ABSTRACT 

Recently, Case-Based Reasoning (CBR) is paid attention, as a methodology 
for aquiring and utilizing knowledge efficiently. We have developped case-
based circuit design support system to illustrate the effectiveness of CBR. 

In design task, it is very important to store and utilize design cases, for the 
designer is often required to cope with a variety of design objects within a 
limited time. This system supports to design new degital circuits using similar 
precedential circuits. 

APPROACH 

Here, we have focused on how to extract the available similar cases. 

Structure-Mapping Engine(SME) is a kernel engine of case retrieval. 
Each case is given the tree-structured representations of its function. 


OVERVIEW OF SYSTEM 

Structural indexing 

Functional hierarchy tree represents hierarchical relations between pri-
mary function and secondary functions in a tree form to arrange the 
functions of the design object systematically. 
Each node of functinal hierarchy tree is a simple sentence representing a 
function. (Fig. 1 ) 





Fig.1 Functional hierarchy tree for a digital clock 

      in additional function with sensing temparature


					- 28 -