• Journal of the Korean Society of Safety
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• v.38 no.3
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• pp.43-50
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• 2023

Silicone tetrachloride (SiCl₄) leak accidents cause enormous human and environmental damage because it is highly toxic. Some handling facilities use water curtains to reduce the impact range of SiCl₄. Although the water curtain is known as one of the most efficient technologies for post-release mitigation, its effect on reducing SiCl₄ concentration needs to be investigated scientifically and quantitatively. In this study, three-dimensional computational fluid dynamics (CFD) was used to investigate the physical and chemical effects of water curtains as a release-mitigation system for SiCl₄. SiCl₄ is released and dispersed five seconds prior to the operation of the water curtain. Once the water curtain works, the SiCl₄ reacts chemically with the water and its concentration decreases rapidly; it reaches an emergency response planning guidelines level 2 (ERPG-2) of 5 parts per million (ppm) at about 570 m. We observed, however, that the physical effect of water curtains on reducing SiCl₄ concentration is insignificant when the chemical effect is eliminated. These results are crucial since they can be a scientific and quantitative basis for the 'technical guidelines for estimating the accident affected range'. In order to protect the public from chemical accidents, more toxic gas mitigation technologies need to be developed.

• Korean Institute of Interior Design Journal
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• v.14 no.1
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• pp.142-150
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• 2005

This study is arranged the principles of the preservation and restoration in pre-modern architecture, presented guideline of the Intoner restoration in there, and attempted relative-analysis by cases of Japan in curtain of Saporo Houheikan. The method of Original- restorations and Repairs must be preserved In materials and technologies in order to hand over the future generations. The process and method of restorations are the important Cultural Properties as Architecture's itself. And Restorations of industrial manufactures hold the the important position in restoration of pre-modern Architectures. Because industrial technologies are developed and forgotten in rapid. Specially, because industrial materials as curtains were apt to recognize as consumption goods, historicity in that are contained the history of fabric, industrial technologies, and relations of traditional technologies. Conclusionaly, restorations of interior materials in our country are required of \circled1the construction of workframe in search and restoration for original preservation, \circled2the conception of refaires and establishment of investigation, \circled3the stocking of restoration-technologies of pre-modern cultural properties of architectures, \circled4the recognitions of record-preservation, \circled5the improvement of organization, upbring of technicians, establishment of theorical systems.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.11
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• pp.578-584
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• 2013

Vertical open display cases are widely used in shopping malls, supermarkets, or retail stores to sell frozen and refrigerated products. Open display cases use air curtains to maintain a reasonable temperature within the storage space, prevent insects from breaking in, and reduce energy usage. In this research, computational fluid dynamics was used to find the optimal condition for reducing energy by considering various conditions such as discharge speed or temperature of air curtains. Results of the study showed that the amount of energy consumed in the display cabinet is influenced by the discharge speed and temperature of the slots installed on the upper area and the amount of air supplied to the storage area inside the shelf. This shows that the amount of discharged air supplied from the storage area influences the formation of air curtain and also the amount of energy consumption. As a result of this study, we learned that the amount of energy used can be reduced by increasing the amount of discharged air within the storage area and enhancing back pressure.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.4
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• pp.306-315
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• 2021

This study analyzed the effects of light-shielding curtains and halogens on spectrum when acquiring hyperspectral images in a greenhouse. The image data of tarp (1.4*1.4 m, 12%) with 30 degrees of angles was achieved three times with four conditions depending on 14 heights using the automatic image acquisition system installed in the greenhouse at the department of Southern Area of National Institute of Crop Science. When the image was acquired without both a light-shielding curtain and halogen lamp, there was a difference in spectral tendencies between direct light and shadow parts on the base of 550 nm. The average coefficient of variation (CV) for direct light and shadow parts was 1.8% and 4.2%, respective. The average CV value was increased to 12.5% regardless of shadows. When the image was acquired only used a halogen lamp, the average CV of the direct light and shadow parts were 2 .6% and 10.6%, and the width of change on the spectrum was increased because the amount of halogen light was changed depending on the height. In the case of shading curtains only used, the average CV was 1.6%, and the distinction between direct light and shadows disappeared. When the image was acquired using a shading curtain and halogen lamp, the average CV was increased to 10.2% because the amount of halogen light differed depending on the height. When the average CV depending on the height was calculated using halogen and light-shielding curtains, it was 1.4% at 0.1m and 1.9% at 0.2 m, 2 .6% at 0.3m, and 3.3% at 0.4m of height, respectively. When hyperspectral imagery is acquired, it is necessary to use a shading curtain to minimize the effect of shadows. Moreover, in case of supplementary lighting by using a halogen lamp, it is judged to be effective when the size of the object is less than 0.2 m and the distance between the object and the housing is kept constant.

• Journal of Bio-Environment Control
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• v.22 no.1
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• pp.73-79
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• 2013

An experiment was conducted to study incidences of heat loss in greenhouse in Gyeongnam province using thermal imaging camera in order to determine ways minimizing greenhouse heat loss. Measurements of this work showed that temperature differences between two experiment zones before and after installation of thermal curtains were about $2.0{\sim}3.0^{\circ}C$ and $1.0{\sim}2.0^{\circ}C$ respectively. There was a high correlation between the temperature data measured using a thermal imaging camera and a temperature sensor. There was no serious difference among areas, but between places on the first and second floor with thermal curtains for heat insulation, there was a relatively larger heat loss on the first floor than the second floor. Then in general the greenhouse types had no particular bearing on this matter, there was a relatively large heat loss in the parts of side wall window, the gaps and the parts folded of horizontal thermal curtains, the gutter parts, and the gaps of thermal curtain in the side wall window and facade back side for heat insulation, aren't completely sealed. It was found that there was a substantial heat loss due to infiltration through cracks on covering material, doors, ventilating openings, roof gables and floors, in particular.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1995.10a
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• pp.64-66
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• 1995

시설하우스용 보온커튼지의 부직포는 시설에 이용되는 보온재중 그 비중이 15.9% 수준에 불과하나 최근 원예시설의 현대화 대형화 사업으로 급속히 증가하고 있는 추세로 온도관리에서 열에너지 절감에 매우 주요한 시설자재이다. 그러나, 시설원예의 구조와 환경관리에 관한 연구가 많은 반면, 보온커튼지의 중요성에 비추어 보온커튼지의 부직포에 관한 물리적 기계적성질이나 광투과성 및 보온성에 관한 연구는 매우 미진한 실정이다. (중략)

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2003.08a
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• pp.185-193
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• 2003

준설, 매립 등의 해상공사가 해양환경에 영향을 미치는 주 요인은 공사중 발생하는 부유토사이다. 이러한 부유토사는 주변 해역으로 확산되어 여러 방식으로 해양생태계에 피해를 유발할 수 있으며, 발생 가능한 피해의 범위와 정도는 부유토사 발생율과 해저 죄적물 입도분포 및 주변 유속에 따라 결정된다. (중략)

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1993.07a
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• pp.124-124
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• 1993

Recently silt curtains have been increasingly used at a dredging or reclaiming site in a sea for the purpose of preventing the neighbouring waters from becoming turbid. However, the hydrodynamic forces acting on such a flexible structure have not been investigated well and the design criteria have not been established. The floating silt cur-tain treated in this study consists of floats, tension cables and curtain canvases. (omitted)

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.1
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• pp.154-160
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• 2004

In this paper, implementation of active noise curtains using multiple channel adaptive filters is presented. The same numbers of single channel LMS algorithms as control loudspeakers is used instead of a multi-channel LMS algorithm to reduce the computational burden of adaptive filter algorithms. In general, a multi-channel LMS algorithm is usually used in active noise control system. but this algorithm has much more computational complexity. The single channel control techniques have less amount of DSP calculation, compared to multiple channel control techniques. A stabilizing procedure for adaptive IIR filters is also proposed to improve the stability of recursive LMS algorithms. Both experimental results of two control techniques using TMS320VC33 digital signal processor show the similar noise reduction, but the single channel control techniques are more efficient in practical active noise curtain applications

• Journal of the Korea Institute of Building Construction
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• v.4 no.1
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• pp.97-103
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• 2004

In case of a fire in road or railway tunnel it is always necessary to keep the escape condition as good as possible. Most of the victims of major fires in tunnels are because they couldn't leave the tunnel in time and were trapped by smoke, or rescue teams couldn't reach the place of the accident due to low visibility and high temperature. In spring 2003 a comprehensive field experiment was undertaken in a large scaled tunnel in Youngin City to test the effectiveness of a new water spray curtain system, designed to the air qualify inside of a tunnel in case of fire during passenger's escape to safe routes, In order to control the smoke propagation, fixed water sprayed nozzles were used to make water curtain system, which can be installed or hanging water piping line below ceiling. The experiment was accompanied by an extensive measurement campaign in order to measure temperature dropping effect and flow conditions as well as CO concentration for various water sprayed curtains produced by sprinkler heads or water spray nozzle. Eventually comparison analysis were undertaken to investigate the performance of water curtains under fixed water pressure. Therefore most effective water curtain system was presented on the basis of water droplet size in long tunnel.