Results 81 to 90 of about 562,872 (260)
On the existence of complex Hadamard submatrices of the Fourier matrices
Demonstratio Mathematica, 2019 We use a theorem of Lam and Leung to prove that a submatrix of a Fourier matrix cannot be Hadamard for particular cases when the dimension of the submatrix does not divide the dimension of the Fourier matrix.
Bond Bailey Madison +2 more
doaj +1 more source
On D4t ‐Cocyclic Hadamard Matrices
, 2016 In this paper, we describe some necessary and sufficient conditions for a set of coboundaries to yield a cocyclic Hadamard matrix over the dihedral group D4t .
V. Álvarez +5 more
semanticscholar +1 more source
A goodness‐of‐fit test for regression models with discrete outcomes
Canadian Journal of Statistics, EarlyView.Abstract Regression models are often used to analyze discrete outcomes, but classical goodness‐of‐fit tests such as those based on the deviance or Pearson's statistic can be misleading or have little power in this context. To address this issue, we propose a new test, inspired by the work of Czado et al.
Lu Yang +2 more
wiley +1 more source
Quenching the Hubbard Model: Comparison of Nonequilibrium Green's Function Methods
Contributions to Plasma Physics, EarlyView.ABSTRACT We benchmark nonequilibrium Green's function (NEGF) approaches for interaction quenches in the half‐filled Fermi–Hubbard model in one and two dimensions. We compare fully self‐consistent two‐time Kadanoff–Baym equations (KBE), the generalized Kadanoff–Baym ansatz (GKBA), and the recently developed NEGF‐based quantum fluctuations approach (NEGF‐
Jan‐Philip Joost +3 more
wiley +1 more source
Enhancing Volatility Prediction: A Wavelet‐Based Hierarchical Forecast Reconciliation Approach
Journal of Forecasting, EarlyView.ABSTRACT Forecasting realized volatility (RV) has been widely studied, with numerous techniques developed to enhance predictive accuracy. Among these techniques, the use of RV decompositions based on intraday asset returns has been applied. However, the use of a frequency‐based decomposition, which provides unique insights into the dynamics of RV ...
Adam Clements, Ajith Perera
wiley +1 more source
The expected adjacency and modularity matrices in the degree corrected stochastic block model
Special Matrices, 2018 We provide explicit expressions for the eigenvalues and eigenvectors of matrices that can be written as the Hadamard product of a block partitioned matrix with constant blocks and a rank one matrix.
Fasino Dario, Tudisco Francesco
doaj +1 more source
3D Surface Profiling via Direct End‐to‐End Regression With a Photonic Geometric Sensor
Laser &Photonics Reviews, EarlyView.Measurements of microscale surface patterns are essential for quality control across semiconductor and biomedical industries, yet the development of miniaturized, intelligent systems remains constrained by the complexity and bulkiness of conventional benchtop metrology.
Ziyao Zhang +13 more
wiley +1 more source
Mathematical Methods in the Applied Sciences, EarlyView.ABSTRACT We study eigenvalue problems for the de Rham complex on varying three‐dimensional domains. Our analysis includes the Helmholtz equation as well as the Maxwell system with mixed boundary conditions and non‐constant coefficients. We provide Hadamard‐type formulas for the shape derivatives under weak regularity assumptions on the domain and its ...
Pier Domenico Lamberti +2 more
wiley +1 more source
Phase‐Pole‐Free Images and Smooth Coil Sensitivity Maps by Regularized Nonlinear Inversion
Magnetic Resonance in Medicine, EarlyView.ABSTRACT Purpose Phase singularities are a common problem in image reconstruction with auto‐calibrated sensitivities due to an inherent ambiguity of the estimation problem. The purpose of this work is to develop a method for detecting and correcting phase poles in non‐linear inverse (NLINV) reconstruction of MR images and coil sensitivity maps ...
Moritz Blumenthal, Martin Uecker
wiley +1 more source
A new scheme for the solution of the nonlinear Caputo–Hadamard fractional differential equations
Alexandria Engineering JournalThis paper introduces a numerical approach by generalizing Legendre wavelets for solving nonlinear Caputo–Hadamard fractional differential equations. The methodology involves the extension of classical Legendre wavelets, namely the generalized Legendre ...
Umer Saeed, Mujeeb ur Rehman
doaj +1 more source