• Proceedings of the KIEE Conference
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• 2005.11a
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• pp.21-23
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• 2005

The electron transport coefficients, the electron drift velocity W, the longitudinal diffusion coefficient $ND_L$ in $C_{3}F_{8}-Ar$ mixture gases were measured by Double shutter drift tube and calculated by multi-term approximation of the Boltzmann equation over the wide E/N range from 0.03 to 100 Td. And an inelastic collision cross sections for $C_{3}F_{8}$ molecular gas were redetermined for quantitative characteristic analysis.

• International Journal of Aeronautical and Space Sciences
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• v.14 no.4
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• pp.341-349
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• 2013

This paper considers the optimum design of flexbeam cross-sections for a full-scale bearingless helicopter rotor, using an efficient hybrid optimization algorithm based on particle swarm optimization, and an improved genetic algorithm, with an effective constraint handling scheme for constrained nonlinear optimization. The basic operators of the genetic algorithm, of crossover and mutation, are revisited, and a new rank-based multi-parent crossover operator is utilized. The rank-based crossover operator simultaneously enhances both the local, and the global exploration. The benchmark results demonstrate remarkable improvements, in terms of efficiency and robustness, as compared to other state-of-the-art algorithms. The developed algorithm is adopted for two baseline flexbeam section designs, and optimum cross-section configurations are obtained with less function evaluations, and less computation time.

• Steel and Composite Structures
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• v.19 no.6
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• pp.1511-1529
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• 2015

This article provides an analysis of the complex character of stress distribution in concrete in stub columns consisting of two HE160A steel sections held together with batten plates and filled with concrete. In such columns, evaluating the effect of concrete confinement and determining the extent of this confinement constitute a substantially complex problem. The issue was considered in close correspondence to rectangular cross section tubular elements filled with concrete, concrete-encased columns, as well as to steel-concrete columns in which reinforcement bars are connected with shackles. In the analysis of concrete confinement in two-chord columns, elements of computational methods developed for different types of composite cross sections were adopted. The achieved analytical results were compared with calculations based on test results.

• Nuclear Engineering and Technology
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• v.13 no.3
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• pp.139-144
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• 1981

Plutionum, neptunium, and uranium isotopes which were produced in the interaction of $^{136}$ Xe and $^{244}$ Pu are separated and determined their cross sections. The cross sections are: $\sigma$($^{245}$ Pu)=66 mb, $\sigma$($^{243}$ Pu)=57 mb, $\sigma$($^{246}$ Pu)=6.0 mb, $\sigma$($^{239}$ Np)=15 mb, $\sigma$($^{240}$ U)=12 mb, $\sigma$($^{245}$ U)=6.4 mb respectively.

• Proceedings of the KIEE Conference
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• 2008.11b
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• pp.85-88
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• 2008

Drift velocities and Distribution Function for electrons in $SF_6$-Ar mixtures gas used by MCS-BEq algorithm has been analysed over the E/N range $30{\sim}300[Td]$ by a two term Boltzmann equation and by a Monte Carlo simulation using a set of electron cross sections determined by other authors, experimentally the electron swarm parameters for 0.2[%] and 0.5[%] $SF_6$-Ar mixtures were measured by time-of-flight method, The results show that the deduced electron drift velocities agree reasonably well with theoretical for a rang of E/N values The results simulation have been compared with present and previously obtained data and respective set of electron collision cross sections of the molecules.

• Proceedings of the KIEE Conference
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• 2002.06a
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• pp.106-109
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• 2002

This paper calculates and gives the analysis of electron swarm transport coefficients as described electric conductive characteristics of pure Ar, pure $SiH_4$, Ar + $SiH_4$ mixture gases ($SiH_4$--0.5%, 2.5%, 5%) over the range of E/N =0.01${\sim}$300[Td]. P=0.1, 1, 5.0[Torr] by Monte Carlo the Backward prolongation method of the Boltzmann equation using computer simulation without using expensive equipment. The results have been obtained by using the electron collision cross sections by TOF. PT.SST sampling, compared with the experimental data determined by the other author. It also proved the reliability of the electron collision cross sections and shows the practical values of computer simulation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.12 no.1
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• pp.88-93
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• 1999

This paper describes the electron transport characteristics in $SiH_4$ gas calculated for the range of E/n:0.5~300(Td) and Pressure:0.5, 1, 2.5(Torr) by the Monte carlo simulation and Boltzmann equation method using a set of electron collision cross sections determined by the reported results. The motion has been calculated to give swarm parameters for the electron drift velocity, longitudinal and transverse diffusion coefficients, the electron ionization coefficients, characteristics energy and the electron energy distribution function. The electron energy distributions function has been analysed in $SiH_4$ at E/N: 30, 50(Td)for a case of the equilibrium region in the mean electron energy and respective set of electron collision cross sections. The results of Monte carlo simulation and Boltzmann equation have been compared with experimental data by ohmori ad Pollock.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.578-580
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• 2005

Energy distribution function for electrons in SF6-Ar mixtures gas used by MCS-BEq algorithm has been analysed over the E/N range 30~300[Td] by a two term Boltzmann equation and by a Monte Carlo Simulation using a set of electron cross sections determined by other authors, experimentally the electron swarm parameters for 0.2[%] and 0.5[%] $SF_6$-Ar mixtures were measured by TOF method, The results show that the deduced electron drift velocities, the electron ionization or attachment coefficients, longitudinal and transverse diffusion coefficients and mean energy agree reasonably well with theoretical for a rang of E/N values. The results obtained from Boltzmann equation method and Monte Carlo simulation have been compared with present and previously obtained data and respective set of electron collision cross sections of the molecules.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.507-508
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• 2006

$SF_6$ gas is widely used in industrial of insulation field. In this paper, $N_2$ is mixed to improve pure $SF_6$ gas characteristics. Electron transport coefficients in $SF_6-N_2$ mixture gases are simulated in range of E/N values from 70 to 400 [Td] at 300K and 1 Torr by using Boltzmann equation method. The results have been obtained by using the electron collision cross sections by TOF, PT, SST sampling, compared with the experimental data determined by the other author. It also proved the reliability of the electron collision cross sections and shows the practical values of computer simulation. The result of Boltzmann equation and Monte Carlo Simulation has been compared with experimental data by Ohmori, Lucas and Carter. The swarm parameter from the swarm study are expected to sever as a critical test of current theories of low energy scattering by atoms and molecules.

• New Physics: Sae Mulli
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• v.68 no.12
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• pp.1331-1337
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• 2018

We present a three-parameter phase shift model whose form is the same as that of Coulombmodified Glauber model obtained from Gaussian nuclear densities. This model is applied to the $^6Li+^{12}C$ and the $^6Li+^{28}Si$ elastic scatterings at $E_{lab}=318MeV$. The calculated differential cross sections provide quite a satisfactory account of the experimental data. The diffractive oscillatory structures observed at forward angles can be explained as being due to the strong interference between the near-side and the far-side scattering amplitudes. The optical potentials for two systems are predicted by using the method of inversion. The calculated inversion potentials are found to be in fairly good agreements with the results determined from the optical model analysis in the surface regions around the strong absorption radius. We also investigate the effects of parameters in the three-parameter phase shift model on the elastic scattering cross sections.