Abstract This work introduces a parametric modal decomposition method for multivariate non-stationary signals based on block-diagonal time-dependent state space representation and Kalman filtering/smoothing. Each second-order block is constructed with the real imaginary parts of each mode instantaneous eigenvalues, thus represents single oscillatory component. The identification state/parameter...

This paper presents a blocked united algorithm for the allpairs shortest paths (APSP) problem. This algorithm simultaneously computes both the shortest-path distance matrix and the shortest-path construction matrix for a graph. It is designed for a high-speed APSP solution on hybrid CPU-GPU systems. In our implementation, two most compute intensive parts of the algorithm are performed on the GP...

A model for single-phase flow in porous media that are hierarchically fissured in regular patterns was derived by a recursive asymptotic expansion technique in [16] and part of [24]. This work rigorously justifies that model. Through recursive homogenization, we extend the doubleporosity model in [5], which has one fracture system and a matrix (rock) block system, to a triple-porosity model tha...

A complete and accurate analysis of the complex spatial structure of heterogeneous hydrocarbon reservoirs requires detailed geological models, i.e. fine resolution models. Due to the high computational cost of simulating such models, single resolution up-scaling techniques are commonly used to reduce the volume of the simulated models at the expense of losing the precision. Several multi-scale ...

Gravity drainage is one of the important recovery mechanisms in fractured carbonate and conventional reservoirs. It occurs due to density difference between the gas in fracture and the oil in matrix as well as in conventional tilted reservoirs. Oil phase will form films which are produced under gravity forces (film flow). Many gas injection experiments have been done on laboratory scales with d...

in this paper, we consider a class of column-weight two quasi-cyclic low-density paritycheck codes in which the girth can be large enough, as an arbitrary multiple of 8. then we devote a convolutional form to these codes, such that their generator matrix can be obtained by elementary row and column operations on the parity-check matrix. finally, we show that the free distance of the convolution...

A tridiagonal matrix with entries given by square matrices is a block tridiagonal matrix; the matrix is banded if off-diagonal blocks are upper or lower triangular. Such matrices are of great importance in numerical analysis and physics, and to obtain general properties is of great utility. The blocks of the inverse matrix of a block tridiagonal matrix can be factored in terms of two sets of ma...

The matrix functions appear in several applications in engineering and sciences. The computation of these functions almost involved complicated theory. Thus, improving the concept theoretically seems unavoidable to obtain some new relations and algorithms for evaluating these functions. The aim of this paper is proposing some new reciprocal for the function of block anti diagonal matrices. More...

for x, where A is a given n × n matrix, and b a given n-vector. We have many opportunities to solve linear equations with the same coefficient matrix and different right-hand sides (RHSs). Therefore, block Krylov subspace methods such as the block Bi-CG (Bl-BCG), block Bi-CGSTAB (Bl-BiCGSTAB) [2], block GMRES (Bl-GMRES) and block QMR (Bl-QMR) methods have been developed for solving block linear...

In this paper, electromagnetic scattering problems are analyzed using an electric field integral equation (EFIE) formulation that is based on loop-star basis functions so as to avoid low-frequency instability problems. Moreover, to improve the convergence rate of iterative methods, a block matrix preconditioner (BMP) is applied to the EFIE formulation based on loop star-basis functions. Because...