scholarly journals ANALYSIS OF THE DEFLECTION OF A TRUSS WITH A DECORATIVE LATTICE

Author(s):  
Mikhail N. Kirsanov

Introduction. A scheme is proposed for a planar symmetric statically determinate beam truss with a rectilinear lower belt, struts, multidirectional braces and a polygonal outline of the upper belt. The belts of the truss are rectilinear, the hinges are ideal. The truss belongs to the class of regular trusses having periodic cells. The supporting rods are not deformable. The truss is evenly loaded around the nodes of the lower belt. Materials and methods. The task is to deduce the dependence of the deflection of the truss on the number of panels in the span. The deflection is obtained from the Maxwell-Mora formula under the assumption that all the rods have the same rigidity. Forces in the structural rods from the effective uniform load and from the unit vertical in the middle of the span are determined by the method of cutting the nodes. The matrix of the system of linear equations of node equilibrium is made up of the cosines of the forces with the coordinate axes. To compile a system of equations and solve it, the program of symbolic mathematics Maple is used. To obtain the general formula, a number of problems of trusses with a number of panels from 2 to 29 are solved. Sequences of the coefficients of the deflection formula have common terms for which homogeneous recurrence equations are also compiled using the methods of the Maple system using specialized operators. Results. The solutions of recurrence equations have the form of polynomials with coefficients that depend on the parity of the number of panels and contain trigonometric functions. The graphs of the solutions obtained are constructed and analysed. Sharp changes of deflection characteristic for such truss and their non-monotonic character are noted. It is shown that for a fixed, independent on the number of panels, length of the span and the total load, the relative deflection with increasing number of panels first decreases, then varies little. Conclusions. The asymptotic property of the solution is obtained by the methods of the Maple system: an inclined asymptote is found. The slope is calculated using the analytical capabilities of Maple. A simple formula is derived for the horizontal displacement of the mobile support from the action of the load. The dependence is monotonic. The height of the truss is included in the denominator of the formula.

1995 ◽  
Vol 38 (3) ◽  
pp. 495-510 ◽  
Author(s):  
C. Brezinski ◽  
A. Salam

Sequence transformations are extrapolation methods. They are used for the purpose of convergence acceleration. In the scalar case, such algorithms can be obtained by two different approaches which are equivalent. The first one is an elimination approach based on the solution of a system of linear equations and it makes use of determinants. The second approach is based on the notion of annihilation difference operators. In this paper, these two approaches are generalized to the matrix and the vector cases.


1924 ◽  
Vol 22 (3) ◽  
pp. 282-286
Author(s):  
E. C. Titchmarsh

I have collected in the present note some theorems regarding the solution of a certain system of linear equations with an infinity of unknowns. The general form of the equations isthe numbers a1, a2, … c1, c2, … being given. Equations of this type are of course well known; but in studying them it is generally assumed that the series depend for convergence on the convergence-exponent of the sequences involved, e.g. that and are convergent. No assumptions of this kind are made here, and in fact the series need not be absolutely convergent. On the other hand rather special assumptions are made with regard to the monotonic character of the sequences an and cn.


Author(s):  
Jack-Kang Chan

We show that the well-known least squares (LS) solution of an overdetermined system of linear equations is a convex combination of all the non-trivial solutions weighed by the squares of the corresponding denominator determinants of the Cramer's rule. This Least Squares Decomposition (LSD) gives an alternate statistical interpretation of least squares, as well as another geometric meaning. Furthermore, when the singular values of the matrix of the overdetermined system are not small, the LSD may be able to provide flexible solutions. As an illustration, we apply the LSD to interpret the LS-solution in the problem of source localization.


2021 ◽  
pp. 51-57

The aim is to optimize the conditions for the synthesis of 3(H)-quinazolin-4-one by the method of mathematical modeling to develop a technology for producing the substance of a new domestic drug used in the treatment of farm animals from helminths. In mathematical modeling, the method of a small number of squares was used. Analytical dependences of the product yield on temperature, reaction time, and molar ratios of the starting materials were determined. A system of linear equations has been compiled. The system of linear equations was performed by the matrix method (A, B, C).The average reaction rate was determined. Based on the results obtained, a 3(H)-quinazolin-4-one diagram using the Maple 18 program and an icon diagram of the reaction duration, temperature, and reaction rate are shown. Based on the results of mathematical modeling, a highly efficient technological scheme for obtaining 3(H)-quinazolin-4-one has been developed. Based on this technology, compound 3(H)-quinazolin-4-one was synthesized in quantitative products at the Institute of Plant Chemistry, at a pilot production plant.The results obtained confirmed the found optimal conditions


2020 ◽  
Vol 20 (4) ◽  
pp. 845-854
Author(s):  
SUAYIP YUZBASI ◽  
NURCAN BAYKUS SAVASANERIL

In this study, a collocation approach based on the Hermite polyomials is applied to solve the singularly perturbated delay differential eqautions by boundary conditions. By means of the matix relations of the Hermite polynomials and the derivatives of them, main problem is reduced to a matrix equation. And then, collocation points are placed in equation of the matrix. Hence, the singular perturbed problem is transformed into an algebraic system of linear equations. This system is solved and thus the coefficients of the assumed approximate solution are determined. Numerical applications are made for various values of N.


Author(s):  
Quan Quan Tan ◽  
Thomas Peyrin

In this article, we propose new heuristics for minimising the amount of XOR gates required to compute a system of linear equations in GF(2). We first revisit the well known Boyar-Peralta strategy and argue that a proper randomisation process during the selection phases can lead to great improvements. We then propose new selection criteria and explain their rationale. Our new methods outperform state-of-the-art algorithms such as Paar or Boyar-Peralta (or open synthesis tools such as Yosys) when tested on random matrices with various densities. They can be applied to matrices of reasonable sizes (up to about 32 × 32). Notably, we provide a new implementation record for the matrix underlying the MixColumns function of the AES block cipher, requiring only 94 XORs.


2019 ◽  
Vol 09 (4) ◽  
pp. 32-45 ◽  
Author(s):  
A.V. Panteleev ◽  
V.S. Saveleva

The article discusses the study of a mathematical model of execution of the production task in the presence of fuzzy information about the matrixes of direct costs and final demand. By solving a problem with fuzzy information we mean the solution of a linear system of equations with a fuzzy matrix and a fuzzy right-hand side described by fuzzy triangular numbers in a form of deviations from the mean. In this task of search of inter-sectoral balance the LU-decomposition method for the matrix of direct cost which is further used for solving the system of linear equations is applied. A software implementation of a numerical method for finding a strong solution of a fuzzy system of linear equations consisting of two successive stages is described. At the first stage, the necessary and sufficient conditions for the existence of a strong solution are verified. At the second stage, the solution of the system is found, which is written in the form of a fuzzy matrix. The influence of the fuzzy numbers parameters on the final result was studied.


2020 ◽  
Vol 12 (2) ◽  
pp. 368-375
Author(s):  
N.B. Ladzoryshyn ◽  
V.M. Petrychkovych ◽  
H.V. Zelisko

The method for solving the matrix Diophantine equations over quadratic rings is developed. On the basic of the standard form of matrices over quadratic rings with respect to $(z,k)$-equivalence previously established by the authors, the matrix Diophantine equation is reduced to equivalent matrix equation of same type with triangle coefficients. Solving this matrix equation is reduced to solving a system of linear equations that contains linear Diophantine equations with two variables, their solution methods are well-known. The structure of solutions of matrix equations is also investigated. In particular, solutions with bounded Euclidean norms are established. It is shown that there exists a finite number of such solutions of matrix equations over Euclidean imaginary quadratic rings. An effective method of constructing of such solutions is suggested.


1965 ◽  
Vol 69 (652) ◽  
pp. 280-283 ◽  
Author(s):  
John Robinson

Summary“The Rank Technique” is a method for automatic selection of redundancies in the Matrix Force Method. The method was developed for the complete linear analysis of general plane frames, but is equally applicable to other forms of two- and three-dimensional configurations whose state can be expressed as a system of linear equations. An attractive feature of the method is that the structure is systematically and automatically investigated to determine its basic characteristics. The first point considered is whether the structure is stable or unstable for the prescribed load conditions; if stable, whether determinate or redundant and if redundant, the degree of redundancy. A consistent set of redundants is automatically isolated. For general structures the technique automatically generates the basic and redundant load systems in an indirect manner which can be made readily available, if required. The initial development of “The Rank Technique” was carried out in collaboration with Robert R. Regl and is given in reference 1.


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