the current paper focuses on some analytical techniques to solve the non-linear duffing oscillator with large nonlinearity. four different methods have been applied for solution of the equation of motion; the variational iteration method, he’s parameter expanding method, parameterized perturbation method, and the homotopy perturbation method. the results reveal that approximation obtained by th...

Semi-solid materials undergo strain localization and shear band formation as a result of granular nature of semi-solid deformation. In the present study, to analyze the shear localization, a unified viscoplastic constitutive model was developed for the homogeneous flow. Then, a linearized analysis of the stability performed by examining the necessary condition for the perturbation growth. For t...

In recent years, the Indian Ocean (IO) has been discovered to have a much larger impact on climate variability than previously thought. This paper reviews processes in which the IO is, or appears to be, actively involved. We begin the mathematical model with a pattern for summer monsoon winds. Three dimensional temperature and velocity fields are calculated analytically for the ocean forced by ...

In this paper, Elzaki Homotopy Perturbation Method is employed for solving linear and nonlinear differential equations with a variable coffecient. This method is a combination of Elzaki transform and Homotopy Perturbation Method. The aim of using Elzaki transform is to overcome the deficiencies that mainly caused by unsatised conditions in some semi-analytical methods such as Homotopy Perturbat...

CONTEXT The dominant and nondominant legs respond asymmetrically during landing tasks, and this difference may occur during an inversion perturbation and provide insight into the role of ankle-evertor and -invertor muscle activity. OBJECTIVE To determine if there is a difference in the ratio of evertor to invertor activity between the dominant and nondominant legs and outer-sole conditions wh...

in this paper, first a new homotopy perturbation method for solving a fractional order nonlinear telegraph equation is introduced. by applying the proposed method, the nonlinear equation is translated to linear equations for per iteration of homotopy perturbation method. then, the obtained problems are solved with separation method. in the examples, it is illustrated that the exact solution is ...

The visual system can detect speed changes of moving objects only by means of alterations of retinal image motion, which is also subject to changes induced by head or eye movements. Here we investigated whether smooth pursuit eye movements affect the ability to localize short speed perturbations of large context stimuli. Psychophysical thresholds for localization, discrimination and detection o...

A forced KdV equation including the special topography effect is derived to describe nonlinear long wave and solitary eddy based on quasi-geostrophic potential vorticity model. We obtain theoretical solution of concrete form stream function through perturbation theory multi-scale analysis methods. It found that joint weak shear basic flow can change cyclone anticyclone structure eddy, in meanti...

in this article, we demonstrate an analytic-numeric solution for some dynamical systems using the multistagehomotopy perturbation method. the method yields results that are in complete agreement with their numericalcounterparts.