The Hipparcos astrometric parameters were obtained through the merging of abscissae data obtained by FAST and NDAC Consortia. Using a diierent weighting scheme, close but diierent astrometric solutions may be obtained. The resulting innuence on acceleration (G) and stochastic (X) solutions is discussed; these solutions are studied from the point of view of the possible signature of astrometric ...

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...

As integrated circuits become more and more complex the need for fast verification becomes increasingly important. Hardware acceleration is used for fast functional verification. This is an area where software tools for logic simulation are too slow to be useful for large designs, since the number of gates is too high [1]. Another trend in today's electronic systems is an increasing amount of s...

We study the spin current tensor of a Dirac particle at accelerations close to the upper limit introduced by Caianiello. Continual interchange between particle spin and angular momentum is possible only when the acceleration is time-dependent. This represents a stringent limit on the effect that maximal acceleration may have on spin physics in astrophysical applications. We also investigate som...

one of the most common methods for controlling and increasing maneuverability of projectiles, especially the ones which move at high altitude and in low density air, is using lateral or reaction jets. the resultant force of the reaction jet is related to the jet and flow parameters. for finding their relation experimental, numerical, and analytical methods have been used. in order to change the...

Introduction: Due to the non-developed mechanization situation, chainsaw is a widely used tool in Iranian forests. This tool can trigger unwelcome disorders (e.g., white finger syndrome) due to the transmitted vibrations from its handle to the body members. Characterizing these vibrations can result in minimizing the intensity of these disorders. This study aims to investigate the effect of dif...