scholarly journals Extensions of Simple Conceptual Graphs: the Complexity of Rules and Constraints

2002 ◽  
Vol 16 ◽  
pp. 425-465 ◽  
Author(s):  
J. F. Baget ◽  
M. L. Mugnier
Keyword(s):  
Knowledge Representation ◽  
Operational Semantics ◽  
Polynomial Hierarchy ◽  
Conceptual Graphs ◽  
Basic Operation ◽  
Graph Homomorphism ◽  
Model Based ◽  
Formal Definitions ◽  
Decidability And Complexity

Simple conceptual graphs are considered as the kernel of most knowledge representation formalisms built upon Sowa's model. Reasoning in this model can be expressed by a graph homomorphism called projection, whose semantics is usually given in terms of positive, conjunctive, existential FOL. We present here a family of extensions of this model, based on rules and constraints, keeping graph homomorphism as the basic operation. We focus on the formal definitions of the different models obtained, including their operational semantics and relationships with FOL, and we analyze the decidability and complexity of the associated problems (consistency and deduction). As soon as rules are involved in reasonings, these problems are not decidable, but we exhibit a condition under which they fall in the polynomial hierarchy. These results extend and complete the ones already published by the authors. Moreover we systematically study the complexity of some particular cases obtained by restricting the form of constraints and/or rules.

Smart VideoText: a video data model based on conceptual graphs

2002 ◽  
Vol 8 (4) ◽  
pp. 328-338 ◽  
Author(s):  
F. Kokkoras ◽  
H. Jiang ◽  
I. Vlahavas ◽  
A.K. Elmagarmid ◽  
E.N. Houstis ◽  
...  
Keyword(s):  
Data Model ◽  
Video Data ◽  
Conceptual Graphs ◽  
Model Based

scholarly journals A step-indexed Kripke model of hidden state

2012 ◽  
Vol 23 (1) ◽  
pp. 1-54 ◽  
Author(s):  
JAN SCHWINGHAMMER ◽  
LARS BIRKEDAL ◽  
FRANÇOIS POTTIER ◽  
BERNHARD REUS ◽  
KRISTIAN STØVRING ◽  
...  
Keyword(s):  
Metric Space ◽  
Possible Worlds ◽  
Operational Semantics ◽  
Kripke Model ◽  
The State ◽  
Local State ◽  
Modular Reasoning ◽  
Proof Rules ◽  
Model Based ◽  
First Sound

Frame and anti-frame rules have been proposed as proof rules for modular reasoning about programs. Frame rules allow the hiding of irrelevant parts of the state during verification, whereas the anti-frame rule allows the hiding of local state from the context.We discuss the semantic foundations of frame and anti-frame rules, and present the first sound model for Charguéraud and Pottier's type and capability system including both of these rules. The model is a possible worlds model based on the operational semantics and step-indexed heap relations, and the worlds are given by a recursively defined metric space. We also extend the model to account for Pottier's generalised frame and anti-frame rules, where invariants are generalised to families of invariants indexed over preorders. This generalisation enables reasoning about some well-bracketed as well as (locally) monotone uses of local state.

Extensible Semantics for Representing Electromechanical Assemblies

2003 ◽  
Author(s):  
Joseph Kopena ◽  
William C. Regli
Keyword(s):  
Knowledge Representation ◽  
Conceptual Graphs ◽  
Markup Language ◽  
Research Areas ◽  
Representation Form ◽  
Over Time

Many representations exist for describing engineering artifacts. These representations come from a wide variety of work in many research areas with differing backgrounds and purposes. No unified representation has emerged combining aspects of existing schemes with an ability to easily grow and be extended over time. In this work we demonstrate the application of methods from the knowledge representation community to the domain of engineering artifacts, in particular electromechanical assemblies. We use conceptual graphs as a formal, cleanly extensible representation form. Aspects of several existing results are combined to create a unified representation and demonstrate the approach. We also discuss translation of the conceptual graphs to the DARPA Agent Markup Language (DAML) in order to utilize and cooperate with efforts to develop ontologies for this domain.

scholarly journals Visual reasoning with graph-based mechanisms: the good, the better and the best

2013 ◽  
Vol 28 (3) ◽  
pp. 249-271 ◽  
Author(s):  
Michel Chein ◽  
Marie-Laure Mugnier ◽  
Madalina Croitoru
Keyword(s):  
Knowledge Representation ◽  
Semantic Annotation ◽  
Logical Reasoning ◽  
Knowledge Representation And Reasoning ◽  
Graph Homomorphism ◽  
Logical Deduction ◽  
Elementary Graph

AbstractThis paper presents a graph-based knowledge representation and reasoning language. This language benefits from an important syntactic operation, which is called a graph homomorphism. This operation is sound and complete with respect to logical deduction. Hence, it is possible to do logical reasoning without using the language of logic but only graphical, thus visual, notions. This paper presents the main knowledge constructs of this language, elementary graph-based reasoning mechanisms, as well as the graph homomorphism, which encompasses all these elementary transformations in one global step. We put our work in context by presenting a concrete semantic annotation application example.

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