NSByGrounding

Nominal Schema Reasoning by Grounding

This page contains the implementations of nominal schema reasoning using naive and smart grounding.

Introduction

In this page we include the empirical evaluation of several ontologies, presented in the next section, chosen from the TONES repository (reference?). For each experiment one or more axioms containing nominal schemas were added to each ontology. The occurences of the nominal schemas are then grounded with all possible combinations of individuals contained in the knowledge bases. Reasoning times for checking satisfiability (using Pellet after grounding) are averaged over 100 runs, and load time is reported separately. We are particularly interested in finding what are the limits of lhis implementation varying both the number of different nominal schemas and their number of occurrences per axiom.

Testing was performed using a 64-bit Windows 7 computer with an Intel(R) Core(TM) i5 CPU processor. A java JDK 1.5 version, allocating 3GB as the minimun for the java heap and 3.5GB as the maximun, was used for each experiment.

Naive Implementation

Although not very time-efficient this implementation will serve as a baseline for development and testing of more optimised algorithms, and also shows that even the grounding approach can be used for small use cases or for initial testing.

The includes testing data obtained from different experimets showing the feasibility of this implementation when the number of different nominal schemas per axiom is low.

The section also includes java code to ground axioms containing nominal schemas to a given ontology. After the grounding reasoning tasks can be performed with the ontology using any reasoner available just as usual (This program was built for testing purposes only and therefore it is not an optimised generic algorithm).

Ontologies used for the Naive Implementation

System	Ontology	Classes	Annotation P.	Data P.	Object P.	Individuals
Fam	4	0	1	11	5