• Journal of Biosystems Engineering
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• v.24 no.3
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• pp.195-208
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• 1999

A computer simulation was carried out to investigate draft characteristics of Korean paddy field for obtaining the basic reference to the selection of optimum moldboard type suitable for Korean paddy field conditions. Cylindrical, cylindroidal, semihelical moldboard plows, and one type of oriental Janggi were used for simulation. A series of soil bin experiments was conducted to compare the experimental results with the predicted drafts from computer simulation using the cylindroidal moldboard plow. The computer model predicted draft force with 1~12% error at 12~16cm plowing depth which is the most conventional plowing depth in the rural area in Korea. Thus, the computer model was considered to be good enough for simulation. Due to the different plowing width of experimental plows, specific draft was selected for comparison by computer simulations. Specific draft of cylindrical moldboard plow was ranged from 3 to 6 N/$\textrm{cm}^2$ according to the soil conditions, plowing speed and plowing depth, 2.5~3.0 N/$\textrm{cm}^2$ for semihelical moldboard plow.

• The Korean Journal of Emergency Medical Services
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• v.16 no.3
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• pp.63-75
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• 2012

Purpose : This study was attempted to explore the paramedic student's experience on simulation education. Methods : Data were collected through in-depth interviews from 15 paramedic students. The study was analyzed by phenomenological method, specifically Colaizzi's method. From the protocol, significant statements were organized into formulated meanings. Results : The formulated meanings were identified 35 themes, 12 theme clusters, and 6 categories. The 6 categories include burden of demonstration, role experience as a paramedic, confidence in field treatment, sense of disjunction caused by difference from real situation, realization and learning by oneself, and sense of stability from hypothetical situation. Conclusion : This study suggested that, even though some negative perceptions were observed, simulation education will fit as a replacement for the field practice of paramedic's students given that more field-like practice environment and repetitive simulation education are present.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.176-187
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• 2015

DC bias will cause abnormal vibration of transformers. Aiming at such a problem, transformer vibration affected by DC bias has been studied combined with transformer core and winding vibration mechanism use multi-physical field simulation software COMSOL in this paper. Furthermore the coupling model of electromagnetic-structural force field has been established, and the variation pattern of inner flux density, distribution of mechanical stress, tension and displacement were analyzed based on the coupling model. Finally, an experiment platform has been built up which was employed to verify the correctness of model.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.4
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• pp.319-326
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• 2004

The soundscape is a novel attempt to offer comfortable sound environments at the urban public spaces by adding pleasant sounds and removing unagreeable ones. Most important factors to be considered therein are to determine what kind of sounds to offer and how to adjust them to the changing circumstances. But, installing, maintaining and adjusting the soundscape system directly in the field will ensue numerous problems as well as high costs. Thus, it is essential to devise a test method to analyse and verify the outcome before the actual installation in the field takes place. This study aims at devising the instrument system that enables to control. with a great ease, numerous variables. reproduce most agreeable sound sources, and can verify the effects on the virtual simulatory settings, which is named as Virtual Acoustic Field Simulation System (VAFSS).

• Journal of Mechanical Science and Technology
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• v.18 no.4
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• pp.597-605
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• 2004

Turbulent temperature field in a channel subject to strong wall injection has been investigated via direct numerical simulation technique. These flows are pertinent to internal flows inside hybrid rocket motors. A simplified model problem where a regression process at the propellant surface is idealized by wall injection has been investigated to understand how the temperature field is modified. The effect of strong wall injection displaces thermal boundary layer away from the wall and this causes a sharp drop of friction temperature. Turbulent diffusivity and dissipation time scale for temperature field are found to show large variations in the streamwise direction under application of wall blowing. It is, thus, expected that more sophisticated turbulence models would be required to predict the disturbed temperature field accurately.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.9
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• pp.407-411
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• 2003

The purpose of this paper is to study the removal of nitrogen oxide(NOx) using a wire-plate type plasma reactor with magnet attached for indoor air purification. In order to produce a more effective reactor, we conducted magnetic field simulations. The results of the magnetic field simulations show that NOx can be removed more effectively. The results from the magnetic field simulation show that when 7 magnets were applied to the reactor, the magnetic flux density was at its highest amount than when using 0, 3, or 5 magnets. From the data obtained by the simulation results a plasma reactor was made and thus, several experiments were conducted. The best removal efficiency was obtained with 14 W AC power to the reactor with 5 magnets.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.5
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• pp.307-311
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• 2016

Although there are existing Residual Current Protective Device (RCD) including detect electric leakage and elements such as short circuit and surge, the occurrence of incidents caused by electric faults, including fire, are still constant. The purpose of this study is to analyze the causes of accidents through the electric field distribution in the interpretation of the fault contact breaker. Simulation results by the arc fault has shown the convergence of temperature and electric field to the defect. Through their simulation results, the main cause of erosion phenomena in circuit breaker bar is the electric arc by concentration of electric field not due to dissolve by temperature.

• Journal of the Korea Society for Simulation
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• v.4 no.2
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• pp.69-78
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• 1995

Simulation is generally used for the performance analysis and optimization of manufacturing systems. Therefore in this paper using the simulation techniques we obtain the information about the efficiency improvement and the optimization. Because simulation optimization method is subjected to the applied field and environment the general simulation optimization method does not exist. So we do not take the fixed optimization procedure but suggest the alternative one which is modified for applied field. This procedure supplies the optimized simulation information and helps improve the productivity of Geared-Motor assembly line. In order to optimize the manufacturing system we use two simulation languages, FACTOR/AIM and SLAMSYSTEM. The former gives the abundant output information. The latter gives the flexibility in simulation modeling.

• International Journal of Contents
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• v.6 no.2
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• pp.6-9
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• 2010

Using symplectic relation and reaction concept, we propose a planar near-field antenna measurement method. A generalized probe compensation equation is deduced to obtain the probe correction formulation. To verify our approach, a reflector antenna with $1{\times}2$ horn array is fabricated and measured in the near-field measurement facility. The near-field measurement results are compared with the physical optics (PO) simulation. The results of measurement and simulation agree very well near to the mainbeam.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.205-208
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• 2001

A lumped electrical circuit is an approximate representation of the field within a curtain frequency range. The finite element modelling is a synonym of the equivalent circuit. The electric conduction field and electric potential wave field have been modelled by an admittance network and an LC low-pass filter network. Here in the present paper, the equivalent magnetic circuit representation is created for a magnetostatic field by the finite element modelling in two dimension.