scholarly journals EFFECTIVENESS EVALUATION OF THE STRUCTURAL COMPACT MATRIX METHOD FOR CALCULATING THE COMPACTNESS COEFFICIENT

Author(s):  
I.E. Eremin ◽  
◽  
D.V. Fomin ◽  

The article examines the efficiency of the structural compact-matrix numerical method in comparison with the classical direct numerical method for calculating the spatial packing density of the simplest hexagonal lattice. The theoretical results of a comparative analysis of the considered numerical meth-ods, as well as a computational experiment, carried out to quantitatively assess their effectiveness, are presented.

2020 ◽  
Vol 19 (6) ◽  
pp. 1173-1188
Author(s):  
A.B. Kogan ◽  
A.N. Pristavka

Subject. The article presents various definitions of the efficiency concept, their changes as the economic science evolves, and describes various methods to measure company performance efficiency, ranging from a simple set of financial indicators to comprehensive systems for effectiveness evaluation. Objectives. The purpose of the study is to systematize the said definitions and identify a category that will meet the current condition of business environment. Methods. The study rests on the retrospective and comparative analysis of interpretations of the efficiency concept in the economic science. We also employ the historical and logical methods of general theoretical research. Results. We identify three approaches to the interpretation of the efficiency concept. Within the selected approaches, we consider the main methods for company performance measurement that have emerged since 1914. The paper formulates criteria, which were used to carry out the comparative analysis of these methods. The analysis enabled to trace all changes in the methods. Conclusions. We propose to use the term Integrated Company Efficiency and to develop methodological framework for measuring the comprehensive efficiency of companies operating in various industries.


2013 ◽  
Vol 397-400 ◽  
pp. 270-273
Author(s):  
Ying Li ◽  
Xiao Bin Li ◽  
Yu Wang ◽  
Wei Zhang

Blast wave is numerical simulated based on FCT method. According to the comparative analysis, taking Henrych empirical formula as a standard, FCT method is more accuracy than Godunov method. Moreover, it has been found that the numerical accuracy is insufficient when the distance is small, it is necessary to develop and modify the numerical method continuously.


2016 ◽  
Vol 19 (1) ◽  
Author(s):  
GEORGI GEORGIEV ◽  
NADEZHDA EVSTATIEVA

A comparative analysis has been carried out on two options of three-phase parametric current sources (inductive-capacitive stabilizers). Their capacities to operate in voltage stabilizer mode have been studied. Such capacities were proven and their conditions were defined. Theoretical results were experimentally checked and confirmed with satisfactory accuracy. Based on theoretical and experimental studies it was proven that the considered systems can operate in both modes – as current and voltage stabilizers.


2011 ◽  
Vol 314-316 ◽  
pp. 810-814
Author(s):  
Mo Wu Lu ◽  
Wei Qiang Zhao

This paper presents a numerical method for kinematics analysis of Multi-link suspension based on displacement matrix method. A mathematical model for kinematics analysis of multi-link suspension is established and the kinematical properties of multi-link suspension are analyzed using this method. The numerical method for solving this problem is discussed and the relevant program is developed. This method simplifies the solving process of kinematics properties analysis of multi-link suspension and is efficient especially for computer-based solving process.


2018 ◽  
Vol 32 (15) ◽  
pp. 1850159
Author(s):  
Yin Long ◽  
Xiao-Jun Zhang ◽  
Kui Wang

In this paper, convergence and approximate calculation of average degree under different network sizes for decreasing random birth-and-death networks (RBDNs) are studied. First, we find and demonstrate that the average degree is convergent in the form of power law. Meanwhile, we discover that the ratios of the back items to front items of convergent reminder are independent of network link number for large network size, and we theoretically prove that the limit of the ratio is a constant. Moreover, since it is difficult to calculate the analytical solution of the average degree for large network sizes, we adopt numerical method to obtain approximate expression of the average degree to approximate its analytical solution. Finally, simulations are presented to verify our theoretical results.


2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Qiaoqin Gao ◽  
Zhijiang Luo ◽  
Guirong Liu

This paper considers a stochastic delay Gilpin-Ayala model with Markovian switching. Using Lyapunov method, we show existence and uniqueness of global positive solution. Then, by using Chebyshev’s inequality, M-matrix method, and BDG’s inequality, stochastic permanence and asymptotic estimations of solutions are studied. Finally, numerical simulations illustrate the theoretical results. Our results generalize and improve the existing results.


1964 ◽  
Vol 60 (4) ◽  
pp. 897-907 ◽  
Author(s):  
M. Wadsworth ◽  
A. Wragg

AbstractThe replacement of the second space derivative by finite differences reduces the simplest form of heat conduction equation to a set of first-order ordinary differential equations. These equations can be solved analytically by utilizing the spectral resolution of the matrix formed by their coefficients. For explicit boundary conditions the solution provides a direct numerical method of solving the original partial differential equation and also gives, as limiting forms, analytical solutions which are equivalent to those obtainable by using the Laplace transform. For linear implicit boundary conditions the solution again provides a direct numerical method of solving the original partial differential equation. The procedure can also be used to give an iterative method of solving non-linear equations. Numerical examples of both the direct and iterative methods are given.


Sign in / Sign up

Export Citation Format

Share Document