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A new semiparametric estimation approach for large dynamic covariance matrices with multiple conditioning variables [PDF]
Journal of Econometrics, 2019 This paper studies the estimation of large dynamic covariance matrices with multiple conditioning variables. We introduce an easy-to-implement semiparametric method to estimate each entry of the covariance matrix via model averaging marginal regression ...
Jia Chen, Degui Li, Oliver Linton
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Tridiagonal matrices: Invertibility and conditioning
Linear Algebra and Its Applications, 1992 The authors consider conditioning of a tridiagonal matrix \(T\), normalized to have unit diagonal, \(\tau_ 1, \dots, \tau_{n-1}\) on the superdiagonal and \(\sigma_ 1, \dots, \sigma_{n-1}\) on the subdiagonal. The cases \(\sigma_ i \tau_ i > 0\) for all \(i\), and \(\sigma_ i \tau_ i < 0\) for all \(i\), are analyzed in detail. An exact formula for the
Luigi Brugnano, D Trigiante
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Conditioning and accurate computations with Pascal matrices
Journal of Computational and Applied Mathematics, 2013 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Pedro Alonso +2 more
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Conditioning of Partial Nonuniform Fourier Matrices with Clustered Nodes [PDF]
SIAM Journal on Matrix Analysis and Applications, 2020 We prove sharp lower bounds for the smallest singular value of a partial Fourier matrix with arbitrary "off the grid" nodes (equivalently, a rectangular Vandermonde matrix with the nodes on the unit circle), in the case when some of the nodes are ...
Dmitry Batenkov +3 more
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Combined matrices and conditioning
Applied Mathematics and Computation, 2021 [EN] In this work, we study a lower bound of the condition number of a matrix by its combined matrix. In particular, we construct a special combined matrix in such a way that the sums of its columns are lower bounds of the condition number of the matrix. Cases for special matrices as unitary matrices are considered.
Rafael Bru +2 more
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Evaluation of several conditioning matrices for the management of radioactive metal beryllium wastes
Journal of Nuclear Materials, 2021 Pauline Bouhier +5 more
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Non-continuous Percoll density gradient: a method for purifying Mycobacterium tuberculosis from dust [PDF]
BMC Infectious DiseasesBackground Mycobacterium tuberculosis (MTB) retains infectivity for 8–10 days in dry dust and survives up to 6–8 months in humid environments. Dust accumulated in ventilation systems and air-conditioning filters serves as a critical reservoir for MTB ...
Lan Wen +9 more
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Conditioning analysis of positive definite matrices by approximate factorizations
Journal of Computational and Applied Mathematics, 1989 The conditioning analysis of positive definite matrices by approximate LU factorizations is usually reduced to that of Stieltjes matrices (or even to more specific classes of matrices) by means of perturbation arguments like spectral equivalence. We show
Robert Beauwens
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Condition Number Estimation of Preconditioned Matrices
PLOS ONE, 2015 The present paper introduces a condition number estimation method for preconditioned matrices. The newly developed method provides reasonable results, while the conventional method which is based on the Lanczos connection gives meaningless results. The Lanczos connection based method provides the condition numbers of coefficient matrices of systems of ...
Noriyuki Kushida
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