Alexander Shchitov, The Exact Estimates of Fourier-Haar Coefficients of Functions of Bounded Variation, IJARM Volume 4, International Journal of Advanced Research in Mathematics (Volume 4)
https://www.scipress.com/IJARM.4.14
Abstract:
    The exact values of the upper bounds of the modulus of Fourier-Haar coefficients of functions of one variable has been obtained on the classes of functions of boundary variations KV<sub>p</sub> (1≤p&lt;∞). The behavior of Fourier-Haar coefficients of functions of several variables has been investigated for functions of boundary variations from the classes V<sub>p,d</sub>(II<sup>d</sup>), KV<sub>p,d</sub> (1≤p&lt;∞) and KV<sup>*</sup><sub>1,d</sub>. On these classes of functions of several variables the exact results has been obtained.
Keywords:
    Exact Estimates, Fourier-Haar Coefficients, Fourier-Haar System, Function of One and Several Variables, Functions of Bounded Variation