• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.4
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• pp.1-13
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• 2022

This study was conducted to investigate the chlorophyll content, photosynthetic characteristics, and growth characteristics of Aster koraiensis and Dendranthema zawadskii var. latiloba according to shading treatment. A. koraiensis and D. zawadskii grew in four different shading treatment plots (0%, 50%, 75% and 95% of full sunlight) for experiments. It was found that as the shading level increased, the total chlorophyll content increased and dark respiration decreased in both A. koraiensis and D. zawadskii, indicating that A. koraiensis and D. zawadskii increase the utilization efficiency for photosynthesis under low light conditions. In addition, as the shading level increased, the net apparent quantum yield increased, resulting in the highest in the 95% shading plot, but the highest photosynthetic rate, water use efficiency, and leaf mass per area (LMA) were shown in the control group than in the shading treatments. The results showed that A. koraiensis and D. zawadskii are heliophytes showing plasticity to light, and if the light is restricted to continue to shade, it may be detrimental to growth. For healthy growth, it is considered suitable to grow A. koraiensis under full light conditions, and D. zawadskii under the light condition that blocks 0-50% of full sunlight.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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• pp.149-152
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• 2008

The purpose of this study is to develop a control software for daylight responsive dimming systems and automated roller shading systems. Developed software in this study is to used determinate sky conditions, calculation of solar profile angle, control height of roller shade, calculation of dimming level(%) for daylight responsive dimming systems.

• Journal of Korean Society of Forest Science
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• v.103 no.1
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• pp.65-71
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• 2014

Cacalia firma is a perennial plant in Asteraceae, Parasenecio that distributed in Korea, China, and Japan. As dietary style changes for well-being life, consumer's demand of functional food and organic vegetables is getting increased. This study was conducted to investigate the optimum light conditions of P. firmus in forest farming. One year old seedlings were grown under four different light conditions 10%, 20%, 30%, and 50% of sunlight by shading (equals 50%, 30%, 20%, and 10% relative brightness respectively) and non-treated control under full sunlight. They were analyzed for early growth and physiological response. Seedlings grown under 75% shading showed similar height, root growth, and leaf water content to control. However, their leaf length, width, and total leaf area were increased, which caused increased leaf dry weight and total dry weight. Especially, seedlings under 95% shading showed 40% increase in height and more leaf growth and leaf water content, although they had shorter main root length and root collar diameter than control. In addition specific leaf area (SLA) and leaf area ratio (LAR) were higher than control and indicated that they were statistically significant difference from control. Higher SLA refers thinner leaf thickness, higher LAR means larger leaf area. The results indicate seedlings under 95% shading have higher water content, thinner leaf, and wider lightinterception areas. It is plausible that P. firmus is active in chlorophyll activities and carbon dioxide assimilation at even lower light conditions. These results suggest that the optimum light level of P. firmus for artificial cultivation in forest farming ranges from 75~95% shading (20%-10% of relative brightness). When salability as 'sanchae' (wild edible greens) is considered, P. firmus could be cultivated under 75% shading in forest farming and expected to have better taste and higher yield. We suggest these results as basic data of P. firmus for possible forest farming.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.1
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• pp.63-73
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• 2022

The differential power processor (DPP) system is used to prevent a decrease in the total power generation due to the partial shading of photovoltaic modules. Compared with traditional series strings and full power processing (FPP) converter solutions, the DPP converter system shows advantages in terms of modularization process, volume, and transformation losses. However, the system has a limitation in that the power generation process of differential power processors produces lower power under certain irradiation conditions. This paper proposes a structure and operating algorithm for differential power processing modules that can use a single power converter for multiple strings. The operational algorithm for the differential power regulators allows the maximum power generation to be maintained in comparison with conventional series-connected and differential power processing methods even under various partial shading conditions. The operation algorithm of the proposed DPP is verified by Matlab/Simulink simulations.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.288-296
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• 1996

The effect of shading on the mineral components, free amino acid, and fatty acid content of tea shoot was examined under different shading conditions. The results are summarized as follows. The content of Total-Nitrogen and theanine in the tea leaves was the highest in the 95% shading as 5.49% and 15580 mg/kg, respectively, while they were the lowest in the unshading. The contents of total free acid were ranged from 24670 to 30210 mg/kg, showing higher content in the 95% shading than that in the unshading. The contents of ammonium nitrogen, potassium, and magnesium were higher in the all treatments of shading than that of unshading but vise versa in calcium content. The content of total fatty acid was the highest in the 55% + 95% shading as 27990 mg/kg, while that of unshading was the lowest as 24356 mg/kg showing the increasing order of $C_{18:3}$, $C_{18:2}$, $C_{18:0}$, $C_{18:1}$, $C_{18:0}$. The quality of tea leaves was improved with the treatment of shading compared to that of unshading showing the best in the 95% shading.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.352-356
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• 2011

It is true that the industrial development has usually been accompanied with urbanization or centralization of population that has inevitably led to high-rise buildings and densely built-up living area in the cities. While it is badly needed to acquire as much green land within the city limits as possible to compensate for reduced space for recreational purpose in parallel with increasingly urbanized area, the living conditions of plants have become seriously devastated due to shortage of sun light walled-off by high-rise buildings and contaminated environment and air. The shade that is generated by high-rise and compact buildings hinders growth of plants, which makes it urgent to develop native ground cover plant that is strongly viable in the shade. For this purpose, Ligularia stenocephala, best known as greens for Ssam (rice and condiments wrapped in leaves) was cultivated under the 30%, 50%, and 80% shadings and observed to see if there would be any changes in soil conditions, growth of plants and chlorophyll contents depending on the shading rate. The leaf number was 10.8 pieces under the 50% shading and 8.4 under the 30%-shading, 7.7 pieces more than that cultivated under lighting. The leaf width turned out to be excellent from cultivation under the 50%- shading, an evidence indicating its possibility of being cultivated as native ground cover plant in the shade. The live weight of the plants cultivated under the shading increased to 31.63 g, 43.39 g and 19.40 g, respectively, compared to 90.43 g of those in the untreated control plot. The increase in growth of roots was particularly significant with 48.48 g in comparison to 12.33 g under 30% shading cultivation. The chlorophyll synthesis amounted to 46.2 under the 50% shading, showing an increase compared to 41.9 under lighting. The chlorophyll synthesis rather shrank under other shading conditions. The cultivation of Ligularia stenocephala under the 50% shading showed the best condition in growth as native ground cover plant.

• Korean Journal of Medicinal Crop Science
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• v.8 no.3
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• pp.209-215
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• 2000

This study was conducted to improve the productivety of Ligusticum chuanxiong HORT. and Cnidium officinale MAKINO by establishing the effects of cultivating conditions. Growth characteristics of underground part of L. chuanxiong under the different mulching treatment showed the highest growth and yield in black vinyl mulching treatment. The highest dry weight of underground parts per plant in mulching treatment was 47.9g at white shading treatment while the lowest one was 16.5g at black shading treatment. Growth characteristics of underground parts C. officinale under the different mulching treatment were the higher in black vinyl mulching rather than in rice straw mulching and white vinyl mulching. Dry weight of underground parts per plant of C. officinale under the different shading treatments was the highest(37.8g) under the white shading while it was lowest(12. 2g) under the black shading.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.4
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• pp.395-398
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• 1991

Physiological reactions of 24 six months old (22.7 kg. body weight) Barki ram lambs, to hot summer conditions, as influenced by asbestos shading at Maryout area were studied. Animals (12 shaded and 12 Unshaded) developed hyperthermia during summer as their rectal temperature (RT) and respiration rate (RR) were always higher (p<0.01) than normal. Asbestos shading caused higher (p<0.05) RT and RR ($39.5^{\circ}C$ and 69.9 r.p.m. vs. 39.2 and 45.7 r.p.m.) of rams at morning (6-8 a.m.) which became lower ($39.9^{\circ}C$ and 104.3 r.p.m. vs. $40.1^{\circ}C$ and 120.5 r.p.m.) in afternoon (2-4 p.m.) as compared to sun exposure. Shading also resulted in higher hematocrit value (PCV) (35.3% vs. 33.0%) and lower (p<0.05) daily weight gain (128.57 vs. 131.43 g). Diurnal (p<0.01) and monthly (p<0.05) RT and RR changes were closely associated with air temperature (AT) fluctuations. Monthly variation (p<0.05) in PCV was evident. Puberty was reached one month later in the shaded as compared to the unshaded group (265 vs. 232.3 day, respectively). It is concluded that asbestos shading prevents efficient heat dissipation to the sky by hyperthermic rams during summer nights. Construction materials for animal shelters are of extreme practical importance.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.2
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• pp.248-251
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• 1983

The effects of shading - 90, 70, 50, 30, 10% on curing burley tobacco was investigated in pipe vinyl houses. The curing in sunlight under transparent materials resulted in an increase in temperature and a decrease in relative humidity. But amount of light on tobacco leaves were less than 10% sun light in all treatments. Shading was delayed curing period, but cured leaves under transparent shading materials were off color and brittle. Filling power and combustibility were deteriorated as decreased shading. But quality of cured leaves were non significant between treatments. Effects of shading were believed that resulted in a decrease in temperature and an increase in relative humidity than light.

• Journal of the Korean Institute of Landscape Architecture
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• v.21 no.1
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• pp.1-12
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• 1993

This studies were conducted to investigate on the shade adaptation of native Sedum kamchaticum and Disporum smilacinum. All plants were grow under the controlled light intensity conditions, which controlled by two shading materials, white and/or black shading net. The results obtained were as follow. 1. Daily changes of the shading area around of the building were various by building height, width and direction. 2. Upper canopy was composed to Pinus densiflora as dominant species in native sites of Disporum species. 3. Many branches of Disporum smilacinum were sprouted after pinching. However their growth were less elongated shorter than those of Disporum viridescens. 4. Sedum sarmentosum was poor growth under the low relative light intensity as 50%, however, the growth of this species closely was similiar as under the full sun condition.