Generalized variance is applied for determination of dispersion in a multivariate population and is a successful measure for concentration of multivariate data. In this article, we consider constructing confidence interval and testing the hypotheses about generalized variance in a multivariate normal distribution and give a computational approach. Simulation studies are performed to compare thi...

introduction abnormal neural impulses in the nervous system may lead to various diseases and disabilities. high frequency alternating currents (hfac) has been used to block the propagation of such impulses and improve the symptoms or disabilities. the technique is safe, reversible, and relatively selective, and its reliability, the optimum stimulation parameters, and elimination of the onset re...

among the all parameters affecting the performance of a downhole de-oiling hydrocyclone, the investigation of internal flow field deserves more attempts especially in the petroleum industry. in this study, the effects of inlet flow rate, inlet oil volume fraction, and oil droplet diameter on the separation efficiency and pressure drop ratio have been investigated along the hydrocyclone body. al...

computational fluid dynamics (cfd) simulations of gas-solid flow through a positive low-pressure pneumatic conveyor were performed using eulerian-eulerian framework. pressure drop in pneumatic conveying pipelines, creation and destruction of plugs along the horizontal and vertical pipes, effect of 90° elbows and u-bends on cross-section concentrations, and rope formation and dispersion were num...

dense medium cyclone is a high capacity device that is widely used in coal preparation. it is simple in design but the swirling turbulent flow, the presence of medium and coal with different density and size fraction and the presence of the air-core make the flow pattern in dmcs complex. in this article the flow pattern simulation of dmc is performed with computational fluid dynamics and fluent...

Multidimensional modelling of open-cycle process of OM355 engine was developed. Calculations for computational mesh were carried out. The results of the model were validated by experimentally measured in-cylinder pressure and the good agreement between calculations and measurements approved the trustworthy of numerical code. Results included pressure, temperature, emission and Rate of heat rel...

The present study involves a novel computational technique, regarding simultaneous use of the pseudo particle method, Poisson integral method and a special-purpose computer originally designed for molecular dynamics simulations (MDGRAPE-3). In the present calculations, the dynamics of two colliding vortex rings have been studied using the vortex method. The present acceleration technique allows...

Model-based predictive control (MPC) is one of the most efficient techniques that is widely used in industrial applications. In such controllers, increasing the prediction horizon results in better selection of the optimal control signal sequence. On the other hand, increasing the prediction horizon increase the computational time of the optimization process which make it impossible to be imple...