The hydro turbine dynamics have a considerable influence on the dynamic stability of power system. In the study of dynamic stability, the system is modeled by the linear differential equations (small  signal analysis). Small signal stability of power systems is needed in all conditions and only is dependent on the conditions of power system performance before commotion occurrence. This paper pr...

Although perturbation techniques are widely applied to analyze nonlinear problems in science and engineering, they are however so strongly dependent on small parameters appeared in equations under consideration that they are restricted only to weakly nonlinear problems. For strongly nonlinear problems which don’t contain any small parameters, perturbation techniques are invalid. So, it seems ne...

In this paper, a new collocation method, which is based on Boubaker polynomials, is introduced for the approximate solutions of a class of two-dimensional linear Fredholm integral equationsof the second kind. The properties of two-dimensional Boubaker functions are presented. The fundamental matrices of integration with the collocation points are utilized to reduce the solution of the integral ...

In this work we demonstrate how to derive the Kohn-Sham equations of time-dependent current-density functional theory from a generating action functional defined on a Keldysh time contour. These Kohn-Sham equations contain an exchange-correlation contribution to the vector potential. For this quantity we derive an integral equation. We further derive an integral equation for its functional deri...

The so-called Hallén integral equation for the current on a finite linear antenna center-driven by a delta-function generator takes two forms depending on the choice of kernel. The two kernels are usually referred to as the exact and the approximate or reduced kernel. With the approximate kernel, the integral equation has no solution. Nevertheless, the same numerical method is often applied to ...

Differential equations involving causal operators have gained much attention of late and some results are assembled in a recent monograph [1]. The term causal is adopted from the engineering literature. Basically, a causal operator is a nonanticipative operator. The theory of these operators has the powerful quality of unifying ordinary differential equations, integrodifferential equations, dif...

In this paper, at first, we introduce $alpha_{mu}$-admissible, $Z_mu$-contraction and  $N_{mu}$-contraction via simulation functions. We prove some new fixed point theorems for defined class of contractions   via $alpha$-admissible simulation mappings, as well. Our results  can be viewed as extension of the corresponding results in this area.  Moreover, some examples and an application to funct...

in this paper, we consider a particular class of integral equations of the fourth kind and show that tractability and differentiability index of the given system are 3. tractability and dierentiability index are introduced based on the-smoothing property of a volterra integral operator and index reduction procedure, respectively. using the notion of index, we give sucient conditions for the...