Oversample Reconstruction Based on a Strong Inter-Diagonal Matrix for an Optical Microscanning Thermal Microscope Imaging System

Based on a strong inter-diagonal matrix and Taylor series expansions,an oversample reconstruction method was proposed to calibrate the optical micro-scanning error. The technique can obtain regular 2 ×2 microscanning undersampling images from the real irregular undersampling images,and can then obtain a high spatial oversample resolution image. Simulations and experiments show that the proposed technique can reduce optical micro-scanning error and improve the system＇s spatial resolution. The algorithm is simple,fast and has low computational complexity. It can also be applied to other electro-optical imaging systems to improve their spatial resolution and has a widespread application prospect.

Decoupling Control Research on Test System of Hydraulic Drive Unit of Quadruped Robot Based on Diagonal Matrix Method

The mathematical model of hydraulic drive unit of quadruped robot was built in this paper. According to the coupling characteristics between position control system and force control system, the decoupling control strategy was realized based on diagonal matrix method in AMESim?. The results of simulation show that using diagonal matrix method can achieve the decoupling control effectively and it can achieve the decoupling control more effectively with the method of not offset pole-zero in the S coordinate. This research can provide theoretical basis for the application of test system of hydraulic drive unit.

The Distribution of Eigenvance of Product Diagonal Dominance Matrix

Let DD_0(R)={A∈C^(n×#)||Rea_(ii)Rea_(jj)|≥A_iA_j,i≠j,i,j∈N}.PD_0(R)={A∈C^(n×#)||Rea_(ii)Rea_(kk)|≥A_iA_jA_k,i≠j≠k,i,j,k∈N}. In this paper,we show DD_0(R)PD_0(R),and the conditions under which the numbers of eigen vance of A∈PD_0(R)\DD_0(R)are equal to the numbers of a_(ii),i∈N in positive and negative real part respectively.Some couter examples are given which present the condnions can not be omitted.

Diagonally loaded SMI algorithm based on inverse matrix recursion

The derivation of a diagonally loaded sample-matrix inversion （LSMI） algorithm on the busis of inverse matrix recursion （i.e.LSMI-IMR algorithm） is conducted by reconstructing the recursive formulation of covariance matrix. For the new algorithm, diagonal loading is by setting initial inverse matrix without any addition of computation. In addition, a corresponding improved recursive algorithm is presented, which is low computational complexity. This eliminates the complex multiplications of the scalar coefficient and updating matrix, resulting in significant computational savings. Simulations show that the LSMI-IMR algorithm is valid.

THE STRESS SUBSPACE OF HYBRID STRESS ELEMENT AND THE DIAGONALIZATION METHOD FOR FLEXIBILITY MATRIX H

The following is proved: 1) The linear independence of assumed stress modes is the necessary and sufficient condition for the nonsingular flexibility matrix; 2) The equivalent assumed stress modes lead to the identical hybrid element. The Hilbert stress subspace of the assumed stress modes is established. So, it is easy to derive the equivalent orthogonal normal stress modes by Schmidt's method. Because of the resulting diagonal flexibility matrix, the identical hybrid element is free from the complex matrix inversion so that the hybrid efficiency, is improved greatly. The numerical examples show that the method is effective.

New Criteria for Judging Generalized Strictly Diagonally Dominant Matrix

Generalized strictly diagonally dominant matrices play a wide and important role in computational mathematics, mathematical physics, theory of dynamical systems, etc.But it is difficult to judge a matrix is or not generalized strictly diagonally dominant matrix.In this paper, by using the properties of α-chain diagonally dominant matrix, we obtain new criteria for judging generalized strictly diagonally dominant matrix, which enlarge the identification range.

GH-CONGRUENCE CANONICAL FORM OF QUATERNION MATRIX AND SIMULTANEOUS DIAGONALIZATION OF MATRICES

In this paper,the GH-congruence canonical forms of positive semidefinite and definte inite and definite(need not be self-conjugate)quaternion matrices are given,and a neccessary and sufficientcondition of GH-congruence for two positive semidifinite(definite)quaternion matrices isgiven also.Then simultaneous GH-congruence reduced forms for two self-conjugate matri-ces and some result about the simultaneous GH-congruence diagonalization of quaternionmatrices are obtained.

REMARKS ON BRUALDI'S THEOREM FOR SPECTRUM INCLUSION REGION OF AN IRREDUCIBLE MATRIX

This paper obtains a necessary and sufficient condition for an irreducible complex matrix whose comparison matrix is a singular M-matrix to be singular. This is used to establish a necessary and sufficient condition for a boundary point of Brualdi’s inclusion region of the eigenvalues of an irreducible complex matrix to be an eigenvalue.

A New Approximation to the Linear Matrix Equation AX = B by Modification of He’s Homotopy Perturbation Method

It is well known that the matrix equations play a significant role in engineering and applicable sciences. In this research article, a new modification of the homotopy perturbation method (HPM) will be proposed to obtain the approximated solution of the matrix equation in the form AX = B. Moreover, the conditions are deduced to check the convergence of the homotopy series. Numerical implementations are adapted to illustrate the properties of the modified method.

Fatigue Behaviour of Metal Matrix Composites

Based mainly on the work done at the authors' laboratory in recent years,this paper examines what is currently known about the cyclic deformation and fatigue properties of metal matrix composites, with particular emphasis on discontinuous fiber (whisker or particulate)-reinforced Al composites. The following items are discussed:fatigue strength and life,cyclic deformation and microstructural evolution,microcrack initiation and growth,fatigue crack propagation behaviour.

Efficient Solutions of Coupled Matrix and Matrix Differential Equations

In Kronecker products works, matrices are sometimes regarded as vectors and vectors are sometimes made in to matrices. To be precise about these reshaping we use the vector and diagonal extraction operators. In the present paper, the results are organized in the following ways. First, we formulate the coupled matrix linear least-squares problem and present the efficient solutions of this problem that arises in multistatic antenna array processing problem. Second, we extend the use of connection between the Hadamard (Kronecker) product and diagonal extraction (vector) operator in order to construct a computationally-efficient solution of non-homogeneous coupled matrix differential equations that useful in various applications. Finally, the analysis indicates that the Kronecker (Khatri-Rao) structure method can achieve good efficient while the Hadamard structure method achieve more efficient when the unknown matrices are diagonal.

Non-Singularity Conditions for Two Z-Matrix Types

A real square matrix whose non-diagonal elements are non-positive is called a Z-matrix. This paper shows a necessary and sufficient condition for non-singularity of two types of Z-matrices. The first is for the Z-matrix whose row sums are all non-negative. The non-singularity condition for this matrix is that at least one positive row sum exists in any principal submatrix of the matrix. The second is for the Z-matrix which satisfies where . Let be the ith row and the jth column element of , and be the jth element of . Let be a subset of which is not empty, and be the complement of if is a proper subset. The non-singularity condition for this matrix is such that or such that for? . Robert Beauwens and Michael Neumann previously presented conditions similar to these conditions. In this paper, we present a different proof and show that these conditions can be also derived from theirs.

ON OPTIMAL BACKWARD PERTURBATION ANALYSIS FOR THE LINEAR SYSTEM WITH BLOCK CYCLIC COEFFICIENT MATRIX

Based on the block style spectral decomposition,this paper deals with the optimal backward perturbation analysis for the linear system with block cyclic coefficient matrix.

Inhibition of matrix metalloproteinase-9 secretion by dimethyl sulfoxide and cyclic adenosine monophosphate in human monocytes

BACKGROUND Matrix metalloproteinases(MMPs),including MMP-9,are an integral part of the immune response and are upregulated in response to a variety of stimuli.New details continue to emerge concerning the mechanistic and regulatory pathways that mediate MMP-9 secretion.There is significant evidence for regulation of inflammation by dimethyl sulfoxide(DMSO)and 3',5'-cyclic adenosine monophosphate(cAMP),thus investigation of how these two molecules may regulate both MMP-9 and tumor necrosis factorα(TNFα)secretion by human monocytes was of high interest.The hypothesis tested in this study was that DMSO and cAMP regulate MMP-9 and TNFαsecretion by distinct mechanisms.AIM To investigate the regulation of lipopolysaccharide(LPS)-stimulated MMP-9 and tumor necrosis factorαsecretion in THP-1 human monocytes by dimethyl sulfoxide and cAMP.METHODS The paper describes a basic research study using THP-1 human monocyte cells.All experiments were conducted at the University of Missouri-St.Louis in the Department of Chemistry and Biochemistry.Human monocyte cells were grown,cultured,and prepared for experiments in the University of Missouri-St.Louis Cell Culture Facility as per accepted guidelines.Cells were treated with LPS for selected exposure times and the conditioned medium was collected for analysis of MMP-9 and TNFαproduction.Inhibitors including DMSO,cAMP regulators,and anti-TNFαantibody were added to the cells prior to LPS treatment.MMP-9 secretion was analyzed by gel electrophoresis/western blot and quantitated by ImageJ software.TNFαsecretion was analyzed by enzyme-linked immuno sorbent assay.All data is presented as the average and standard error for at least 3 trials.Statistical analysis was done using a two-tailed paired Student t-test.P values less than 0.05 were considered significant and designated as such in the Figures.LPS and cAMP regulators were from Sigma-Aldrich,MMP-9 standard and antibody and TNFαantibodies were from R&D Systems,and amyloid-βpeptide was from rPeptide.RESULTS In our investigation of MMP-9 secretion from THP-1 human monocytes,we made the following findings.Inclusion of DMSO in the cell treatment inhibited LPSinduced MMP-9,but not TNFα,secretion.Inclusion of DMSO in the cell treatment at different concentrations inhibited LPS-induced MMP-9 secretion in a dosedependent fashion.A cell-permeable cAMP analog,dibutyryl cAMP,inhibited both LPS-induced MMP-9 and TNFαsecretion.Pretreatment of the cells with the adenylyl cyclase activator forskolin inhibited LPS-induced MMP-9 and TNFαsecretion.Pretreatment of the cells with the general cAMP phosphodiesterase inhibitor IBMX reduced LPS-induced MMP-9 and TNFαin a dose-dependent fashion.Pre-treatment of monocytes with an anti-TNFαantibody blocked LPSinduced MMP-9 and TNFαsecretion.Amyloid-βpeptide induced MMP-9 secretion,which occurred much later than TNFαsecretion.The latter two findings strongly suggested an upstream role for TNFαin mediating LPS-stimulate MMP-9 secretion.CONCLUSION The cumulative data indicated that MMP-9 secretion was a distinct process from TNFαsecretion and occurred downstream.First,DMSO inhibited MMP-9,but not TNFα,suggesting that the MMP-9 secretion process was selectively altered.Second,cAMP inhibited both MMP-9 and TNFαwith a similar potency,but at different monocyte cell exposure time points.The pattern of cAMP inhibition for these two molecules suggested that MMP-9 secretion lies downstream of TNFαand that TNFαmay a key component of the pathway leading to MMP-9 secretion.This temporal relationship fit a model whereby early TNFαsecretion directly led to later MMP-9 secretion.Lastly,antibody-blocking of TNFαdiminished MMP-9 secretion,suggesting a direct link between TNFαsecretion and MMP-9 secretion.

Criteria Condition for Generalized Diagonally Dominant Matrices

In this paper, we provide some new necessary and sufficient conditions for generalized diagonally dominant matrices and also obtain some criteria for nongeneralized dominant matrices.

Criteria Conditions for Generalized Diagonally Dominant Matrices

In this paper, some new sufficient conditions for generalized dominant matrices are given, and some results in [1] are generalized and improved.

Completeness of the system of eigenvectors of off-diagonal operator matrices and its applications in elasticity theory

This paper deals with off-diagonal operator matrices and their applications in elasticity theory. Two kinds of completeness of the system of eigenvectors are proven, in terms of those of the compositions of two block operators in the off-diagonal operator matrices. Using these results, the double eigenfunction expansion method for solving upper triangular matrix differential systems is proposed. Moreover, we apply the method to the two-dimensional elasticity problem and the problem of bending of rectangular thin plates on elastic foundation.

Necessary and Sufficient Condition for Generalized Diagonal Dominance Matrices

In the paper,a necessary and sufficeent condition for generalized diagonal domiance matrices is given.Further, the relations among all generalized positive definite matrices are shown, also,some flaws and mistakes in the references are corrected.

GENERALIZED DIAGONALIZATION OF MATRICES OVER QUATERNION FIELD

A concept of [GRAPHICS] diagonalization matrix over quaternion field is given, the necessary and sufficient conditions for determining whether a quaternion matrix is a [GRAPHICS] diagonalization one are discussed, and a method of [GRAPHICS] diagonalization of matrices over quaternion field is given.

Criteria Conditions for Generalized Diagonally Dominant Matrices

In this paper, we provide some new criteria conditions for generalized strictly diagonally dominant matrices, such that the corresponding results in [1] are generalized and improved.