGF Behavioral Representation Logical Data Model
Components
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SIMTECH Demonstration
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Explicit vs. Metamodel Schemas

• XML DTD and/or XML Schema design often involves
  decisions over the use of explicit tags or
  representation of names in data
• ltmaxspeed unitsmphgt45lt/maxspeedgt vs.
• ltparametergt ltnamegtmaxspeedlt/namegt ltunitsgtmphlt/u
  nitsgt ltvaluegt45lt/valuegt lt/parametergt

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Semantic Problems for XML

• Synonymy and polysemy
• ltPERSONgt vs. ltINDIVIDUALgt
• is ltSPIDERgt an arachnid or software?
• Structural differences
• ltPERSONgtltNAMEgtLee Lacylt/NAMEgtltPERSONgt vs.
• ltPERSONgtltNAMEgt ltFNAMEgtLeelt/FNAMEgt ltLNAMEgtLacylt/
  LNAMEgt lt/NAMEgtlt/PERSONgt

Based on Hendler, 2001
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Resource Description Framework (RDF)

• RDF data consists of nodes and attached
  attribute/value pairs
• Nodes can be any web resources
• Attributes are named properties of nodes
• Values are either atomic (text strings, numbers,
  etc.) or other resources or metadata instances
• Supports labeled directed graphs
• XML used as graph serialization syntax for
  storing and communicating RDF instances
• Provides basic ontological primitives
• Classes and relations (properties)
• Class (and property) hierarchy
• RDF triples assert facts about resources

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Why RDF Is Not Enough

• Expressive inadequacy
• Only range/domain constraints (on properties)
• No properties of properties (unique, transitive,
  inverse etc.)
• No equivalence, disjointness, coverings etc.
• No necessary and sufficient conditions (for class
  membership)
• Poorly (un) defined semantics

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Semantic Web (SW)

• Provides agent-readable descriptions of data,
  information, and knowledge
• Built on top of XML and RDF
• Envisioned by Tim Berners-Lee and researched by
  DARPA team and others
• W3C is beginning a Semantic Web initiative
• Used to define ontologies and associated instance
  data
• Huge potential for Modeling and Simulation
  community

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What is an Ontology?
Thesauri narrower term relation
Frames (properties)
General Logical constraints
Formal is-a
Catalog/ ID
Informal is-a
Formal instance
Disjointness, Inverse, part-of
Terms/ glossary
Value Restrs.
TAXONOMY
ONTOLOGY
Based on McGuinness, 2001 http//www.daml.org/2
001/06/swday-ontologies/Ontologies-talk-060401_fil
es/frame.htm
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Beyond XMLAgent Semantics

• DARPA developing an Agent Markup Language (DAML)
• A semantic language that ties the information
  on a page to machine readable semantics (ontology)

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DARPA DAML Research Team

• BBN
• Booz-Allen and Hamilton
• Cycorp
• Dynamics Research Corporation (DRC)
• GRCI
• Lockheed Martin Management and Data Systems
• SRI
• Teknowledge

• Carnegie Melon University
• University of Southern California Information
  Sciences Institute
• MIT (W3C)
• Stanford University
• UMBC
• University of West Florida
• Yale University

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Benefits

• Standard representation of object-oriented
  concepts across the web
• Extensibility of ontologies through namespaces
• Support for complex queries involving semantic
  joins over multiple data sets

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A new/old model of DoD partnering

• DARPA
• Funds a new generation of www technology
• Works closely with W3C to create a web standard
• Works closely with EU on international acceptance
• Brings DoD users (J2,J3,J6) in as early adopters

Based on Hendler, 2001
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Layered Architecture

DAMLOIL
DC
PICS
XHTML
SMIL
RDF(S)
HTML
XML(S)
Based on Horrocks, 2001 http//www.cs.man.ac.uk/
horrocks/Slides/
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DAML Status

• DAMLOIL ontology language released on World Wide
  Web
• Annotated walkthrough
• Examples
• Full definition
• RDFS Resource Description Framework Schema
• Provides 100 mapping to XML
• Open discussion group run by W3C
  www-rdf-logic_at_w3.prg
• Denotational (and axiomatic) Semantics published
• First formal semantics for a web language
• Proposal to W3C for standardization ongoing

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www.DAML.org

• Language Specifications
• DAML Newsletter (you can subscribe)
• Collection of web tools
• Ontology library
• 157 ontologies as of July 9, 2001
• DAML crawler
• over 14,000 pages w/2,000,000 DAML statements,
  5/15/01
• Web tracking software used for baselining DAML
  use
• Over 500,000 hits in first 6 months

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DAML Military Examples

• Army CALL Thesaurus
• Army Equipment (based on WARSIM Equipment
  Knowledge Acquisition Tool schema)
• Military task lists (e.g., UJTL) under
  development
• Army CALL University After Next (UAN) Warrior
  Knowledge Network (WKN) Human Intelligence
  (HUMINT) interrogation procedure representation
  just started
• Intelink (DIA) HUMINT report representation
  small sample developed currently extending

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CALL Thesaurus Ontology
Term
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Military Equipment Ontology

• Army Military Equipment Characteristic
  Performance (CP) Ontology
• Provides framework to compose Army equipment from
  the System Unit to individual component (i.e.,
  radio) level
• Ontology is modeled after data model used by
  WARSIM and that housed by the FDB (Functional
  Description of the Battlespace)

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DAML Query Demonstration

• Semantic web DAML Demonstration
• Uses Call Thesaurus and Military Equipment CP
  ontologies and data to demonstrate the potential
  of the semantic web
• Demonstration is composed of
• Thesaurus Lookup Term
• Military Equipment Lookup
• Complex query involving multiple ontologies by
  using thesaurus lookup results to find military
  equipment terms

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DAML Query Demonstration
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HUMINT Report Representation

• Unclassified Force Protection Sample HUMINT
  report provided
• Classes identified included
• Organization, Person (who)
• Activity, Event (what)
• Timeframe (when)
• Location Area (where)
• Conclusion (why)

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Intelligence Report Ontology
INNOVATIVE SOLUTIONS THROUGH PEOPLE, PROCESSES,
AND TECHNOLOGY
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Ontology Design Issue

• Explicit description of classes vs. encoding of
  information as data
• Explicit definition
• Requires extensive maintenance of ontology
• Supports complex queries
• Encoding
• Requires companion encoding standard (e.g., DIS
  enumeration document, SEDRIS environmental data
  coding specification)
• Decision will be made on case-by-case basis with
  sponsors goals paramount but will affect
  usefulness of cross-ontology joins

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Potential Encoding Sources

• Events
• Fineberg Verb Taxonomy
• Kansas Event Data System (KEDS)
• World Events Interaction Survey (WEIS) Codes
• BML operations / tasks
• UJTL / service task lists
• Things
• FDMS taxonomy
• DIS Enumeration Document

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Potential MS Applications of Semantic Web
Technologies

• Human Behavior Representation (e.g., CHRIS)
• Glossaries / Taxonomies / Thesauri (e.g., CSS)
• CGF Behavior Development (e.g., TRAC-M research
  effort)
• Knowledge Acquisition (e.g., FDMS)
• METL development (e.g., JTIMS)
• Scenario Development (e.g., MSDL)
• Unit Order of Battle (e.g., UOB DAT)
• Data Provisioning (e.g., AMSO SIMTECH effort)
• HLA FEDEP Tool Architecture (e.g., DIFs)
• Web Services (e.g., fly-out model responsibility)
• AAR / logger data

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CSS Thoughts

• DMSO CSS provides definitions, unlike Army CALL
  thesaurus
• DAML thesaurus ontology based on ANSI standard
  for representing thesauri information
• CSS validated and traceable to Authoritative Data
  Sources (ADSs)
• DAML thesauri ontology could be extended to
  support definitions and ADS traceability
• CSS could be ported to semantic web instance
  data
• Once represented as SW content, terms can be
  manipulated using standard SW tools and other
  MS-related SW applications can link to terms

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Battle Management Language

• Standard verbiage or vocabulary used by
  simulation programmers or workstation controllers
  to describe planning and executing military
  functions currently performed by human
  controllers
• Key factors supporting automated Course of Action
  (COA) analysis
• Unit identification (who)
• Operation / Task (what)
• Operation time (when)
• Operation location (where)
• Operation purpose / mission (why)

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BML Thoughts

• BML Users Guide Annex A contains CSS-like
  definitions
• Value of BML is in knowledge representation
  structure developed (i.e., units, timeframe,
  etc.) and specified vocabulary (i.e., Users
  Guide Annex A)
• BML KR structure could be used as the basis for
  an ontology for orders
• BML vocabulary could be migrated into ontology
  instance data similarly to CSS

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Preliminary BML Order Ontology
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Summary

• Web technology continues to evolve
• XML is being used for MS applications
• Semantic Web technologies emerging that provide
  potential solutions to DoD MS challenges
• Research and proof-of-concept demonstrations
  needed to show benefits

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Questions?Lee LacyLLacy_at_DRC.com