Showing papers on "Knowledge extraction published in 1976"

Observations on the interaction between coding and efficiency knowledge in the PSI Program Synthesis System

Abstract: This paper discusses how the synthesis phase of the PSI system constructs programs from high level program models by using coding knowledge and efficiency knowledge. In our preliminary implementation, these knowledge bases are separated into distinct modules, the coding expert and the efficiency expert. We describe how the coding expert uses rule-based programming knowledge to produce alternative algorithm and data structure choices, and how the efficiency expert selects the best choice by estimating the costs of the alternatives using analysis of algorithm techniques. Communication between the modules centers around descriptions of partially developed programs which are produced by the coding expert and analyzed by the efficiency expert. Our system has implemented several small programs. From our experience with these modules, we conclude that there is a strong interaction between coding and efficiency knowledge which necessitates a corresponding complexity in the communication mechanism.

Working Papers in Acquisition of Knowledge for Image Understanding Research.

Abstract: : Use of knowledge has facilitated complex problem solving in many areas of research. However, in the Image Understanding area, we do not have any systematic treatment and codification of knowledge that is useful in image perception. Further, we do not even have adequate tools for acquiring the necessary knowledge base. In this report we present an experimental paradigm for knowledge acquisition, discuss an analysis technique, and illustrate the different types of knowledge that seem to be useful in image understanding research. In the first paper, three major aspects of knowledge are presented: primitive Feature Extraction Operators, Rewriting Rules, and Flow of Control. A limited number of Feature Extraction Operators were repeatedly used by the subjects to specify location, size, shape, quantity, color, texture, and patterns, of various components found in scenes. Six types of Rewriting Rules were identified; assertions, negative assertions, context-free, conditional, generative, and analytical inferences. Flow of Control exhibited characteristics of an hypothesize and test paradigm capable of using imprecise, conflicting hypotheses in cooperation with others in a multi-dimensional problem space. The second paper discusses the picture-puzzle paradigm and the various ways in which it can be used as a tool for acquisition of knowledge. The third paper deals with a computer program that assists the transcription of typical protocols obtained from the picture puzzle tasks. Finally, the last paper of the report discusses the pros and cons of using eye-fixation data to acquire knowledge used in some of the tasks of the picture-puzzle paradigm.