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  • Title/Summary/Keyword: Monte Carlo collision

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The analysis on the Energy Distribution Function for Electron in SiH4-Ar Gas Mixtures (SiH4-Ar혼합기체의 전자분포함수 해석)

  • Kim, Sang-Nam
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.53 no.2
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    • pp.65-69
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    • 2004
  • This paper calculates and gives the analysis of electron swarm transport coefficients as described electric conductive characteristics of pure Ar, pure SiH4, Ar-SiH4 mixture gases(SiH4-0.5%, 2.5%, 5%) over the range of E/N = 0.01~300[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. Electron swann parameters in argon were drastically changed by adding a small amount of mono-silane. The electron drift velocity in these mixtures showed unusual behaviour against E/N. It had negative slope in the medium range of E/N, yet the slope was not smooth but contained a small hump. The longitudinal diffusion coefficient also showed a corresponding feature in its dependence on E/N. A two-tenn approximation of the Boltzmann equation analysis and Monte Carlo simulation have been used to study electron transport coefficients.

Diffusion Coefficients in SF6Ar Gas used by MCS-BE Algorithm (MCS-BEq 알고리즘에 의한 SF6Ar 혼합기체의 확산계수)

  • Kim, Sang-Nam
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2006.05a
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    • pp.298-301
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    • 2006
  • This paper describes the electron energy distribution function characteristics in SF6Ar gas calculated for range of E/N values from 50700[Td] by the Monte Carlo simulation(MCS) and Boltzmann equation(BE) method using a set of electron collision cross sections determined by the authors and the values of electron swarm parameters are obtained by time of flight(TOF) method. In this dissertation the results of the combined experimental and theoretical studies designed to understand and predict the spatial growth and transport coefficients for electrons in SF6 and SF6Ar mixtures have described. The ionization and attachment coefficients in pure SF6 and SF6Ar mixtures have been calculated over the range of 10SF6 molecule and for Ar atom proposed by other authors. The results obtained in this work will provide valuable information on the fundamental behaviors of electrons in weakly ionized gases and the role of electron attachment in the choice of better gases and unitary gas dielectrics or electro negative components in dielectric gas mixtures.

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A Two-Dimensional Particle-in-cell Simulation for the Acceleration Channel of a Hall Thruster

  • Lim, Wang-Sun;Lee, Hae-June;Lee, Jong-Sub;Lim, Yu-Bong;Seo, Mi-Hui;Choe, Won-Ho;Seon, Jong-Ho;Park, Jae-Heung
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2008.03a
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    • pp.557-560
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    • 2008
  • A two-dimensional particle-in-cell(PIC) simulation with a Monte-Carlo Collision(MCC) has been developed to investigate the discharge characteristics of the acceleration channel of a HET. The dynamics of electrons and ions are treated with PIC method at the time scale of electrons in order to investigate the particle transport. The densities of charged particles are coupled with Poisson's equation. Xenon neutrals are injected from the anode and experience elastic, excitation, and ionization collisions with electrons, and are scattered by ions. These collisions are simulated by using an MCC model. The effects of control parameters such as magnetic field profile, electron current density, and the applied voltage have been investigated. The secondary electron emission on the dielectric surface is also considered.

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Novel Collision Warning System using Neural Networks (신경회로망을 이용한 새로운 충돌 경고 시스템)

  • Kim, Beomseong;Choi, Baehoon;An, Jhonghyun;Hwang, Jaeho;Kim, Euntai
    • Journal of the Korean Institute of Intelligent Systems
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    • v.24 no.4
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    • pp.392-397
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    • 2014
  • Recently, there are many researches on active safety system of intelligent vehicle. To reduce the probability of collision caused by driver's inattention and mistakes, the active safety system gives warning or controls the vehicle toward avoiding collision. For the purpose, it is necessary to recognize and analyze circumstances around. In this paper, we will treat the problem about collision risk assessment. In general, it is difficult to calculate the collision risk before it happens. To consider the uncertainty of the situation, Monte Carlo simulation can be employed. However it takes long computation time and is not suitable for practice. In this paper, we apply neural networks to solve this problem. It efficiently computes the unseen data by training the results of Monte Carlo simulation. Furthermore, we propose the features affects the performance of the assessment. The proposed algorithm is verified by applications in various crash scenarios.

The Effect of the Collision Process Between Molecules on the Rates of Thermal Relaxation of the Translational-Rotational-Vibrational Energy Exchange (분자간 충돌과정에 따른 병진-회전-진동에너지의 이완율)

  • Heo, Joong-Sik
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.12
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    • pp.1494-1500
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    • 2004
  • A zero-dimensional direct simulation Monte Carlo(DSMC) model is developed for simulating diatomic gas including vibrational kinetics. The method is applied to the simulation of two systems: vibrational relaxation of a simple harmonic oscillator and translational-rotational-vibrational energy exchange process under heating and cooling. In the present DSMC method, the variable hard sphere molecular model and no time counter technique are used to simulate the molecular collision kinetics. For simulation of diatomic gas flows, the Borgnakke-Larsen phenomenological model is adopted to redistribute the translational and internal energies.

A Simulation of Diffusion coefficients for electrons in SF6-Ar Gas Mixtures (시뮬레이션에 의한 SF6-Ar혼합기체의 확산계수)

  • Seong, Nak-Jin;Kim, Sang-Nam
    • Proceedings of the KIEE Conference
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    • 2006.10b
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    • pp.163-166
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    • 2006
  • Energy distribution function for electrons in SF6-Ar mixtures gas used by MCS-BEq algorithm has been analysed over the E/N range 30300(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(%) SF6-Ar mixtures were measured by time-of-flight(TOF) method, The results show that the deduced longitudinal diffusion coefficients and transverse diffusion coefficients 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.

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Probabilistic Approach to Predicting Residual Longitudinal Strength of Damaged Double HullVLCC

  • Huynh, Van-Vu;Lee, Seung-Hyun;Cho, Sang-Rai
    • Journal of Ocean Engineering and Technology
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    • v.25 no.3
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    • pp.1-10
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    • 2011
  • This paper estimates the residual longitudinal strength of a damaged double hull VLCC (Very Large Crude Carrier) under combined vertical and horizontal bending moments using Smith's method. The damage estimated in this study occurred due to collision or grounding accidents. The effects of the randomness of the yield stress, plate thickness, extent of damage, and the combination of these three parameters on the ultimate hull girder strength were investigated. Random variables were generated by a Monte Carlo simulation and applied to the double hull VLCC described by the ISSC (International Ship and Offshore Structures Congress) 2000 report.

Ionization and Attachment Coefficients in Mixtures of SF6 and He (SF6He 혼합기체의 전리와 부착계수)

  • Kim, Sang-Nam
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2005.05a
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    • pp.342-345
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    • 2005
  • This paper describes the electron energy distribution function characteristics in SF6He gas calculated for range of E/N values from 50700[Td] by the Monte Carlo simulation(MCS) and Boltzmann equation(BE) method using a set of electron collision cross sections determined by the authors and the values of electron swarm parameters are obtained by time of flight(TOF) method. The results gained that the values of the electron swarm parameters such as the electron drift velocity, the electron ionization or attachment coefficients, longitudinal and transverse diffusion coefficients agree with the experimental and theoretical for a range of E/N. The results of Boltzmann equation and Monte carlo simulation have been compared with experimental data by Pollock, Ohmori, cottrell and Walker.

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Energy Distribution Function in SF6Ar Mixtures Gas used by Simulation (MCS-BEq 시뮬레이션에 의한 SF6Ar 에너지 분포함수)

  • Kim, Sang-Nam
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2007.05a
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    • pp.193-196
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    • 2007
  • Energy distribution function for electrons in SF6Ar mixtures gas used by Simulation has been analysed over the E/N range 30300[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[%] SF6Ar mixtures were measured by time-of-flight (TOF) method. 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.

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Energy Distribution Function for Electrons in SF6+Ar Mixtures Gas used by MCS-BEq Algorithm (MCS-BEq에 의한 SF6+Ar 혼합기체의 에너지 분포함수)

  • Kim, Sang-Nam;Ha, Sung-Chul
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.878-881
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    • 2002
  • 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[%] SF6+Ar mixtures were measured by time-of-flight(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.

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