26,688 research outputs found
PSO modelling and PID controlled of automatic fish feeder system
Automatic fish feeding system is an electronic device that is designed to distribute fish
pellets at particular time with maximum speed regulation. There are three (3) main
parts in the system which are storage, dispenser and distribution parts. A problem has
been reported that the distribution part was not performed at the required speed. The
main objective of this study is to improve the performance of fish feeding system by
using PID controller through ARX modelling. In this study, raw data at distribution
part with speed of 130 rpm, 160 rpm, 190 rpm, 220 rpm and 250 rpm were extracted
and used to determine ARX equation parameters as transfer function by using PSO
algorithm to optimize ARX model parameter. Validation tests used was residual
analysis. The best transfer function was then used as a modelling plant in the
simulation process with PID controller to determine the optimum PID parameters.
Finally, implementation of a PID controller into real time system was done to verify
whether this system improved or not. The PSO analysis showed that the best ARX
model was at 190 rpm speed because of well superimposed predicted model with the
actual system. The lowest normalized output MSE value is 0.0042015 , the lowest
convergence output error value is 0.0040886, the stable pole zero map and correlation
test verify the accuracy of the model reaching a 95% confidence level. ARX model
parameters obtained using the PSO algorithm are two inputs ( , ) and two outputs
( , ). The input parameter obtained is (β 0.3391, β 0.4329) while the output
parameter is (β 0.06498, β 0.08334). The optimum PID parameter value obtained by
the auto tune method is = β 3.4854, = β 50.2207 and = 0.05815. In
conclusion, the PID controller successfully improved the performance of the fish
feeding system with the highest percentage of speed change of 92.59%
Comparison of performance and emission characteristics between ceramic and metallic catalytic converter
Catalytic converters have been widely used on vehicles and have already been proved for many years to be the most effective technical solution to reduce exhaust emissions from gasoline engines where ceramic and metallic catalytic converters are the most common types of catalytic converter used. This study focuses to examine the performance of ceramic and metallic catalytic converters through simulation and experimental in terms of flow distribution and pollutant gases conversion. ANSYS Fluent 16.2 has been used for the simulation process and Mitsubishi 4G93 1800cc gasoline engine with difference speed and 25% constant load were used for the emission measurement using Kane Auto 5-1 series exhaust gas analyser. Simulation process has been conducted to measure pressure, velocity and temperature distribution through the ceramic and metallic catalytic converter and for the experimental process, the performances and pollutant gases conversion were recorded to compare both type of catalytic converters. Based on the simulation results, ceramic honeycomb catalytic converter shows higher pressure distribution 181.1 Pa on the inlet region compares to metallic sinusoidal. On the other hands, metallic sinusoidal catalytic converter has better velocity distribution of 14.3 ms- 1and temperature distribution of 1100 Kat the inlet region. Through the experimental results, metallic sinusoidal catalytic converter performs a better reduction of CO compares to ceramic honeycomb catalytic convetier while ceramic honeycomb performs better reduction than metallic sinusoidal catalytic converter for HC and NOx conversion. It can be concluded that metallic corrugated catalytic converter has performs better flow distribution through the substrates while ceramic converters reduce a higher percentage of CO and NOx pollutant gases
Entropy of (2+1)-dimensional de Sitter black hole to all orders in the Planck length
We calculate the statistical entropy of a scalar field on the background of
(2+1)-dimensional de Sitter space without an artificial cutoff considering
corrections to all orders in the Planck length from a generalized uncertainty
principle (GUP) on the quantum state density. The desired entropy proportional
to the horizon perimeter is obtained.Comment: 10 pages, two references adde
Robust Half-Metallic Character and Large Oxygen Magnetism in a Perovskite Cuprate
The new perovskite cuprate material SrCaReCuO, which
behaves ferrimagnetically and shows an unusually high Curie temperature ( 440 K), is found from density-functional theory calculation to display
several surprising properties after hole doping or chemical substitution: (1)
Half metal (HM) is realized by replacing Re with W or Mo while remains
high; (2) hole-doped SrCaReCuO is also HM with high
. Moreover, we find that the O atoms will carry a large magnetic moment
after hole doping, which is in sharp contrast with the generally accepted
concept that magnetism in solid requires partially filled shells of or
electrons in cations. The material SrCaReCuO is therefore
expected to provide a very useful platform for material design and development.Comment: 5 pages and 4 figure
The third-order law for increments in magnetohydrodynamic turbulence with constant shear
We extend the theory for third-order structure functions in homogeneous
incompressible magnetohydrodynamic (MHD) turbulence to the case in which a
constant velocity shear is present. A generalization is found of the usual
relation [Politano and Pouquet, Phys. Rev. E, 57 21 (1998)] between third-order
structure functions and the dissipation rate in steady inertial range
turbulence, in which the shear plays a crucial role. In particular, the
presence of shear leads to a third-order law which is not simply proportional
to the relative separation. Possible implications for laboratory and space
plasmas are discussed
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