Post on 05-Jan-2016
THE SUPPORTING ROLE OF ONTOLOGY IN A
SIMULATION SYSTEM FOR COUNTERMEASURE
EVALUATION
Nelia LombardDPSS, CSIR
Ontologies and Simulations What are the possible advantages that an
ontology might have in the simulation environment?
Can an ontology provide solutions to some of the challenges to be dealt with in the countermeasure simulation system?
Introduction
Contents
What is an OntologyThe Countermeasure Simulation SystemPossible Role of Ontology in the Simulation
SystemConstructing the OntologyLessons Learned Conclusions and Future Development
What is Ontology?Study the meaning of being
How an object relates to the world and to itself
Describes the world
Not a taxonomy
Taxonomy:
Oryx->Helicopter->Aircraft->Transport
Ontology:Oryx has
countermeasuresOryx can hover
Ontology in Information Systems and Computing
• The artifact present, in a formal way, the knowledge of a domain as a set of concepts and relationships between the concepts, for the purpose of reasoning.
Use of Ontologies• Share a common understanding of the structure of
information and the concepts– A common vocabulary
• Enable reuse of the domain knowledge– For example, time ontology
• Make domain assumptions explicit• Separate domain knowledge from the operational
knowledge• Analysis of domain knowledge
The Countermeasure Simulation System
Purpose: Evaluate countermeasure
designDetermine aircraft
vulnerability
Simulate the interaction between models as results of specific events
Use realistic models
The Countermeasure Simulation System
The Simulation Scenario
• Type of aircraft: e.g. Oryx
• Flight plan: How will the Oryx fly?
• Type of missile threat
• Type of countermeasure and the dispensing logic
• Atmospheric conditions: e.g. clear skies or fog
• Terrain model
The Countermeasure Simulation System
Extensible Markup Language (XML) is a set of rules for encoding documents in machine-readable format
Model parameters are set up in XML files
Simulation output written to XML files
<Scenario>Name=”TestPoint1” <Movings> <Moving> FileName =”Oryx.xml” Type=”DPSSORYX” /> </Movings> <Observers> <Observer> FileName=”ThreatType1.xml” Type=”BaseMissile” /></Observers> <Atmosphere> FileName=”Atmo.xml” /> </Scenario>
The Countermeasure Simulation System
• Simulation results processed to show effectiveness of countermeasure against threat
• Results:
– 3D Viewer – Videos
Possible Role of Ontology in the Countermeasure Simulation
System
To know what is available in the system
Guideline for new models
High-level description
Verify and validation of scenarios
Reverse engineer previous simulations
Constructing the Ontology
• Where will it be used?
• How can it add benefit?
• Purpose
• To capture concepts in a simulation scenario
• Scope• A Simulation Scenario
Creating the Ontology (1)
Identify the classes
• Scenario, Target, Threat, Atmosphere,
Countermeasure
• Define object properties
• Relationships between classes
• Target has countermeasure• Scenario has target
• Define data properties
• Position, Velocity
Creating the Ontology (2)
Create individuals
Specific objects used in the simulation Target: Oryx Atmosphere: Fog Countermeasure: Flare Scenario: ScenarioFlareLeftOryx200ft30kn
Classes in the Ontology
Object Properties
Data Properties
Ontology: Lessons Learned
• Naming of classes• Consistency
• Agreement
• Classes versus instances• Match the real world
• Modeling roles as classes• Classes can loose their roles over time
Conclusions
Clear, common understanding of what is in the domain
High-level description
Capture the meaning of objects
Future functionality: Use ontology to set up scenario and to reason about validity of scenario
Commentary
Questions? Suggestions Input