• The Journal of Sustainable Design and Educational Environment Research
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• v.12 no.2
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• pp.61-70
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• 2013

As the existing school building power consumption is expressed by total power consumption, in the view of energy saving is disadvantage. The the power consumption of school building is divided as cooling, heating, lighting and others. The cooling power consumption, heating power consumption, lighting power consumption can be calculated using real total power consumption that gained from Korea Electric Power Corporation(KEPCO). The power consumption for cooling and heating can be calculated using heat transmittance, wall area and floor area, and for lighting is calculated by artificial lighting calculation. but this calculation methods is difficult for laymen. This study was carried out in order to establish the regression equation for cooling power consumption, heating power consumption, lighting power consumption and other power consumption in school building. In order to verify the validity of the regression equation, it is compared regression equation results and calculation results based on real power consumption. As the results, difference between regression result and calculation results for cooling and heating power consumption showed 0.6% and 3.6%.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.158-164
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• 2016

That's the reason why LED lighting has to employ AC power inlet. However, LED is a kind of diode, semiconductor, it's driven by DC power. With whis reason all of LED lighting should have AC/DC converter in its systems. This converter causes energy loss, it's the target for lesson the energy loss. To reduce this energy loss, DC power distribution structure can be used. LED lighting system using LVDC is a kind of DC power distribution structure, but LVDC has severe voltage drop which makes non-uniform brightness in lighting system. In this paper, we suggest a novel structure for the uniform brightness in LVDC LED lighting system using IoT based network system. The constructed test-bed system of suggested structure shows this structure can con control the brightness with uniformity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.10
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• pp.830-836
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• 2012

An efficient cooling system is essential for the electronic packaging such as a high-luminance LED lighting. A special heat transport technology, Pulsating Heat Pipe (PHP), can be applied to the cooling of LED lighting. In this paper, the operational characteristics of the PHP in the imposed thermal boundary conditions of LED lighting were experimentally investigated. The experimental PHP was made of copper tubes of internal diameter of 2.1 mm. The working fluids of ethanol, FC-72, water, acetone and R-123 were chosen for comparison. The results showed that an optimum range of charging ratio exists for high cooling performance; 50% for most of the fluids. Among the five working fluids, water showed the highest heat transfer rate of 260 W. Two distinguished characteristics of pulsating direction were identified. It is also identified that high vapor pressure gradient is one of key parameters for better heat transfer performance.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.2
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• pp.1-7
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• 2015

The Light Emitting Diode(LED) lighting control system proposed in this thesis is made up of a sensor module, a microcontroller, Bluetooth wireless communication, LED Driver, and LED downlight. The sensor module, comprised of an infrared sensor, an illumination sensor, and a temperature sensor, was designed to one Printed Circuit board(PCB). The system is able to identify the environment information collected by the sensor, and make it possible to control lighting automatically and manually through sensors. In addition, depending on users' conditions, a color temperature can be controlled. CS-1000, a spectroradiometer, was employed to measure the changing values of a color temperature in 8 steps. According to a test, it was found that it was possible to change a color temperature from 3187K of Warm White LED to 5598K of Cool White LED. The Bluetooth based wireless communication technique makes it possible to control more lighting devices than other wireless communication techniques does.

• Current Optics and Photonics
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• v.7 no.6
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• pp.755-760
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• 2023

In this paper, an illumination optical system that can mitigate the saturation phenomenon in the center of an image (caused by the typical flexible-endoscope illumination system using LEDs with Lambertian light distribution) is designed. When an LED with Lambertian light distribution is used as a light source, the amount of light in the center of the endoscopic illumination system is relatively high, compared to the periphery, causing saturation in the image. Since this phenomenon causes difficulty in detecting the patient's lesion, it is necessary to find a lighting-system design that can alleviate the saturation phenomenon. Therefore, in this paper a lighting system with bat-wing light distribution, which can lower the intensity at the center and secure the maximum amount of light at the maximum light distribution angle, is designed. In addition, to check the performance of the designed lighting system, a simulation of illumination and luminance is conducted for a system using a common aspherical lens with otherwise the same components. As a result, it is confirmed that the lighting system designed in this paper effectively reduces the luminance value at the center and secures more luminance values at the periphery than the familiar lighting system.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.1
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• pp.23-32
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• 2004

This study aims to examine constraints on visits to urban community parks and to find ways to elevate the efficient use of parks. To achieve this, the study relied on empirical study method and the descriptive method; additionally, present condition survey was performed with a user interview, on the assumption that a park visit is a form of leisure. As a result, the item of 'insufficient lighting facilities' shows the highest mean and the item of 'low quality of park' follows Previous research also revealed that the item of 'the lack of lighting facilities' is a major factor on user dissatisfaction, so a design and management program for night time users are fully researched and elaborately accomplished. Also, the high response of 'low quality of park' shows that the park supply policy in Korea focusses mainly on quantity so far, and it shows that user's dissatisfaction for park facilities becomes one of the major constraints of park visit. The factor analysis, on the object of 35 items except 2 items, appeared 5 factors: accessibility, inner discord, companion, family matters, park-itself-matters. Oneway Anova test showed that 4 factors except 'park-itself-matters' have reliable difference in constraint cognition by age and education. The visit constraint of 'park-itself-matters' did not appear different by any personal characteristics. Without regard to personal characteristics, it is regarded that this factor has the greatest effect upon park visits. In general, people who are disadvantaged strongly cognize constraints even in leisure such as a park visit, which is a simple and inexpensive leisure activity. Therefore, a park like a pocket park, which is small but located in a neighborhood, is more needed than a central park like a symbolic and huge park in every new city. Careful concern for night activity should be accomplished in the planning process.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.8
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• pp.10-19
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• 2007

Use of various lighting simulation software has been increased Lighting simulation software can be categorized into two types. One is for optical design while the other is for estimation and analysis of lighting design. Photopia 2.0 is typical software for optical design of a luminare and Lumen-micro 2000, Relux 2006, Lightscape 3.2 and AGI 32 are software for lighting design. Through using various lighting simulation software some different results can be found under the same conditions. Therefore, the purpose of this paper is to compare measured and simulated photometric data of different types of luminaires and to compare simulated values from Lumen-micro 2000, Relux 2006, Lightscape 3.2 and AGI 32 under the same conditions. In addition, the reasons for such differences are analyzed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.3
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• pp.558-566
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• 2015

LED, the next-generation light source, rapidly develops and has advantages of low power, high efficiency, and long life. Accordingly, an interest in lightings by using LED rises. If emotional lighting is implemented by using LED, all colors can be represented by using 3 primary colors of light, differently from the conventional single-color lighting. LED emotional lightings which can control human emotions continue to be developed thanks to these advantages. This study was conducted to design an algorithm for expressing LED emotional lighting in line with the situation and temperature by extracting colors for concentration and resting situations in indoor environment and mixing them with colors of the temperature felt by user. The LED emotional lighting designed with a neuro-fuzzy system was found to have effects on user's emotions during concentration and resting.

• Transactions on Electrical and Electronic Materials
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• v.11 no.3
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• pp.138-144
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• 2010

Optical analysis is necessary to optimize light emitting diode (LED) safety street lighting. In this study, optical analysis was conducted for 100 W LED safety street lighting. Experimental research on such a single LED was the first undertaken. Simulation modeling based on the optical properties of the single LED has compared between average road illuminances and has them analyzed with Korean Industrial Standards for LED safety street lighting (KS C7658:2009). The simulation results demonstrated that the illumination performance (average road illuminance) was 75.3 lx at a height of 4 m and an area of $32\;m^2$, 45.25 lx at a height of 5 m and an area of $72\;m^2$, and 30.05 lx at a height of 6 m and an area of $128\;m^2$. 100 W safety street lighting (model CE180-ST-OS) designed by simulation was also compared between product and 100 W simulation modeling, and error rates averaged 5.6%. The 100 W LED safety street lighting base designed in simulation modeling was proven by comparison experiments. Through the simulations and the corresponding analysis, it was found that the tested 100 W LED safety street lamp had reasonable performance. The design method for LED safety street lamps has been summarized based on the optical analysis.

• Horticulture, Environment, and Biotechnology : HEB
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• v.59 no.6
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• pp.827-833
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• 2018

Plasma lighting systems have been engineered to simulate sunlight. The objective of this study was to determine the effects of plasma lighting on tomato plant growth, photosynthetic characteristics, flowering rate, and physiological disorders. Tomato plants were grown in growth chambers at air temperatures of $25/23^{\circ}C$ (light/dark period), in a $16h\;day^{-1}$ light period provided by four different light sources: 1 kW and 700 W sulfur plasma lights (1 SPL and 0.7 SPL), 1 kW indium bromide plasma light, and 700 W high pressure sodium lamp (0.7 HPS) as a control. The totaldry weight and leaf area at 0.7 SPL were approximately 1.2 and 1.3 times greater, respectively, than that of 0.7 HPS at the 62 days after sowing (DAS). The maximum light assimilation rate was observed at 1 SPL at the 73 DAS. In addition, the light compensation and saturation points of the plants treated with plasma lighting were 98.5% higher compared with HPS. Those differences appeared to be related to more efficient light interception, provided by the SPL spectrum. The percentage of flowering at 0.7 SPL was 30.5%, which was higher than that at 0.7 HPS; however, there were some instances of severe blossom end rot. Results indicate that plasma lighting promotes tomato growth, flowering, and photosynthesis. Therefore, a plasma lighting system may be a valuable supplemental light source in a greenhouse or plant factory.