Paper Info
Title
Using Cultural Algorithms To Re-Engineer Large-Scale Semantic Networks
Abstract
Evolutionary computation has been successfully applied in a variety of problem domains and applications. In this paper we discuss the use of a specific form of evolutionary computation known as Cultural Algorithms to improve the efficiency of the subsumption algorithm in semantic networks. We identify two complementary methods of using Cultural Algorithms to solve the problem of re-engineering large-scale dynamic semantic networks in order to optimize the efficiency of subsumption: top-down and bottom-up. The top-down re-engineering approach improves subsumption efficiency by reducing the number of attributes that need to be compared for every node without impacting the results. We demonstrate that a Cultural Algorithm approach can be used to identify these defining attributes that are most significant for node retrieval. These results are then utilized within an existing vehicle assembly process planning application that utilizes a semantic network based knowledge base to improve the performance and reduce complexity of the network. It is shown that the results obtained by Cultural Algorithms are at least as good, and in most cases better, than those obtained by the human developers. The advantage of Cultural Algorithms is especially pronounced for those classes in the network that are more complex. The goal of bottom-up approach is to classify the input concepts into new clusters that are most efficient for subsumption and classification. While the resultant subsumption efficiency for the bottom-up approach exceeds that for the top-down approach, it does so by removing structural relationships that made the network understandable to human observers. Like a Rete network in expert systems, it is a compilation of only those relationships that impact subsumption. A direct comparison of the two approaches shows that bottom-up semantic network re-engineering creates a semantic network that is approximately 5 times more efficient than the top-down approach in terms of the cost of subsumption. In conclusion, we will discuss these results and show that some knowledge that is useful to the system users is lost during the bottom-up re-engineering process and that the best approach for re-engineering a semantic network requires a combination of both of these approaches.
Year
DOI
Venue
2005
10.1142/S0218194005002506
INTERNATIONAL JOURNAL OF SOFTWARE ENGINEERING AND KNOWLEDGE ENGINEERING
Keywords
Field
DocType
evolutionary computation, cultural algorithms, semantic networks, knowledge-base re-engineering, knowledge maintenance, subsumption, top-down re-engineering
Data mining,Computer science,Expert system,Evolutionary computation,Knowledge maintenance,Algorithm,Knowledge-based systems,Semantic network,Artificial intelligence,Knowledge base,Cultural algorithm,Machine learning
Journal
Volume
Issue
ISSN
15
4
0218-1940
Citations 
PageRank 
References 
4
0.49
2
Authors
2
Name
Order
Citations
PageRank
Nestor Rychtyckyj16410.43
Robert G. Reynolds2610188.20