Results 31 to 40 of about 1,052,390 (266)

Practical method to solve large least squares problems using Cholesky decomposition

open access: yesGeodesy and Cartography, 2015
In Geomatics, the method of least squares is commonly used to solve the systems of observation equations for a given number of unknowns. This method is basically implemented in case of having number observations larger than the number of unknowns ...
Ghadi Younis
doaj   +1 more source

Symmetric indefinite triangular factorization revealing the rank profile matrix [PDF]

open access: yes, 2018
We present a novel recursive algorithm for reducing a symmetric matrix to a triangular factorization which reveals the rank profile matrix. That is, the algorithm computes a factorization $\mathbf{P}^T\mathbf{A}\mathbf{P} = \mathbf{L}\mathbf{D}\mathbf{L}^
Dumas, Jean-Guillaume, Pernet, Clement
core   +3 more sources

Pivot-Free Block Matrix Inversion [PDF]

open access: yes2006 Eighth International Symposium on Symbolic and Numeric Algorithms for Scientific Computing, 2006
We present a pivot-free deterministic algorithm for the inversion of block matrices. The method is based on the Moore-Penrose inverse and is applicable over certain general classes of rings. This improves on previous methods that required at least one invertible on-diagonal block, and that otherwise required row- or column-based pivoting, disrupting ...
openaire   +3 more sources

Lossy Compression using Adaptive Polynomial Image Encoding

open access: yesAdvances in Electrical and Computer Engineering, 2021
In this paper, an efficient lossy compression approach using adaptive-block polynomial curve-fitting encoding is proposed. The main idea of polynomial curve fitting is to reduce the number of data elements in an image block to a few coefficients.
OTHMAN, S.   +3 more
doaj   +1 more source

Walsh–Hadamard Kernel Feature-Based Image Compression Using DCT with Bi-Level Quantization

open access: yesComputers, 2022
To meet the high bit rate requirements in many multimedia applications, a lossy image compression algorithm based on Walsh–Hadamard kernel-based feature extraction, discrete cosine transform (DCT), and bi-level quantization is proposed in this paper. The
Dibyalekha Nayak   +3 more
doaj   +1 more source

Isospectral flows on a class of finite-dimensional Jacobi matrices

open access: yes, 2012
We present a new matrix-valued isospectral ordinary differential equation that asymptotically block-diagonalizes $n\times n$ zero-diagonal Jacobi matrices employed as its initial condition. This o.d.e.\ features a right-hand side with a nested commutator
Chatterjee, Debasish   +3 more
core   +2 more sources

A block Hankel generalized confluent Vandermonde matrix [PDF]

open access: yes, 2012
Vandermonde matrices are well known. They have a number of interesting properties and play a role in (Lagrange) interpolation problems, partial fraction expansions, and finding solutions to linear ordinary differential equations, to mention just a few ...
Klein, Andre, Spreij, Peter
core   +2 more sources

USE OF THE TREND-FACTOR MODEL TO IMPROVE THE ACCURACY FORECASTS

open access: yesСтатистика и экономика, 2016
In this paper we propose a method toimprove the accuracy of the trend-factormodel on the assumption that the increasein endogenous variable-screens dependnot only on time but also deviations fromtheir trend of exogenous variables, provedby the ...
Irina V. Orlova, Viktor B. Turundaevsky
doaj   +1 more source

Deep Subspace Clustering with Block Diagonal Constraint

open access: yesApplied Sciences, 2020
The deep subspace clustering method, which adopts deep neural networks to learn a representation matrix for subspace clustering, has shown good performance.
Jing Liu, Yanfeng Sun, Yongli Hu
doaj   +1 more source

On the Marginal Distribution of the Diagonal Blocks in a Blocked Wishart Random Matrix [PDF]

open access: yesInternational Journal of Analysis, 2016
Let A be a (m1+m2)×(m1+m2) blocked Wishart random matrix with diagonal blocks of orders m1×m1 and m2×m2. The goal of the paper is to find the exact marginal distribution of the two diagonal blocks of A. We find an expression for this marginal density involving the matrix-variate generalized hypergeometric function.
Víctor Ayala   +3 more
openaire   +3 more sources

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