published_or_final_version / abstract / toc / Civil Engineering / Doctoral / Doctor of Philosophy

The Rational Chebyshev Function was first introduced by Bernstein (1926), used by Sharpe (1953), then later by Heldman (1955) to design elliptic-characteristic filters. Namely for a filter of order N, we have N/2 equal ripples in the passband and N/2 equal ripples in the stopband of the magnitude response. Here, the same mechanics are used but are now producing a new and different type of response. It has N/2 ripples in the passband but only one ripple in the stopband for all orders. As N increases from three, the result is a substantial saving in number of capacitors in the passive ladder realization of the above function as compared to that of traditional elliptic filters of the same order N. It also has been discovered that the above ladder's element values can be expressed as explicit expressions involving only the coefficients of the transfer function. These expressions can also be used for other types of filters. Numerically, the design can be carried out by a Fortran program or a set of programs on a programmable calculator. The design is termed automated because the user needs only to give the three specifications: the filter order N, the stopband zeros Z, and the passband ripple amount R(p). The program automatically selects the starting point for the given case and proceeds. The numerical results of the above programs over a range of specifications has led to a surprising and simple expression relating the above specifications to the minimum stopband attenuation. This is a useful relationship for the designer to estimate the zero position when using the programs.

No description available.

Thesis (doctoral)--Rheinischen Friedrich-Wilhelms-Universität, Bonn, 1980. / Includes bibliographical references (p. 252-258).

Thesis (M.Sc.)--Memorial University of Newfoundland, 2004. / Restricted until May 2005. Bibliography: leaves 75-83.

Este trabalho faz uma relação entre primalidade de números inteiros e os polinômios de Chebyshev, estudando resultados recentemente descobertos. Um dos principais resultados é uma generalização do Pequeno Teorema de Fermat, que mostra a congruência, Tn(a) =a ( mod n) para n primo, em que Tn(x) é o n- ésimo polinômio de Chebyshev. A recíproca desse resultado, se verdadeira, conduziria a um teste de primalidade determinístico eficiente. Através de cálculo computacional, mostramos que para n < 1,9 x 104 , a recíproca é verdadeira. Além disso, os resultados dessa simulação, podem servir de base para o desenvolvimento de um algoritmo probabilístico para verificação da primalidade. Alguns testes de primalidade existentes na literatura, assim como definições e propriedades algébricas dos polinômios de Chebyshev também são apresentadas. / This work makes a relation between integer primality and Chebyshev polynomials, discussing recently found results. One of the most important results is a generalization of Fermat's little theorem. lt shows that Tn(a) =a ( mod n ), for n prime, where Tn(x) is the ndegree Chebyshev polynomial. The converse o f this result, if true, would lead to an efficient deterministic primality test. Tbrough a machine computation, we show that for n < 1,9 x 1 04 , the converse is true. The results of this simulation may serve to structure a probabilistic primality testing algorithm. Also, some existent primality tests, as well as definitions and algebraic properties o f Chebyshev polynomials are presented.

Este trabalho faz uma relação entre primalidade de números inteiros e os polinômios de Chebyshev, estudando resultados recentemente descobertos. Um dos principais resultados é uma generalização do Pequeno Teorema de Fermat, que mostra a congruência, Tn(a) =a ( mod n) para n primo, em que Tn(x) é o n- ésimo polinômio de Chebyshev. A recíproca desse resultado, se verdadeira, conduziria a um teste de primalidade determinístico eficiente. Através de cálculo computacional, mostramos que para n < 1,9 x 104 , a recíproca é verdadeira. Além disso, os resultados dessa simulação, podem servir de base para o desenvolvimento de um algoritmo probabilístico para verificação da primalidade. Alguns testes de primalidade existentes na literatura, assim como definições e propriedades algébricas dos polinômios de Chebyshev também são apresentadas. / This work makes a relation between integer primality and Chebyshev polynomials, discussing recently found results. One of the most important results is a generalization of Fermat's little theorem. lt shows that Tn(a) =a ( mod n ), for n prime, where Tn(x) is the ndegree Chebyshev polynomial. The converse o f this result, if true, would lead to an efficient deterministic primality test. Tbrough a machine computation, we show that for n < 1,9 x 1 04 , the converse is true. The results of this simulation may serve to structure a probabilistic primality testing algorithm. Also, some existent primality tests, as well as definitions and algebraic properties o f Chebyshev polynomials are presented.

Este trabalho faz uma relação entre primalidade de números inteiros e os polinômios de Chebyshev, estudando resultados recentemente descobertos. Um dos principais resultados é uma generalização do Pequeno Teorema de Fermat, que mostra a congruência, Tn(a) =a ( mod n) para n primo, em que Tn(x) é o n- ésimo polinômio de Chebyshev. A recíproca desse resultado, se verdadeira, conduziria a um teste de primalidade determinístico eficiente. Através de cálculo computacional, mostramos que para n < 1,9 x 104 , a recíproca é verdadeira. Além disso, os resultados dessa simulação, podem servir de base para o desenvolvimento de um algoritmo probabilístico para verificação da primalidade. Alguns testes de primalidade existentes na literatura, assim como definições e propriedades algébricas dos polinômios de Chebyshev também são apresentadas. / This work makes a relation between integer primality and Chebyshev polynomials, discussing recently found results. One of the most important results is a generalization of Fermat's little theorem. lt shows that Tn(a) =a ( mod n ), for n prime, where Tn(x) is the ndegree Chebyshev polynomial. The converse o f this result, if true, would lead to an efficient deterministic primality test. Tbrough a machine computation, we show that for n < 1,9 x 1 04 , the converse is true. The results of this simulation may serve to structure a probabilistic primality testing algorithm. Also, some existent primality tests, as well as definitions and algebraic properties o f Chebyshev polynomials are presented.

This thesis is concerned with the qualitative and quantitative properties of solutions of certain classes of ordinary di erential equations (ODEs); in particular linear boundary value problems of second order ODE's and non-linear ODEs of order at most four. The Lyapunov's second method of special functions called Lyapunov functions are employed extensively in this thesis. We construct suitable complete Lyapunov functions to discuss the qualitative properties of solutions to certain classes of non-linear ordinary di erential equations considered. Though there is no unique way of constructing Lyapunov functions, We adopt Cartwright's method to construct complete Lyapunov functions that are required in this thesis. Su cient conditions were established to discuss the qualitative properties such as boundedness, convergence, periodicity and stability of the classes of equations of our focus. Another aspect of this thesis is on the quantitative properties of solutions. New scheme based on interpolation and collocation is derived for solving initial value problem of ODEs. This scheme is derived from the general method of deriving the spline functions. Also by exploiting the Trigonometric identity property of the Chebyshev polynomials, We develop a new scheme for approximating the solutions of two-point boundary value problems. These schemes are user-friendly, easy to develop algorithm (computer program) and execute. They compare favorably with known standard methods used in solving the classes of problems they were derived for

Este trabalho apresenta um método numérico rigoroso para encontrar soluções de equilíbrio para equações diferenciais parciais usando base de Chebyshev. Aplicações do método são apresentadas para a equação de Alen-Cahn e Swift-Hohenberg. / This work presents a rigorous numerical method to find equilibrium solutions to partial differential equations using Chebyshev basis. Applications are presented to the Alen-Cahn and Swift-Hohenberg equations.