• Publications of The Korean Astronomical Society
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• v.24 no.1
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• pp.43-51
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• 2009

We present a Monte-Carlo simulation code, which solves the problem of dust-scattering in interstellar dust clouds with arbitrary light source distribution and dust density structure, and calculate the surface brightness distribution. The method is very flexible and can be applied to radiative transfer problems occurring not only in a single dust cloud, but also in extragalactic dust environment. We compare, for performance test, the result of Monte-Carlo simulation with the well-known analytic approximation for a spherically symmetric homogeneous cloud. We find that the Code approximation gives a very accurate result.

• Journal of Magnetics
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• v.16 no.4
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• pp.323-327
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• 2011

By means of Monte Carlo simulation, we investigate the effects of interface roughness and temperature on the exchange bias and coercivity in ferromagnetic (FM)/antiferromagnetic (AFM) bilayers. Both exchange bias and coercivity are strongly dependent on interface roughness. For a perfect uncompensated interface a domain wall is formed in the AFM system during FM reversal, which results in a very small exchange bias. However, a finite interface roughness leads to a finite value of the exchange bias due to the existence of pinned spins at the AFM surface adjacent to the mixed interface. It is observed that the exchange bias decreases with increasing temperature, consistent with the experimental results. It is also observed that a bump in coercivity occurs around the blocking temperature.

• Journal of the Optical Society of Korea
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• v.19 no.5
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• pp.444-448
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• 2015

We describe the radiative transfer of a Gaussian beam in a water medium using the Monte Carlo method offering basic propagation behaviors. The simulation shows how the energy of the initial Gaussian beam is redistributed as it propagates in coastal water, and also depicts the dependence of the propagation behavior on inherent optical properties of the ocean water such as the single scattering albedo as well as on laser beam parameters, e.g. the M squared. Our results may widen the applicability of LIDARs by providing a couple of design considerations for a bathymetric LIDAR.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2823-2829
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• 2010

We investigated the solvent effects on the relative free energies of binding of $Na^+$ and $Li^+$ ions to 12-crown-4 and ${\Delta}log\;K_s$ (the difference of stability constant of binding) by a Monte Carlo simulation of statistical perturbation theory (SPT) in several solvents. Comparing the relative free energies of binding of $Na^+$ and $Li^+$ ions to 12-crown-4, in $CH_3OH$ of this study with experimental works, there is a good agreement among the studies. We have reported the quantitative free energy polarity (of solvent) relationships (QFPR) of the relationship between the relative free energies and solvent polarity studied on the solvent effects on the relative free energies of binding of $Na^+$ and $Li^+$ ions to 12-crown-4.

• Journal of Radiation Protection and Research
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• v.42 no.3
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• pp.154-157
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• 2017

Background: Shielding properties of compound or mixture is presented in terms of mass attenuation coefficients using Monte Carlo simulation. Mass attenuation coefficients of cement, gypsum and the mixture of gypsum and $PbCO_3$ has been investigated using monte carlo MCNPX. Materials and Methods: The mass attenuation coefficients of cement, gypsum and the mixture of gypsum and $PbCO_3$ were calculated for photon energies 365.5, 661.6, 1,173.2, and 1,332.5 keV energies. Results and Discussion: The simulated values of mass attenuation coefficients were compared avaialable experimental results, theoretical values by XCOM and found good comparability of the results. Conclusion: Standard simulation geometry used in the present investigation would be very useful for various types of sample for shielding and dosimetry applications.

• Structural Engineering and Mechanics
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• v.4 no.6
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• pp.703-715
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• 1996

In stochastic analysis, the randomness of the structural parameters is taken into consideration and the response variability is obtained in addition to the conventional (mean) response. In the present paper the structural response variability of plate structure is calculated using the weighted integral method and is compared with the results obtained by different methods. The stochastic field is assumed to be normally distributed and to have the homogeneity. The decomposition of strain-displacement matrix enabled us to extend the formulation to the stochastic analysis with the quadratic elements in the weighted integral method. A new auto-correlation function is derived considering the uncertainty of plate thickness. The results obtained in the numerical examples by two different methods, i.e., weighted integral method and Monte Carlo simulation, are in a close agreement. In the case of the variable plate thickness, the obtained results are in good agreement with those of Lawrence and Monte Carlo simulation.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.1
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• pp.83-89
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• 2015

Selection of efficient supplier is a very important process as risk or uncertainty of a supply chain and its environment are increasing. Previous deterministic DEA and probabilistic DEAs are very limited to handle various types of risk and uncertainty. In this paper, I propose an improved probabilistic DEA which consists of two steps; Monte Carlo simulation and statistical decision making. The simulation results show that the proposed method is proper to distinguish supplier's performance and provide statistical decision background.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.683-686
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• 2008

Flood damage has been increased due to the abnormal climate and extreme rainfall. So, quantitative and qualitative hydrologic data should be improved in oder to enhance accuracy of hydrologic forecast. However, research regarding hydrologic data have not been thorough enough. Therefore, in this study, monte carlo simulation was applied to rainfall runoff model to improve the reliability of runoff analysis and risk analysis. Rainfall-Stage-Discharge curve was developed as a consequence of MCS and it is possible to get correct rating curve for high water level.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.321-323
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• 2004

We developed the monte-carlo simulation code for analysis of the On signal in dental medium. In calculation, we obtain the two different propagation signals as a function of the probing depth. Signal 2 begins to exceed the signal 1 at a very small probing depth(=60${\mu}{\textrm}{m}$). For reduce the signal, detection area is limited to radius and detection angle. As numerical result, probing depth becomes appoximately 500${\mu}{\textrm}{m}$.

• 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.