• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.4
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• pp.97-103
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• 2004

In general the starting current of single phase induction motor is 3 to 6times of the rated current It make flickering an electric lamp, dispersion a TV screen, insulation destructing an electric motor and momentary blazing of house wiring. Thus it happens losing an electric power loss and reducing an efficiency and a life of home electrical apparatus. In this paper, we proposed the method of reducing staring current with 3.7(%) using TRIAC and ACCT(alternated current transformer) in order to improve the above problem And also we verified semipermanent system with using semiconductor element.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.7
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• pp.9-14
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• 2005

In this study, we investigated the actual conditions of illumination environment of study rooms in detached houses. From the results, fluorescent lamp as a lighting source and direct lighting method were mainly used. The additional use of local lighting was 48.2[%], and it was not efficient for detailed work. The average illuminance of general lighting and local lighting were 131.41[lx] and 322.57[lx], respectively, and these level were only 54[%] of the lowest illumination standard. This indicates that the lighting levels and the environment are so poor. The satisfaction level of users, however, was relatively high, suggesting insufficient recognition of importancy of lighting for efficient work.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.45-45
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• 2019

This experiment was carried out using artificial clay and LED in the plastic film house (irradiation time: 08:00~18:00/day). Seedlings (n = 63 per $3.3m^2$) of ginseng was planted on May 17, 2018. LED was combined with red and blue light in a 3:1 ratio and irradiated with different light intensity. The average air temperature from April to September was $12.3^{\circ}C$ $-26.0^{\circ}C$ and it was the the highest at $26.0^{\circ}C$ in August. The test area where fluorescent lamp was irradiated tended to be somewhat higher than the LED irradiation area. The chemical properties of the test soil are as follows. pH levels was 5.3~5.5, EC levels 0.45~0.52 dS/m and OM levels 33~37%. The total nitrogen content was 0.35~0.47% and the available $P_2O_5$ contents was 13.7~16.0 mg/kg, which was lower than the suitable level of 70~200 mg/kg. Exchangeable cations K and Mg contents were within acceptable ranges, but the Ca contents was $28{\sim}38cmol^+/kg$ levels higher than the permissible level ($2{\sim}6cmol^+/kg$). Germination of ginseng leaves took 8~9 days and the overall germination rate was 70~75%. The photometric characteristics of LED light intensity are as follows. The greater the light intensity, the higher the PAR (Photosynthetic Action Radiation) value, illuminance and solar irradiation. Photosynthetic rate was also increased with higher light intensity was investigated at $1.7{\sim}3.2{\mu}mol\;CO_2/m^2/s$. Leaf temperature ($23.7{\sim}24.8^{\circ}C$) by light intensity was the same trend. The growth of aerial parts (plant height etc.) were generally excellent when irradiated with 3 times the light intensity, the growth of the ginseng aerial parts were excellent as follows. The plant height was 42.6 cm, stem length was 25.2 cm, leaf length was 9.6 cm and stem diameter was 5.0 mm. The growth of underground part (root length etc.) was the same, and the root length was 24.4 cm, the tap root length was 6.0 cm, diameter of taproot was 18.2 mm and the fresh root weight was 17.2 g. There were no disease incidence such as Alternaria blight, Gray mold and Anthracnose. Disease of Damping off occurred 2.2~3.6% and incidence ratio of rusty root ginseng was 14.6~20.7%. Leaf discoloration rate was 13.7~48.9% and increased with increasing light intensity. Ginsenoside content of ginseng by light intensity is under analysis.

• 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.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.3
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• pp.465-470
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• 2017

This paper designs and implements a smart garden system using probabilistic filter algorithm using SLAM that can be used in apartment or veranda. To do this, we used Arduino and environtal sensors, which are open hardware controllers, and designed to control and observe automatic water supply, lighting, and growth monitoring with three wireless systems (Bluetooth, Ethernet, WiFi). This system has been developed to make it possible to use it in an indoor space such as an apartment, rather than a large-scale cultivation system such as a conventional plant factory which has already been widely used. The developed system collects environmental data by using soil sensor, illuminance sensor, humidity sensor and temperature sensor as well as control through smartphone app, analyzes the collected data, and controls water pump, LED lamp, air ventilation fan and so on. As a wireless remote control method, we implemented Bluetooth, Ethernet and WiFi. Finally, it is designed for users to enable remote control and monitoring when the user is not in the house.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.4
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• pp.1-7
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• 2009

This study investigated the actual conditions of the illumination environment from agricultural youth study room. The result, average space of the study room was 11.42[$m^2$]. The illuminant uses the fluorescent lamp mainly, Method of using illumination was only general illumination the case which uses 73.8[%]. Method of light distribution was a direct lighting mainly. The house which has a stand illumination was also 45.7[%], The percentage using the stand illumination which was a local illumination was nothing but in 20[%] of the whole subject of investigation, therefore eye work could not effective. The internal illuminance was average 131.82[lx], the desk illuminance was 253.64[lx] which was the minimum permitted limit and poor. Uniformity ratio of illuminance appeared with average 35.61[%]. The satisfaction with 3.93 points to be high for illumination environment, therefore it was thought that the recognition of illumination was very insufficient.

• Journal of the Speleological Society of Korea
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• no.76
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• pp.37-42
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• 2006

The Dielectric Barrier Discharge (DBD) is a nonequilibrium gas discharge that is generated in the space between two electrodes, which are separated by an insulating dielectric layer. The dielectric layer can be put on either of the two electrodes or be inserted in the space between two electrodes. If an AC or pulse high voltage is applied to the electrodes that is operated at applied frequency from 50Hz to several MHz and applied voltages from a few to a few tens of kilovolts rms, the breakdown can occur in working gas, resulting in large numbers of micro-discharges across the gap, the gas discharge is the so called DBD. Compared with most other means for nonequilibrium discharges, the main advantage of the DBD is that active species for chemical reaction can be produced at low temperature and atmospheric pressure without the vacuum set up, it also presents many unique physical and chemical process including light, heat, sound and electricity. This has led to a number of important applications such as ozone synthesizing, UV lamp house, CO2 lasers, et al. In recent years, due to its potential applications in plasma chemistry, semiconductor etching, pollution control, nanometer material and large area flat plasma display panels, DBD has received intensive attention from many researchers and is becoming a hot topic in the field of non-thermal plasma.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.1
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• pp.110-117
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• 2012

This study was performed to determine light-adaptability under indoor lighting for Korean wild Daphniphyllum macropodum, and to provide an introduction plan for indoor spaces of landscape architecture. The experimental plants, Daphniphyllum macropodum were purchased from a farmhouse in Jejudo as anannualplant, and it was acclimatized in the glass-green house of the general farm of Gyeongnam National University of Science and Technology for40 days. The experiment was performed from February 15, 2010 to November 15, 2010. First, in the case of the fluorescent lamp, the growth and development condition was poor because the plants withered, or the leaves fell off under the 100lux to 500lux, but the condition under 1,000lux was good In the aspects of the number of leaves, form of the tree, photosynthesis rate in its body, and the value of sight, the best light intensity for the growth condition was under the 1,000lux. Second, in the case of the LED light, the growth and development condition was poor because the plants withered, or the leaves fell off under 100lux to 1,000lux, but the smooth growth and development was done under a more light intensity. The best intensity for the growth condition was under 2,000lux. Third, in the case of the three-wave light, the withering was serious by 1,000lux, and the growth and development was the worst amongst the four introduced lighting systems, therefore, growth under the three-wave light was incongruous. The best intensity for the growth condition was under 2,000lux. Fourth, in the case of the optical fiver, the withering did not existed under 100lux and growth was possible. The growth and development was the amongst in the four introduced lighting systems. Generally, in the more light intensity, more growth was observed, but the value of sight was higher under 1,000lux than under 2,000lux because the falling rate of leaves and the form of the tree was stable. The most effective light was under 1,000lux due to the high photosynthesis in its body. When Daphniphyllum macropodum is introduced into the indoor landscaping space considering the light, the optical fiber, fluorescent lamp, and LED light are suitable to introduce. The three-wave light is unfit. The most proper light intensity by the light source, in the case of the optical fiber, and fluorescent lamp, is 1,000lux, and, in the case of LED light, is 2,000lux. The wild Daphniphyllum macropodum is the species of tree to substitute the Schefflera actinophylla which is the introduced species, and it is expected to be use as the central tree in indoor spaces.

• Journal of Bio-Environment Control
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• v.25 no.1
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• pp.42-48
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• 2016

Angelica gigas, belonging family Apiaceae, is a perennial and famous medical plant growing in Korea, Japan, and China. The aims of this study was to analyze the growth and accumulated Decursin and its precursor Decursinol angelate of A.gigas grown under fluorescent lamp and LED. A. gigas 'Manchu' were sowed and managed for seedlings stage in a glass house for 4 weeks. One hundred twenty seedlings with 3 true leafs were transplanted at an ebb & flow system with fluorescent lamp and LED [red: peak wavelength 660nm, blue: peak wavelength 455 nm, white = 3:2:4 ratio] irradiated at $180{\pm}7{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ at the top of plant canopy for 5 weeks. The number of leaves increased by 13.5% in the LED treatment, though it is not statistically significant. Leaf length/width ratio of A. gigas grown under the fluorescent lamps was 24% bigger than the LED treatment and also the stem was 13% larger. Maximum root length was similar to both groups. Fresh weight and dry weight of shoots grown under the LED increased by 50% and 42% and the both weights of roots increased by 125% and 45%, respectively. The contents of Decursin and Decursinol angelate grown under the florescent lamps were larger than LED by 188% and 27% in shoot and 78% and 8% in root. The contents of Decursin and Decursinol angelate per plant grown under LED and florescent lamps were 132mg and 122mg. In conclusion, functional materials in A. gigas were increased by florescent light and its growth was promoted by LEDs light.