Accession Number : ADA181378

Title :   Processing Waveforms as Trees for Pattern Recognition.

Descriptive Note : Technical rept.,

Corporate Author : RICE UNIV HOUSTON TX DEPT OF ELECTRICAL AND COMPUTER ENGINEERING

Personal Author(s) : Shaw,Scott W ; DeFigueiredo,Rui J

PDF Url : ADA181378

Report Date : May 1986

Pagination or Media Count : 63

Abstract : Waveforms may be represented symbolically such that their underlying, global structural composition is emphasized. One such symbolic representation is the relational tree. The relational tree is a computer data structure that descirbes the relative size and placement of peaks and valleys in a waveform. Researchers have developed various distance measures which serves as tree metrics. A tree metric defines a tree space. We are able to cluster groups of tree by proximity in tree space. Linear discriminants are used to reduce vector space dimensionality and to improve cluster performance. A tree transformation operating on a regualr tree langauge accomplishes this same goal in a tree space. Under certain restrictions, relational trees form a regular tree language. Combining these concepts yields a waveform recognition system. This system recognizes waveforms even when they have undergone a monotonic transformation of the time axis. The system performs well with high signal to noise ratios, but further refinements are necessary for a working waveform interpretation system.

Descriptors :   *PATTERN RECOGNITION, *WAVEFORMS, CLUSTERING, TREES, COMPUTERS, DATA BASES, GLOBAL, DISCRIMINATE ANALYSIS, LINEAR SYSTEMS, SIZES(DIMENSIONS), LANGUAGE, RANGE(DISTANCE), SIGNALS, SIGNAL TO NOISE RATIO, TRANSFORMATIONS, VECTOR SPACES, DATA PROCESSING

Subject Categories : Cybernetics

Distribution Statement : APPROVED FOR PUBLIC RELEASE