• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2003.11a
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• pp.197-201
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• 2003

The purpose of this study is to analyze the slopes of control algorithm and dimming levels based on different inputs and parameters. Different parameters such as photosensor aiming angles, sky types, and seasonal changes were considered. To determine the slopes of control algorithm and dimming levels, photosensor signals and workplan illuminance values were simulated by DayDim program, which is a lighting calculation and analysis tool. A typical small office space was used for simulation and three different sky types in three different seasons were considered. This study shows that differences in dimming levels can occur according to different sky types, if system calibration is conducted in a particular sky type.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.195-199
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• 2006

This study aims to measure amount of the reduction ratio of energy consumptions by the daylight responsive dimming systems, which uses daylighting and electric lighting. The results of this study show that the reduction ratio of electric power is better 'clear sky' by sky condition and 'window side of room' by zoning. When calculating reduction ratio of energy consumptions with used times in real office space, it tells that the result of real office was higher ratio than that of experimental space. For this study which presents efficient use of daylight in office environment, it will be basis of improving energy performance.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.2
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• pp.178-184
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• 1992

The changes in contents of chlorophyll and free proline in the seedling leaves of ten rice cultivars as affected by salt stress were checked in order to obtain the basic information on the judgement of the degrees of salt injury. The difference in salt injury among the cultivars was clearly observed about 25 days after 6% salt treatment. Chlorophyll content was decreased in both Gayabyeo and Taebaegbyeo for 14 days after different salt treatment as salt concentration was increased and the decreased tendency was much higher in Taebaegbyeo than in Gayabyeo over 0.4% salt concentration. Chlorophyll content in Gayabyeo after 0.6% salt treatment was decreased slowly, while in Taebaegbyeo, deminished very rapidly as time progressed, therefore it decreased by about 16% in Gayabyeo and 67% in Taebaebyeo compared to the control at 20 days, respectively. The relationship between chlorophyll content and the degrees of salt injury in ten rice cultivars showed significant negative correlation at 10 day after 0.6% salt treatment. Free proline content in Gayabyeo was increased gradually for 14 days after different salt treatment as salt became higher, while in Taebaebyeo, it was increased rapidly under 0.6% but rather decreased under 0.8% salt concentration. Particularly, it was much higher Taebaegbyeo than in Gayabyeo under salt concentration from 0.4 to 0.6%. Free proline content in Gayabyeo after 0.6% salt treatment was increased from 15 days, on the other hand in Taebaegbyeo, it was increased from 5 days, but rather decreased from 20 days, and it was 6 times higher in Taebaegbyeo than in Gayabyeo at 10 days. There was significant positive correlation between free proline content and the degrees of salt injury in ten rice cultivars at 10 days after 0.6% salt treatment. From the above results, chlorophyll and free proline content may be used as an indicative character of intensity of salt stress as well as varietal difference in resistance to salt stress in the seedling stage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.1
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• pp.8-14
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• 1993

To investigate selection efficiency for protein content and hardness in a wheat breeding program, two crosses were made between soft wheat (SW) ‘Chokwang’ and hard wheat (HW) ‘Lancota’, and between HW ‘Suwon 210’ and SW ‘Atlas 66’. F2 progeny lines from the crosses were separated into 4 groups as HW + high protein (HP), HW + low protein (LP), SW + HP and SW + LP by measuring protein content and sedimentation value in F4 generation. The subsequent populations were tested for protein content, sedimentation value, mixogram pattern and bread quality. HP group selected from F4 again had a higher protein content in F5 generation than LP group, but there was no significant difference between two groups in F6 generation. In sedimentation value, the significant difference was recognizable only between the groups of HW + HP and. SW + LP. Plant based investigation in F6 revealed that the distribution pattern for protein content and sedimentation value shifted from the low to high by the four groups with the order of SW + LP, HW + LP, SW + HP, HW + HP. Such a trend was most noticeable in the progenies of the cross between ‘Suwon 210’ and ‘Atlas 66’. Mixogram pattern that shows flour characteristics differed greatly among the groups, indicating a high selection efficiency for the traits. Bread volume in F6 of HW + HP was found to be higher than that of SW + LP, only from the cross between ‘Suwon 210’ and ‘Atlas 66’.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.5
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• pp.433-442
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• 2012

The influence of outdoor sky conditions on photosensor signals were examined to determine an appropriate index that is effectively used for optimum illuminance fluctuation when a daylight dimming system is used for a small office. Field measurements were conducted under various sky conditions. Results indicate that the outdoor global and vertical illuminance fluctuated within narrow ranges under clear and overcast sky conditions. The fluctuation of sky ratio under partly-cloudy sky caused wide ranges of illumnance fluctuation. A partially-shielded photosensor at backwall produced 56% of light output from fixtures controlled by a photosensor at ceiling. This implies that the photosensor at backwall does not always guarantee target illuminance due to the less output. The fluctuation of light output from fixtures were insignificant under clear and overcast sky. The fluctuation range of photosensor illuminance under partly-cloudy sky caused wide fluctuation ranges of light output. Regression result implies that the outdoor vertical illuminance was recommended for an effective index that is used for control of light output.

• The Magazine for Energy Service Companies
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• s.54
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• pp.64-69
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• 2008

야간의 잉여전력으로 열을 저장해두었다 주간에 이용하는 축열공조에는 50여년에 걸친 긴 역사가 있었다. 이 방식이 가지는 효용에 일찍부터 눈뜬 선각자들의 노력에도 불구하고 당초 보급은 늦어져 그다지 진전이 없었다고 한다. 이러한 정세가 일변한 것은 전력공급에 병목현상이 생겨 부하 평준화가 안정공급에 있어 필요불가결의 과제가 되었기 때문이다. 특히 공조는 피크성이 강한 수요이므로 공조용 전력을 야간으로 옮기는 작업의 이점이 큰 것은 당연하다. 비 수요시간대의 요금이 큰 폭으로 떨어짐으로써 수요자측에서 보아도 야간의 전력을 어떻게 활용할까하는 것은 매력적인 연구테마였다. 이리하여 축열공조가 관심을 불러 보급이 기도에 놓인 지 2O년 가까이 되었다. 처음에는 물을 사용한 축열이 대부분이었으나, 축열조 용량의 제약으로 얼음을 만들어 저장하는 빙축열방식이 도입되어 현재의 표준적인 축열방식이되었다. 그러나 빙축열에도 비용상의 문제가 있어 전면적인 보급에 이르기까지는 아직 연구의 여지가 더 남아있는 듯하다. 한편, 교토의정서의 발효 등에 의해 지구환경에 대한 관심이 높아지게 되었다. 이 같은 배경 속에 건물및 건축설비의 에너지절약 기술의 중요성이 대두되고, 특히 창 주변의 공조방식, 조광제어, 축열 공조시스템 등, 건물부하의 직접적인 저감과 전력부하 평준화에 의한 환경부하저감 및 운영비용의 저감을 목적으로 한 건물일체형 설비시스템을 적극적으로 도입하기에 이르렀다. 환경을 배려한 건축구조.설비시스템의 채택 사례가 증가하며 건축물 종합환경성능 평가시스템과 성능검증 등 건물설비의 평가.검증 수법도 연구되어 건물에 적합한 운용면에서의 사고가 중요함이 인식되었다. 이와 같이 건축구조와 설비시스템의 양면에서 에너지절약성 및 환경성, 쾌적성, 편리성의 추구가 적극적으로 도입되는 가운데, 슬래브축열시스템은 건축구조와 공조설비가 균형있게 융합됨으로써 초기비용의 삭감과 부하 평준화에 의한 경제성 향상, 복사에의한 실내환경의 향상 등의 효과를 기대할 수있는 시스템으로 추목받고 있다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2005.04a
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• pp.20-27
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• 2005

Solar radiation causes non-uniform temperature distribution in the structure, depending on the shape of the structure and its shadows. Especially in cases of curved steel box girder bridges, non-uniform temperature distribution due to solar radiation can reduce bridge life and serviceability when combined with another load combination. In this study, the method for predicting the temperature distribution of curved bridges developed by Kim et al., was used to predict the non-uniform temperature distribution which served as a basis for structural analysis of 3-D bridge behavior. In order to seek the most unfavorable conditions of solar radiation, observation data from the Korea Meteorological Administration for solar radiation were analyzed. The region of the most high solar radiation condition was selected and its one year variation of the solar radiation data was considered. From this analysis, the most unfavorable solar radiation condition with lower solar altitude and intense solar radiation was selected. Based on the selected solar radiation condition, structural behavior of curved bridges with diverse bridge direction, span length, radius and support conditions are analyzed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.4
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• pp.381-387
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• 1985

Development and maturation of wheat were studied with reference to the quality of grain and milling properties. 1000-kernel weight and test weight increased as the wheat matured and as the orginal moisture decreased. The time of maturity was estimated 40 days after heading. Moisture content of wheat grain had a correlation coefficient of -0.877＊＊ with 1000-kernel weight, of -0.761＊＊ with test weight, and of 0.915＊＊ with pearling index. The milling data suggest that even in the early stages of maturing, the endosperm represented at large proportion of the grain. However, milling score was relatively constant at about 40 days. Break-Reduction flour ratio was a great difference between wheat varieties. 1000-kernel weight had a high significant correlation of +0.603＊＊ with milling yield, of -0.958＊＊ with ash content, and of +0.956＊＊ with milling score.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.6
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• pp.7-15
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• 2003

The purpose of this simulation study is to determine the window transmittance by RADIANCE lighting simulation tool where the horizontal blind is installed. Parameters such as sky types, seasonal changes, altitude, azimuth, and horizontal blind angle at a 0$^{\circ}$, 45$^{\circ}$, 90$^{\circ}$ were considered. The simulation results present that measured directional transmittances have different values according to each directional property of the horizontal blind. In addition, methodology was described to apply window transmittance data to DayDim program which is a lighting calculation and analysis tool especially for the performance of daylight responsive dimming systems.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.2
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• pp.1-8
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• 2002

The electronic ballast have much more shaking of arc than magnetic ballast because of acoustic resonance phenomenon. but it has used mare than before. In this paper, we made metal halide lamp modeling by modifying modeling of mercury lamp. To avoid acoustic resonance phenomenon, We calculated acoustic resonance frequency band. We proposed design of LCC circuit. Also, electronic ballast simulator for metal halide lamp was developed by simulink LCC parameters of inverter was decided on the basis of simulation results. After development of prototype ballast, it was verified the characteristics of simulator.