The main purpose of this research is portfolio optimization in Tehran securities exchange using the black hole algorithm and the Gravitational Research algorithm. We also propose an algorithm named Hybrid Algorithm which combines the two algorithms above to cover the weaknesses of these two algorithms. Finally we compare the results with the Markowitz model and choose the optimal algorithm.<br ...

In this paper, we present a comparative numerical analysis to determine the refractive index of photonic crystal fibers (PCFs) by using FDFD method and used the results to evaluate the confinement losses of PCFs by considering the effects of air-hole rings in the cladding. It is shown that by increasing the wavelength, the imaginary part of refraction index rises, resulting in increase of conf...

The aim of our study is to analyze the impact of insertion holes in the middle of obstacles on the flow around a surface-mounted cube, In order to do this; we studied four configurations of obstacles in a channel with a Reynods number based on obstacle height ReH = 40000. The hexahedral structured meshes were used to solve the fluid dynamics equations .The finite volume method are employed to s...

Stress concentration factors have been examined in a functionally graded material (FGM) plate with central holes in different shapes in this essay. The material properties change along the thickness of plate. ABAQUS software has been utilized for modeling of problem in which subroutine of ABAQUS sub-program was used for modeling of the targeted material. The considering shapes for hole in plate...

The electric arc furnace (EAF) is used to produce high quality steel from steel scraps. The EAF uses plasma arc to generate heat for melting scarp or direct reduced iron (DRI). The liquid metal should be drained from the tap hole. Manual tapping operation of the EAF in the hot environment around the furnace is a potentially dangerous and time consuming task for the workers. Therefore, it is ess...

we design a novel nano-ring resonator using two-dimensional photonic crystal (2d-phc), for bio-sensing applications. the structure of biosensor is created by two-curve-shaped ring resonator which sandwiched by two waveguides. these are configured by removing one row of air holes. the refractive index of sensing hole is changed by binding an analyte. hence, intensity of the transmission spectrum...

oxides of nitrogen are the major emission from a diesel engine. it is due to heterogeneous diffusion combustion system with fuel-rich regions, which produce high local temperature around the periphery of the spray where high formation rate of no is promoted. various techniques are therefore employed to reduce the nox emission like egr, scr, etc. in this present work a rotating injector is a tec...

tube hydroforming (thf) process is used to produce the complex components from the initial cylindrical tubes. in this paper, t- shape component was formed using a tube hydroforming machine and the residual stresses of hydroformed tube was determined by hole drilling method. subsequently, the thickness distribution and residual stresses of final tube were investigated using experimental and fini...

in this study, behavior of pin-loaded glass fiber reinforced with polyethylene laminated composites with different stacking sequence and different dimensions has been observed experimentally and stress analysis was performed using ansys software. the aim is to investigate stresses, failure strength and failure mode of composite laminates containing a pin loaded hole when the material exhibits l...