October 1962 - Vol. 5 No. 10

This paper presents a new manner of dispersing strings for a Polyphase merge. If the number of strings dispersed is between two levels acceptable by Polyphase merge, a more economical technique of reaching the next level for Polyphase merge is shown and proved.

This paper provides an account of the Shadow language that is used to describe syntax and of a corresponding subroutine that enables a computer to perform syntactic analysis. The input to this subroutine consists of a string to be analyzed and a description of the syntax that is to be used. The syntax is expressed in the Shadow language. The output consists of a trace table that expresses the results of the syntactic analysis in a tabular form. Several versions of the subroutine and some associated programs have been in use now for over three years. The present account of the language and the subroutine contains a summary of material that has been described previously in unpublished reports and also some additional discussion of the work in relation to the more general questions of problem-oriented languages and string transformations.

The use of programmed digital computers as general pattern classification and recognition devices is one phase of the current lively interest in artificial intelligence. It is important to choose a class of signals which is, at present, undergoing a good deal of visual inspection by trained people for the purpose of pattern recognition. In this way comparisons between machine and human performance may be obtained. A practical result also serves as additional motivation. Clinical electrocardiograms make up such a class of signals. The approach to the problem presented here centers upon the use of multiple adaptive matched filters that classify normalized signals. The present report gives some of the background for the application of this method.