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    Chapter

    Walsh Series with Monotone Decreasing Coefficients

    Let {c n }, n = 0, 1, …, be a monotone decreasing sequence of real numbers, i. e., Δc n c n - cn+1 ≥ 0 for n = 0, 1, …...

    B. Golubov, A. Efimov, V. Skvortsov in Walsh Series and Transforms (1991)

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    Chapter

    Divergent Walsh-Fourier Series. Almost Everywhere Convergence of Walsh-Fourier Series of L2 Functions

    In Chapter 2 we saw that even for a continuous function it is necessary to impose additional conditions to insure that its Walsh- Fourier series converges at every point. Without such conditions, as we remarke...

    B. Golubov, A. Efimov, V. Skvortsov in Walsh Series and Transforms (1991)

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    Chapter

    Summability of Walsh Series by the Method of Arithmetic Means

    As we saw in §2.3, there exist continuous functions whose Walsh- Fourier series diverge at a given point. We shall show in Chapter 9 that there exist integrable functions whose Walsh-Fourier series diverge eve...

    B. Golubov, A. Efimov, V. Skvortsov in Walsh Series and Transforms (1991)

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    Chapter

    Generalized Multiplicative Transforms

    Let 1 ≤ p < ∞. A complex valued function f(x) is said to belong to L p (0, ∞) if ∫0|f(x)| p dx > ∞. The norm of f(x) in the space L p ...

    B. Golubov, A. Efimov, V. Skvortsov in Walsh Series and Transforms (1991)

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    Chapter

    Lacunary Subsystems of the Walsh System

    The Rademacher system, {r k (x)} = {w2 k , k = 0,1,…, which was used to define the Walsh system (see §1.1), is a typical example of what is called a lac...

    B. Golubov, A. Efimov, V. Skvortsov in Walsh Series and Transforms (1991)

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    Chapter

    Other Applications of Multiplicative Functions and Transformations

    Filtering is one of the fundamental techniques of digital signal processing. By a digital filter we shall mean a transformation which takes a sequence of numbers {x(n)}, called the input, in another sequence {y(n

    B. Golubov, A. Efimov, V. Skvortsov in Walsh Series and Transforms (1991)

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    Chapter

    Operators in the Theory of Walsh-Fourier Series

    In this chapter, and the next, we shall obtain several results about Walsh-Fourier series by using properties of operators which take one space of measurable functions to another. We begin with definitions and...

    B. Golubov, A. Efimov, V. Skvortsov in Walsh Series and Transforms (1991)

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    Chapter

    Applications of Multiplicative Series and Transforms to Digital Information Processing

    In the last decade interest has increased significantly in applications of the Walsh system and its generalizations, especially applications to digital information processing. This interest stems from a peculi...

    B. Golubov, A. Efimov, V. Skvortsov in Walsh Series and Transforms (1991)

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    Chapter

    Walsh-Fourier Series. Basic Properties

    Within the collection of all Walsh series, Walsh-Fourier series play a crucial role. These are the series of the form (1.4.1) whose coefficients are given by the formula

    B. Golubov, A. Efimov, V. Skvortsov in Walsh Series and Transforms (1991)

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    Chapter

    Approximations by Walsh and HAAR Polynomials

    Let f(t) be a function continuous on the interval [0, 1]. Consider the 10.1.1 $$\begin{array}{*{20}{c}} {{{E}_{n}}(f) = \mat...

    B. Golubov, A. Efimov, V. Skvortsov in Walsh Series and Transforms (1991)

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    Chapter

    Walsh Functions and Their Generalizations

    Consider the function defined on the half open unit interval [0, 1) by $${{r}_{0}}(x) = \left\{ {\begin{array}{*{20}{c}} 1 & {for x \in [0, ...

    B. Golubov, A. Efimov, V. Skvortsov in Walsh Series and Transforms (1991)

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    Chapter

    General Walsh Series and Fourier-Stieltjes Series. Questions on Uniqueness of Representations of Functions by Walsh Series

    In this chapter we shall consider general Walsh series, i. e., series whose coefficients are not necessarily Walsh-Fourier coefficients of some function. For the study of these series, the function which is th...

    B. Golubov, A. Efimov, V. Skvortsov in Walsh Series and Transforms (1991)