A comparative study between Elliptic Fourier and B-spline descriptors for object contour representation

2014 ◽  
Author(s):  
Ll. Ferrer-Arnau ◽  
V. Parisi-Baradad ◽  
J.A. Soria ◽  
K. Nasreddine ◽  
A. Benzinou
Keyword(s):  
Comparative Study ◽  
B Spline ◽  
Contour Representation ◽  
Object Contour

A comparative study of modified cubic B-spline differential quadrature methods for a class of nonlinear viscous wave equations

2018 ◽  
Vol 35 (1) ◽  
pp. 315-333
Author(s):  
Ramesh Chand Mittal ◽  
Sumita Dahiya
Keyword(s):  
Wave Equation ◽  
Comparative Study ◽  
Wave Equations ◽  
Differential Quadrature ◽  
Two Dimensional ◽  
Nonlinear Odes ◽  
Content Type ◽  
B Spline ◽  
Cpu Time ◽  
Quadrature Methods

Purpose In this study, a second-order standard wave equation extended to a two-dimensional viscous wave equation with timely differentiated advection-diffusion terms has been solved by differential quadrature methods (DQM) using a modification of cubic B-spline functions. Two numerical schemes are proposed and compared to achieve numerical approximations for the solutions of nonlinear viscous wave equations. Design/methodology/approach Two schemes are adopted to reduce the given system into two systems of nonlinear first-order partial differential equations (PDE). For each scheme, modified cubic B-spline (MCB)-DQM is used for calculating the spatial variables and their derivatives that reduces the system of PDEs into a system of nonlinear ODEs. The solutions of these systems of ODEs are determined by SSP-RK43 scheme. The CPU time is also calculated and compared. Matrix stability analysis has been performed for each scheme and both are found to be unconditionally stable. The results of both schemes have been extensively discussed and compared. The accuracy and reliability of the methods have been successfully tested on several examples. Findings A comparative study has been carried out for two different schemes. Results from both schemes are also compared with analytical solutions and the results available in literature. Experiments show that MCB-DQM with Scheme II yield more accurate and reliable results in solving viscous wave equations. But Scheme I is comparatively less expensive in terms of CPU time. For MCB-DQM, less depository requirements lead to less aggregation of approximation errors which in turn enhances the correctness and readiness of the numerical techniques. Approximate solutions to the two-dimensional nonlinear viscous wave equation have been found without linearizing the equation. Ease of implementation and low computation cost are the strengths of the method. Originality/value For the first time, a comparative study has been carried out for the solution of nonlinear viscous wave equation. Comparisons are done in terms of accuracy and CPU time. It is concluded that Scheme II is more suitable.

scholarly journals Comparative Study on Different Types of Regression Applied to Unemployment in Maramures County of Romania

2016 ◽  
Vol 26 (3) ◽  
pp. 44-61
Author(s):  
Magnolia Tilca ◽  
Meda Bojor
Keyword(s):  
Linear Regression ◽  
Comparative Study ◽  
Programming Language ◽  
Polynomial Regression ◽  
Statistical Computing ◽  
Spline Regression ◽  
B Spline ◽  
Regression Spline ◽  
Different Types ◽  
Predicted Values

Abstract We are studying the economic phenomenon of the unemployment in Maramures County of Romania. To obtain plausible conclusions regarding this study we apply different types of regression: the linear regression, polynomial regression, spline and B-spline regression. In this paper we focus on the numerical side of the research and we compare the predicted values, the graphic representation of the evolution, the future predictions and the errors generated by the regressions mentioned above. The calculations are performed in R, a programming language for statistical computing. An implementation in R is given.

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