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We address the problem of constructing elliptic polytopes in R^d, which are convex hulls of finitely many two-dimensional ellipses with a common center. Such sets arise in the study of spectral properties of matrices, asymptotics of long…

Numerical Analysis · Mathematics 2021-07-07 Thomas Mejstrik , Vladimir Yu. Protasov

This paper presents an optimised algorithm implementing the method of slices for analysing the stability of slopes. The algorithm adopts an improved physically based parameterisation of slip lines according to their geometrical…

Computational Engineering, Finance, and Science · Computer Science 2024-12-03 Leonardo Maria Lalicata , Andrea Bressan , Simone Pittaluga , Lorenzo Tamellini , Domenico Gallipoli

With the introduction of machine learning in high-stakes decision making, ensuring algorithmic fairness has become an increasingly important problem to solve. In response to this, many mathematical definitions of fairness have been…

Machine Learning · Computer Science 2024-06-04 Edward Small , Wei Shao , Zeliang Zhang , Peihan Liu , Jeffrey Chan , Kacper Sokol , Flora Salim

This work is devoted to the development and analysis of a linearization algorithm for microscopic elliptic equations, with scaled degenerate production, posed in a perforated medium and constrained by the homogeneous Neumann-Dirichlet…

Numerical Analysis · Mathematics 2020-08-11 Anh-Khoa Vo , Ekeoma Rowland Ijioma , Nhu-Ngoc Nguyen

We present a numerical algorithm for nonnegative matrix factorization (NMF) problems under noisy separability. An NMF problem under separability can be stated as one of finding all vertices of the convex hull of data points. The research…

Machine Learning · Statistics 2015-03-06 Tomohiko Mizutani

The statistical problem of parameter estimation in partially observed hypoelliptic diffusion processes is naturally occurring in many applications. However, due to the noise structure, where the noise components of the different coordinates…

Methodology · Statistics 2018-11-13 Susanne Ditlevsen , Adeline Samson

In a previous paper, I demonstrated the accuracy of simple, precessing, power ellipse (p-ellipse) approximations to orbits of low-to-moderate eccentricity in power-law potentials. Here I explore several extensions of these approximations to…

Astrophysics of Galaxies · Physics 2015-06-23 Curtis Struck

This paper deals with model order selection in context of correlated noise. More precisely, one considers sources embedded in an additive Complex Elliptically Symmetric (CES) noise, with unknown parameters. The main difficultly for…

Methodology · Statistics 2017-10-19 Eugénie Terreaux , Jean-Philippe Ovarlez , Frédéric Pascal

We propose an adaptive finite element algorithm to approximate solutions of elliptic problems whose forcing data is locally defined and is approximated by regularization (or mollification). We show that the energy error decay is…

Numerical Analysis · Mathematics 2022-07-26 Luca Heltai , Wenyu Lei

Automated segmentation of the fetal head in ultrasound images is critical for prenatal monitoring. However, achieving robust segmentation remains challenging due to the poor quality of ultrasound images and the lack of annotated data.…

Computer Vision and Pattern Recognition · Computer Science 2025-08-28 Linkuan Zhou , Zhexin Chen , Yufei Shen , Junlin Xu , Ping Xuan , Yixin Zhu , Yuqi Fang , Cong Cong , Leyi Wei , Ran Su , Jia Zhou , Qiangguo Jin

We study the robustness of classifiers to various kinds of random noise models. In particular, we consider noise drawn uniformly from the $\ell\_p$ ball for $p \in [1, \infty]$ and Gaussian noise with an arbitrary covariance matrix. We…

Machine Learning · Computer Science 2018-06-25 Jean-Yves Franceschi , Alhussein Fawzi , Omar Fawzi

In the context of unfitted finite element discretizations the realization of high order methods is challenging due to the fact that the geometry approximation has to be sufficiently accurate. Recently a new unfitted finite element method…

Numerical Analysis · Mathematics 2017-09-01 Christoph Lehrenfeld , Arnold Reusken

Subspace-based signal processing techniques, such as the Estimation of Signal Parameters via Rotational Invariant Techniques (ESPRIT) algorithm, are popular methods for spectral estimation. These algorithms can achieve the so-called…

Information Theory · Computer Science 2024-10-29 Zhiyan Ding , Ethan N. Epperly , Lin Lin , Ruizhe Zhang

Inferring unknown conic sections on the basis of noisy data is a challenging problem with applications in computer vision. A major limitation of the currently available methods for conic sections is that estimation methods rely on the…

Methodology · Statistics 2020-03-05 Subharup Guha , Sujit K. Ghosh

In this paper, neural network approximation methods are developed for elliptic partial differential equations with multi-frequency solutions. Neural network work approximation methods have advantages over classical approaches in that they…

Numerical Analysis · Mathematics 2023-11-08 Deok-Kyu Jang , Hyea Hyun Kim , Kyungsoo Kim

Precision weak gravitational lensing experiments require measurements of galaxy shapes accurate to <1 part in 1000. We investigate measurement biases, noted by Voigt and Bridle (2009) and Melchior et al. (2009), that are common to shape…

Instrumentation and Methods for Astrophysics · Physics 2015-05-18 Gary M. Bernstein

In this paper, we propose a new ellipsoidal mixture model. This model is based a new probability density function belonging to the family of elliptical distributions and designed to model points spread around an ellipsoidal surface. Then,…

Methodology · Statistics 2023-09-22 Denis Brazey , Antoine Godichon-Baggioni , Bruno Portier

Quality-Diversity optimisation algorithms enable the evolution of collections of both high-performing and diverse solutions. These collections offer the possibility to quickly adapt and switch from one solution to another in case it is not…

Neural and Evolutionary Computing · Computer Science 2023-04-26 Manon Flageat , Antoine Cully

We reconsider the ellipsoid method for linear inequalities. Using the ellipsoid representation of Burrell and Todd, we show the method can be viewed as coordinate descent on the volume of an enclosing ellipsoid, or on a potential function,…

Optimization and Control · Mathematics 2023-09-27 Michael J. Todd

Calibration of devices with different modalities is a key problem in robotic vision. Regular spatial objects, such as planes, are frequently used for this task. This paper deals with the automatic detection of ellipses in camera images, as…

Computer Vision and Pattern Recognition · Computer Science 2020-02-25 Levente Hajder , Tekla Tóth , Zoltán Pusztai