recent studies show significant reduction of postural stability in transtibial amputees (ttas) especially when a perturbation is applied. however, no record has been seen on the consequences of such perturbation on the stump-socket interface pressure (ssip). our objective was to investigate whether such perturbation impose excessive pressures on the stump. we were also interested on the type of...

abstract background: several studies have examined the reflex response of ankle musculature to sudden inversion in noninjured and injured subjects. to date, there have been no studies to determine the effect of versatile degrees & conditions of perturbation on the ankle musculature latency. the purpose of this study was to measure and determine whether there was a difference in ankle musculatur...

singular perturbation problems have been studied by many mathematicians. since the approximate solutions of these problems are as the sum of internal solution (boundary layer area) and external ones, the formation or non-formation of boundary layers should be specified. this paper, investigates this issue for a singular perturbation problem including a first order differential equation with gen...

We investigate the primordial curvature perturbation by observation of dark matter substructure. Assuming a bump in spectrum wavenumber k>1 Mpc^{-1}, we track evolution host halo and subhalos semi-analytic way. Taking into account possible uncertainties evaluation tidal stripping effect on subhalo growth, find new robust bound with from number observed dwarf spheroidal galaxies our Galaxy obser...

In this paper, the homotopy perturbation method (HPM) is considered for finding approximate solutions of two-dimensional viscous flow. This technique provides a sequence of functions which converges to the exact solution of the problem. The HPM does not need a small parameters in the equations, but; the perturbation method depends on small parameter assumption and the obtained results. In most ...

the present study introduces a new technique of homotopy perturbation method for the solution of systems of fractional partial differential equations. the proposed scheme is based on laplace transform and new homotopy perturbation methods. the fractional derivatives are considered in caputo sense. to illustrate the ability and reliability of the method some examples are provided. the results ob...

In this paper we examine fluctuation and frequency of the governing equation ofoscillator with odd and even nonlinearities without damping and we present a new efficientmodification of the He’s homotopy perturbation method for this equation. We applied standard andmodified homotopy perturbation method and compare them with the numerical solution (NS), also weapplied He’s Energy balance method (...

In this paper, we investigate a singular perturbation problem including a fourth order O.D.E. with general linear boundary conditions. Firstly, we obtain the necessary conditions of solution of O.D.E. by making use of fundamental solution, then by compatibility of these conditions with boundary conditions, we determine that, for given perturbation problem, whether boundary layer is formed or not.

The present study introduces a new technique of homotopy perturbation method for the solution of systems of fractional partial differential equations. The proposed scheme is based on Laplace transform and new homotopy perturbation methods. The fractional derivatives are considered in Caputo sense. To illustrate the ability and reliability of the method some examples are provided. The results ob...

In this paper, the Kadomtsev-Petviashvili equation is solved by using the Adomian’s decomposition method , modified Adomian’s decomposition method , variational iteration method , modified variational iteration method, homotopy perturbation method, modified homotopy perturbation method and homotopy analysis method. The existence and uniqueness of the solution and convergence of the proposed...