• 대한방사선방어학회:학술대회논문집
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• 2011.04a
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• pp.126-127
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• 2011

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.7
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• pp.657-664
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• 2011

This study proposes an inverse method for estimating the boundary temperature in a gas-filled, onedimensional parallel domain enclosed by parallel plates. The distance between the plates is considered submicron to one mm. In the current method, it is assumed that the conditions of both heat flux and temperature are simultaneously applicable to one boundary, while no conditions are applicable to the other boundary The temperature on one of the boundaries should be inversely determined from the known temperature and heat flux on the other boundary. This study proposes a procedure for estimating the unknown boundary temperature through Monte Carlo simulation. Both the forward and inverse problems employ the Monte Carlo approach. The forward (direct) problem is solved by using the direct simulation Monte Carlo while the inverse solution is obtained by the simulated annealing.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.3
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• pp.242-253
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• 2011

The typical missions for the current stand-off UAVs are surveillance and reconnaissance. On the other hand, the primary mission for the future UCAS will be combat mission such as SEAD under the man-made ultimately hostile environment including SAM, antiaircraft artillery, threat radar, etc. Therefore, one of the most important challenges in UCAS design is improvement of survivability. The current studies for aircraft combat survivability are focused on the improvement of susceptibility and vulnerability of manned aircraft system. Although the survivability design methodology for UCAS might be very similar to the manned combat system but there are some differences in mission environment, system configuration, performance between manned and unmanned systems. So the parameters and their sensitivities which affect aircraft combat survivability are different in qualitatively and quantitatively. The susceptibility related parameters for F-16 C/D and X-45A as an example of manned and unmanned system are identified and the susceptibility parameter sensitivities are analyzed by using Monte-Carlo Simulation in this study.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.6
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• pp.625-633
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• 2015

In this study, a coupled probabilistic framework is developed to assess wind risk on apartment buildings by using the convolution of wind hazard and fragility functions. In this framework, typhoon induced extreme wind is estimated by applying the developed Monte Carlo simulation model to the climatological data of typhoons affecting Korean peninsular from 1951 to 2013. The Monte Carlo simulation technique is also used to assess wind fragility function for 4 different damage states by comparing the probability distributions of the window system's resistance performance and wind load. Wind hazard and fragility functions are modeled by the Weibull and lognormal probability distributions based on simulated wind speeds and failure probabilities. The modeled functions are convoluted to obtain the wind risk for the different damage levels. The developed probabilistic framework clearly shows that wind risk are influenced by various important characteristics of terrain and apartment building such as location of building, exposure category, topographic condition, roof angle, height of building, etc. The risk model presented in this paper can be used as tools to predict economic loss estimation and to establish wind risk mitigation plan for the existing building inventory.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.3
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• pp.203-211
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• 2023

A Markov chain Monte Carlo (MCMC) simulation is proposed for probabilistic full waveform inversion (FWI) in a layered half-space. Dynamic responses on the half-space surface are estimated using the thin-layer method when a harmonic vertical force is applied. Subsequently, a posterior probability distribution function and the corresponding objective function are formulated to minimize the difference between estimations and observed data as well as that of model parameters from prior information. Based on the gradient of the objective function, a proposal distribution and an acceptance probability for MCMC samples are proposed. The proposed MCMC simulation is applied to several layered half-space examples. It is demonstrated that the proposed MCMC simulation for probabilistic FWI can estimate probabilistic material properties such as the shear-wave velocities of a layered half-space.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.62.1-62.1
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• 2005

• Journal of Radiation Protection and Research
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• v.26 no.2
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• pp.67-71
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• 2001

In order to shield the neutrons affecting the background of Low Level Gamma Ray Spectrometer, a neutron shielder was designed. The method used in this study for neutron shielding was the deceleration of fast neutrons by high density polyethylene(HDPE) and the absorption of those slowing-down neutrons by $B_4C$. The calculation results of neutron Interaction in HDPE using Monte Carlo simulation code MCNP4B showed that the thermal-neutron flux was maximum at 10 cm thickness of HDPE. The results also showed that 95% of the thermal neutrons were absorbed by 2 mm thickness of $B_4C$ absorber Consisted of 30 w% $B_4C$ and 70 w% polymer. The results of the Monte Carlo calculation were in good agreement with the experimental value obtained by a neutron shielding apparatus designed for this purpose.

• Journal of Conservation Science
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• v.27 no.2
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• pp.127-134
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• 2011

In this study, there has been investigated the simulation of irradiation dose using Monte Carlo methodology and experimental substantiation for the biological control of wooden cultural property. In the evaluation of fungal contamination on wooden cultural property, Dongyae, from exhibition storage, Aureobasidium pullulans was mainly identified. But these microorganisms were completely inactivated by 20 kGy gamma irradiation. For dosimetry simulation of Dongyae, Monte Carlo methodology with MCNP was used. The real dosimetry was measured using alanin dosimeters (at 7 different points on the front plan and 7 points on the back plan). Simulated and experimental results are compared and good agreement is observed. These result shows that irradiation can offer biologic control of wooden cultural property by optimal irradiation dose through high penetration power and Monte Carlo simulation.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2004.11a
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• pp.33-35
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• 2004

방사선치료를 위한 고에너지 광자선의 품질관리를 위해 사용하는 TLD의 광자선 선질에 대한 에너지 의존도를 몬테카를로 모사법을 사용하여 평가하였다. IAEA 선량보증사업에 이용되는 LiF TLD 및 홀더를 EGS4기반의 사용자 코드인 DOSIMETER 와 MCNP4C 몬테카를로 코드를 사용하여 기하학구조를 구성하고, Co, 4, 6,10 밑 15 MV 광자선을 시뮬레이션하였다. DOSIMETER계산 결과를 통해 TLD의 에너지 보정인자가 실험 데이터와 일치함을 확인할 수 있었으며, 이와 별도로 캡슐에 의한 교란량도 무시할 수 없음을 발견하였다.

• Journal of radiological science and technology
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• v.40 no.2
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• pp.269-274
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• 2017

In this research, we simulated the elementary star shielding ability using Monte Carlo simulation to apply medical radiation shielding sheet which can replace existing lead. In the selection of elements, mainly elements and metal elements having a large atomic number, which are known to have high shielding performance, recently, various composite materials have improved shielding performance, so that weight reduction, processability, In consideration of activity etc., 21 elements were selected. The simulation tools were utilized Monte Carlo method. As a result of simulating the shielding performance by each element, it was estimated that the shielding ratio is the highest at 98.82% and 98.44% for tungsten and gold.