Resonant electromagnetic actuators have been broadly used as vibration motors for mobile devices given their ability of generating relatively fast, strong, and controllable vibration force at a given resonant frequency. Mechanism of the actuators that is based on mechanical resonance, however, limits their use to a situation where their resonant frequencies are known and unshifted. In reality, ...

Two Lagrangian formulations for describing the damped harmonic oscillator have been introduced by Bateman. For these models we construct higher derivative generalizations which enjoy l-conformal Newton-Hooke symmetry. It is shown that dynamics of generalized systems corresponds to Pais-Uhlenbeck a particular choice its frequencies.

in this paper, a new analytical method is proposed to study the effect of crack and axial load on vibration behavior and stability of the cracked columns. using the local flexibility model, the crack has been simulated by a torsional spring with connecting two segments of column in crack location. by solving governing eigenvalue equation, the effect of crack parameters and axial load on the nat...

We calculate the tidal interaction of a uniformly rotating 1 M⊙ star with an orbiting companion at various phases of core hydrogen burning from the ZAMS to core hydrogen exhaustion. By using the traditional approximation we reduce the solution of the non-adiabatic oscillation equations for the tidal forcing of a rotating star to a one dimensional problem by solving a separate eigenvalue problem...

We consider a damped/driven nonlinear Schrödinger equation in $$\mathbb {R}^n$$ , where n is arbitrary, $${\mathbb {E}}u_t-\nu \Delta u+i|u|^2u=\sqrt{\nu }\eta (t,x), \quad \nu >0,$$ under odd periodic boundary conditions. Here $$\eta (t,x)$$ random force which white time and smooth space. It known that the Sobolev norms of solutions satisfy $$ \Vert u(t)\Vert _m^2 \le C\nu ^{-m}, uniformly $$t...

The current article is concerned with a comprehensive investigation of achieving the simplest solution non-conservative coupled nonlinear forced oscillators. mainly depends on non-perturbative method. It yielding an equivalent linear system. advantage this system that its coefficients are easily computed and they include effects original coefficients. This linearization approach allows quasi-ex...

In this paper, two kinds of vibrations are considered for a composite Timoshenko rotor: longitudinal-torsional vibration and two plane transverse one. The kinetic and potential energies and virtual work due to the gyroscopic effects are calculated and the set of six governing equations and boundary conditions are derived using Hamilton principle. Differential quadrature method (DQM) is used as ...