• Title/Summary/Keyword: Characteristic Equation

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Analysis of Dynamic Behavior in GMAW System (GMA용접 시스템의 동적 거동에 대한 해석)

  • 이재영;최재형;이지혜;유중돈
    • Journal of Welding and Joining
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    • v.18 no.5
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    • pp.41-48
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    • 2000
  • Dynamic behaviors of the GMAW system are simulated using the short-circuit transfer model and the characteristic equations fir the power supply, wire system and arc. The conventional wire equation, which relates the rate change of the wire extension to the wire feed rate and melting rate, is modified to include effects of the molten drop attached at the wire tip. The modified wire equation describes behaviors of the GMAW system more precisely and provides information about the initial bridge volume for short-circuit transfer. The proposed short-circuit model predicts the variation of parameters such as the current, voltage, short-circuit frequency and time considering the effects of the surface tension and electromagnetic force due to current. The calculated results are in broad agreements with the experimental results under the argon shielding condition.

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Dynamic Characteristic Analysis of Linear Oscillatory Actuator Considering Inverter Driver (인버터 특성을 고려한 리니어 진동 엑추에이터의 동특성 해석)

  • Eum, Sang-Joon;Lim, Ki-Chae;Kim, Duk-Hyun;Kang, Gyu-Hong;Hong, Jung-Pyo;Kim, Gyu-Tak
    • Proceedings of the KIEE Conference
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    • 2000.07b
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    • pp.897-899
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    • 2000
  • This paper deals with the dynamic characteristic analysis of Linear Oscillatory Actuator (LOA) considering Sine Pulse Width Modulation (SPWM) method with H-bridge driver. The input current shape obtained by the driver has great influence on the driving performance of LOA. Therefore, according to the various current shapes, the analysis is achieved by using the combined equation between kinetic and electric circuit equation. Moreover, the parameters in the electric circuit equation are accurately estimated by using FEM.

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Real gas equation of state and upwind scheme (실제기체 상태방정식과 풍상차분기법)

  • Choi Jeong-Yeol;Kim Chin-Su;Oh Se-Jong
    • 한국전산유체공학회:학술대회논문집
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    • 2000.05a
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    • pp.153-158
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    • 2000
  • For the analysis of compressible flow with real gas effect, characteristic form of Roe's Riemann solver was derived again using real gas equation of state and variable specific heal and it was extended to multi component reactive system. From this study, it is known that some correction should be made for the use of existing numerical algorithm. 1) Sonic speed and characteristic variable should be corrected with real gas effect. 2) Roe's average was applicable only with the assumption of constant properties. 3) Artificial damping term and characteristic variables should be corrected but their influence may not be significant.

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Starting Characteristic Analysis of a Slotless type Permanent Magnet Linear Synchronous Motor using 3-D Space Harmonic Method (3차원 공간고조파법을 이용한 슬롯리스형 영구자석 선형 동기 전동기의 기동특성 해석)

  • An, Ho-Jin;Gang, Gyu-Hong;Kim, Gyu-Taek
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.51 no.7
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    • pp.379-386
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    • 2002
  • This paper deals with dynamic analysis method of a slotless type permanent magnet linear synchronous motor(PMLSM) using 3-dimensional space harmonic method. The results are good agreement with FEA results because that slotless type PMLSM has simple structure and no saturation of core. And then, Under open-loop control, starting characteristic is analyzed by voltage equation combining with dynamic equation. In order to obtain more accuracy results, this paper use instantaneous back-EMF and thrust instead of back-EMF constant and thrust constant.

Transient and Stationary Analyses of the Surplus in a Risk Model

  • Cho, Eon Young;Choi, Seung Kyoung;Lee, Eui Yong
    • Communications for Statistical Applications and Methods
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    • v.20 no.6
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    • pp.475-480
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    • 2013
  • The surplus process in a risk model is stochastically analyzed. We obtain the characteristic function of the level of the surplus at a finite time, by establishing and solving an integro-differential equation for the distribution function of the surplus. The characteristic function of the stationary distribution of the surplus is also obtained by assuming that an investment of the surplus is made to other business when the surplus reaches a sufficient level. As a consequence, we obtain the first and second moments of the surplus both at a finite time and in an infinite horizon (in the long-run).

The Characteristic Calulation of Carboxylic Ion Exchanger.

  • Son, Won Geun;Kim, Tae Il;Kim, Sang Heon;Park, Su Gil;Jeong, Jang Hun
    • Bulletin of the Korean Chemical Society
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    • v.22 no.6
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    • pp.559-564
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    • 2001
  • A method for calculating the main characteristics of a potentiometric titration curve in a carboxylic ion exchanger has been investigated. The potentiometric titration curves of simple electrolyte and ion exchangers (polyelectrolytes) showed a great difference between them. The acidity parameters of the ion exchangers, the thermodynamic constant (pK0), apparent equilibrium constant (K), and correction for the apparent equilibrium constant (b), were introduced and used to express the characteristics of the carboxylic ion exchanger. A characteristic equation related to the acidity parameters of the ion exchangers systems was derived. A fibrous carboxylic cation exchanger was used and potentiometric titration curves at different concentrations of the supporting electrolyte were obtained . To prove the validity of the characteristic equation, the concentration of the supporting electroyte was varied. In the present study, good agreement between the data points and the fitted curves was found in all the cases. The g (number of moles of alkali to 1 g of ion exchanger) of carboxylic ion exchanger was calculated from the concentration of supporting electrolyte (C), pH of the solution, and degree of neutralization of ion exchanger (x).

A Study on Dynamic Characteristic Analysis of Straight Bevel Gear (직선베벨기어의 동특성해석에 관한 연구)

  • Lyu, Sung-Ki;Shin, Gue-Su
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.12
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    • pp.157-164
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    • 1995
  • Straight belvel gear is used mainly for steering system, final reduction and differential gear in the automobile. The more high load, high velocity driving bevel gear, the more unsafe and unpleasant. In thid study, we get a kinematic equation by modelling straight bevel gear pair with simple elastic system, the dynamic characteristic analysis about this system, we got the dynamic load factor of tooth surface. Comparing the value of dynamic load factor by calculation with the measured value of Terauchi's experimental results is similar. We think it useful to analysis the vibration and the noise of straight bevel gear in operation with the analytic method of dynamic load of straight bevel gear using in this study.

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Electron Energy Distribution function in CH4 by MCS-BEq (MCS-BEq에 의한 CH4기체에서 전자에너지 분포함수)

  • Kim, Sang-Nam
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.62 no.1
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    • pp.18-22
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    • 2013
  • This paper describes the information for quantitative simulation of weakly ionized plasma. We must grasp the meaning of the plasma state condition to utilize engineering application and to understand materials of plasma state. Using quantitative simulations of weakly ionized plasma, we can analyze gas characteristic. In this paper, the electron transport characteristic in $CH_4$ has been analysed over the E/N range 0.1~300[Td], at the 300[$_{\circ}\;K$] by the two term approximation Boltzmann equation method and Monte Carlo Simulation. Boltzmann equation method has also been used to predict swarm parameter using the same cross sections as input. The behavior of electron has been calculated to give swarm parameter for the electron energy distribution function has been analysed in $CH_4$ at E/N=10, 100 for a case of the equilibrium region in the mean energy. A set of electron collision cross section has been assembled and used in Monte Carlo simulation to predict values of swarm parameters. 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.

Characteristic Responses of Biosensor Based on $H^+$-Selective Membrance Electrode (H$^+$ 선택성 막 전극을 이용한 바이오센서의 감응 특성)

  • Kim, Ki-Myo;Park, Sung-Bae;Hwang, Myoung-Seok;Hur, Moon-Hye;Ahn, Moon-Kyu
    • YAKHAK HOEJI
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    • v.40 no.6
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    • pp.625-631
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    • 1996
  • The $H^+$-selective membrane consists of tridodecylamine, 2-nitrophenyl octyl ether and a little amount of additive in carboxylated PVC matrix, where penicillinase(Pcase ) and glutaraldehyde may be covalently attached to the matrix. When the $H^+$-selective electrode was used as a detector of biosensor, calibration curve calculated from Nernst equation was not linear. So we investigated the characteristic responses of the $H^+$-selective electrode to the product H+ from hydrolysis of penicillin-G(Pc-G) and plotted calibration curve correlating potential to concentration of Pc-G linearly. The optimal concentration of buffer solution was theoretically calculated and was also experimented. We tried to explain the linear curve of potential to concentration of Pc-G by using Henderson-Hasselbach equation. This method is more effective in calibration curve plotting than any other previous methods. The results obtained may help in further developing pH electrodes with improved analytical preformance.

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Prediction of the Volumetric Water Content Using the Soil-Water Characteristic Curve on an Unsaturated Soil (흙-수분 특성곡선 방정식을 이용한 체적함수비의 예측)

  • Song, Chang-Seob
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.7 no.6
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    • pp.39-48
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    • 2004
  • The purpose of this paper was to confirm the application of the equation of the soil-water characteristic curve on an unsaturated soil. To this ends, a series of suction test was conducted on the selected 4 kinds of soil which is located in Korea, using the modified pressure extractor apparatus. And it was carried out to analyze the experimental parameters which can describe the soil-water characteristics, were determined by using the data obtained from the experiment. From the results, it was found that the matric suction was varied according to the grain size distribution, amount of fine grain particle and void ratio. Also it was found that the residual volumetric water content was decreased with the void ratio, but the index related air entry value, the soil parameter related water content and the parameter with residual water content were increased with the void ratio. And the application of equation of the soil-water characteristic curve was confirmed for the various conditions and the various state by the comparison between the volumetric water content measured by the experiment and the predicted values.