Shoichi Kojima

A circuit comparison system with rule-based functional isomorphism checking

A circuit comparison system is described which compares two networks and points out inconsistencies. A novel approach is used to handle functionally isomorphic circuits which most conventional programs can not handle. Three techniques are included: network reduction, graph isomorphism-based comparison, and rule-based functional isomorphism checking for inconsistencies. The system is efficient even for large networks and can eliminate false errors in flexible manner.<<ETX>>

Error repair and knowledge acquisition via case-based reasoning

Abstract To cope with the knowledge acquisition bottleneck, the authors propose a new architecture combining rule-based reasoning (RBR), case-based reasoning (CBR) and knowledge acquisition technology in a system which solves pattern search problems. The RBR part searches for specified patterns in a large space represented by a network structure such as an LSI circuit diagram, which contains a great number of patterns and variations. It then carries out specified actions, such as fault diagnosis, on the patterns that are found. The outputs of the RBR part are transferred to the CBR part. The user of the system detects and repairs a few pattern detection errors caused by the RBR part. The CBR part detects and repairs all remaining errors which can be estimated from the user detected ones. The repaired results are sent back to the RBR part to recover the RBR output. The repaired results are also stored automatically in the case base. Similar cases are grouped in a same case family. The knowledge acquisition part relates each case family to an incomplete rule in the RBR knowledge base and proposes modifying the rule. Eventually, the system can obtain refined rules with the cooperation of domain experts. Thus, the problem solving process and knowledge acquisition process are performed cyclically. The architecture was successfully applied to a pair condition extraction problem for an analog LSI circuit layout system.

KASE project toward effective diagnosis system development

Abstract The Knowledge Acquisition Support Environment (KASE) and some case studies on expert system development are described. DiPROS is a diagnostic expert system building tool, which has a knowledge base editor and an inference engine specialized for diagnostic tasks. DiKAST is an interactive knowledge-acquisition (KA) tool, which guides repairs on defects in the knowledge base. In order to build this KA facility, many kinds of KA interview strategies were formalized. We applied KASE tools in building a defect diagnosis system for a color picture tube manufacturing plant. The prototype system was able to be developed in a short time by the domain experts alone, who had no previous experience in computer programming.

Knowledge modeling environment for job-shop scheduling problem

The scheduling model and method must be designed to be application-domain dependent so as to reflect a set of constraints, objectives and preferences which reside in the target problem. We analyzed the scheduling process of human experts in a knowledge-base level and have developed a task-specific shell named ARES/SCH. ARES/SCH possesses a primitive task library that is a collection of domain-independent and generic components of scheduling mechanisms. The whole scheduling method can be described as a combinational flow-chart of primitive tasks. Memory module mounting shop (MMS) scheduling is shown as an example of ARES/SCH applications. It was apparent that ARES/SCH contributes to the rapid development of scheduling systems and supports a wide range of scheduling domains.<<ETX>>