• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.6
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• pp.488-492
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• 2013

Current limiting diode (CLD) was fabricated using junction field effect transistor (JFET) structured two small cells and eight large cells. Two small cells and eight large cells were connected in parallel and the obtained constant current was 110 mA. The application of CLD in each of the parallel circuits on chip on board (COB) type LED lighting source, could significantly reduce the current deviation within the parallel circuits. The applications of CLD on AC power small lighting source, battery power low voltage parallel lighting source and AC flat lighting source were investigated.

• International journal of advanced smart convergence
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• v.9 no.4
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• pp.203-208
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• 2020

In this paper, we propose the design and implementation of a desktop LED stand and smart app that automatically adjusts color temperature and illuminance for optimal brightness and eye health by improving the structural problem of the LED stand. It is a tabletop LED stand that supports optimal brightness through color temperature control and heat transfer through infrared LED to relieve eye strain through blood circulation and muscle movement. The LED stand works with the smartphone to automatically adjust the optimal brightness and color temperature for the user's environment. In addition, the brightness of the infrared LED is adjusted to a living frequency of 4Hz to relax the eye muscles and reduce eye strain. This study implemented an effective measured data-based system of previous studies through the color temperature and illumination of LED lighting, and near-infrared rays, and presented meaningful results by conducting an experiment to prove the effect through subjects.

• Journal of Mushroom
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• v.11 no.1
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• pp.24-31
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• 2013

As a result of advenced research, Penicillium growth inhibition effect in media of cauliflower mushroom by different LED lighting color inhibited all treated groups, but blue wavelength treatment group was unfitted for culture of cauliflower mushroom due to lots of spore of penicillium. So, to investigated characteristics of mycelial growth of cauliflower mushroom according to different LED wavelength and LED wavelength color. As a results, all red wavelength treatment groups found highest mycelial growth tendency. Thus, mycelial growth investigated different quantity of red lighting wavelength conditions. The quantity of lighting wavelength was low intention, 1.41 ${\mu}mol/m^2S$ treatment group found highest mycelial growth. Effects of mycelial growth by subculture found difference of statistical in one time to carry out a subculture treatment group. Mycelial growth by different quantity of LED lighting in different media composition of wood chip media indicated highest trend in the Korean pine treatment groups. To cultured treatment group for 84th days found difference of statistical, when a quantity of LED lighting red wavelength 2.11 ${\mu}mol/m^2S$ treated in wood chip of the Korean pine media. In conclusion, good culture condition of cauliflower mushroom estimated quantity of red lighting wavelength 2.11 ${\mu}mol/m^2S$ in wood chip media of the Korean pine for 84th days.

• The Journal of the Korea Contents Association
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• v.12 no.2
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• pp.52-59
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• 2012

Recently, LEDs are used in various fields such as lightings, billboards, displays, and so on. In this paper, we tried to combine a costume with LEDs in a performance environment. To meet the environmental requirements, we propose a digital costume platform which consists of wireless network, an embedded system, a control jacket, a digital skin, and a pattern authoring tool. It is utilized for making a digital costume with LED lighting effects. The embedded system controls LED lighting according to the signals from a show control system through wireless networks. The control jacket can carry the embedded system and connect it with LEDs. The digital skin means a costume with LEDs. The LEDs were designed to fit in performance concept in point of aesthetic. The pattern authoring tool enables users to make timeline-based changing patterns of LED lighting. The proposed platform is a new lighting element in performances. It can expand stage representation techniques and be used as a special effect. It will play a role as a moving light in performances. We evaluated stable operations of our platform by employing it in live performances.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.6
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• pp.706-713
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• 2020

To control the LED lighting for broadcasting, LED current control using tri-stimulus values is used for RGB LEDs. For the convenience of control, this control is approximated as a linear function or used as an appropriate value through trial and error. Also, it is not suitable for broadcast lighting because it does not use a diffuser plate applied for mixing sufficient light and color required for actual it. In this study, a neural network with excellent nonlinear function approximation is used as a control method for LED panels for broadcast lighting. We intend to implement an LED panels controller suitable for the desired chromaticity coordinates and dimming values of intensity. As a result of the performance evaluation, the errors of the xy chromaticity coordinates are mostly ±0.02 and the acceptable range of ANSI C78.377A was satisfied. The average errors of the xy chromaticity coordinate are xerror=0.0044 and yerror=0.0030, respectively, and we confirmed the superiority and stable performance of the proposed algorithm.

• Journal of Navigation and Port Research
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• v.34 no.10
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• pp.763-768
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• 2010

Today the light of mankind since the dawn of mankind and that they were living "lives" on the huge influence across space is a dynamic energy. Because of this, when all human beings with the light and you can feel more comfortable with a stable mind to the beauty and the pursuit of happiness is to have instincts. In this paper, a fuzzy control system using a combination of external environmental factors, respectively, the conversion of quantitative uncertainty information into the LED lighting is designed to express algorithms, available in indoor circadian control circuit was designed and fabricated LED. Factor in the external environment temperature, humidity, and light intensity values to the controller through the sensor to accept these values and the optimal values for lighting the fuzzy control algorithm is converted into human emotion to feel comfortable to express through the dimming control LED lighting.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.10
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• pp.25-33
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• 2015

LED lightings combined with IT technology can provide variable illumination environments that can be controlled by users according to their emotional need and preferences. This is one of the most beneficial functions compared with conventional lightings offering only fixed color and brightness. There is however lack of analysis data for creating practical lighting solutions satisfying user preferences in a wide range of applications from residential to commercial places. To materialize the technical advantages of user-controllable LED lightings, more observation data are required in various situations. Therefore, dissimilar emotional needs are determined in the present study for compartmental office spaces (staff lounge room, meeting room and desk job place) through subjective experiments by 45 observers. The optimum lighting conditions (CCT and illuminance) are finally obtained using Response Surface Method and relevant prediction functions are also deduced. The final outcome can be applied for making user-preferred office illumination products.

• Journal of the Optical Society of Korea
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• v.16 no.3
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• pp.203-209
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• 2012

Visible light communications (VLC) use modern solid-state light-emitting diodes (LEDs) to broadcast information. Emerging white-light LEDs allow the combination of lighting and optical wireless communication in one optical source. In this paper, a new LED lighting design using one-chip-type white LEDs is proposed for efficient illumination and optical wireless communications under the existence of several obstacles. Lighting and communication performance are analyzed to show the effectiveness of the proposed LED lighting. Specifically, the signal-to-noise ratio considering intersymbol interference and the bit-error rate of variable pulse position modulation (VPPM) with dimming control are considered.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.12
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• pp.23-30
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• 2009

LEDs are increasingly used for many applications including automotive, aviation, display, transportation and special lighting applications. Generally, the RGB multichip LED luminaire applied to signboard, emotional lighting system and display device and the white LED luminaire applied to general lighting system. white LED spectra for general lighting should be designed for high luminous efficacy as well as good color rendering. This paper describes characteristics of LED luminaire white LED and RGB multichip LED. Two type of LED luminaire prototype used experiment physical, electrical and optic test and performance analyzed. RGB multi-chip and phosphor-type white LED luminaire were analyzed by experiment on their color characteristics and luminous efficacy of radiation, distribution curve, and electrical characteristics. Research work is in progress to develop an improved performance for optic and electrical works well for two type of LED luminaires.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.3
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• pp.674-679
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• 2011

In this paper, we experimented and analyzed about electric fire risk assessment methods of LED lightings for outdoor. LED lighting is composed of AC power lines, AC/DC converter, DC power lines and LED lamps. There are some risk factors of electric fire in LED lighting such as short circuit between power lines or power line and ground, dielectric breakdown, leakage current, abnormal voltage inflow, poor contacts(connections), etc. As a result of this study, insulation coverings of wire was ignited due to dielectric breakdown between power lines and molten marks were formed in copper conductor. LED lighting was blown out while short circuit, beside that, electrical disorder did not occur. When abnormal voltage was inflowed, electronic components such as varistor, condenser were damaged. Partial heating was produced and insulation was melted and carbonized by arc and heating while poor contacts were happened. We expect that the results of this study would be helpful for electrical safety of LED lightings for outdoor.