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Discrete structures in gravity [PDF]
Journal of Mathematical Physics, 2000 Discrete approaches to gravity, both classical and quantum, are reviewed briefly, with emphasis on the method using piecewise-linear spaces. Models of three-dimensional quantum gravity involving 6j-symbols are then described, and progress in generalizing these models to four dimensions is discussed, as is the relationship of these models in both three ...
REGGE, Tullio, WILLIAMS R. M.
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Learning discrete structures for cancer radiomics [PDF]
APL BioengineeringRadiomics methods are essential in cancer image analysis due to their excellent ability in extracting quantitative imaging features. Existing radiomics methods adopt either statistical models for data preprocessing and feature engineering or deep ...
Jielong Yang +7 more
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Method for Obtaining Coefficients of Powers of Multivariate Generating Functions
Mathematics, 2023 There are several general concepts that allow obtaining explicit formulas for the coefficients of generating functions in one variable by using their powers. One such concept is the application of compositae of generating functions.
Dmitry Kruchinin +2 more
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Combinatorial Generation Algorithms for Some Lattice Paths Using the Method Based on AND/OR Trees
Algorithms, 2023 Methods of combinatorial generation make it possible to develop algorithms for generating objects from a set of discrete structures with given parameters and properties.
Yuriy Shablya
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Nonstationary discrete theory of excitation of periodic structures and its application for simulation of traveling-wave tubes [PDF]
Известия высших учебных заведений: Прикладная нелинейная динамика, 2021 Aim. This article presents a review of the nonstationary (time-domain) discrete theory of excitation of periodic electromagnetic structures and discusses applications of the theory for simulation of traveling-wave tube (TWT) microwave power amplifiers ...
Ryskin, Nikita Mikhailovich +4 more
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Discrete orthogonal structures
Computers & Graphics, 2023 To represent smooth geometric shapes by coarse polygonal meshes, visible edges often follow special families of curves on a surface to achieve visually pleasing results. Important examples of such families are principal curvature lines, asymptotic lines or geodesics. In a surprisingly big amount of use-cases, these curves form an orthogonal net.
Felix Dellinger, Xinye Li, Hui Wang
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Pearson Correlation and Discrete Wavelet Transform for Crack Identification in Steel Beams
Mathematics, 2022 Discrete wavelet transform is a useful means for crack identification of beam structures. However, its accuracy is severely dependent on the selecting mother wavelet and vanishing moments, which raises a significant challenge in practical structural ...
Morteza Saadatmorad +4 more
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Results in Physics, 2022 This paper focuses on the semi-discrete complex short pulse equation which may describe the ultra-short pulse propagation in optical fiber. First, we study the continuous limit of the semi-discrete complex short pulse equation and establish a certain ...
Zhe Lin, Xiao-Yong Wen
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Discrete Quadratic-Phase Fourier Transform: Theory and Convolution Structures
Entropy, 2022 The discrete Fourier transform is considered as one of the most powerful tools in digital signal processing, which enable us to find the spectrum of finite-duration signals.
Hari M. Srivastava +3 more
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Coherent Dynamics of Quantum Systems with Non-Uniform Fourier Space Excited by Laser Radiation
Zanco Journal of Pure and Applied Sciences, 2022 The algorithm is presented to solve dynamical equations for excitation of molecular models with multiple energy levels. It uses only discrete structures: discrete orthogonal polynomials constructed specially in Fourier space of the probability amplitudes,
Sary Banjak , Vadim Savva
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