one of the debates concerning concepts of “medial motion” and “traversal motion” is the question of which of these two concepts of motion corresponds to motion in the corporeal world. in the present article we intend to employ the language of mathematics to present a model for each of these two concepts to study the above mentioned problem. as a result, medial motion represents a covering funct...

in this paper, chaotic motion analysis and its control for a non-planar non-linear cantilever beam with axial and lateral parametric excitation in the free end is accomplished. this is a new method for control of chaotic motion of a non-linear planar beam. in this survey, internal resonance of the beam is 2:1 and the initial resonance is in the outside of plane and it is assumed a sub-resonance...

A quantum theory of a two and three-level laser with injected atomic coherence is developed by using a density operator method, to the best of our knowledge, for the first time. The initial atomic coherence plays an essential role. At steady state, the equation of motion for the density operator yields to exhibit laser without inversion and a phase locking but no threshold for the laser fie...

In the current study, the effects of Casimir force and squeeze film damping on pull-in instability and dynamic behavior of electrostatically actuated nano and micro electromechanical systems are investigated separately. Linear elastic membrane theory is used to model the static and dynamic behavior of the system for strip, annular and disk geometries. Squeeze film damping is modeled using nonli...

in this paper, time-domain dynamic analysis of dam - infinite reservoir is studied. a numerical method, discrete singular convolution (dsc), which seems to be efficient and simple, has been used to model the mixed boundary conditions. after a brief introduction, dsc is applied to model the equation of motion of fluid-structure with constant cross section subjected to el-centro (1940) earthquake...

Introduction: Nowadays tendency to apply more degrees of freedom in high-tech radiotherapy systems, and consequent complex process to optimize dose calculation and delivery algorithms, is a challenge of radiation therapy optimization. Faster MLC speed, dose rate, Gantry angle variation, and other degrees, which have been utilized in IMRT, IMAT, VMAT, improved modulation of inte...

In order to investigate the effects of non-linear springs in vibrating behavior of vehicles, the independent suspension of conventional vehicles could be modeled as a non-linear single degree of freedom system. The equation of motion for the system would be a non-linear third order ordinary differential equation, when considering the elasticity of rubber bushings in joints of shock absorber. It...

We present new CO(1–0) and HCN(1–0) observations of the barred spiral galaxy NGC1530 at resolutions of 1.8′′ and 3.6′′ respectively. Both CO and HCN are abundant in the nucleus, where we detect two strong, curved shock fronts curling around a possible nuclear ring. The ring is clumpy and may be elongated along the bar. The kinematics of the gas can be fit with a model with infall motions up to ...