Speech sample estimation from composite zerocrossings and encoding via adaptive switching of transforms

This thesis investigates the potential use of zerocrossing information for speech sample estimation. It provides 21 new method tn) estimate speech samples using composite zerocrossings. A simple linear interpolation technique is developed for this purpose. By using this method the A/D converter can be avoided in a speech coder. The newly proposed zerocrossing sampling theory is supported with results of computer simulations using real speech data. The thesis also presents two methods for voiced/ unvoiced classification. One of these methods is based on a distance measure which is a function of short time zerocrossing rate and short time energy of the signal. The other one is based on the attractor dimension and entropy of the signal. Among these two methods the first one is simple and reguires only very few computations compared to the other. This method is used imtea later chapter to design an enhanced Adaptive Transform Coder. The later part of the thesis addresses a few problems in Adaptive Transform Coding and presents an improved ATC. Transform coefficient with maximum amplitude is considered as ‘side information’. This. enables more accurate tfiiz assignment enui step—size computation. A new bit reassignment scheme is also introduced in this work. Finally, sum ATC which applies switching between luiscrete Cosine Transform and Discrete Walsh-Hadamard Transform for voiced and unvoiced speech segments respectively is presented. Simulation results are provided to show the improved performance of the coder

Programmierung in Pascal

Das hier frei verfügbare Skript gehört zu einer gleichnamigen Vorlesung, die von Prof. Dr. Lutz Wegner bis zum Wintersemester 1998/99 am damaligen Fachbereich 17 Mathematik/Informatik der Universität Kassel gehalten wurde. Thema ist die Einführung in die Programmierung, wie sie am Anfang fast aller Informatik-, Mathematik- und verwandter Ingenieurstudiengänge steht. Hier erfolgt die Einführung mit der Programmiersprache Pascal, die Niklaus Wirth (ehemals ETH Zürich) bereits 1968 entwickelte. Sie gilt als letzte Vertreterin der rein prozeduralen Sprachen und führt in der Regel zu sauber strukturierten Programmen. In der damals auf PCs weit verbreiteten Turbo Pascal Variante geht es auch um Objektorientierung, die charakteristisch für das heutige Programmierparadigma mit Java ist. Alte (und neu geschriebene) Pascal-Programme lassen sich problemlos mit den Free Pascal Open Source Compilern (www.freepascal.org) übersetzen und unter allen gängigen Betriebssystemen zur Ausführung bringen. Wer hierfür eine fachlich präzise und trotzdem vergleichsweise gut lesbare Einführung mit Hinweisen auf guten und schlechten Programmierstil braucht, wird hier fündig und kommt über den Stickwortindex am Ende auch schnell zu Einzelthemen wie Parameterübergabe oder das Arbeiten mit Pointern.

Laplace Transforms pdf

Exam questions and solutions in PDF

Laplace Transforms

Exam questions and solutions in LaTex

Programación avanzada en Turbo Pascal.

Este manual ofrece los conceptos fundamentales para la programación con el lenguaje de programación Pascal. La obra se estructura en seis partes: 1. Lenguaje de programación de alto nivel : el Pascal. 2. Conceptos avanzados de lenguaje de alto nivel. 3. Diseño y evaluación de algoritmos. 4. Tipos abstractos de datos. 5. Tipos abstractos de datos avanzados. 6. Nuevos conceptos de programación.

En torno al Triángulo Aritmético que algunos llaman de Pascal : la autoría (I).

Se analiza el origen del triángulo aritmético también conocido como Triángulo de Pascal. Se pone en duda que este matemático fuera el autor de este concepto. Para ello se hace un recorrido histórico hasta el origen del triángulo.

En torno al triángulo aritmético que algunos llaman de Pascal : un universo nacido de la nada (IV).

Reflexiones en torno al triángulo aritmético. En el artículo se analiza la estructura del propio triángulo a partir del estudio de sus propiedades. El estudio se centra en la combinatoria y los órdenes numéricos principalmente.

En torno al triángulo aritmético que algunos llaman de Pascal : símbolo del anonimato científico (V).

Se estudia la relación del triángulo aritmético de Pascal con la combinatoria y las potencias. Así se exponen las aportaciones del matemático Pascal en torno a estos temas y a la aplicación de los mismos.

En torno al triángulo aritmético que algunos llaman de Pascal : el método, contra el método (VII).

Reflexiones en torno a los diferentes pensamientos sobre el método científico. Así se revisan las teorías de Descartes y su Discurso del Método. A continuación se expone la visión del matemático Pascal en contra del propio método. Finalmente, se explica el pensamiento de Feyerabend en relación al método científico y la educación en general.

En torno al triángulo aritmético que algunos llaman de Pascal : la trascendencia (II).

Reflexiones sobre el concepto de triángulo aritmético. Se analiza su aplicación e importancia y finalmente se hace una aproximación al álgebra china.

Feature-point detection using distance transforms: Application to tracking tropical convective complexes

The identification, tracking, and statistical analysis of tropical convective complexes using satellite imagery is explored in the context of identifying feature points suitable for tracking. The feature points are determined based on the shape of complexes using the distance transform technique. This approach has been applied to the determination feature points for tropical convective complexes identified in a time series of global cloud imagery. The feature points are used to track the complexes, and from the tracks statistical diagnostic fields are computed. This approach allows the nature and distribution of organized deep convection in the Tropics to be explored.

Linear and nonlinear generalized Fourier transforms

This article presents an overview of a transform method for solving linear and integrable nonlinear partial differential equations. This new transform method, proposed by Fokas, yields a generalization and unification of various fundamental mathematical techniques and, in particular, it yields an extension of the Fourier transform method.

Comparison of extrasystolic ECG signal classifiers using discrete wavelet transforms

This work compares and contrasts results of classifying time-domain ECG signals with pathological conditions taken from the MITBIH arrhythmia database. Linear discriminant analysis and a multi-layer perceptron were used as classifiers. The neural network was trained by two different methods, namely back-propagation and a genetic algorithm. Converting the time-domain signal into the wavelet domain reduced the dimensionality of the problem at least 10-fold. This was achieved using wavelets from the db6 family as well as using adaptive wavelets generated using two different strategies. The wavelet transforms used in this study were limited to two decomposition levels. A neural network with evolved weights proved to be the best classifier with a maximum of 99.6% accuracy when optimised wavelet-transform ECG data wits presented to its input and 95.9% accuracy when the signals presented to its input were decomposed using db6 wavelets. The linear discriminant analysis achieved a maximum classification accuracy of 95.7% when presented with optimised and 95.5% with db6 wavelet coefficients. It is shown that the much simpler signal representation of a few wavelet coefficients obtained through an optimised discrete wavelet transform facilitates the classification of non-stationary time-variant signals task considerably. In addition, the results indicate that wavelet optimisation may improve the classification ability of a neural network. (c) 2005 Elsevier B.V. All rights reserved.