• Journal of Biosystems Engineering
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• v.39 no.2
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• pp.87-95
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• 2014

Purpose: The purpose of this study was to design a variable frequency LED light system for plant factory which combined red, blue, green, white, and UV lights and controlled the ratio of the light wavelength. In addition, this study evaluated the performance of each combination of LED to verify the applicability. Methods: Four combinations of LED (i.e. Red+Blue, Red+Blue+Green, Red+Blue+White, Red+Blue+UV) were designed using five types of LED. The system was designed to control the duty ratio of each wavelength of LED by 1% interval from 0~100%, the pulse by 1Hz interval from 1~20kHz. Response characteristics of the control system, spectral distribution of each combination, light uniformity and uniformity ratio were measured to test the performance of the system. Results: Clean waveforms were measured from 10Hz to 10kHz regardless of duty ratio. Frequency distortion was observed within 5% of inflection point at frequencies above 10kHz regardless of duty ratio, but it was judged negligible. Spectra showed a normal distribution, and maximum PPF with duty ratio of 100% was $271.4{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ for the Red+Blue combination. PPF of the Red+Blue+Green combination was $258.9{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, and that of the Red+Blue+White combination was $273.9{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. PPF of the Red+Blue+UV combination was $267.7{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Uniformity ratio for the area excepting border showed 0.90 for the Red+Blue and Red+Blue+White combinations, 0.87 for the Red+Blue+Green combination, and 0.88 for the Red+Blue+UV combination. The light was irradiated evenly at the area excepting border, so it was suitable for plant growing. Conclusions: From the results of this study, response characteristics of the control system, spectral distribution of each combination, light uniformity and uniformity ratio were suitable for applying into the plant factory.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.4
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• pp.395-403
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• 2013

Fishing efficiency of the squid jigging vessel using the LED and metal halide fishing lamp combination was analyzed to reduce the cost for fishing operation utilizing the fishing light system for high degree of efficiency in the squid jigging fishery (one of the representative coastal and offshore fisheries in Korea). This study aims to improve the nature of existing LED lamps and to develop fan-shaped LED lights having 180W of power and ${\pm}45^{\circ}$ angle of light intensity distribution. The marine experiment for making a comparison of their fishing efficiency was tested by a 9.77 tons fishing vessel from Oct. through Dec. 2012. As a result, experimental fishing vessel showed slightly higher fishing efficiency than the average of metal halide lamp-equipped vessel and 20% energy savings. This means that the combination of LED and metal halide lamps would provide an efficient way to lower energy consumption while maintaining fishing efficiency.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.2
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• pp.24-31
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• 2011

The purpose of this study is to find an efficient way using dimmable LED lamps to describe specific target illuminance and color temperature. This study used 14 dimmable LED lamps as same or different color temperature. The method of study is to measure of electric power consumption using different color temperature of dimmable LED lamps that were combination of two or three dimmable LED lamps by simultaneously dimming. Through this method, the electric power consumption was compared with all combinations of the illuminance and color temperature.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.35-36
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• 2014

본 논문은 Rear Combination LED Lamp 동작 시 전류와 광출력의 변동폭를 최소화하는 LED 조명광원의 특성을 고려하여 정전류 회로의 구현이 유리한 DC/DC 컨버터의 EMC 고효율 필터를 제안하여 외부의 전자계로부터 장애를 유발하지 않고, 일정 수준의 전자파 환경에서도 오동작 없이 원할하게 작동될 수 있도록 관련 기기 상호간의 전파 환경을 개선하는 고효율 Filter를 제안 하고자 한다. 본 논문에서 제안한 Filter는 EMI 측정을 통해 타당성과 우수성을 검증하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.571-574
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• 2004

The LED backlight can be designed to have the desired uniformity by using many combination of reflector patterns. The uniformity of the LED backlight can improve by applying the specially designed reflector patterns. In this paper, it was shown that the 72.7% of luminance uniformity of the LED backlight with reflector patterns was obtained by computer simulation.

• Journal of Plant Biotechnology
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• v.41 no.3
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• pp.123-126
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• 2014

This paper is suitable for household plant factory by design and using both energy-saving LED and solar technology. Conventional household plant factory only depending on natural sunlight is sensitive for the change of external environment. Another a big problem of conventional common household plant factory is large power consumption. Recently interest in wellbeing food such as chemical-free is increased abruptly. To solve these two problems, this paper describes hybrid type of household plant. In particular, reducing the power photosynthesis photon flux density (PPFD) is kept uniform to enhance the growth of the plant. Ambient light sensor is adopted for the control of proper combination of sunlight and LED to keep PPFD constant.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.10
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• pp.135-141
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• 2013

In this paper, we installed three high brightness red, green, and blue LED in one socket and made one pixel unit. And we also developed the full-color display board module and control unit which can express various images such as text, graphics, video image with the combination of pixel units and a number of modules. LED display driver module have a driver circuit within the combination of the RGB pixel dot on unit area. These modules of the existing form can be high priced because of implementation a fixed resolution in specific space and installation space. To overcome these shortcomings, we developed a LED driver and LED pixel modules free in array at random pitch intervals. Display board module of this paper enabled to display smoothly video image which have many data processing quantity through dragging data speed up 36 frames per second. Also there are an effect which is provided more clear image because of improving the flickering of the existing display board.

• International journal of advanced smart convergence
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• v.6 no.1
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• pp.76-81
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• 2017

This paper presents a low cost and flexible IoT enabled smart LED controller using Arduino that is used for emergency exit signs. The Internet of Things (IoT) is become a global network that put together physical objects using network communications for the purpose of inter-communication of devices, access information on internet, interaction with users as well as permanent connected environment. A crucial point in this paper, is underlined on the potential key points of applying the Arduino platform as low cost, easy to use microcontroller with combination of various sensors applied in IoT technology to facilitate and establishment of intelligent products. To demonstrate the feasibility and effectiveness of the system, devices such as LED strip, combination of various sensors, Arduino, power plug and ZigBee module have been integrated to setup smart emergency exit sign system. The general concept of the proposed system design discussed in this paper is all about the combination of various sensor such as smoke detector sensor, humidity, temperature sensor, glass break sensors as well as camera sensor that are connected to the main controller (Arduino) for the purpose of communicating with LED exit signs displayer and dedicated PC monitors from integrated system monitoring (controller room) through gateway devices using Zig bee module. A critical appraisal of the approach in the area concludes the paper.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.4
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• pp.1-5
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• 2012

By using LED optical devices and improving the efficiency of optical devices as well as lighting apparatus for humans, LED lighting industry puts the purpose of manufacturing the main products related with information, electric, large-sized LCD BLU, automobile, shipbuilding, agriculture, medical treatment, environment, and telecommunications, etc. Moreover, the main products and the industrial lighting products are manufactured with fusion, as the result, LED lighting industry provides various effects as well as sources of technology based on practical use of LED technology in order to develop the industry from the perspective of the lower price, the higher efficiency, the higher function, the deeper reliance. In the future, not only the development of new LED technology but also the fusion and combination of digital IT technologies using wire-wireless communication, sensor, controller, and artificial intelligence will be expected to create new industrial fields.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2005.05a
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• pp.275-278
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• 2005

This study suggests experimental designs for interior products utilizing LEDs that are ideal for expressing diversity of light. It also attempts to develop various products by incorporating economic efficiency and diverse colors of LEDs into interior elements. LED door handles offer a range of 6-color LED lighting strips as a safety lighting system, while multi-function furniture (CUBE-scape) consists of LEDs with double-sided emitted lighting on completely transparent track structures. Both products are designed to make interior elements more user-friendly as they make most use of unique effects of LED such as light vibration and changes. Also the combination of plastic material-Technogel$^{\circledR}$, polypropylene, polycarbonate- maximize the LED lighting effect and diversify the designed item selection.