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We use radial estimates for pseudodifferential operators to describe long time evolution of solutions to $ i u_t - P u = f $ where $ P $ is a self-adjoint 0th order pseudodifferential operator satisfying hyperbolic dynamical assumptions and…

Analysis of PDEs · Mathematics 2019-07-31 Semyon Dyatlov , Maciej Zworski

Mode-based model-reduction is used to reduce the degrees of freedom of high dimensional systems, often by describing the system state by a linear combination of spatial modes. Transport dominated phenomena, ubiquitous in technical and…

Numerical Analysis · Mathematics 2020-02-28 Julius Reiss

We analyze temporal approximation schemes based on overlapping domain decompositions. As such schemes enable computations on parallel and distributed hardware, they are commonly used when integrating large-scale parabolic systems. Our…

Numerical Analysis · Mathematics 2018-03-30 Eskil Hansen , Erik Henningsson

We introduce a variational multiscale closure modeling strategy for the numerical stabilization of proper orthogonal decomposition reduced-order models of convection-dominated equations. As a first step, the new model is analyzed and tested…

Numerical Analysis · Mathematics 2015-03-19 Traian iliescu , Zhu Wang

Accurate polyp segmentation remains challenging due to irregular lesion morphologies, ambiguous boundaries, and heterogeneous imaging conditions. While U-Net variants excel at local feature fusion, they often lack explicit mechanisms to…

Image and Video Processing · Electrical Eng. & Systems 2025-02-27 Pu Wang , Huaizhi Ma , Zhihua Zhang , Zhuoran Zheng

The dynamics and thermal structure of the surface layers of stars with outer convection zones can be studied in some detail by means of numerical simulations of time-dependent compressible convection. In an effort to investigate the…

Astrophysics · Physics 2007-05-23 Matthias Steffen

Multiperforated plates exhibit high gradients and a loss of regularity concentrated in a boundary layer for which a direct numerical simulation becomes very expensive. For elliptic equations the solution at some distance of the boundary is…

Analysis of PDEs · Mathematics 2024-08-22 Kersten Schmidt , Sven Pfaff

Sea surface temperature (SST) is uniquely important to the Earth's atmosphere since its dynamics are a major force in shaping local and global climate and profoundly affect our ecosystems. Accurate forecasting of SST brings significant…

Machine Learning · Computer Science 2023-04-20 Xiaohan Li , Gaowei Zhang , Kai Huang , Zhaofeng He

We present a convex approach to probabilistic segmentation and modeling of time series data. Our approach builds upon recent advances in multivariate total variation regularization, and seeks to learn a separate set of parameters for the…

Machine Learning · Statistics 2015-11-17 Matt Wytock , J. Zico Kolter

Problems with localized nonhomogeneous material properties present well-known challenges for numerical simulations. In particular, such problems may feature large differences in length scales, causing difficulties with meshing and…

Numerical Analysis · Mathematics 2021-11-23 Alex Viguerie , Silvia Bertoluzza , Alessandro Veneziani , Ferdinando Auricchio

Shape constraints enable us to reflect prior knowledge in regression settings. A unimodality constraint, for example, can describe the frequent case of a first increasing and then decreasing intensity. Yet, data shapes often exhibit…

Applications · Statistics 2016-06-07 Claudia Köllmann , Katja Ickstadt , Roland Fried

When a solid plate is withdrawn from a partially wetting liquid, a liquid layer dewets the moving substrate. High-speed imaging reveals alternating thin and thick regions in the entrained layer in the transverse direction at steady state.…

Fluid Dynamics · Physics 2020-11-18 Mengfei He

We introduce a new class of growth models, with a surface restructuring mechanism in which impinging particles may dislodge suspended particles, previously aggregated on the same column in the deposit. The flux of these particles is…

Statistical Mechanics · Physics 2013-03-14 J. S. Oliveira Filho , T. J. Oliveira , J. A. Redinz

We study an atmospheric column and its discretization. Because of numerical considerations, the column must be divided into two parts: (1) a surface layer, excluded from the computational domain and parameterized, and (2) the rest of the…

Numerical Analysis · Mathematics 2023-05-17 Simon Clément , Florian Lemarié , Eric Blayo

Pseudo-parabolic equations have been used to model unsaturated fluid flow in porous media. In this paper it is shown how a pseudo-parabolic equation can be upscaled when using a spatio-temporal decomposition employed in the…

Analysis of PDEs · Mathematics 2018-10-09 Arthur J. Vromans , Fons van de Ven , Adrian Muntean

We investigate possibilities to speed up iterative algorithms for non-blind image deconvolution. We focus on algorithms in which convolution with the point-spread function to be deconvolved is used in each iteration, and aim at accelerating…

Computer Vision and Pattern Recognition · Computer Science 2013-04-29 Martin Welk , Martin Erler

Dynamical systems across the sciences, from electrical circuits to ecological networks, undergo qualitative and often catastrophic changes in behavior, called bifurcations, when their underlying parameters cross a threshold. Existing…

Machine Learning · Computer Science 2024-03-22 Noa Moriel , Matthew Ricci , Mor Nitzan

We consider dissipative periodically forced systems and investigate cases in which having information as to how the system behaves for constant dissipation may be used when dissipation varies in time before settling at a constant final…

Dynamical Systems · Mathematics 2015-06-29 James A. Wright , Jonathan H. B. Deane , Michele Bartuccelli , Guido Gentile

Machine learning techniques have been shown to be effective to recognize different phases of matter and produce phase diagrams in the parameter space interested, while they usually require prior labeled data to perform well. Here, we…

Sea surface temperature (SST) is a fundamental determinant of global climate dynamics and economic activity. Reliable projections of future SST patterns depend critically on a rigorous characterization of the underlying spatial random…

Methodology · Statistics 2026-05-07 Leonardo Marchesin , Alessandra Menafoglio , Piercesare Secchi