• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.1
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• pp.1-6
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• 2006

The advantages of LED(Light Emitting Diode) are low electric power consumption long life time and excellent visibility. In order to design and develope the marine lantern using LED, technical trends and standards about the marine lantern were analyzed and sample products were manufactured and evaluated in comparing with existing marine lantern The performance of developed LED lantern is better than that of the existing marine lantern using an incandescent lamp. The electric power consumption of our products is 30[%] and the luminous intensity is two or fen times brighter than existing marine lantern.

• Journal of the Korean Institute of Educational Facilities
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• v.21 no.6
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• pp.28-32
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• 2014

본 투고에서는 2008년 환경부의 용역으로 실시된 "보육시설의 실내공기질 진단 및 개선 시범사업"의 결과를 바탕으로 우리나라 보육시설의 실내공기 오염 실태와 함께 개선방안, 그리고 개선효과에 대하여 소개하였다. 서울, 경기, 인천 지역의 61개 시설을 대상으로 실내공기질 측정과 설문조사를 실시한 결과 폼알데하이드와 총 휘발성유기화합물은 일부시설에서 "다중이용시설 등의 실내공기질 관리법" 기준치를 초과하는 것으로 나타났다. 반면 이산화탄소와 미세먼지는 조사 대상 시설 중 50 % 이상이 기준치를 초과하는 것으로 나타났다. 따라서 보육시설의 실내공기질 개선을 위해서는 각 오염물질의 발생원별로 유지관리 대책이 필요한 것으로 조사되었다. 또한 오염원인별 분석결과, 대부분 시설의 실외오염물질 농도가 실내보다 낮게 나타나 외기의 오염이 실내에 미치는 영향은 미비한 것으로 나타났으며, 계절에 따른 실내공기오염은 동절기에 낮은 외기온도로 인하여 실내를 하기 때문에 하절기에 비해 더 높게 나타났다. 공간에 따른 오염물질의 농도는 이산화탄소와 미세먼지의 경우 아동이 늘 상주하는 교실의 오염이 가장 심한 것으로 나타났으며 폼알데하이드와 총휘발성유기화합물의 경우 놀이실의 오염도가 교실에 비해 더 높게 나타났다. 개선방안별 개선효과에 있어서는 환기계획 몇 환기설비 설치, 지하공간 습기 문제 개선에서 가장 높은 효과가 나타났다. 향후 보육시설의 쾌적하고 건겅한 실내환경의 유지관리를 위해서는 보육종사자들이 활용할 수 있는 유지관리 지침 또는 매누얼에 대한 보급이 필요할 것으로 판단된다.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.12
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• pp.635-640
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• 2016

Although microbial fuel cell (MFC) can produce electricity from organics in wastewater, nitrogen removal is required for application of process for wastewater treatment plant. This study developed flat-panel air-cathode MFCs (FA-MFCs) comprised of two large separator electrode assemblies (SEAs) and evaluate total nitrogen removal according to three inoculum sources and pre-nitrification acclimation. The nitrification efficiencies were >99% regardless of inoculum sources under the phase for pre-nitrification acclimation. The total nitrogen removal efficiencies of FA-MFCs without pre-nitrification acclimation were the highest at the low organic conditions (<300 mg-COD/L) under the phase for nitrification and denitrification. The increase of organic concentration influenced the total nitrogen removal efficiency, positively. The organics were removed >95% but were not used for heterotrophic denitrification totally. This study suggests that application of FA-MFC system for wastewater treatment can allow the simultaneous removal of organic and nitrogen compounds, although this affects the low electricity production.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.284-290
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• 2007

Thermal insulation effectiveness of the aluminum insulator depending on the direction of its glossing face, number of layer and allocation position was investigated. Modules were assembled by the combination of the variables levels and experimented for the case of 100 W and 40 W heating in the modules. The temperatures in the modules with the aluminum insulator were higher than those of the modules with polyester curtains. For the modules with one layer aluminum insulator, the inside temperatures of the modules with the direction of the glossing face outward were higher than those of the modules of inward. For two layer of aluminum insulator, the directions of those glossing faces were recommended to be the same direction for higher thermal insulation effectiveness. For the modules without heating, the temperature difference between the modules were not significant. The black globe temperatures in the modules were changed with the similar tendencies with the dry bulb temperatures in the modules. Those of the black globes were higher than those of the dry bulb temperatures as a whole. It was more distinguished for the modules of inward direction.

• Journal of Bio-Environment Control
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• v.10 no.1
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• pp.42-49
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• 2001

This study was carried out to develop a fuzzy control technique of ventilation window for controlling a temperature in a greenhouse. To reduce the fuzzy variables, the inside air temperature shop was taken as one of fuzzy variables, because the inside air temperature variation of a greenhouse by ventilation at the same window aperture is affected by difference between inside and outside air temperature, outside wind speed and the wind direction. Therefore, the antecedent variables for fuzzy algorithm were used the control error and its slop, which was same value as the inside air temperature slop during the control period, and the conclusion variable was used the window aperture opening rate. Through the basic and applicative control experiment with the control period of 3 minutes the optimum ranges of fuzzy variables were decided. The control error and its slop were taken as 3 and 1.5 times compared with target error in steady state, and the window opening rate were taken as 30% of full size of the window aperture. To evaluate the developed fuzzy algorithm in which the optimized 19 rules of fuzzy production were used, the performances of fuzzy control and PID control were compared. The temperature control errors by the fuzzy control and PID control were lower than 1.3$^{\circ}C$ and 2.2$^{\circ}C$ respectively. The accumulated operating size of the window, the number of operating and the number of inverse operating for the fuzzy control were 0.4 times, 0.5 times and 0.3 times of those compared with the PID control. Therefore, the fuzzy control can operating the window more smooth and reduce the operating energy by 1/2 times of PID control.

• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.306-316
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• 2006

In this study, the effect of the shade level, water flow rate applied to the shades and the temperature of water on the greenhouse cooling was investigated depending on the shade level of 0, 35, 55, 75%, and water flow rate and water temperature by the test on the small wooden frames to find out the low cost cooling method. With increasing of the dry bulb temperature of outside air, the dry bulb temperature in the wooden frames increased. For the frames with the shade and water, inside temperatures of the frames were lower of -0.2$\sim$-1.2$^{\circ}C$ than the temperature of the outside air and higher than the water temperature. For the frames without water, inside temperatures of the frames were higher of 1.7$\sim$4$^{\circ}C$ than the outside and not affected by the shade level very much. The water flow rate and the temperature of the water were not the important factors to decrease the inside temperatures in the frames. The black globe temperature became lower with increasing of shade level. The shade frames with water curtain showed the best cooling effect because of reducing thermal radiation and cooling the plastic film cover. The surface temperatures of the plastic film cover for the water supplied modules became lower with increasing of the shade level. The relative humidity was decreased with the dry bulb temperature in the frame increasing and not affected by the dry bulb temperature of the outside air for the frames with the shade and water.

• Journal of Bio-Environment Control
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• v.6 no.3
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• pp.143-150
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• 1997

In order to produce young leaf of butterbur(Petasites japoflicus MAX.) in early spring, the planting date and relationship between abscisic acid(ABA) content and dormancy were investigated. Under open field condition, the dormancy of rootstock was initiated in the beginning of October, was the deepest in the middle of November and was completely broken in the end of December. When those periods were converted by the low accumulation hour below 5$^{\circ}C$, 900 hours were required approximately. This means that the rootstock needs for dormant breaking necessitates under the low temperature. In relationship between growing period and ABA content, the ABA in root-stock did not exist during maximum growing period, from April to September. This means that the ABA together with other substances in rootstock can be transferred to the shoot part with sprouting. While shoot part withered by decreacing the open field temperature since October, the ABA intiated to exist in rootstock. This means that the ABA in the shoot part can be transferred to the rootstock part. Therefore, it was concluded that the ABA which has been known that inhibiting growth and inducing dormancy was closely related with dormancy of rootstock.

• Journal of Korean Society of Steel Construction
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• v.20 no.1
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• pp.43-53
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• 2008

Because the torque control method, which is also caled the clamping method in domestic construction sites, is affected by a variation of the torque coefficient, quality control of the torque coefficient is essential. This study was focused to evaluate the effects of several environmental factors and errors when installing bolts while tightening high-strength bolts. Conditioning environmental parameters include wet, rusty and exposure-to-air-only conditions. In addition, because of errors in workability such as instalation of two washers, upset washers are selected. During the tests, torque, torque coefficient, tension and angle of nut rotation were obtained using a bolt testing machine. Test specimens of four types of bolts (High-Strength Hexagon bolt on KS B 1010, Torque Shear Bolt on KS B 2819, High-Strength Hexagon bolt coated with zinc, and ASTM 490 bolt) were recomended. Based on test results, the tightening characteristics subjected to environmental parameters were investigated and compared with the results in normal condition.

• Food Science and Preservation
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• v.17 no.2
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• pp.223-229
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• 2010

Anchovy soy sauce was fermented at ambient temperature in 20 L new Onggi, used Onggi, stainless steel, and plastic containers, and sauce quality was analyzed. Microporous insulated Onggi containers were found to promote fermentative microbial growth, thus creating desirable conditions for the preparation of good-quality anchovy soy sauce. The use of used Onggi containers yielded an anchovy soy sauce with high contents of total nitrogen and free amino acids, which afforded good sensory qualities with respect to odor, taste, and overall acceptability.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.15 no.2
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• pp.55-60
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• 2009

Gochujang was prepared and fermented in 20 L new and reused Onggis, stainless and plastic containers. Quality attributes of the Gochujang were analyzed during the fermentation at room temperature. The microporous Onggicontainers, were found to promote the fermentative microbial growth, helping to create the desirable condition for good quality Gochujang. Reused Onggi resulted in Gochujang with higher content of amino nitrogen and free amino acids, and lower reducing sugar than new Onggi, which provided good sensory qualities in odor, taste and overall acceptability.