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We have observed a common problem of solving for the marginal covariance of parameters introduced in new observations. This problem arises in several situations, including augmenting parameters to a Kalman filter, and computing weight for…

Signal Processing · Electrical Eng. & Systems 2020-05-12 Jianzhu Huai

A key observation underlying this paper is the fact that the range invariance condition for convergence of regularization methods for nonlinear ill-posed operator equations -- such as coefficient identification in partial differential…

Numerical Analysis · Mathematics 2023-07-26 Barbara Kaltenbacher

In this article, we present a new approach to averaging in non-Hamiltonian systems with periodic forcing. The results here do not depend on the existence of a small parameter. In fact, we show that our averaging method fits into an…

Dynamical Systems · Mathematics 2010-06-15 Mickaël D. Chekroun , Michael Ghil , Jean Roux , Ferenc Varadi

Choosing the regularization parameter for inverse problems is of major importance for the performance of the regularization method. We will introduce a fast version of the Lepskij balancing principle and show that it is a valid parameter…

Numerical Analysis · Mathematics 2010-08-04 Frank Bauer

To study asymptotic structures, we regularize Einstein's field equations by means of conformal transformations. The conformal factor is chosen so that it carries a dimensional scale that captures crucial asymptotic features. By choosing a…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Niklas Rohr , Claes Uggla

Stability of stationary solutions of parabolic equations is conventionally studied by linear stability analysis, Lyapunov functions or lower and upper functions. We discuss here another approach based on differential inequalities written…

Functional Analysis · Mathematics 2012-06-26 A. G. Ramm , V. Volpert

In this paper we describe a covariant canonical formalism for a free time-like (massive) as well as space-like (tachyonic) particle in the framework of nonstandard synchronization scheme. In this scheme one is able to introduce absolute…

High Energy Physics - Theory · Physics 2007-05-23 Jakub Rembielinski , Pawel Caban

Nonrelativistic conformal groups, indexed by l=N/2, are analyzed. Under the assumption that the "mass" parametrizing the central extension is nonvanishing the coadjoint orbits are classified and described in terms of convenient variables.…

Mathematical Physics · Physics 2015-06-04 K. Andrzejewski , J. Gonera , P. Maslanka

We consider the problem of conformal prediction under covariate shift. Given labeled data from a source domain and unlabeled data from a covariate shifted target domain, we seek to construct prediction sets with valid marginal coverage in…

Machine Learning · Statistics 2025-07-02 Sunay Joshi , Shayan Kiyani , George Pappas , Edgar Dobriban , Hamed Hassani

In recent years, data dimensionality has increasingly become a concern, leading to many parameter and dimension reduction techniques being proposed in the literature. A parameter-wise co-clustering model, for data modelled via continuous…

Machine Learning · Statistics 2020-10-01 M. P. B. Gallaugher , C. Biernacki , P. D. McNicholas

We review curvature-based hyperbolic forms of the evolution part of the Cauchy problem of General Relativity that we have obtained recently. We emphasize first order symmetrizable hyperbolic systems possessing only physical characteristics.

General Relativity and Quantum Cosmology · Physics 2012-08-27 Yvonne Choquet-Bruhat , James W. York, , Arlen Anderson

The aim of this paper is to establish a nonlinear variational approach to the reconstruction of moving density images from indirect dynamic measurements. Our approach is to model the dynamics as a hyperelastic deformation of an initial…

Numerical Analysis · Mathematics 2015-12-01 Martin Burger , Jan Modersitzki , Sebastian Suhr

High-dimensional compositional data arise naturally in many applications such as metagenomic data analysis. The observed data lie in a high-dimensional simplex, and conventional statistical methods often fail to produce sensible results due…

Methodology · Statistics 2016-01-19 Yuanpei Cao , Wei Lin , Hongzhe Li

We discuss how the presence of a suitable symmetry can guarantee the perturbative linearizability of a dynamical system - or a parameter dependent family - via the Poincar\'e Normal Form approach. We discuss this at first formally, and…

Mathematical Physics · Physics 2015-06-17 D. Bambusi , G. Cicogna , G. Gaeta , G. Marmo

The well-known solution theory for (systems of) linear ordinary differential equations undergoes significant changes when introducing an additional real parameter. Properties like the existence of fundamental sets of solutions or…

Classical Analysis and ODEs · Mathematics 2021-03-22 Vyacheslav M. Boyko , Michael Kunzinger , Roman O. Popovych

We consider the problem of asymptotic convergence to invariant sets in interconnected nonlinear dynamic systems. Standard approaches often require that the invariant sets be uniformly attracting. e.g. stable in the Lyapunov sense. This,…

Dynamical Systems · Mathematics 2007-05-23 Ivan Tyukin , Erik Steur , Henk Nijmeijer , Cees van Leeuwen

We review the recently developed relation between the traditional algebraic approach to conformal field theories and the more recent probabilistic approach based on stochastic Loewner evolutions. It is based on implementing random conformal…

High Energy Physics - Theory · Physics 2007-05-23 Denis Bernard

Compositional data arise in many real-life applications and versatile methods for properly analyzing this type of data in the regression context are needed. When parametric assumptions do not hold or are difficult to verify, non-parametric…

Methodology · Statistics 2023-09-07 Michail Tsagris , Abdulaziz Alenazi , Connie Stewart

We describe and analyse Levenberg-Marquardt methods for solving systems of nonlinear equations. More specifically, we propose an adaptive formula for the Levenberg-Marquardt parameter and analyse the local convergence of the method under…

Molecular Networks · Quantitative Biology 2019-02-22 Masoud Ahookhosh , Francisco J. Aragón Artacho , Ronan M. T. Fleming , Phan T. Vuong

Many common loss functions such as mean-squared-error, cross-entropy, and reconstruction loss are unnecessarily rigid. Under a probabilistic interpretation, these common losses correspond to distributions with fixed shapes and scales. We…

Machine Learning · Computer Science 2020-10-05 Mark Hamilton , Evan Shelhamer , William T. Freeman