Results 11 to 20 of about 45,782 (275)
The approximation of a totally positive band matrix by a strictly banded totally positive one [PDF]
Linear Algebra and Its Applications, 1982 AbstractEvery nonsingular totally positive m-banded matrix is shown to be the product of m totally positive one-banded matrices and, therefore, the limit of strictly m-banded totally positive matrices. This result is then extended to (bi)infinite m-banded totally positive matrices with linearly independent rows and columns.
Allan Pinkus
exaly +4 more sources
The Totally Positive Completion Problem: The 3-by-n Case
Special Matrices, 2021 The 3-by-n TP-completable patterns are characterized by identifying the minimal obstructions up to natural symmetries. They are finite in number.
Carter D. +4 more
doaj +2 more sources
Generating Totally Positive Toeplitz Matrix from an Upper Bidiagonal Matrix
Advances in Linear Algebra & Matrix Theory, 2015 In this paper, we construct one of the forms of totally positive Toeplitz matrices from upper or lower bidiagonal totally nonnegative matrix. In addition, some properties related to this matrix involving its factorization are presented.
Mohamed A. Ramadan, Mahmoud M. Abu Murad
exaly +3 more sources
Coherence Matrix Estimation With Total Positivity Regularization for Interferometric Phase Linking
IEEE Journal of Selected Topics in Applied Earth Observations and Remote SensingInterferometric phase linking has become a critical step in distributed scatterer interferometry, yet its performance is significantly affected by inaccuracies in the coherence matrix and its inverse, such as the precision matrix.
Changjun Zhao, Yan Yan, Hanwen Yu
doaj +2 more sources
Totally Positive Wronskian Matrices and Symmetric Functions [PDF]
AxiomsThe elements of the bidiagonal decomposition (BD) of a totally positive (TP) collocation matrix can be expressed in terms of symmetric functions of the nodes. Making use of this result, and studying the relation between Wronskian and collocation matrices
Pablo Díaz +2 more
doaj +3 more sources
Covariance Matrix Estimation under Total Positivity for Portfolio Selection [PDF]
Journal of Financial Econometrics, 2020 Abstract Selecting the optimal Markowitz portfolio depends on estimating the covariance matrix of the returns of N assets from T periods of historical data. Problematically, N is typically of the same order as T, which makes the sample covariance matrix estimator perform poorly, both empirically and theoretically.
Agrawal, Raj, Roy, Uma, Uhler, Caroline
openaire +3 more sources
Gaussian Markov Random Fields and totally positive matrices [PDF]
, 2023 The present paper focuses on the study of the conditions under which the covariance matrix of a multivariate Gaussian distribution is totally positive, paying particular attention to multivariate Gaussian distributions that are Gaussian Markov Random ...
Juan Baz +7 more
core +1 more source
Doubly constrained totally positive line insertion
Special Matrices, 2020 It is shown that in any TP matrix, a line (row or column) with two speci˝ed entries in any positions (and the others appropriately chosen) may be inserted in any position, as long as the two entries are consistent with total positivity.
Johnson Charles R., Allen David W.
doaj +1 more source
The development and evaluation of psychometric properties of the Economic-Psychological Resilience Scale (EPRS) [PDF]
پژوهشهای علوم شناختی و رفتاری, 2022 The present study aimed to develop the Economic-Psychological Resilience Scale (EPRS) and evaluate its psychometric properties. To this end, a descriptive research method was used.
Somayeh Pourehsan +1 more
doaj +1 more source
Progressive Iterative Approximation with Preconditioners
Mathematics, 2020 The progressive iterative approximation (PIA) plays an important role in curve and surface fitting. By using the diagonally compensated reduction of the collocation matrix, we propose the preconditioned progressive iterative approximation (PPIA) to ...
Chengzhi Liu, Zhongyun Liu
doaj +1 more source