Fast and High Accuracy Numerical Methods for the Solution of Nonlinear Klein–Gordon Equations

2011 ◽  
Vol 66 (12) ◽  
pp. 735-744 ◽  
Author(s):  
Akbar Mohebbi ◽  
Zohreh Asgari ◽  
Alimardan Shahrezaee

In this work we propose fast and high accuracy numerical methods for the solution of the one dimensional nonlinear Klein-Gordon (KG) equations. These methods are based on applying fourth order time-stepping schemes in combination with discrete Fourier transform to numerically solve the KG equations. After transforming each equation to a system of ordinary differential equations, the linear operator is not diagonal, but we can implement the methods such as for the diagonal case which reduces the time in the central processing unit (CPU). In addition, the conservation of energy in KG equations is investigated. Numerical results obtained from solving several problems possessing periodic, single, and breather-soliton waves show the high efficiency and accuracy of the mentioned methods.

1991 ◽  
Vol 24 (12) ◽  
pp. 159-164 ◽  
Author(s):  
J. S. d'Avila ◽  
C. M. Matos ◽  
M. R. Cavalcanti ◽  
J. Andrade ◽  
J. Marques

The reduction of the heavy metals concentration in liquid effluents is difficult and the existing methods available are expensive and their efficiencies ate in general low. The normal procedure adopted is based on the recirculation of the “chorume”, sometimes with a high content of heavy metals, into the liquid effluent flux of the central processing unit having in general a biological treatment. Depending on the heavy metal concentration the efficiency of the biological process decreases, or in certain cases, collapses completely. Activated peat by using the acid process or the one developed by the Universidade Federal de Sergipe and Instituto de Tecnologia e Pesquisas de Sergipe becomes an excellent heavy metals sorbent, which in certain analytical conditions has a very high efficiency. The overall process is controlled by diffusion and is governed by a first order kinetics. The use of activated peat shows in several situations that this process is a feasible alternative to getting the reduction of heavy metals concentrations in simulated effluents with one or more cations. Preliminary results show a significant matrix influence. The organic matter presence in the effluent may alter the sorption efficiency depending on its composition. The optimum analytical condition varies with the effluent quality and promotes the highest efficiency in the reduction of heavy metals concentrations.


2020 ◽  
Vol 35 (23) ◽  
pp. 2050140
Author(s):  
Eduardo López ◽  
Clara Rojas

We solve the one-dimensional time-independent Klein–Gordon equation in the presence of a smooth potential well. The bound state solutions are given in terms of the Whittaker [Formula: see text] function, and the antiparticle bound state is discussed in terms of potential parameters.


2007 ◽  
Vol 56 (2) ◽  
pp. 1041
Author(s):  
Li Mi-Shan ◽  
Tian Qiang

Hard drives are the one which needs to be accessed in an efficient manner so that it is feasible to get better recital of the central processing unit. Now a day’s magnetic disks are capable of providing more input output bandwidth yet a huge amount of this bandwidth is lost due to the access time of the hard disk. This paper discusses an analysis of performance of various disk scheduling algorithms with their merits and demerits


2011 ◽  
Vol 84 (3) ◽  
pp. 037001 ◽  
Author(s):  
Abdelmalek Boumali ◽  
Abdelhakim Hafdallah ◽  
Amina Toumi

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Monika Žecová ◽  
Ján Terpák

The contribution deals with the fractional heat conduction models and their use for determining thermal diffusivity. A brief historical overview of the authors who have dealt with the heat conduction equation is described in the introduction of the paper. The one-dimensional heat conduction models with using integer- and fractional-order derivatives are listed. Analytical and numerical methods of solution of the heat conduction models with using integer- and fractional-order derivatives are described. Individual methods have been implemented in MATLAB and the examples of simulations are listed. The proposal and experimental verification of the methods for determining thermal diffusivity using half-order derivative of temperature by time are listed at the conclusion of the paper.


2015 ◽  
Vol 62 (3-4) ◽  
pp. 101-119 ◽  
Author(s):  
Wojciech Artichowicz ◽  
Dzmitry Prybytak

AbstractIn this paper, energy slope averaging in the one-dimensional steady gradually varied flow model is considered. For this purpose, different methods of averaging the energy slope between cross-sections are used. The most popular are arithmetic, geometric, harmonic and hydraulic means. However, from the formal viewpoint, the application of different averaging formulas results in different numerical integration formulas. This study examines the basic properties of numerical methods resulting from different types of averaging.


2020 ◽  
Vol 98 (10) ◽  
pp. 939-943
Author(s):  
Eduardo López ◽  
Clara Rojas

We present a study of the one-dimensional Klein–Gordon equation by a smooth barrier. The scattering solutions are given in terms of the Whittaker Mκ,μ(x) function. The reflection and transmission coefficients are calculated in terms of the energy, the height, and the smoothness of the potential barrier. For any value of the smoothness parameter we observed transmission resonances.


2017 ◽  
Vol 14 (4) ◽  
pp. 172988141772467 ◽  
Author(s):  
Yanting Jiang ◽  
Jia Yan ◽  
Ci’en Fan ◽  
Wenxuan Shi ◽  
Dexiang Deng

Generating a group of category-independent proposals of objects in an image within a very short time is an effective approach to accelerate traditional sliding window search, which has been widely used in preprocessing step of object recognition. In this article, we propose a novel object proposals generation method to produce an order set of candidate windows covering most of object instances. With combination of gradient and local binary pattern, our approach achieves better performance than BING in finding occluded objects and objects in dim lighting conditions. In experiments on the challenging PASCAL VOC 2007 data set, we show that our approach is significantly more accurate than BING. In particular, using 2000 proposals, we achieve 97.6% object detection rate and 69.3% mean average best overlap. Moreover, our proposed method is very efficient and takes only about 0.006 s per image on a laptop central processing unit. The detection speed and high accuracy of proposed method mean that it can be applied to recognizing specific objects in robot visions.


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