• 제목/요약/키워드: J-A model

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Phasor Analysis of Sensorless Vector Control System Model for Induction Motor (유도전동기 센서리스 벡터제어 시스템 모델의 페이저 해석)

  • Lee, H.J.;Hwang, J.H.;Seong, S.J.
    • Proceedings of the KIEE Conference
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    • 1998.07f
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    • pp.2015-2017
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    • 1998
  • This paper deals with the design of a field oriented control system model for the high performance induction motor using Matlab with Simulink. The proposed control system model, which is not used the speed and flux sensor, contains IM model, Tranformation, Decoupling, FFOC(Field Flux Orientation Controller), Torque calculator and PI Controller to control speed, torque. Results present the stator and rotor flux phasor trajectory, the startup and transient response of speed, torque and stator current with field oriented control and the response to changes in reference speed with no load. This paper shows that the propose control system is more robust than other vector control system, and suggest the enchanced model, using Matlab with Simulink for the high performance in induction motor control.

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Analysis of Dynamic Characteristics of a Vehicle Undergoing Turning and Braking (선회중 제동을 고려한 차량의 동특성 연구)

  • Kang, J.S.;Yun, J.R.;Min, H.K.;Lee, J.M.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.3 no.3
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    • pp.109-118
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    • 1995
  • This paper presents a mathematical vehicle model to analyze the dynamic characteristics of a vehicle undergoing braking in a turn. Two kinds of field tests, braking in a steady state turn and braking in a J-turn are performed. Computer simulation results are compared with test results and the braking effect on a vehicle cornering behavior is examined. Also, sensitivity analysis is applied to determine the effect of design parameter changes on the response of vehicle dynamic system.

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Calculation of Turbulent Flows around a Ship Model in Drift Motion (사항중인 모형선 주위의 난류 유동 계산)

  • Kim Y. G.;Kim J. J.;Kim H. T.
    • 한국전산유체공학회:학술대회논문집
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    • 1999.05a
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    • pp.66-72
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    • 1999
  • A numerical simulation method has been under development for solving turbulent flows around a ship model in maneuvering motion using the Reynolds Averaged Navier-Stokes equations. The method used second-order finite differences, collocated grids, pressure-Poisson equation and four-stage Runge-Kutta scheme as key components of the solution method. A modified Baldwin-Lomax model is used for the turbulence closure. This paper presents a preliminary result of the computational study on turbulent flows past a ship model in drift motion. Calculations are carried out for a Series 60 $C_B=0.6$ ship model, for which detailed experimental data are available. The results of the present calculations are compared with the experimental data for hydrodynamic forces acting on the model as well as velocity distributions at longitudinal sections. Only fair agreements has been achieved. The computational results show the complex asymmetrical shear flow patterns including three-dimensional separations followed by formation of bilge vortices both in bow and stern regions.

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Surrogate based model calibration for pressurized water reactor physics calculations

  • Khuwaileh, Bassam A.;Turinsky, Paul J.
    • Nuclear Engineering and Technology
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    • v.49 no.6
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    • pp.1219-1225
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    • 2017
  • In this work, a scalable algorithm for model calibration in nuclear engineering applications is presented and tested. The algorithm relies on the construction of surrogate models to replace the original model within the region of interest. These surrogate models can be constructed efficiently via reduced order modeling and subspace analysis. Once constructed, these surrogate models can be used to perform computationally expensive mathematical analyses. This work proposes a surrogate based model calibration algorithm. The proposed algorithm is used to calibrate various neutronics and thermal-hydraulics parameters. The virtual environment for reactor applications-core simulator (VERA-CS) is used to simulate a three-dimensional core depletion problem. The proposed algorithm is then used to construct a reduced order model (a surrogate) which is then used in a Bayesian approach to calibrate the neutronics and thermal-hydraulics parameters. The algorithm is tested and the benefits of data assimilation and calibration are highlighted in an uncertainty quantification study and requantification after the calibration process. Results showed that the proposed algorithm could help to reduce the uncertainty in key reactor attributes based on experimental and operational data.

Pyrolysis Characteristics of Sawdust and Rice Husk (톱밥과 왕겨의 열분해 특성 연구)

  • Park, Dong Kyoo;Seo, Myung Won;Goo, Jeong Hoi;Kim, Sang Done;Lee, See Hoon;Lee, Jae Goo;Song, Byung-Ho
    • Applied Chemistry for Engineering
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    • v.18 no.5
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    • pp.415-423
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    • 2007
  • Pyrolysis characteristics of sawdust and rice husk as biomass resources in a thermogravimetric analysis were determined. Experiments were carried out with a linear heating rate under inert atmosphere of $N_2$ gas. Pyrolysis of the biomass can be classified as a lower temperature reaction zone where the major component of holocellulose is thermally decomposed and a high temperature reaction zone where lignin is thermally decomposed. The obtained data was analyzed by the two-step consecutive reaction model. Activation energies of sawdust and rice husk are found to be respectively 82.5 kJ/mol and 85.1kJ/mol in the low temperature zone according to the first order reaction model and 19.7 kJ/mol, 22.0 kJ/mol in the high temperature zone according to the three-way transport model. The reaction rate constant with variation of heating rate can be well predicted by the kinetic compensation relation of Gaur-Reed.

A TENTATIVE PLAN ON AN ARRANGEMENT AND A MODEL OF UNIVERSITY LIBRARY BUILDING (대학도서관건립(大學図書館建立)에 있어서 배치(配置)와 모형(模型)에 관(関)한 시안(試案) -특(特)히 "J대학" 제(第) 2 도서관(図書館)을 중심(中心)으로-)

  • Choe, Jung-Tai
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.5 no.1
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    • pp.165-184
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    • 1981
  • This study is concerned with a tentative plan on an arrangement and a model of university library building which is the 2nd (branch) library of J. National University in North Jeonla province. At first, it is necessary to have built new library building for undergraduate student in J. National University. Secondary, I studied on the site problems, a model, size and an arrangement planning in this campus. Finally, at least, to install modernized facilities for this library have to require as follows: 1. General Reading Room 2. Reference Room 3. Basic Reading Room 4. Free Reading Room 5. Reserved Room 6. Periodical Room 7. Seminar and Group Study Room 8. Brousing Room 9. Smoking Room 10. Display Hall.

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