• Journal of architectural history
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• v.26 no.1
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• pp.83-92
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• 2017

This paper studied Lee Han-Choel's career who was known as the first Korean who had participated in several survey and repair projects of Korean historic buildings as a field engineer during the Japanese colonial era. This paper investigated documents and drawings to find out what he had done specifically in the field, and distinguished the records he had written by handwriting comparison method. In addition, the author analyzed the contents of the articles he published and clarified their significance in Korean architectural history. Through this study, the author expected to clarify Lee's historical status as the first Korean modern expert in the field of historic building conservation, and to supplement the research for the history of Korean during the Japanese colonial era.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.208-213
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• 2016

In order to detect the exact position of high-speed train, it is necessary to obtain location information from the transponder tag installed along the track. When the transponder tag receives the energizing signal from the train, it sends a telegram to the reader, which includes location information. In high-speed railway environment, this telegram can be corrupted by electromagnetic interference caused by onboard electric train power equipments or wayside devices. In order to assess the performance of transponder system under this harsh environment, we carried out field test using HEMU-430X. Field test results are briefly introduced and discussed for the evaluation of the transponder system under development.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.285-291
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• 2003

An experimental method to measure Q-parameter in-situ is described. The basic idea comes from the fact that the side necking near a crack tip indicates the loss of stress triaxiality, which can be scaled by Q. From the out-of-plane displacement and the in-plane strain near the surface of side necking, stress field averaged through the thickness is calculated and then Q is determined from the difference between the stress field and the HRR field corresponding to the identical J-integral. To prove the validity, three-dimensional finite element analysis has been performed for a CT configuration with side-groove. Q-value which was calculated directly from the near-tip stress field is compared with that determined by simulating the experimental procedure according to the proposed method, that is, the Q-value determined from the lateral displacement and the inplane strain. Also, the effect of location where the displacement and strain are measured is explored.

• Journal of the Korean Society of Safety
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• v.13 no.1
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• pp.70-76
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• 1998

The smoke filling process for the atrium space containing a fire source is simulated using two types of deterministic fire models : Zone model and Field model. The zone model used is the CFAST(version 1.6) model developed at the Building and Fire Research Laboratories, NIST in the USA. The field model is a self-developed fire field model based on Computational Fluid Dynamics(CFD) theories. This article is focused on finding out the smoke movement and temperature distribution in atrium space which is cubic in shape. A computational procedure for predicting velocity and temperature distribution in fire-induced flow is based on the solution, in finite volume method and non-staggered grid system, of 3-dimensional equations for the conservation of mass, momentum, energy, species and so forth. The fire model i. e. Zone model and Field model predicted similar results for the clear height and the smoke layer temperature.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.95-97
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• 1999

This paper describes electromagnetic repulsion force of multipolar axial magnetic field type electrodes for vacuum interrupter used in vacuum circuit breaker. It was distinguished that repulsion force of multipolar axial magnetic field type electrode in consideration of eddy current effect between upper electrode and lower electrode by finite element method. And it was found out that suitable contact weight of multipolar axial magnetic field type electrode for vacuum circuit breaker from repulsion force analysis results by finite element method.

• Management & Information Systems Review
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• v.14
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• pp.51-65
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• 2004

We consider the Fuzzy clustering which is devised for partitioning a set of objects into a certain number of groups by assigning the membership probabilities to each object. The researches carried out in this field before show that the Fuzzy clustering concept is involved so much that for a certain set of data, the main purpose of the clustering cannot be attained as desired. Thus we Propose a new objective function, named as Fuzzy-Entroppy Function in order to satisfy the main motivation of the clustering which is classifying the data clearly. Also we suggest Mean Field Annealing Algorithm as an optimization algorithm rather than the ISODATA used traditionally in this field since the objective function is changed. We show the Mean Field Annealing Algorithm works pretty well not only for the new objective function but also for the classical Fuzzy objective function by indicating that the local minimum problem resulted from the ISODATA can be improved.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.300-305
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• 2004

A preliminary study on. field emitter array cathodes was conducted aiming at applying for electrodymanic tether (EDT) propulsion systems. The EDT propulsion systems are assumed to use for active removal systems of post-mission spacecraft, which would otherwise become space debris. A survey on field emit-ter array cathode technology was conducted, and it showed that carbon nanotube (CNT) emitters are suit-able to EDT application. Trial fabrications and evaluation tests of CNT emitters were conducted, which demonstrated a target emission current density of 10 ㎃/$\textrm{cm}^2$. It was found out that the most important technical issue for developing CNT emitters is to improve the performance against voltage breakdown between the emitter and the opposite electrode.

• Journal of the Korean Society of Tobacco Science
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• v.12 no.2
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• pp.91-101
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• 1990

A field experiment was conducted to find out the effects of field productivity, variety and nitrogen rate on the yield, quality, chemical constituents and physical properties of burley cured leaf in three field with different productivity(Degree of field productivity: A ; high, B ; medium, C : low) during successive two years(1988~89). The yield and quality were remarkably lowered when nitrogen fertilizer being applied much in low productive field. As compared with Burley 21, KB101 showed high yield, particularly the yield of KB101 in low productive field was relatively high. The effect of nitrogen rate on the yield was somewhat different according to field productivity and production year. When the nitrogen fertilizer being applied above 22.5kg/10a, the added nitrogen had no effect on the yield. Total nitrogen content of cured leaf grown in low productive field was high while total alkaloid was low, therefore total alkaloid/total nitrogen ratio was remarkably low. The lightness, red and yellow color of cured leaf grown in low productive field was remarkably low. As compared with Burley 21, the contents of total alkaloid and total nitrogen and shatter resistance index of cured leaf was somewhat low, while the filling power, lightness, red and yellow color were slightly high. Total nitrogen content of cured leaf was increased remarkably by nitrogen addition, but total alkaloid was not increased though the nitrogen fertilizer being applied above 22.5kg/10a. The filling power and shatter resistance index of cured leaf grown in high nitrogen plot, and the lightness and yellow color were low while the red color was relatively high. It comes into question that the visual quality being increased as well as increment of yield and nitrogenous compounds by nitrogen addition in high productive field. In low productive field, it is considerable that nitrogen addition for high yield should be prohibited because it causes the decrement of yield and quality, on the contrary.

• Journal of the Korean Society for Library and Information Science
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• v.51 no.2
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• pp.133-156
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• 2017

This study was performed to find out how to improve the usefulness and effectiveness of the field practice program in Library and Information Science by diagnosing the practical instructor's perception of the overall field practice in the Library and Information Science. To achieve this goal, we conducted a research on the current situation and a measurement in perception of the field practice program through a survey of practical instructors at practical training institutions. We, then, analyzed the factors affecting the perception and examined the relationship between the effects. As a result of investigating the factors affecting the perception of field practice, 'operational accountability for the field practice program' was found to be a significant factor among other factors such as the general characteristics of the practical instructors, the characteristics of library related work and the field practice status of the practical training institutions. And factors of 'practice environment' and 'practice instruction method' have been identified to have a significant impact as a result of analyzing how the six factors constituting the perception of field practice effect on the overall perception of field practice of the practical instructors.

• Journal of Power System Engineering
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• v.13 no.1
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• pp.13-18
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• 2009

In this study, flow characteristics at the regulators, which is very important for clean gas supply systems for semiconductors and LCD industries, are investigated. Numerical simulations are carried out to visualize flows at regulators for several flow rates and to investigate pressure losses at some parts in the regulator. Velocity field at the regulator along with the detailed velocity field near the spring and near the valve is shown. New regulator models are proposed in this paper, and numerical simulations are also carried out to visualize flows at regulator for several flow rates, and to investigate pressure losses at the parts in new models. Pressure drops a lot across the valve seat. Pressure drop increases as mass flow rate increases. Especially for small opening, pressure drop increases rapidly as mass flow rate becomes large.