• Journal of Industrial Technology
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• v.20 no.A
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• pp.285-293
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• 2000

In 1970's, the analysis of shallow substructure was the interests of geological engineering and environmental problems. And seismic refraction method was applied to detect those structures. From 1980's, digital electric industry is rapidly developed and high resolution prospecting equipment is supplied. And seismic reflection method is applied to achieve various data gathering and data analysis. In this study, geophysical prospecting method is applied to calculate the basic data of limestone yield production. Seismic shallow reflection method is used to detect the depth of bedrock and electrical resistivity method is used to detect of limestone layer boundary.

• Journal of Industrial Technology
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• v.21 no.B
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• pp.223-232
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• 2001

This study is finding the most appropriate model of kangwondo watershed. To synthesize each hydrograph, It is found to several parameters which are used in existing hydrographes. then the synthestic hydrograph is compared and investigated with many hydrographes of the rivers in kanwondo. These methods, Nakayasu, Clark, SCS are used to calculate the run-off of this watershed. When the calculated run-off is compared with real rating-curves, then it is found that the SCS method using the Clark's concentrantion time is the best way on this area having large watershed, long river length and gentle water slope, the Nakayasu method is more suitable on this area having small watershed, short river length and steep water slope. Also it is founded from analyzing run-off hydrographes, peak run-off and peak time that the Clark's method applied Kirpich's concentration time way is suitable in the area of kangwondo.

• Journal of Industrial Technology
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• v.20 no.A
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• pp.303-309
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• 2000

Seismic reflection method is applied to detect shallow location of limestone in Chechon area. The data using hammer source is compared with that of weight drop. Small size hammer and weight-drop are used as energy source and 100Hz geophones are used for data aquisition. Data processing is conducted utilizing the available processing technique of "Geobit", which is seismic data processing software developed by KIGAM. The result of above data processing, the velocity of topsoil layer is 1,250m/sec. The velocity of this area is higher than other area because loading trucks pass this area and make this layer compact. And in limestone area, hammer is proposed to energy source instead of weight drop because the energy propagates the layer very well.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.5
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• pp.714-721
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• 2018

This study proposes a risk evaluation method based on RAM and AHP data in order to prevent subjectivity of risk assessment. The risk assessment consist of Risk Likelihood(RL) and Risk Consequence(RC) in five levels. However, risk analysis of warships is hard to make a judgment because of small quantity production(Ship), long building period, equipment changes, complexity, various kinds of equipments, etc. The proposed RAM data and AHP analysis method are used to quantify each level quantitatively. RAM(MTBF) date is used to classify the RL, and AHP analysis is used to classify the RC. These scientific and data-based method will increase objectivity as well as efficiency of risk evaluation.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.11a
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• pp.239-241
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• 2007

In this paper we describe streamer propagations characterizing underwater pre-breakdown and breakdown behaviour under impulse voltages. Streamer corona branches in lower resistivities are much thicker and brighter than those in higher resistivities. The negative streamer channels not only have more branches but also widely spread out than the positive streamer channels. The succession of streamer coronas during re-breakdown produces a stepwise propagation. The pre-breakdown currents consist of the conduction current and streamer corona current pulses.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.49-51
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• 2004

This paper presents a realization of fault detection algorithm and Fieldbus based communication for condition monitoring of check valve. We first acquired the AE(Acoustic Emission) sensor data at the KAERI check valve test loop, extract fault features through the learned Neural network, and send the processed data to a remote site. The overall system has been implemented and experimental results are given to show its effectiveness.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2213-2216
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• 1997

Efficient Switching of IGBT's requires fast gate drivers with high peak currents. This Paper will review the requirements for effient, reliable gate drive of IGBT's and behaviour of an IGBT switching chacteristcs. The purpose of the present paper is to investigate the switching loss mechanisms in IGBT such as MOSFETs in order to give a support to designers of IGBT gate drive circuits in selecting the more appropriate IGBTs to be used on the basics of design repuirements.

• Journal of radiological science and technology
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• v.19 no.2
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• pp.45-49
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• 1996

To determine the utility of spiral computed tomography(CT) in the evaluation of carotid artery stenosis, spiral CT images of 10 patients were compared with both ones of conventional angiography and magnetic resonance(MR) angiography. The severeness of stenosis was determined for each Internal carotid artery on the basis of arterial narrowness : mild stenosis : 40 % or less, moderate stenosis = $40{\sim}70%$, severe stenosis = greater than 70 % of arterial narrowness. The short examination and clear depiction of the arterial lumen In areas of complex or low flow make CT angiography attractive alternative to MR angiography. Spiral CT angiography shows normal and abnormal carotid anatomy well when compared with conventional anglography.

• Journal of the Korean Ceramic Society
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• v.38 no.8
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• pp.687-692
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• 2001

Silicon nitride-La-silicon oxynitride ceramics were fabricated by Spark Plasma Sintering (SPS). The density, crystalline phase and microstructure were compared with those obtained by Hot Pressing (HP). The full density was achieved within 40 min by spark plasma sintering at 1$650^{\circ}C$, whereas the same result was required by hot pressing with a dwell time of 500 min at higher temperature. There were some differences in the microstructure and second phases in the sintered ceramics, which are attributed to the rapid densification in the spark plasma sintering. The fine and acicular grain microstructure appeared in spark plasma sintering.

• Journal of The Korean Digital Architecture Interior Association
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• v.1 no.1
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• pp.9-15
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• 2001

This research is to grasp the identify the curriculum development procedure for architectural computer graphics. In order to achieve the above purpose, this study was carried out job analysis of architectural graphic designer. Architectural Computer Graphics Curriculum is developed by tasks analysis. Each characteristics are as fellow: 1. job-related knowledges are based on architectural design parts, 2. skilled workers should be made on the base of job analysis and O.J.T(On the job training) 3. trained students are related many kinds of all industry parts of Architecture & interior Especially college students have needs for design part of architecture fit on study in these curriculum.