Semantic Web Applications for Modeling and Simulation July 11, 2001 DMSO Technical Exchange Meeting Lee W. Lacy Dynamics Research Corporation Captain Joel

Semantic Web Applications for Modeling and Simulation

July 11, 2001

DMSO Technical Exchange Meeting

Lee W. Lacy

Dynamics Research Corporation

Captain Joel Pawloski

U.S. Army TRAC-M

TRAC-Monterey

INNOVATIVE SOLUTIONS THROUGH PEOPLE, PROCESSES, AND TECHNOLOGY


Agenda

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

Applications



The Evolving Web

Web ofKnowledge

HyperText Markup Language (HTML)

HyperText Transfer Protocol (HTTP)

Resource Description Framework (RDF)eXtensible Markup Language (XML) Self-Describing Documents

Formatted DocumentsFoundation of the Current Web

Proof, Logic andOntology Languages(e.g., DAML+OIL)

Shared terms/terminologyMachine-Machine communication

1990

2000

2010

Based on Berners-Lee, Hendler; Nature, 2001



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



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



XML DIF Method

Janus CCTT

ModSAF

XML-basedData Interchange

File (DIF)



M&S 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



Specific U.S. Army M&S XML Research Initiatives

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

TRAC-Monterey



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



Scenario Content Analysis

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



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)



MSDL Schema

• Defined using XML DTD and XML Schema

• Sample scenarios marked up



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



Current CGF Systems

Today’s CGF systems are built in a stove-piped manner

WARSIMCCTT ModSAF

•Ada Finite State Machines

•Asynchronous Augmented Finite State

Machines (translated into “C” code)

•Behavioral Description Frames•Fundamental Behaviors (C++ code)



“Perfect World” Behavior Sharing

In a perfect world, we’d all speak thesame language

BehaviorsRepresented in

Common Language Using XMLSystem

#3

System#1

System#2

System#4



CGF Behavioral Representation Logical Data Model Components

Behavior Specification Logical Data Model Components

Knowledge RepresentationConstructs

Com

ple

xity

Metadata

Declarative

Procedural

Strategic



SIMTECH Demonstration

EquipmentCharacteristics andPerformance Data

in XML

AMSAA

NGIC

OTB

CombatXXI



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– <maxspeed units=“mph”>45</maxspeed> vs.– <parameter> <name>maxspeed</name> <units>mph</units><value>45</value> </parameter>


Dynamics Research CorporationSemantic Problems for XML

• Synonymy and polysemy– <PERSON> vs. <INDIVIDUAL>– is <SPIDER> an arachnid or software?

• Structural differences– <PERSON><NAME>Lee Lacy</NAME><PERSON> vs.– <PERSON><NAME> <FNAME>Lee</FNAME>

<LNAME>Lacy</LNAME> </NAME></PERSON>

Based on Hendler, 2001



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



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



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


Dynamics Research CorporationWhat is an Ontology?

Catalog/ID

GeneralLogical

constraints

Terms/glossary

Thesauri“narrower

term”relation

Formalis-a

Frames(properties)

Informalis-a

Formalinstance

Value Restrs.

Disjointness, Inverse, part-

of…

TAXONOMY ONTOLOGYBased on McGuinness, 2001: http://www.daml.org/2001/06/swday-ontologies/Ontologies-talk-060401_files/frame.htm



Beyond XML:Agent Semantics

• DARPA developing an Agent Markup Language (DAML)– A “semantic” language that ties the

information on a page to machine readable semantics (ontology)



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



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



A new/old model of DoD partnering

Semantic Web Res. (EU)

W3CDAML

www.semanticweb.org

www.daml.orgwww.w3.org/RDF/

C2 linkRDF

XML

RDF-S

DAML-ONT

DAML-LOGIC

US/EU Joint Efforts

(S. Decker, Coord)

Horus

Research efforts:SHOEOILEC OntoWeb

Intl Workshops

Tools

Lang Spec

Demos

Ctr for Army Lessons Learned

EU W3CMembers/directors

(Dan Brickley, coord)

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



Layered Architecture

DAML+OIL

HTML

XHTML

XML(S)

SMIL RDF(S)

DC PICS

Based on Horrocks, 2001: http://www.cs.man.ac.uk/~horrocks/Slides/



DAML Status

• DAML+OIL 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: [email protected]

– Denotational (and axiomatic) Semantics published• First formal semantics for a web language

– Proposal to W3C for standardization ongoing



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



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



CALL Thesaurus Ontology

Term

BT

NT

CALL Term

name

descriptorFor

RT

entryTermFor

preferredTermFor

ACK

AFUSE

UF

domain

subClassOf

inverseOf

subPropertyOf

range & domain

Legand



Military Equipment Ontology

• Army Military Equipment Characteristic & Performance (C&P) 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)



DAML Query Demonstration

Semantic web DAML Demonstration• Uses Call Thesaurus and Military Equipment C&P

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



DAML Query Demonstration



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)

Intelligence Report Ontology

Event

LocationArea

TimeframeActivityEquipment

Organization

PersonPerson

DescriptionNote

IntelligenceReport

Conclusion

Building

Metadata

TerroristOrganization

subclassOf

partOf

describedAs

locatedIn

within

memberOf

Vehicle

MotorcycleAutomobile

subclassOf

subclassOf subclassOf

drivenBy

locatedIn

Country

subclassOfresultedIn

conclusion metadata

event

conclusionEvent

Subject, directObject,

indirectObject, source

Subject

directObject

indirectObject

regarding

source

timeframe




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 sponsor’s goals paramount but will affect usefulness of cross-ontology “joins”



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



Potential M&S 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



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 M&S-related SW applications can link to terms



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)



BML Thoughts

• BML User’s 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., User’s 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



Preliminary BML Order Ontology

Timeframe

Operation

Formation

Task

Unit

partOf

LocationtakesPlaceAt

layedOutIn

takesPlaceWithin

arrangedAt

supports

performsperforms



Summary

• Web technology continues to evolve• XML is being used for M&S applications• Semantic Web technologies emerging that provide

potential solutions to DoD M&S challenges• Research and proof-of-concept demonstrations

needed to show benefits



Questions?

Lee [email protected]