Toward Ontology-Based Component Composition

1
Toward Ontology-Based Component Composition

• Kenneth Baclawski and Artan Simeqi
• College of Computer Science
• Northeastern University

2
Component Composition

• Increasingly common software development
  technique.
• Feature interaction is a serious problem.
• Validation is very hard and rarely done.
• Prospects for improvement are dismal
• Lamport predicted that it would not be a
  practical concern within the next 10 years.

3
Pseudo-Programming Languages

• General purpose languages for specifying
  component composition.
• Only support limited kinds of component connector
  and system requirement.
• The main technique for specifying component
  composition today.
• Actually make it harder to validate compositions!
  (Lamport 1997)

4
Back to Basics Mathematics

• Mathematical proofs are already inherently
  compositional.
• Mathematics is more general and more powerful
  than any PPL.
• Why are we trying to improve on mathematical
  reasoning?

5
Ontology

• Shared understanding within a community.
• Formal, declarative semantic model
• An ontology may include
• Vocabulary terms
• Taxonomic and other relationships
• Constraints, inference rules and assertions
• Theorems, lemmas and corollaries
• An ontology is a mathematical theory.

6
Ontology-Based Computing

• Apply general mathematical reasoning to
  specialized domains specified by ontologies.
• By contrast, PPLs apply specialized reasoning
  without any domain specificity.

PPL
Domains
Ontology
Mathematical Constructs
7
Suggested Approach

• Theory is the fundamental building block.
• Theories can be composed using the colimit.
• A theory can be interpreted using concrete models
• Ontologies, requirements, environments and
  component specifications are theories.
• Justification (proof trace) is a formal proof
  represented as a data structure that can be
  queried and manipulated using automated tools.

8
Metamodel for Ontology-based Component Composition
9
Dynamic Composition and Reconfiguration for
Sensor Systems

• Extreme test case for ontology-based component
  composition
• These are hard real-time systems that can operate
  at a nanosecond time scale.
• Validation for a reconfiguration must occur
  without human interaction in seconds while a
  mission is occurring.
• Lives depend on correctness.

10
Conclusion

• Ontology-based computing is emerging as an
  important new computing paradigm.
• Basing component composition on ontologies has
  many advantages
• Grounded in general mathematical reasoning
• Tractability can be addressed
• Close connection with the domain language
• Uses the compositionality of mathematics.