Results 101 to 110 of about 53,939 (225)

Automated Bandwidth Selection for Inference in Linear Models With Time‐Varying Coefficients

Journal of Time Series Analysis, EarlyView.
ABSTRACT The problem of selecting the smoothing parameter, or bandwidth, for kernel‐based estimators of time‐varying coefficients in linear models with possibly endogenous explanatory variables is considered. We examine automated bandwidth selection by means of cross‐validation, a nonparametric variant of Akaike's information criterion, and bootstrap ...
Charisios Grivas, Zacharias Psaradakis
wiley   +1 more source

On Best Multiplier Approximation of k-Monotone by Trigonometric Polynomial

Al-Mustansiriyah Journal of Science
The main goal of this paper is to study the degree of the best multiplier approximation of monotone unbounded functions in L_(p,λ_n)-space on the closed interval [-π,π] by means of K-functional, which we represented with, K(f,L_(p,λ_n ),W_(p,λ_n)^1,W ̃_(
Saheb K. Al-Saidy, Hasan W. Maktoof, Abdul Khaleq O. Mazeel, Baba Galadima Agaie   +3 more
doaj   +1 more source

On the approximation by trigonometric polynomials in weighted Lorentz spaces

Journal of Function Spaces and Applications, 2010
We obtain estimates of structural characteristics of 2π-periodic functions by the best trigonometric approximations in weighted Lorentz spaces, and show that the order of generalized modulus of smoothness depends not only on the rate of the best ...
Vakhtang Kokilashvili, Yunus E. Yildirir
doaj   +1 more source

The Accuracy Smoothness Dilemma in Prediction: A Novel Multivariate M‐SSA Forecast Approach

Journal of Time Series Analysis, EarlyView.
ABSTRACT Forecasting presents a complex estimation challenge, as it involves balancing multiple, often conflicting, priorities and objectives. Conventional forecast optimization methods typically emphasize a single metric, such as minimizing the mean squared error (MSE), which may neglect other crucial aspects of predictive performance. To address this
Marc Wildi
wiley   +1 more source

Automated Three‐Dimensional Reflection Traveltime Modelling to Extract 3D Dipping Layer Geometries

Geophysical Prospecting, Volume 74, Issue 4, May 2026.
ABSTRACT Steep geological structures are critical for improved understanding of tectonic processes and fluid circulation, particularly in crystalline settings. However, accurately determining their geometry at depth remains a challenge for conventional 2D surveys.
Samuel Zappalá, Michael Westgate, Alireza Malehmir   +2 more
wiley   +1 more source

Omnibus goodness‐of‐fit tests for univariate continuous distributions based on trigonometric moments

Statistica Neerlandica, Volume 80, Issue 2, May 2026.
ABSTRACT We propose a new omnibus goodness‐of‐fit test based on trigonometric moments of probability‐integral‐transformed data. The test builds on the framework of the LK test introduced by Langholz and Kronmal [J. Amer. Statist. Assoc. 86 (1991), 1077–1084], but fully exploits the covariance structure of the associated trigonometric statistics.
Alain Desgagné, Frédéric Ouimet
wiley   +1 more source

Robust Inverse Material Design With Physical Guarantees Using the Voigt‐Reuss Net

International Journal for Numerical Methods in Engineering, Volume 127, Issue 7, 15 April 2026.
ABSTRACT We apply the Voigt‐Reuss net, a spectrally normalized neural surrogate introduced in [38], for forward and inverse mechanical homogenization with a key guarantee that all predicted effective stiffness tensors satisfy Voigt‐Reuss bounds in the Löwner sense during training, inference, and gradient‐driven optimization.
Sanath Keshav, Felix Fritzen
wiley   +1 more source

An Explicit, Compact, and Rotation‐Agnostic Formulation for Equivalent Nodal Loads for Point‐Loaded Beams

International Journal for Numerical Methods in Engineering, Volume 127, Issue 7, 15 April 2026.
ABSTRACT In time‐marching dynamical simulations, treatment of contact forces in deformable bodies represented by finite element meshes requires a compromise between simulation fidelity and computational costs. External forces directly evaluated at the mesh nodes offer better computational performance at the cost of modelling fidelity.
Alexander R. Schock, Mark Reckzin, Robert G. Langlois   +2 more
wiley   +1 more source

The Approximation of Functions of Several Variables with Bounded p-Fluctuation by Polynomials in the Walsh System

Mathematics
This paper presents direct and inverse theorems concerning the approximation of functions of several variables with bounded p-fluctuation using Walsh polynomials.
Talgat Akhazhanov, Dauren Matin, Zhuldyz Baituyakova   +2 more
doaj   +1 more source

Isoperimetric inequalities on slabs with applications to cubes and Gaussian slabs

Communications on Pure and Applied Mathematics, Volume 79, Issue 4, Page 1012-1072, April 2026.
Abstract We study isoperimetric inequalities on “slabs”, namely weighted Riemannian manifolds obtained as the product of the uniform measure on a finite length interval with a codimension‐one base. As our two main applications, we consider the case when the base is the flat torus R2/2Z2$\mathbb {R}^2 / 2 \mathbb {Z}^2$ and the standard Gaussian measure
Emanuel Milman
wiley   +1 more source