Results 31 to 40 of about 54,917 (203)

Sparse Sums of Positive Semidefinite Matrices [PDF]

ACM Transactions on Algorithms, 2015
Many fast graph algorithms begin by preprocessing the graph to improve its sparsity. A common form of this is spectral sparsification, which involves removing and reweighting the edges of the graph while approximately preserving its spectral properties. This task has a more general linear algebraic formulation in terms of approximating sums of rank-one
de Carli Silva, Marcel K., Harvey, Nicholas J. A., Sato, Cristiane M.   +2 more
openaire   +3 more sources

Efficient Positive Semidefinite Matrix Approximation by Iterative Optimisations and Gradient Descent Method

Risks
We devise two algorithms for approximating solutions of PSDisation, a problem in actuarial science and finance, to find the nearest valid correlation matrix that is positive semidefinite (PSD).
Vali Asimit, Runshi Wang, Feng Zhou, Rui Zhu   +3 more
doaj   +1 more source

Positive Maps and Separable Matrices

, 2016
A linear map between real symmetric matrix spaces is positive if all positive semidefinite matrices are mapped to positive semidefinite ones. A real symmetric matrix is separable if it can be written as a summation of Kronecker products of positive ...
Nie, Jiawang, Zhang, Xinzhen
core   +1 more source

Fractional Zero Forcing via Three-color Forcing Games [PDF]

, 2015
An $r$-fold analogue of the positive semidefinite zero forcing process that is carried out on the $r$-blowup of a graph is introduced and used to define the fractional positive semidefinite forcing number. Properties of the graph blowup when colored with
Hogben, Leslie, Hogben, Leslie, Palmowski, Kevin, Roberson, David, Young, Michael   +4 more
core   +4 more sources

Measuring Sphericity in Positive Semi-Definite Matrices

Axioms
The measure of sphericity for positive semi-definite matrices plays a crucial role in understanding their geometric properties, especially in high-dimensional settings.
Dário Ferreira, Sandra S. Ferreira
doaj   +1 more source

A Parallel Approximation Algorithm for Positive Semidefinite Programming

, 2011
Positive semidefinite programs are an important subclass of semidefinite programs in which all matrices involved in the specification of the problem are positive semidefinite and all scalars involved are non-negative.
Jain, Rahul, Yao, Penghui
core   +1 more source

Positive semidefinite matrix supermartingales

Electronic Journal of Probability
EJP.
Wang, Hongjian, Ramdas, Aaditya
openaire   +2 more sources

An Iterative Method for Symmetric Positive Semidefinite Linear System of Equations

Demonstratio Mathematica, 2014
In this paper, a new two-step iterative method for solving symmetric positive semidefinite linear system of equations is presented. A sufficient condition for the semiconvergence of the method is also given.
Salkuyeh Davod Khojasteh
doaj   +1 more source

A Unifying Approach to Self‐Organizing Systems Interacting via Conservation Laws

Advanced Intelligent Discovery, EarlyView.
The article develops a unified way to model and analyze self‐organizing systems whose interactions are constrained by conservation laws. It represents physical/biological/engineered networks as graphs and builds projection operators (from incidence/cycle structure) that enforce those constraints and decompose network variables into constrained versus ...
F. Barrows, G. Zhang, S. Anand, Z. Chen, J. Lin, A. Desai, S. Martiniani, F. Caravelli   +7 more
wiley   +1 more source

A counterexample to the Drury permanent conjecture

Special Matrices, 2017
We offer a counterexample to a conjecture concerning the permanent of positive semidefinite matrices. The counterexample is a 4 × 4 complex correlation matrix.
Hutchinson George
doaj   +1 more source