• 한국전기전자재료학회논문지
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• 제20권2호
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• pp.135-141
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• 2007

The conduction-cooled HTS SMES is operated in cryogenic and high vacuum condition. Thus, Insulation design at cryogenic temperature and high vacuum is a key and an important element that should be established to accomplish miniaturization that is a big advantage of HTS SMES. However, the behaviors of insulators for cryogenic conditions in vacuum are virtually unknown. Therefore, we need active research and development of insulation concerning application of the conduction-cooled HTS SMES. Therefore, in this study, we experimented about insulation characteristic high vacuum and cryogenic similar to driving condition of SMES system. Also, investigated about insulation characteristic of suitable some materials to insulator for conduction-cooled HTS SMES. As this results, we possessed basis data for insulation materials selection and insulation design for development of 600 kJ class conduction-cooled HTS SMES.

• 한국해양공학회지
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• 제22권3호
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• pp.41-46
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• 2008

It is a recent trend for advanced ships and submarines to incorporate composite structures with viscoelastically damping material. Much research has been done on curve-fitting techniquesto identify vibration characteristic parameters such as natural frequencies, modal damping ratios, and mode shapes of the composite structure. In this study, an advanced technique for accurately determining vibration characteristic of a circular cylindrical shell-attached viscoelastically damping material is used, based on a multi-degree of freedom (MDOF) curve-fitting method. First, an initial value is obtained by using a linear least square method. Next, using the initial value, the exact modal parameters of the composite circular cylindrical shell are obtained by using a nonlinear least square method. Results show computation time is greatly decreased and accurate results are obtained by the MDOF curve-fitting method.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2007년도 추계 학술논문 발표대회
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• pp.67-70
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• 2007

In this study, the characteristic of strength development of high volume fly ash concrete(HVFAC) was experimentally investigated. The production of one ton of portland cement releases about 0.87ton of CO2 into the atmosphere. HVFAC is an emerging material technology and is environmentally friendly because of its reduced use of portland cement, reduced CO2 emissions. For this purpose, two levels of W/B were selected. Seven levels of fly ash replacement ratios and two levels of silica fume replacement ratios were adopted. In the concrete mix, the water content of 125kg/m3 was used, which is less than that of usual water content. As a result, it was observed that the slump of concrete was increased with the increasing fly ash replacement ratio and when the silica fume was incorporated into the concrete, the slump was significantly decreased at the same condition. It appeared that the compressive strength gradually decreased with increasing fly ash replacement ratio at the early age, but the difference of strength up to replacement ratio of 50% was little at the age of 91 days because of the pozzolanic reaction of fly ash.

• 한국정보통신학회논문지
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• 제14권5호
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• pp.1085-1092
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• 2010

본 논문에서는 최적화 알고리즘인 PSO를 이용하여 한국인의 생활자계 노출실태 조사 시 확보한 16세 이하의 미취학 아동, 초등학생, 중학생 실측 데이터베이스를 활용하여, 자계노출의 정도를 실측에 의하지 않고 추정할 수 있는 '24시간 소아고노출 생활자계 추정식'을 개발하였다. 24시간 개인자계 노출량 추정식의 입력 데이터는 성, 연령, 주거형태, 주거지 크기, 선로이격거리 및 송전전압을 사용하였다. 그리고 16세 이하에 대해서 24시간 고노출 개인자계 노출분포, 자계노출의 특성, 특정 조건별 자계노출특성 등을 분석하였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1018-1020
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• 2003

The costal area where takes up over 32% in domestic teritory is considered as very importantly because it has not only economic facilities such as harbor and an industrial complex but also recreation facilities. Moreover, the tidal flat area has been used as culture ponds and salt farms because this area is occupied by various oceanic species. Also, the tidal flat area has played an important role to purify ocean pollution and maintain an ecosystem. However, the costal ecosystem has seriously threatened by domestic reclamation projects and a large-scale tide embankment during recent 10 years in Korea. This serious problem results in loosing 34%(810$km^2$) of the entire domestic costal area. In this paper, the micro-landform in the tidal flat area, which is called as Garolim bay in Korea, is classified by using Landsat TM images also verified through a filed report. Through the result of this, the tidal flat area is expected to manage efficiently especially through analyzing sediment environment and characteristic of grain size by using satellite images.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.226-227
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• 2006

The conduction-cooled HTS SMES is operated in cryogenic and high vacuum condition. Thus, Insulation design at cryogenic temperature and high vacuum is a key and an important element that should be established to accomplish miniaturization that is a big advantage of HTS SMES. Therefore, we need active research and development of insulation concerning application of the conduction-cooled HTS SMES. Therefore, in this study, we experimented about insulation characteristic high vacuum and cryogenic similar to driving condition of SMES system. Also, investigated about insulation characteristic of suitable some materials to insulator for conduction-cooled HTS SMES. As this results, we possessed basis data for insulation materials selection and insulation design for development of 600 kJ class conduction-cooled HTS SMES.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.349-352
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• 2003

A personal low-frequency stimulator is a portable device to relax muscle pains of a person. The stimulator generates combined low-frequency pulses to be applied to pads attached to painful muscles. This paper reports a development of such device with its characteristic analyses. The major components of our stimulator are MCU, high-voltage generating circuit part, high-voltage switching circuit part, input switch part and display unit. High-voltage generating circuit is designed by using a boost converter circuit and allows user control of the output voltage. High-voltage switching circuit, controlled by MCU, generates output voltage to be applied to pads. Input switch part is composed of power supply, intensity selection, mode selection and memory. Display unit adopts a text LCD module to display modes, Intensity, output frequency and user set-up time. Our designed safety circuit, to protect human body from possible electric shock, slowly increases the output voltage to the selected output intensity. It continuously checks the output pulse shape and disable the output when dangerous pulses are detected. This paper also shows some experimental results.

• 농촌계획
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• 제4권2호
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• pp.29-40
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• 1998

The landscape of rural settlement incurred the loss and worsening of its main feature in the modernization which was progressed by the inner and outer cause - the growth of urbanization and improvement of living and dwelling environment. This study investigates the visual characteristic of land-use in rural and analyzes relations between visual quantities by land-use and a pre(essence of landscape. And it is suggested the basic data of a planning and a management in rural by making clear characteristics and influences of landscape preference elements The visual characteristic of landscape elements that is based on the rural land-use is classified harmony, variety, variables and particulate. And it is classified the object of landscape by recognizing images of landscape produce space, natural environment, settlement place and cultivated land of a special products. In the analysis of landscape preference, it appears that the harmony has a great influence on a suburban, a rural, a mountainous district, and a hamlet in psychology elements and the volume of forest area in visual elements. As a result, it requests rural scenes in harmony with the natural environment. So, the landscape planning which has the regional development and the identity as the rural settlement can be represented by the preservation and development of regional feature.

• 한국정밀공학회지
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• 제29권9호
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• pp.946-957
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• 2012

The objective of this paper is to investigate into the development of a thin flat panel photo-bioreactor case with characteristics shapes. The thin flat panel photo-bioreactor case was designed to be manufactured from a plastic thermoforming process. A proper design with a relatively high rigidity was obtained through the structural analyses for different designs of the photo-bioreactor case. The thermoforming analyses were performed. From the results of the thermoforming analyses, a proper forming condition and the formability of the designed plastic photo-bioreactor case were estimated. The thermoforming moulds for the flat panel photobioreactor cases were manufactured. The thermoforming experiments were performed to examine the manufacturability of the designed flat panel photo-bioreactor cases. From the results of the thermoforming experiments, it was shown that thin flat panel photo-bioreactor cases with characteristic shapes can be manufactured from the designed thermoforming mould and process.

• 융복합기술연구소 논문집
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• 제7권2호
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• pp.13-16
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• 2017

The design of sealing mechanisms of a manual pressure valve was analyzed with FE analysis for a hydrogen fuels charge and discharge system of FCEV. The damage prediction of the O-ring with respect to the material models of rubbers was calculated by the gap analysis of the backup ring and O-ring according to the internal pressure. Two kinds of the rubber material characteristic models were adopted to the O-ring. One was the linear elastic and the other was hyperelastic of Ogden $3^{rd}$ order model. The experimental data of urethane of Shore hardness 90 was utilized to the curve fitting of hyperelastic properties. It was found that the contact pattern of the backup ring was different in two models and the sealing mechanism was better in the case of the hyperelastic characteristic model.