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Abstract This paper presents a new approach for finding exact solutions to certain classes of nonlinear partial differential equations (NLPDEs) by combining the variation of parameters method with classical techniques such as the method of characteristics. Our primary focus is on NLPDEs of the form $$u_{tt}+a(x,t)u_{xt}+b(t)u_{t}=\alpha (x,t)+ G(u)(u_{t}+a(x,t)u_{x})e^{-\int b(t)dt}$$ u tt + a ( x , t ) u xt + b ( t ) u t = α ( x , t ) + G ( u ) ( u t + a ( x , t ) u x ) e - ∫ b ( t ) d t and $$u_{t}^{m}(u_{tt}+a(x,t)u_{xt})+b(t)u_{t}^{m+1}=e^{-(m+1)\int b(t)dt}(u_{t}+a(x,t)u_{x}) F(u,u_{t}e^{\int b(t)dt}).$$ u t m ( u tt + a ( x , t ) u xt ) + b ( t ) u t m + 1 = e - ( m + 1 ) ∫ b ( t ) d t ( u t + a ( x , t ) u x ) F ( u , u t e ∫ b ( t ) d t ) . We provide numerical validation through several examples to ensure accuracy and reliability. Our approach enhances the applicability of analytical solution methods for a broader range of NLPDEs.

A review of the basic Hansen's ideal frame algorithms for accurate numerical integration of perturbed elliptic motion is carried out. The fundamental approaches rely on the use of nonsingular variables and differ in the ways in which the ellipse in the orbital plane is determined. It is well known that the accuracy of the propagation of the orbit geometry is notably increased when using time-regularization techniques to transform the independent variable. However, this is at the expense of adding a differential equation to compute the time, which gathers the Lyapunov-type instabilities that are removed from the coordinates. The asynchronism resulting from errors in the numerical integration of the time may be palliated with the use of time elements, to which end a constant and a linear nonsingular time element are presented, which are new to our knowledge. [ABSTRACT FROM AUTHOR]

A review of the basic Hansen’s ideal frame algorithms for accurate numerical integration of perturbed elliptic motion is carried out. The fundamental approaches rely on the use of nonsingular variables and differ in the ways in which the ellipse in the orbital plane is determined. It is well known that the accuracy of the propagation of the orbit geometry is notably increased when using time-regularization techniques to transform the independent variable. However, this is at the expense of adding a differential equation to compute the time, which gathers the Lyapunov-type instabilities that are removed from the coordinates. The asynchronism resulting from errors in the numerical integration of the time may be palliated with the use of time elements, to which end a constant and a linear nonsingular time element are presented, which are new to our knowledge.

This paper investigates the synchronization of inertial reaction-diffusion Cohen-Grossberg-type neural networks. Compared with the existing works concerning reaction-diffusion neural networks, the main innovation of this paper is that two design strategies of feedback synchronization controllers are proposed based on the types of time delays. For the systems with bounded differentiable delays, the sufficient conditions for synchronization are derived under the framework of Lyapunov method. If the time delay of the addressed system is unbounded or non-differentiable, it can also realize synchronization by employing the method of variation of parameters and some analytical techniques. Moreover, the proposed methods are applicable to various boundary conditions. The correctness of the obtained criteria is verified by three numerical examples. [ABSTRACT FROM AUTHOR]