The characteristics of composite rightand left-handed CRLH transmission lines periodically loaded with Schottky varactors are discussed in relation to the development of solitons. CRLH lines are highly dispersive and thus, when appropriately designed, compensate the effect of nonlinearity introduced by the Schottky varactors to support solitons. The reductive perturbation method applied to the ...

in recent years, numerous approaches have been applied for finding the solutions of functional equations. one of them is the optimal homotopy asymptotic method. in current paper, this method has been applied for obtaining the approximate solution of fisher equation. the reliability of the method will be shown by solving some examples of various kinds and comparing the obtained outcomes with the ...

The propagation of the solitary wave in a dusty plasma bounded in finite geometry has been investigated. By employing the reductive perturbation method, we obtain a quasi Korteweg-de Vries-type equation. It is noted that the larger the value of viscosity coefficient μ(0), the stronger the damping of the solitary wave. On the other hand, the larger the value of the radius of bounded geometry R, ...

we introduce and discuss the homotopy perturbation method, the adomian decomposition method and the variational iteration method for solving the stefan problem with kinetics. then, we give an example of the stefan problem with  kinetics and solve it by these methods.

The renormalization group method of Goldenfeld, Oono and their collaborators is applied to asymptotic analysis of vector fields. The method is formulated on the basis of the theory of envelopes, as was done for scalar fields. This formulation actually completes the discussion of the previous work for scalar equations. It is shown in a generic way that the method applied to equations with a bifu...

the dynamical behaviour of the forced escape oscillator, which depends on the parameter values we considered, have been studied numerically using the techniques of phase portraits and poincar'{e} sections. also, we employed perturbation methods such as lindstedt's method to obtain the frequency-amplitude relation of escape oscillator.

We investigate the hard nonresonant excitation of the forced Duffing equation with a positive damping parameter E. Using the symbolic manipulation system MACSYMA, a computer algebra system. we derive the two term perturbation expansion by the method of multiple time scales. The resulting approximate solution is valid for small values of the coefficient e As the damping parameter e increases, th...

هدف اصلی این تحقیق یافتن جواب تحلیلی رده ای از معادلات انتگرال فوق منفرد نوع دوم به نام پراندتل است که در مباحث فنی من جمله مکانیک پدید می آید. بدین منظور از یک روش بهبود یافته‌ی جدید و سریع بر اساس روش اختلال هموتوپی استفاده می شود. با ارائه‌ی مثال‌هایی نشان خواهیم داد که روش اختلال هموتوپی استاندارد در حالت کلی برای حل این رده از معادلات انتگرال همگرا نبوده و روش اختلال هموتوپی اصلاح شده نیز ...

In this paper, the piecewise homotopy perturbation method (PHPM) is employed to solve the Hamilton– Jacobi–Bellman (HJB) equation arising in the optimal control problems. The method is a simple modification of the standard homotopy perturbation method (HPM), in which it is treated as an algorithm in a sequence of small intervals (i.e. time step) for finding accurate approximate solutions to the...