this study is investigated the optimum parameters for a tuned mass damper (tmd) under the seismic excitation. shuffled complex evolution (sce) is a meta-heuristic optimization method which is used to find the optimum damping and tuning frequency ratio for a tmd. the efficiency of the tmd is evaluated by decreasing the structural displacement dynamic magnification factor (ddmf) and acceleration ...

in this paper, the effect of bedrock inclination on seismic performance of slopes is investigated. the study was conducted based on dynamic analysis of different slopes, evaluation of the earthquake acceleration in sliding mass, and calculating the permanent displacement of the slope, using newmark sliding block. the investigation indicates that variation of the bedrock inclination may cause th...

As early as in 1907, Einstein showed that the light speed must be larger at spacetime points with higher gravitational potential. This idea is used here to present a relativistic version of a recent model which explains the acceleration of the Pioneer 10 spaceship as the effect of a universal adiabatic acceleration of light. This phenomenon would have the same observational signature as an acce...

Energetic ions have been observed since the very first laser-plasma experiments. Their origin was found to be the charge separation of electrons heated by the laser, which transfers energy to the ions accelerated in the field. The advent of ultra-intense lasers with pulse lengths in the femtosecond regime resulted in the discovery of very energetic ions with characteristics quite different from...

trajectories generally used to describe the space and time required to perform a desired motion task for a mobile robot or manipulator system. in this paper, we considered a cubic polynomial trajectory for the problem of moving a mobile robot from its initial position to a goal position in over a continuous set of time. along the path, the robot requires to observe a certain acceleration profil...

a new mechanical cultivator was proposed for mechanical weeding in part one. the precise point method was used to geometric design of this new cultivator. the aim of this research is selecting the suitable mechanism of the studied mechanisms in part one. the velocity and acceleration of links (kinematic) is the base of dynamic analysis of the systems. the variation of velocity, acceleration and...