vibration generated by vehicles during road transport has an important effect on the agricultural products damage process, particularly vegetable and fruit. modulus of elasticity is one of the most important mechanical properties of fruits and its variation can be described as one of the damage criteria during transportation. this research was conducted to evaluate the effects of vibration para...

Semi-active base isolation system has been proposed mainly to mitigate the base drift of isolated structures while in most cases, its application causes the maximum acceleration of superstructure to be increased. In this paper, designing optimal semi-active base isolation system composed of linear base isolation system with low damping and magneto-rheological (MR) damper has been studied for co...

introduction air pollution has harmful effect on human health and the environment. accordingly, considerable effort has been put to analyze the air pollutants. one important issue is the spatial distribution of these pollutants. dispersion of the pollutants released from sources on the ground is mostly driven by the planetary boundary layer where turbulent flow causes mixing of the content of t...

in this paper, chebyshev acceleration technique is used to solve the fuzzy linear system (fls). this method is discussed in details and followed by summary of some other acceleration techniques. moreover, we show that in some situations that the methods such as jacobi, gauss-sidel, sor and conjugate gradient is divergent, our proposed method is applicable and the acquired results are illustrate...

this paper aims to discuss the requirements of safe and smooth trajectory planning of transporter mobile robots to perform non-prehensile object manipulation task. in non-prehensile approach, the robot and the object must keep their grasp-less contact during manipulation task. to this end, dynamic grasp concept is employed for a box manipulation task and corresponding conditions are obtained an...

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 a simple tool for seismic design of steel structures for a selected ductility level is presented. For this purpose, a consistent set of earthquakes is selected and sorted based on the maximum acceleration of ground surface. The selected records are applied as the base motion to a single-degree-of-freedom system with strain hardening and the maximum response acceleration is determi...

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...

the earth’s gravity field dedicated missions, champ, grace and goce have opened up a new era for the study of the earth’s gravity field. the missions measure different functionals on the earth’s gravitational potential which are represented in terms of the stokes coefficients or the so-called geopotential models. the mapping process of the observations into the coefficients is called recovery o...

A hardware fault tolerance scheme for large multicomputers executing time-consuming non-interactive applications is described. Error detection and recovery are done mostly by software with little hardware support. The scheme is based on simultaneous execution of identical copies of the application on two subnetworks of the system. Normal system operation is periodically suspended and the logica...