Multiple classifier fusion using the fuzzy integral.

Fusion of multiple classifier decisions is a powerful method for increasing classification rates in difficult pattern recognition problems. Researchers have found that in many applications it is better to fuse multiple relatively simple classifiers than to build a single sophisticated classifier to achieve better recognition rates. Ideally, the combination function should take advantage of the strengths of individual classifiers and of all possible subsets of classifiers, avoid their weaknesses, and use all the dynamically available knowledge about the inputs, the outputs, the classes, and the classifiers. Automatic reading of handwritten numerals is a difficult problem because of the great variations involved in the shape of the characters. In this thesis an evidence fusion technique, based on the notion of fuzzy integral is utilized to combine the results of different classifiers and realize a robust algorithm for high accuracy handwritten numeral recognition. Both source relevance as well as source evidence are utilized to achieve significant enhancements. The most important advantage of this system is that not only is the evidence combined but that the relative importance of the different sources is also considered. Various conventional and fuzzy integral based fusion methods are explained in detail and experimental results obtained are compared. A method is introduced to improve the fuzzy densities of the classifiers which would improve the fusion results. In this method we use the correction factors obtained from the performance matrices to alter the initial fuzzy densities. Experiments on handwritten numeral recognition are described and compared. These experiments show that very low error rates can be achieved by fusing several low performance classifiers.Dept. of Electrical and Computer Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1999 .B45. Source: Masters Abstracts International, Volume: 39-02, page: 0558. Adviser: M. Ahmadi. Thesis (M.A.Sc.)--University of Windsor (Canada), 1999

Probabilistic Neural Network based Approach for Handwritten Character Recognition

In this paper, recognition system for totally unconstrained handwritten characters for south Indian language of Kannada is proposed. The proposed feature extraction technique is based on Fourier Transform and well known Principal Component Analysis (PCA). The system trains the appropriate frequency band images followed by PCA feature extraction scheme. For subsequent classification technique, Probabilistic Neural Network (PNN) is used. The proposed system is tested on large database containing Kannada characters and also tested on standard COIL-20 object database and the results were found to be better compared to standard techniques

Reconocimiento de notación matemática escrita a mano fuera de línea

El reconocimiento automático de expresiones matemáticas es uno de los problemas de reconocimiento de patrones, debido a que las matemáticas representan una fuente valiosa de información en muchos a ́reas de investigación. La escritura de expresiones matemáticas a mano es un medio de comunicación utilizado para la transmisión de información y conocimiento, con la cual se pueden generar de una manera sencilla escritos que contienen notación matemática. Este proceso puede volverse tedioso al ser escrito en lenguaje de composición tipográfica que pueda ser procesada por una computadora, tales como LATEX, MathML, entre otros. En los sistemas de reconocimiento de expresiones matem ́aticas existen dos m ́etodos diferentes a saber: fuera de l ́ınea y en l ́ınea. En esta tesis, se estudia el desempen ̃o de un sistema fuera de l ́ınea en donde se describen los pasos b ́asicos para lograr una mejor precisio ́n en el reconocimiento, las cuales esta ́n divididas en dos pasos principales: recono- cimiento de los s ́ımbolos de las ecuaciones matema ́ticas y el ana ́lisis de la estructura en que est ́an compuestos. Con el fin de convertir una expresi ́on matema ́tica escrita a mano en una expresio ́n equivalente en un sistema de procesador de texto, tal como TEX