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In this paper we provide a categorisation and implementation of digital ink features for behaviour characterisation. Based on four feature sets taken from literature, we provide a categorisation in different classes of syntactic and…

Computer Vision and Pattern Recognition · Computer Science 2018-10-10 Alexander Prange , Michael Barz , Daniel Sonntag

Approximate solution of the ensemble representability problem for density operators of arbitrary order is obtained. This solution is closely related to the ``Q condition'' of A.J.Coleman. The representability conditions are formulated in…

Chemical Physics · Physics 2007-05-23 A. I. Panin

The author has introduced in a recent paper a new class of operators, called co-Toeplitz operators, with symbols in a co-algebra. This is the categorical dual to Toeplitz operators which have symbols in an algebra. The mapping from a symbol…

Mathematical Physics · Physics 2018-10-30 Stephen Bruce Sontz

The present paper deals with the spectral and the oscillation properties of a linear pencil $A-\lambda B$. Here $A$ and $B$ are linear operators generated by the differential expressions $(py")"$ and $-y"+ cry$, respectively. In particular,…

Spectral Theory · Mathematics 2011-12-13 J. Ben Amara , A. A. Shkalikov , A. A. Vladimirov

This letter announces and summarizes results obtained in arXiv:1111.5051 and considers several natural extensions. The aforementioned paper proposes a procedure to reconstruct coefficients in a second-order, scalar, elliptic equation from…

Analysis of PDEs · Mathematics 2012-03-07 Guillaume Bal , Gunther Uhlmann

The quadratic programming over one inequality quadratic constraint (QP1QC) is a very special case of quadratically constrained quadratic programming (QCQP) and attracted much attention since early 1990's. It is now understood that, under…

Optimization and Control · Mathematics 2016-11-25 Yong Hsia , Gang-Xuan Lin , Ruey-Lin Sheu

We study the spectral properties of positive absolutely minimum attaining operators defined on infinite dimensional complex Hilbert spaces and using that derive a characterization theorem for such type of operators. We construct several…

Spectral Theory · Mathematics 2017-11-07 J. Ganesh , G. Ramesh , D. Sukumar

Motivated by a quaternionic formulation of quantum mechanics, we discuss quaternionic and complex linear differential equations. We touch only a few aspects of the mathematical theory, namely the resolution of the second order differential…

Mathematical Physics · Physics 2015-06-26 S. De Leo , G. C. Ducati

Why do we need quantization to describe vision? What are the quadrature operators of the electromagnetic field? Is it possible to measure them? What are the characteristic functions useful for? In this brief tutorial we provide the…

Quantum Physics · Physics 2021-10-08 Stefano Olivares

We develop direct and inverse scattering theory for one-dimensional Schroedinger operators with steplike potentials which are asymptotically close to different finite-gap periodic potentials on different half-axes. We give a complete…

Spectral Theory · Mathematics 2008-11-20 Anne Boutet de Monvel , Iryna Egorova , Gerald Teschl

Characteristic formulae give a complete logical description of the behaviour of processes modulo some chosen notion of behavioural semantics. They allow one to reduce equivalence or preorder checking to model checking, and are exactly the…

Logic in Computer Science · Computer Science 2026-03-27 Luca Aceto , Antonis Achilleos , Aggeliki Chalki , Anna Ingolfsdottir

An ordinary differential operator of the fourth order with coefficients converging at infinity sufficiently rapidly to constant limits is considered. Scattering theory for this operator is developed in terms of special solutions of the…

Spectral Theory · Mathematics 2008-02-05 D. R. Yafaev

Translated into the language of representations of quivers, a challenge in matrix pencil theory is to find sufficient and necessary conditions for a Kronecker representation to be a subfactor of another Kronecker representation in terms of…

Representation Theory · Mathematics 2007-05-23 Yang Han

This paper studies the problem of reconstructing binary matrices that are only accessible through few evaluations of their discrete X-rays. Such question is prominently motivated by the demand in material science for developing a tool for…

Combinatorics · Mathematics 2007-05-23 Alberto Del Lungo , Andrea Frosini , Maurice Nivat , Laurent Vuillon

In this paper, we briefly explain the spectral expansion problem for differential operators defined on the entire real line, generated by a differential expression with periodic, complex-valued coefficients.

Spectral Theory · Mathematics 2025-10-15 O. A. Veliev

Two types of Poisson pencils connected to classical R-matrices and their quantum counterparts are considered. A representation theory of the quantum algebras related to some symmetric orbits in $sl(n)^*$ is constructed. A twisted version of…

q-alg · Mathematics 2008-02-03 D. Gurevich , J. Donin , V. Rubstov

By Fagin's Theorem, NP contains precisely those problems that can be described by formulas starting with an existential second-order quantifier, followed by only first-order quantifiers (ESO formulas). Subsequent research refined this…

Logic in Computer Science · Computer Science 2023-10-03 Max Bannach , Florian Chudigiewitsch , Till Tantau

We investigate a family of bilevel imaging learning problems where the lower-level instance corresponds to a convex variational model involving first- and second-order nonsmooth sparsity-based regularizers. By using geometric properties of…

Optimization and Control · Mathematics 2023-03-21 Juan Carlos De los Reyes

This paper is concerned with the inverse problem of determining the shape of penetrable periodic scatterers from scattered field data. We propose a sampling method with a novel indicator function for solving this inverse problem. This…

Numerical Analysis · Mathematics 2023-05-24 Dinh-Liem Nguyen , Kale Stahl , Trung Truong

The completeness of the group classification of systems of two linear second-order ordinary differential equations with constant coefficients is delineated in the paper. The new cases extend what has been done in the literature. These cases…

Classical Analysis and ODEs · Mathematics 2013-03-27 S. V. Meleshko , S. Moyo G. F. Oguis