Results 51 to 60 of about 2,001,462 (190)
Frequency‐dependent contraction rates for the Bayesian method to the inverse source problem
Transactions of the London Mathematical Society, Volume 13, Issue 1, December 2026.Abstract This paper addresses an inverse source problem for acoustic waves in a range of frequencies. Our study has two main goals. First, although the problem is severely ill‐posed with a logarithmic stability estimate, we demonstrate, through careful analysis of the forward map's singular values, that increasing the frequency range enhances stability,
Pu‐Zhao Kow, Jenn‐Nan Wang
wiley +1 more source
Orthogonal projections on martingale $H^{1}$ spaces of two parameters
Illinois Journal of Mathematics, 1994 Given natural numbers \(n\) and \(i\) so that \(1\leq i\leq 2^ n\), let \((n, i)\) denote the ``dyadic interval'' \(\left[{i- 1\over 2^ n}, {i\over 2^ n}\right]\), \(h_{(n, i)}\) the \(L^ \infty\)-normalized Haar function supported on \((n, i)\), and \(h_{(n, i)\times (m, j)}(s, t)= h_{(n, i)}(s) h_{(m, j)}(t)\) (for \(s,t\in [0, 1]\)). If \(F= \sum c_{
openaire +3 more sources
Stochastic Gradient Descent in High Dimensions for Multi‐Spiked Tensor PCA
Communications on Pure and Applied Mathematics, Volume 79, Issue 10, Page 2291-2369, October 2026.ABSTRACT We study the high‐dimensional dynamics of online stochastic gradient descent (SGD) for the multi‐spiked tensor model. This multi‐index model arises from the tensor principal component analysis (PCA) problem with multiple spikes, where the goal is to estimate the unknown signal vectors within the N$N$‐dimensional unit sphere through maximum ...
Gérard Ben Arous +2 more
wiley +1 more source
Survival Analysis of Fatigue Lifetime in Aged Elastomers Using Weibull and Cox Regression Models
Fatigue &Fracture of Engineering Materials &Structures, Volume 49, Issue 9, Page 3854-3873, September 2026.ABSTRACT Fatigue tests conducted on elastomers inherently exhibit significant variability. Aging may induce stiffening and embrittlement, leading to premature failures outside the specimen gauge length and resulting in right‐censored data. Combined with the limited number of specimens, this leads to large uncertainties in fatigue lifetime estimation ...
M. Caillat +4 more
wiley +1 more source
Liver International, Volume 46, Issue 9, September 2026.ABSTRACT Background & Aims Prognostic non‐invasive tests for liver‐related events in compensated cirrhosis are needed. Endotrophin, a fragment of type VI alpha 3 collagen involved in fibrosis and inflammation, has been associated with adverse outcomes in several chronic diseases.
Thomas Wiggers +7 more
wiley +1 more source
Bayesian Inference for Multivariate Monotone Densities
Scandinavian Journal of Statistics, Volume 53, Issue 3, Page 1206-1229, September 2026.ABSTRACT We consider a nonparametric Bayesian approach to estimation and testing for a multivariate monotone density. Instead of following the conventional Bayesian approach of imposing a prior that satisfies the monotonicity restriction, we place a prior on the step heights via binning and a Dirichlet distribution. The resulting posterior distribution
Kang Wang, Subhashis Ghosal
wiley +1 more source
Invariant Measure and Universality of the 2D Yang–Mills Langevin Dynamic
Communications on Pure and Applied Mathematics, Volume 79, Issue 8, Page 1973-2102, August 2026.ABSTRACT We prove that the Yang–Mills (YM) measure for the trivial principal bundle over the two‐dimensional torus, with any connected, compact structure group, is invariant for the associated renormalised Langevin dynamic. Our argument relies on a combination of regularity structures, lattice gauge‐fixing and Bourgain's method for invariant measures ...
Ilya Chevyrev, Hao Shen
wiley +1 more source
Journal of Applied Econometrics, Volume 41, Issue 5, Page 549-566, August 2026.ABSTRACT We present four novel tests of equal predictive accuracy and encompassing á Pitarakis (2023, 2025) for factor‐augmented regressions. Factors are estimated using cross‐section averages (CAs) of grouped series and our theoretical findings are empirically relevant: asymptotic normality, robustness to an overspecification of the number of factors,
Alessandro Morico, Ovidijus Stauskas
wiley +1 more source
A Joint Test of Unconfoundedness and Common Trends
Journal of Applied Econometrics, Volume 41, Issue 5, Page 684-709, August 2026.ABSTRACT We introduce an overidentification test of two alternative assumptions to identify the average treatment effect on the treated in a two‐period panel data setting: unconfoundedness and common trends. Under unconfoundedness, treatment assignment and post‐treatment outcomes are independent, conditional on control variables and pre‐treatment ...
Martin Huber, Eva‐Maria Oeß
wiley +1 more source
Stop Using Limiting Stimuli as a Measure of Sensitivities of Energetic Materials
Propellants, Explosives, Pyrotechnics, Volume 51, Issue 8, Page 1386-1400, August 2026.ABSTRACT Accurately estimating the sensitivity of explosive materials is a potentially life‐saving task that requires standardised protocols across nations. One of the most widely applied procedures worldwide is the so‐called ‘1‐In‐6’ test from the United Nations (UN) Manual of Tests in Criteria, which estimates a ‘limiting stimulus’ for a material. In
Dennis Christensen, Geir Petter Novik
wiley +1 more source