• Title/Summary/Keyword: Monte Carlo (MC) simulation

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A Monte Carlo Simulation for the Newly Developed Head-and-Neck IMRT Phantom: a Pilot Study (제작된 선량 검증용 IMRT 팬텀의 몬테칼로 시뮬레이션: 예비적 연구)

  • Kang, Sei-Kwon;Cheong, Kwang-Ho;Ju, Ra-Hyeong;Cho, Byung-Chul;Oh, Do-Hoon;Kim, Su-SSan;Kim, Kyoung-Ju;Bae, Hoon-Sik;Han, Young-Yih;Shin, Eun-Hyuk;Park, Sung-Ho;Lim, Chun-Il
    • Progress in Medical Physics
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    • v.18 no.3
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    • pp.126-133
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    • 2007
  • A head-and-neck phantom was designed in order to evaluate remotely the quality of the delivery dose of intensity modulated radiation therapy (IMRT) in each institution. The phantom is homogeneous or inhomogeneous by interchanging the phantom material with the substructure like an air or bone plug. Monte Carlo simulations were executed for one beam and three beams to the phantom and compared with ion chamber and thermoluminescent dosimeter (TLD) measurements of which readings were from two independent institutions. For single beam, the ion chamber results and the MC simulations agreed to within about 2% TLDs agreed with the MC results to within 2% or 7% according to which institution read the TLDs. For three beams, the ion chamber results showed -5% maximum discrepancy and those of TLDs were $+2{\sim}+3%$. The accuracy of the TLD leadings should be increased for the remote dose monitoring. MC simulations are a valuable tool to acquire the reliability of the measurements in developing a new phantom.

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The effect of front edge on efficiency for point and volume source geometries in p-type HPGe detectors

  • Esra Uyar ;Mustafa Hicabi Bolukdemir
    • Nuclear Engineering and Technology
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    • v.54 no.11
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    • pp.4220-4225
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    • 2022
  • Monte Carlo (MC) simulations are increasingly being used as an alternative or supplement to the gamma spectrometric method in determining the full energy peak efficiency (FEPE) necessary for radionuclide identification and quantification. The MC method is more advantageous than the experimental method in terms of both cost and time. Experimental calibration with standard sources is difficult, especially for specimens with unusually shaped geometries. However, with MC, efficiency values can be obtained by modeling the geometry as desired without using any calibration source. Modeling the detector with the correct parameters is critical in the MC method. These parameters given to the user by the manufacturer are especially the dimensions of the crystal and its front edge, the thickness of the dead layer, dimensions, and materials of the detector components. This study aimed to investigate the effect of the front edge geometry of the detector crystal on efficiency, so the effect of rounded and sharp modeled front edges on the FEPE was investigated for <300 keV with three different HPGe detectors in point and volume source geometries using PHITS MC code. All results showed that the crystal should be modeled as a rounded edge, especially for gamma-ray energies below 100 keV.

Numerical Analysis and Simulation for the Pricing of Bond on Term-Structure Interest Rate model with Jump (점프 항을 포함하는 이자율 기간구조 모형의 채권 가격결정을 위한 수치적 분석 및 시뮬레이션)

  • Kisoeb Park
    • Journal of Internet Computing and Services
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    • v.25 no.2
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    • pp.93-99
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    • 2024
  • In this paper, we derive the Partial Differential Bond Price Equation (PDBPE) by using Ito's Lemma to determine the pricing of bond on term-structure of interest rate (TSIR) model with jump. From PDBPE, the Maclaurin series (MS) and the moment-generating function (MGF) for the exponential function are used to obtain a numerical solution (NS) of the bond prices. And an algorithm for determining bond prices using Monte Carlo Simulation (MCS) techniques is proposed, and the pricing of bond is determined through the simulation process. Comparing the results of the implementation of the above two pricing methods, the relative error (RE) is obtained, which means the ratio of NS and MCS. From the results, we can confirm that the RE is less than around 2.2%, which means that the pricing of bond can be predicted very accurately using the proposed algorithms as well as numerical analysis. Moreover, it was confirmed that the bond price obtained using the MS has a relatively smaller error than the pricing of bond obtained by using the MGF.

Application and Research of Monte Carlo Sampling Algorithm in Music Generation

  • MIN, Jun;WANG, Lei;PANG, Junwei;HAN, Huihui;Li, Dongyang;ZHANG, Maoqing;HUANG, Yantai
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.10
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    • pp.3355-3372
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    • 2022
  • Composing music is an inspired yet challenging task, in that the process involves many considerations such as assigning pitches, determining rhythm, and arranging accompaniment. Algorithmic composition aims to develop algorithms for music composition. Recently, algorithmic composition using artificial intelligence technologies received considerable attention. In particular, computational intelligence is widely used and achieves promising results in the creation of music. This paper attempts to provide a survey on the music generation based on the Monte Carlo (MC) algorithm. First, transform the MIDI music format files to digital data. Among these data, use the logistic fitting method to fit the time series, obtain the time distribution regular pattern. Except for time series, the converted data also includes duration, pitch, and velocity. Second, using MC simulation to deal with them summed up their distribution law respectively. The two main control parameters are the value of discrete sampling and standard deviation. Processing the above parameters and converting the data to MIDI file, then compared with the output generated by LSTM neural network, evaluate the music comprehensively.

Development of Molecular Simulation Software for the Prediction of Thermodynamic Properties (열역학 물성 예측을 위한 분자 시뮬레이션 소프트웨어의 개발)

  • Chang, Jaee-On
    • Korean Chemical Engineering Research
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    • v.49 no.3
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    • pp.361-366
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    • 2011
  • By using Monte Carlo simulation method we developed a new molecular simulation software which can be used to predict the thermodynamic properties of organic compounds. Starting from molecular structure and intermolecular potential function, rigorous statistical mechanical principles give a probability distribution for the behavior of a system containing many molecules, which enables us to calculate macroscopic thermodynamic properties of the system. The software developed in this work, cheMC, is based on Windows platform providing with easy access. One can efficiently administrate simulations by using an intuitive interface equipped with visualization tool and chart generation. It is expected that molecular simulations supplement the equation of state approach and will play a more important role in the study of thermodynamic properties.

Analysis of Interference between UWB and ITS

  • Park, Se-Ho;Kim, Eun-Cheol;Kim, Jin-Young
    • Journal of electromagnetic engineering and science
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    • v.9 no.4
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    • pp.202-210
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    • 2009
  • In this paper, we have analyzed the effect of interference between ultra-wideband(UWB) and intelligent transport systems(ITS). The maximum possible UWB emission power and minimum possible distance between UWB devices and ITS are found. In order to analyze the interference, we employ the Monte-Carlo(MC) method. We consider six situations, which are indoor office line-of-sight(LOS), indoor office non-line-of-sight(NLOS), indoor residential LOS, indoor residential NLOS, outdoor rural LOS, and outdoor rural NLOS environments. From the simulation results, it is confirmed that coexistence between UWB and ITS devices can be realized in accordance with the emission mask of 19.3 dB for indoor application or 19.3 dB for an image system. And in the outdoors, coexistence between UWB and ITS devices can be realized if the emission mask is at least 1.6 dB for vehicles' radar systems.

Molecular Modeling of the Chiral Recognition of Propranolol Enantiomers by a β-Cyclodextrin

  • Kim, Hyun-myung;Jeong, Karp-joo;Lee, Sang-san;Jung, Seun-ho
    • Bulletin of the Korean Chemical Society
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    • v.24 no.1
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    • pp.95-98
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    • 2003
  • Enantioselectivity of the propranolol on β-cyclodextrin was simulated by molecular modeling. Monte Carlo (MC) docking and molecular dynamics (MD) simulations were applied to investigate the molecular mechanism of enantioselective difference of both enantiomeric complexes. An energetic analysis of MC docking simulations coupled to the MD simulations successfully explains the experimental elution order of propranolol enantiomers. Molecular dynamics simulations indicate that average energy difference between the enantiomeric complexes, frequently used as a measure of chiral recognition, depends on the length of the simulation time. We found that, only in case of much longer MD simulations, noticeable chiral separation was observed.

Investigations on the Chain Conformation of Weakly Charged Polyelectrolyte in Solvents by Using Efficient Hybrid Molecular Simulations

  • Chun, Myung-Suk;Lee, Hyun-Su
    • Macromolecular Research
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    • v.10 no.6
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    • pp.297-303
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    • 2002
  • We have investigated the microstructural properties of a weakly charged polyelectrolyte modeled with both Hookean spring and Debye-Huckel potential, by employing a novel hybrid scheme of molecular dynamics (MD) and Monte Carlo (MC) simulations. Although the off-lattice pivot step facilitates the earlier computations stage, it gives rise to oscillations and hinders the stable equilibrium state. In order to overcome this problem, we adopt the MC off-lattice pivot step in early stage only, and then switch the computation to a pure MD step. The result shows that the computational speed-up compared to the previous method is entirely above 10 to 50, without loss of the accuracy. We examined the conformations of polyelectrolyte in solvents in terms of the end-to-end distance, radius of gyration, and structure factor with variations of the screening effects of solvent and the monomer charges. The emphasis can favorably be given on the elongation behavior of a polyelectrolyte chain, with observing the simultaneous snapshots.

Development of Rating Curve for High Water Level in an Urban Stream using Monte Carlo Simulation (Monte Carlo Simulation을 이용한 도시하천의 고수위 Rating Curve 개발)

  • Kim, Jong-Suk;Yoon, Sun-Kwon;Moon, Young-Il
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.4
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    • pp.1433-1446
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    • 2013
  • In this study, we proposed a methodology to develop Rating Curves for high water level using rainfall generation by the Monte Carlo Simulation (MCS) technique, optimized rainfall-runoff model, and flood routing model in an urban stream. The developed stage discharge Rating Curve based on observed data was contained flow measurement errors and uncertainties. The standard error ($S_e$) for observations was 0.056, and the random uncertainty ($2S_{mr}$) was analyzed by ${\pm}1.43%$ on average, and up to ${\pm}4.27%$. Moreover, it was found that the Rating Curve extensions by way of logarithmic and Stevens methods were overestimated to compare with the urban basin scale. Finally, we confirmed that the high water level extension by random generation of hydrological data using MCS can be reduced uncertainty of the high water level, and it will consider as a more reliable approach for high water level extension. In the near future, this results can be applied to real-time flood alert system for urban streams through construction of the high water level extension system using MCS procedures.

A Monte Carlo Simulation Model Development for Electron Beam Lithography Process in the Multi-Layer Resists and Compound Semiconductor Substrates (다층 리지스트 및 화합물 반도체 기판 구조에서의 전자 빔 리소그래피 공정을 위한 몬테 카를로 시뮬레이션 모델 개발)

  • 손명식
    • Journal of the Korean Vacuum Society
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    • v.12 no.3
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    • pp.182-192
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    • 2003
  • A new Monte Carlo (MC) simulator for electron beam lithography process in the multi-layer resists and compound semiconductor substrates has been developed in order to fabricate and develop the high-speed PHEMT devices for millimeter-wave frequencies. For the accurate and efficient calculation of the transferred and deposited energy distribution to the multi-component and multi-layer targets by electron beams, we newly modeled for the multi-layer resists and heterogeneous multi-layer substrates. By this model, the T-shaped gate fabrication process by electron beam lithography in the PHEMT device has been simulated and analyzed. The simulation results are shown along with the SEM observations in the T-gate formation process, which verifies the new model in this paper.