Results 31 to 40 of about 1,052,390 (266)
Practical method to solve large least squares problems using Cholesky decomposition
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]
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]
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
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
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
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]
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
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
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]
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