Results 31 to 40 of about 1,236,961 (324)

The Fourier analysis in inhomogeneous media

St. Petersburg Polytechnical University Journal: Physics and Mathematics, 2023
In the paper, the definition and basic properties of the Fourier transform (FT) are discussed. It has been shown with specific examples that integral solutions of the model inhomogeneous equation, the nonstationary Cauchy problem on an inhomogeneous ...
Gnevyshev Vladimir, Belonenko Tatyana
doaj   +1 more source

Families of spectral sets for Bernoulli convolutions [PDF]

, 2010
In this paper, we study the harmonic analysis of Bernoulli measures. We show a variety of orthonormal Fourier bases for the L^2 Hilbert spaces corresponding to certain Bernoulli measures, making use of contractive transfer operators.
Karen, Keri A. Kornelson, L. Shuman, Palle E. T. Jorgensen   +3 more
core   +1 more source

Experimental forecast of thermal conditions in the South Kuril region in summer by modified Fourier method

Известия ТИНРО, 2021
Time series of air temperature and sea surface temperature in South Kuril region in July and August are extrapolated to 2020–2024 using modified method of Fourier decomposition. Both cyclic harmonic components and linear trend are accounted.
T. A. Shatilina, G. Sh. Tsitsiashvili, T. V. Radchenkova   +2 more
doaj   +1 more source

Effect of Slot Opening Width on the Air-Gap Magnetic Field of a Direct Drive Permanent Magnet Motor

Applied Sciences, 2019
The direct drive permanent magnet motor (DDPMM) is a promising candidate for applications because of its high efficiency, high power density, and low maintenance costs.
Yaofei Han, Shaofeng Chen, Caixia Gao, Mengzhen Gao, Jikai Si, Yihua Hu   +5 more
doaj   +1 more source

On twisted Fourier analysis and convergence of Fourier series on discrete groups

, 2008
We study norm convergence and summability of Fourier series in the setting of reduced twisted group $C^*$-algebras of discrete groups. For amenable groups, F{\o}lner nets give the key to Fej\'er summation.
A. Connes, A. Connes, A. Figà-Talamanca, A. Kleppner, A. Kleppner, A. Paterson, A. Valette, A. Valette, A. Valette, A.L. Carey, A.Yu. Ol’shanskiĭ, B. Dorofaeff, C. Berg, C. Nebbia, C.A. Akemann, E. Bédos, E. Ghys, E.G. Effros, Erik Bédos, F. Luef, F. Luef, G. Fendler, G. Fendler, G. Mackey, G. Pisier, G. Zeller-Meier, I. Chatterji, J. Bellissard, J. Bellissard, J. Brodzki, J. Cannière de, J. Dixmier, J. Dixmier, J. Dixmier, J.-L. Sauvageot, J.-L. Sauvageot, J.A. Packer, J.A. Packer, J.A. Packer, J.A. Packer, J.A. Packer, J.E. Humphreys, J.M. Cohen, J.P. Pier, K. Gröchenig, K.R. Davidson, L.B. Schweitzer, M. Bożejko, M. Bożejko, M. Bożejko, M. Bożejko, M. Bożejko, M. Cowling, M. Cowling, M. Cowling, M. Gromov, M. Leinert, M. Marcolli, M.A. Picardello, N. Higson, N. Ozawa, N. Weaver, N.B. Backhouse, N.B. Backhouse, P. Eymard, P. Jolissaint, P. Jolissaint, P. Jolissaint, P. la Harpe de, P. la Harpe de, P. la Harpe de, P.-A. Cherix, R. Exel, R. Ji, R. Mercer, R.B. Howlett, Roberto Conti, S. Wagon, T. Januszkiewicz, U. Haagerup, U. Haagerup, V. Flory, V. Mathai, V. Paulsen, X. Chen   +84 more
core   +2 more sources

A unified mode decomposition method for physical fields in homogeneous cosmology [PDF]

, 2013
The methods of mode decomposition and Fourier analysis of classical and quantum fields on curved spacetimes previously available mainly for the scalar field on Friedman- Robertson-Walker (FRW) spacetimes are extended to arbitrary vector bundle fields on ...
Avetisyan, Zhirayr G.
core   +2 more sources

On the Validity of the Local Fourier Analysis [PDF]

Journal of Computational Mathematics, 2019
Local Fourier analysis (LFA) is a useful tool in predicting the convergence factors of geometric multigrid methods (GMG). As is well known, on rectangular domains with periodic boundary conditions this analysis gives the exact convergence factors of such methods.
Carmen Rodrigo, Ludmil T. Zikatanov, Francisco J. Gaspar   +2 more
openaire   +3 more sources

Current measurements in the intermittent-contact mode of atomic force microscopy using the Fourier method: a feasibility analysis

Beilstein Journal of Nanotechnology, 2020
Atomic force microscopy (AFM) is an important tool for measuring a variety of nanoscale surface properties, such as topography, viscoelasticity, electrical potential and conductivity.
Berkin Uluutku, Santiago D. Solares
doaj   +1 more source

The scale levels identification for the plowland topography organization

Бюллетень Почвенного института им. В.В. Докучаева, 2019
The identification of factor and indicational features, which are characterized by the high informativity and field of view in relation to the soil cover organization, plays a very important role in the soil mapping.
N. V. Minayev, A. A. Nikitin, D. N. Kozlov   +2 more
doaj   +1 more source

Hands‐on protocol for preparing water‐soluble fractions from agri‐food samples for NMR‐based metabolomics analysis

FEBS Open Bio, EarlyView.
This research protocol outlines a workflow for nuclear magnetic resonance (NMR)‐based metabolomics in the agri‐food sector. Using two case studies—strawberry leaves (solid matrix) and wine (liquid matrix)—it details the procedures for sample preparation, data acquisition, and processing.
Andrea Fernández‐Veloso, Jaime Hiniesta‐Valero, Alejandra Guerra‐Castellano, Miguel A. De la Rosa, Irene Díaz‐Moreno   +4 more
wiley   +1 more source