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The problem of reducing the bias of maximum likelihood estimator in a general multivariate elliptical regression model is considered. The model is very flexible and allows the mean vector and the dispersion matrix to have parameters in…

Statistics Theory · Mathematics 2016-02-01 Tatiane F. N. Melo , Silvia L. P. Ferrari , Alexandre G. Patriota

The task of estimating a matrix given a sample of observed entries is known as the \emph{matrix completion problem}. Most works on matrix completion have focused on recovering an unknown real-valued low-rank matrix from a random sample of…

Statistics Theory · Mathematics 2014-08-27 Olga Klopp , Jean Lafond , Eric Moulines , Joseph Salmon

Circular targets are widely used in LiDAR-camera extrinsic calibration due to their geometric consistency and ease of detection. However, achieving accurate 3D-2D circular center correspondence remains challenging. Existing methods often…

Computer Vision and Pattern Recognition · Computer Science 2025-11-11 Jiajun Jiang , Xiao Hu , Wancheng Liu , Wei Jiang

This work addresses the finite-time enclosing control problem where a set of followers are deployed to encircle and rotate around multiple moving targets with a predefined spacing pattern in finite time. A novel distributed and continuous…

Optimization and Control · Mathematics 2022-02-02 Liang Zhang

As the spherical object can be seen everywhere, we should extract the ellipse image accurately and fit it by implicit algebraic curve in order to finish the 3D reconstruction. In this paper, we propose a new ellipse fitting algorithm which…

Computer Vision and Pattern Recognition · Computer Science 2015-03-26 Shenghui Xu

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

Computer model calibration is a crucial step in building a reliable computer model. In the face of massive physical observations, a fast estimation for the calibration parameters is urgently needed. To alleviate the computational burden, we…

Statistics Theory · Mathematics 2022-11-24 Shurui Lv , Yan Wang , Jun Yu

In this paper, we study adaptive finite element approximations in a perturbation framework, which makes use of the existing adaptive finite element analysis of a linear symmetric elliptic problem. We prove the convergence and complexity of…

Numerical Analysis · Mathematics 2010-02-05 Lianhua He , Aihui Zhou

Calibration methods have been widely studied in survey sampling over the last decades. Viewing calibration as an inverse problem, we extend the calibration technique by using a maximum entropy method. Finding the optimal weights is achieved…

Methodology · Statistics 2009-09-23 Fabrice Gamboa , Jean-Michel Loubes , Paul Rochet

The ability to obtain reliable point estimates of model parameters is of crucial importance in many fields of physics. This is often a difficult task given that the observed data can have a very high number of dimensions. In order to…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-15 Janis Fluri , Aurelien Lucchi , Tomasz Kacprzak , Alexandre Refregier , Thomas Hofmann

We propose a precise ellipsometric method for the investigation of coherent light with a small ellipticity. The main feature of this method is the use of compensators with phase delays providing the maximum accuracy of measurements for the…

Instrumentation and Detectors · Physics 2017-06-21 Nazar Al-wassiti , Evelina Bibikova , Nataliya Kundikova

Shape-constrained optimization arises in a wide range of problems including distributionally robust optimization (DRO) that has surging popularity in recent years. In the DRO literature, these problems are usually solved via reduction into…

Optimization and Control · Mathematics 2024-06-13 Henry Lam , Zhenyuan Liu , Dashi I. Singham

Identifying the underlying models in a set of data points contaminated by noise and outliers, leads to a highly complex multi-model fitting problem. This problem can be posed as a clustering problem by the projection of higher order…

Computer Vision and Pattern Recognition · Computer Science 2018-08-01 Ruwan Tennakoon , Alireza Sadri , Reza Hoseinnezhad , Alireza Bab-Hadiashar

In this paper, a B-spline chained multiple random matrices representation is proposed to model geometric characteristics of an elongated deformable object. The hyper degrees of freedom structure of the elongated deformable object make its…

Robotics · Computer Science 2020-04-14 Gang Yao , Ryan Saltus , Ashwin Dani

We study the problem of fitting circles (or circular arcs) to data points observed with errors in both variables. A detailed error analysis for all popular circle fitting methods -- geometric fit, Kasa fit, Pratt fit, and Taubin fit -- is…

Methodology · Statistics 2009-07-03 A. Al-Sharadqah , N. Chernov

Absolute pose estimation is a fundamental problem in computer vision, and it is a typical parameter estimation problem, meaning that efforts to solve it will always suffer from outlier-contaminated data. Conventionally, for a fixed…

Computer Vision and Pattern Recognition · Computer Science 2019-12-17 Yinlong Liu , Xuechen Li , Manning Wang , Guang Chen , Zhijian Song , Alois Knoll

Uncertainty in probabilistic classifiers predictions is a key concern when models are used to support human decision making, in broader probabilistic pipelines or when sensitive automatic decisions have to be taken. Studies have shown that…

Machine Learning · Computer Science 2021-09-09 Nicolas Posocco , Antoine Bonnefoy

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

Various packing problems and simulations of hard and soft interacting particles, such as microscopic models of nematic liquid crystals, reduce to calculations of intersections and pair interactions between ellipsoids. When constrained to a…

Soft Condensed Matter · Physics 2022-10-12 Andraž Gnidovec , Anže Božič , Urška Jelerčič , Simon Čopar

This thesis presents important insights and concepts related to the topic of the extraction of geometric primitives from the edge contours of digital images. Three specific problems related to this topic have been studied, viz., polygonal…

Computer Vision and Pattern Recognition · Computer Science 2013-05-17 Dilip K. Prasad