Theoretical method for calculating porosity and permeability under self-regulating effect

In order to study the effect of stress-sensitivity and matrix shrinkage on coalbed methane production,equivalent matrix particle model is proposed considering the process of adsorption and desorption.Calculating mathematical models for calculating porosity and permeability which considered matrix shrinkage by combining diameter model and desorption were established.The calculations of porosity and permeability under self-regulating effect were obtained by combining traditional stress-sensitivity equations.The changes of porosity and permeability in different reservoirs were calculated and analyzed through a variety of basic parameters.The results show that high coal rank reservoir has the biggest range ability of porosity and permeability under the same pressure difference conditions,followed by the middle rank and the low rank.The research observed the positive relationship between stress-sensitivity and declining period of porosity and permeability in low rank coal reservoir,and the inverse relationship between matrix shrinkage and declining period of porosity and permeability.The stronger the matrix shrinkage is,the earlier declining period and rise period will occur.

SOME BASIC PROBLEMS IN NUMERICALLY SIMULATING EFFECTIVE PROPERTIFS AND LOCAL FIELDS OF COMPOSITE MATERIALS

It is pointed out that to numerically estimate the effective properties and local fields of matrix-inclusion composites,a commonly adopted method is accompanied with some serious draw- backs.We call this method the nominal loading scheme(NLS),which considers the actual inclusion distribution inside a finite domain,Ω say,treats the external domain of Ω to be of the pure matrix ma- terial,and imposes the actural traction,σ~∞ say on the remote boundary.It thus gives rise to the fol- lowing basic problems:(i)Can NLS be improved remarkably just by adjusting σ~∞?(it)What is the relationship between the size of Ω and the,scale of inclusions?(iii)Which choice is better in calculating the effective properties,the whole domain Ω or an appropriately selected sub-domain of Ω? Targeting these problems,the equivalent loading,scheme (ELS)and equivalent matrix scheme(EMS)are proposed.It is theoretically analyzed that both ELS and EMS can be used to precisely simulating the effective properties and local fields of matrix-inclusion composites,and both ELS and EMS are self-approved. As an application,ELS combined with a m-called pseudo-dislocations method is used to evaluate the effective properties and local fields of two-dimensional two-phase compos- ites with close-packed circular inclusions,or randomly distributed circular inclusions, or randomly distributed mierocracks.The results show that substituting the remote trac- tion σ~∞ with the effective stress field σ~E suggested by IDD scheme is a simple and effec- tive method,and the estimation of the effective properties and local fields is very close to the accurate,solution.

An optimized run-length based algorithm for sparse remote sensing image labeling

Labeling of the connected components is the key operation of the target recognition and segmentation in remote sensing images.The conventional connected-component labeling(CCL) algorithms for ordinary optical images are considered time-consuming in processing the remote sensing images because of the larger size.A dynamic run-length based CCL algorithm(Dy RLC) is proposed in this paper for the large size,big granularity sparse remote sensing image,such as space debris images and ship images.In addition,the equivalence matrix method is proposed to help design the pre-processing method to accelerate the equivalence labels resolving.The result shows our algorithm outperforms 22.86% on execution time than the other algorithms in space debris image dataset.The proposed algorithm also can be implemented on the field programming logical array(FPGA) to enable the realization of the real-time processing on-board.

The application of fuzzy equivalence relation based on the quotient space in cluster analysis

A fuzzy clustering analysis model based on the quotient space is proposed. Firstly, the conversion from coarse to fine granularity and the hierarchical structure are used to reduce the multidimensional samples. Secondly, the fuzzy compatibility relation matrix of the model is converted into fuzzy equivalence relation matrix. Finally, the diagram of clustering genealogy is generated according to the fuzzy equivalence relation matrix, which enables the dynamic selection of different thresholds to effectively solve the problem of cluster analysis of the samples with multi-dimensional attributes.

Smith Form of Triangular Multivariate Polynomial Matrix

The Smith form of a matrix plays an important role in the equivalence of matrix.It is known that some multivariate polynomial matrices are not equivalent to their Smith forms.In this paper,the authors investigate mainly the Smith forms of multivariate polynomial triangular matrices and testify two upper multivariate polynomial triangular matrices are equivalent to their Smith forms respectively.

An equivalence canonical form of a matrix triplet over an arbitrary division ring with applications

We in this paper give a decomposition concerning the general matrix triplet over an arbitrary divisionring F with the same row or column numbers. We also design a practical algorithm for the decomposition of thematrix triplet. As applications, we present necessary and suficient conditions for the existence of the generalsolutions to the system of matrix equations DXA = C1, EXB = C2, F XC = C3 and the matrix equation AXD + BY E + CZF = Gover F. We give the expressions of the general solutions to the system and the matrix equation when thesolvability conditions are satisfied. Moreover, we present numerical examples to illustrate the results of thispaper. We also mention the other applications of the equivalence canonical form, for instance, for the compressionof color images.

New Results on the Equivalence of Bivariate Polynomial Matrices

This paper investigates the equivalence problem of bivariate polynomial matrices.A necessary and sufficient condition for the equivalence of a square matrix with the determinant being some power of a univariate irreducible polynomial and its Smith form is proposed.Meanwhile,the authors present an algorithm that reduces this class of bivariate polynomial matrices to their Smith forms,and an example is given to illustrate the effectiveness of the algorithm.In addition,the authors generalize the main result to the non-square case.

On the Organizational Problem

The organizational problem is how to arrange the order of play for the annual club tournament under the following cocnditions. There are n many teams enter and one court available. The tournament rules are that team has to play a match against every other team. Each team should have a reasonalbe rest between games. We give some method to consider the problem and completely solve the problem in the case that n=5