Results 41 to 50 of about 5,774,152 (370)
A Cautionary Note on Generalized Linear Models for Covariance of Unbalanced Longitudinal Data [PDF]
, 2012 Missing data in longitudinal studies can create enormous challenges in data analysis when coupled with the positive-definiteness constraint on a covariance matrix.
Chen, Min +3 more
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On some positive definite functions [PDF]
Positivity, 2015 We study the function $(1 - \|x\|)\slash (1 - \|x\|^r),$ and its reciprocal, on the Euclidean space $\mathbb{R}^n,$ with respect to properties like being positive definite, conditionally positive definite, and infinitely divisible.
Rajendra Bhatia +2 more
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Многоязычие в образовательном пространстве, 2021 The purpose of this study is to conduct a comparative typological analysis of the means of expressing the category “Definiteness / Indefiniteness” in German, Tatar and Russian languages and, building on this analysis, to develop a system of exercises ...
A. A. Sibgatullina
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Computational geometry of positive definiteness
Linear Algebra and its Applications, 2012 AbstractIn matrix computations, such as in factoring matrices, Hermitian and, preferably, positive definite elements are occasionally required. Related problems can often be cast as those of existence of respective elements in a matrix subspace. For two dimensional matrix subspaces, first results in this regard are due to Finsler.
Seiskari, Otto, Huhtanen, Marko
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A new positive definite geometric mean of two positive definite matrices
Linear Algebra and its Applications, 1997 AbstractWe introduce and study a new positive definite (in certain singular cases, positive semidefinite) geometric mean of two positive definite (under certain conditions, positive semidefinite) matrices.
Vlastimil Pták, Miroslav Fiedler
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On Recursive Edit Distance Kernels with Application to Time Series Classification [PDF]
, 2014 This paper proposes some extensions to the work on kernels dedicated to string or time series global alignment based on the aggregation of scores obtained by local alignments.
Gibet, Sylvie, Marteau, Pierre-François
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Extension of positive definite functions
Journal of Mathematical Analysis and Applications, 2015 Let $ \subset\mathbb{R}^n$ be an open, connected subset of $\mathbb{R}^n$, and let $F\colon - \to\mathbb{C}$, where $ - =\{x-y\colon x,y\in \}$, be a continuous positive definite function. We give necessary and sufficient conditions for $F$ to have an extension to a continuous positive definite function defined on the entire Euclidean space ...
Jorgensen, Palle, Niedzialomski, Robert
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Negative volatility spillovers in the unrestricted ECCC-GARCH model [PDF]
, 2009 Copyright @ 2010 Cambridge University Press.This paper considers a formulation of the extended constant or time-varying conditional correlation GARCH model that allows for volatility feedback of either the positive or negative sign.
Conrad, C, Karanasos, M
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Remedies for Misapplications of Sylvester’s Criterion: A Pedagogic Illustration
Spreadsheets in Education, 2021 Sylvester’s criterion, which verifies the positive definiteness of any real symmetric matrix by examining the signs of all leading principal minors, is an excellent analytical tool.
Clarence C.Y. Kwan
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Positive definiteness and positive differences
Journal of Combinatorial Theory, Series A, 1972 AbstractA previous inequality [2] in certain context, which holds in the application to the monotonicity of correlations in classical discrete Heisenberg ferromagnets with 2-dimensional spin [3], is extended to positive definiteness of a function on a group.
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