The harmonic balance method is used to construct approximate frequency–amplitude relations and periodic solutions to the relativistic oscillator. By combining linearization of the governing equation with the harmonic balance method, we construct analytical approximations to the oscillation frequencies and periodic…

Numerical calculation of Fresnel patterns through fast Fourier transforms usually requires an extremely large number of samples in order to fulfil the Nyquist sampling condition. In many applications, the cut-off frequency of the system is much below the limit fixed…

The second-order harmonic balance method is used to construct three approximate frequency-amplitude relations for a conservative nonlinear singular oscillator in which the restoring force is inversely proportional to the dependent variable. Two procedures are used to solve the nonlinear differential…

An analytical approximate technique for conservative nonlinear oscillators is proposed. This method is a modification of the generalized harmonic balance method in which analytical approximate solutions have rational form. This approach gives us not only a truly periodic solution but…

Our intention in this paper is to shortly address some of the basic categories that determine the paradigm of sport culture as we know it. We do believe that by understanding these basic categories the changes of prevailing sport paradigm,…

The current study attempts to describe the free time of City of Havana (Cuba) population older than 15 years, distinguishing between word days, weekends and vacation and holiday periods, determining the population's socio-demographic profile. The object population of study numbers…

This paper deals with the non-linear oscillation of a simple pendulum and presents an approach for solving the non-linear differential equation that governs its movement by using the harmonic balance method. With this technique it is possible to easily obtain…

The aims of this study were to describe body composition and physical fitness changes during a whole-season in elite children tennis players. A total of 7 elite children tennis players participated in the study. Whole body composition by dual energy…

In this work, the parameters of motor evoked potentials of upper and lower extremity muscles were evaluated, under magnetic stimulation of cerebral cortex motor areas, spinal segments, and nerve tibialis in athletes adapted to work of various duration and intensity…

The methods of differential geometry are used with the assumption that rays of light follow geodesic trajectories in a space whose metric is determined by the refraction index. Keeping this in mind, we show that these hypotheses are equivalent to…