• 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 Korea Multimedia Society
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• v.16 no.11
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• pp.1325-1337
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• 2013

Music affects sensitivity and emotion of human, emotional power of the music has been applied to various fields. Especially, to visualize as well as listen to music is able to create various atmosphere. In this paper, we proposed sensitivity control system for interaction with people to merge music and lighting. Because existing FT(Fourier Transform) has not information about the time, to analyze information of changed signal according to the time is difficult. In order to solve such a problem, we use STFT(Short Time Fourier Transform) method to analyze music signal. and also, we classified music for three genre and compared the frequency characteristics according to genre, and control the color, brightness of LED light based on the frequency components within analysis range. Unlike existing LED lighting control study using music, we had color control of emotional lighting and brightness control using variation amount of music signal in this paper. Proposed lighting control system will be able to utilize various industry fields as well as emotional lighting.

• Journal of Advanced Navigation Technology
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• v.15 no.6
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• pp.1111-1117
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• 2011

We was designed the portable LED light which can shadowless shooting and developed using a high-power LED that medical attention as a new lighting components for structural confirmation of oral dental area, medical and surgical lesions in the local area. LED which applied to the development, was used the 3-color LEDs for possible of implement a variety of colors and adjusted the light intensity. It is being magnified of delicacy expressiveness and three-dimensional for tone of the subject-specific. It has been developed a highly efficient light module that LED is used to consider the electrical characteristics and optical properties. SMPS has We was designed the portable LED light which can shadowless shooting and developed using a high-power LED that medical attention as a new lighting components for structural confirmation of oral dental area, medical and surgical lesions in the local area. LED which applied to the development, was used the 3-color LEDs for possible of implement a variety of colors and adjusted the light intensity. It is being magnified of delicacy expressiveness and three-dimensional for tone of the subject-specific. It has been developed a highly efficient light module that LED is used to consider the electrical characteristics and optical properties. SMPS has produced for use in mobile that can be driven at low voltage. In addition, it was also possible to implement a variety of colors from monochromatic Light to polychromatic light using by PWM control method and were available 32,768.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.93-96
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• 2008

Recently, as development of the luminaire industry, many people are interest of the outdoor and indoor lighting environment. Also, as increasing of people activity at night, the role of lighting is more important. In these days, the issue of LEDs lighting environment is using loud colors of LEDs which are the most of primary colors (R, G, B). It is often disliked by same people. Therefore, it is necessary to use of natural color in lighting design using LEDs. The colors of the LEDs are composed of combination of R, G, B diodes. This paper performs to investigate preference of various colors and color patterns of LEDs. The purposes of this study are to suggest standardization and natural colors instead of primary colors using LEDs.

• Journal of Industrial Technology
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• v.31 no.A
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• pp.95-101
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• 2011

According to recent technological developments in high-power LEDs, the stage lighting is one of most important areas to apply power LED system. Moving light for color rendering of stage uses the RGBW(red, green, blue, white) color mixing method. LED moving light system needs to have a wide range of dimming control as enough to operate at very low power. Also LED dimming system should not be induced color-shift and flicker in camera. This paper is experimentally verified the LED Moving Light driving circuit of 200Watt level designed to satisfy the above characteristics which applied the DC current-controlled and PWM mixed dimming method.

• Journal of the Korean Institute of Educational Facilities
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• v.18 no.2
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• pp.25-33
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• 2011

This study performs the objective evaluation on simple comparison and calculation works by students under LED illumination conditions according to three types of color temperatures (7000K, 5000K, 3000K) in the classroom, Since the objective of this study is to develop an electric lighting conditions suitable for students in the classroom, the learning performance under three types of LED illumination conditions were analyzed. The 4 kinds of simple tests concerning with learning performance were developed and test results under natural light and LED illumination by 3 types of color temperatures were analyzed. There were differences by t-test in most cases among simple experiment results of different illumination conditions ($p{\leq}.05$). It was confirmed that illumination condition plays an important role when students simply compare words or perform arithmetic calculations. The experimental results of this study might be applied to designing better luminous environment.

• 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 Advanced Marine Engineering and Technology
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• v.39 no.4
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• pp.495-500
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• 2015

Currently the fish aquaculture industry of Korea is focused on the mass culture of flatfish (Paralichthys olivaceus) and and rockfish (Sebastes schlegeli) with completely controlled culture techniques. Recently, there has been considerable interest in new species development, such as the starry flounder (Platichthys stellatus). The value of starry flounder (Platichthys stellatus) as a raw fish increases with time because it is tasty, light, and bouncy. In this paper, the growth characteristics dependent on the LED wavelengths and the optimal growth conditions of the starry flounder were studied. In these experiments 4 different kinds of LED lighting, configurations were designed and prepared using red, green, blue and white, respectively. The fish aquaculture experiments were conducted over 10 weeks in four fish tanks, each installed with a different color of LED lighting. 10 starry flounders of 13 ~ 17g were placed into each tank. The effects of each color of light on the growth rate of the starry flounders were then examined. As a result, the starry flounders under the green LED lighting showed the highest growth rate, followed by the white, red, and blue LED lighting. Based on these results, a green light provides a suitable breeding environment for the starry flounder.

• Science of Emotion and Sensibility
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• v.18 no.2
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• pp.37-44
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• 2015

LED lighting has an advantage of adjusting color temperature. This change of color temperature may derive change in behavioral and physiological responses of the visual perception for indoor environments. This research examined the changes of behavioral and physiological responses caused by the color temperature. The environment was configured that the indoor temperature was 20 degrees centigrade or less as the perceived uncomfortable environment in winter. Then, the comfortable sensation vote (CSV) and the results of 3-back working memory test were measured as behavioral responses. In addition, the Electrodermal Activity (EDA) and Electrocardiogram (ECG) were measured as the responses of autonomics nervous system (ANS) in the three conditions of color temperature (red: 3862K, white: 5052K, blue: 11,460K). As a result, behavioral responses were not significant by the condition of color temperature, but the tendency of occupants' physiological relaxation appeared in the blue color temperature condition compared with the white color temperature condition. Although the color temperature of LED lighting might be a small factor in terms of the characteristics of indoor environment, it suggests that the color temperature could have an impact on the physiological changes in the parasympathetic nervous system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.666-671
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• 2016

This paper introduces a device providing close local lighting to the affected part, where the operation-purpose astral lamp alone cannot shed light directly, in an operation room of hospitals or clinics, which helps clinical doctors perform safe treatment of the affected part deep inside a human body. This medical assisting lighting is a device necessary to prevent fatal operation failures, which can occur with minute operation processes, such as tumor removal or angiorrhaphy. The components, such as the light source and power supply were designed to be low power consuming and small in size, have a narrow angle lens was used to increase the light spreading effect and focused illumination. The end-caps of the light transmission device using an optical cable and the lighting device were designed in the waterproof type to enable disinfection of these devices after use for the next patients. According to the measurement of the light source properties made after development of the retractor lighting device, the illumination intensity was 490 lux, the brightness was $11,550cd/m^2$, general color rendering index was 78, color temperature was 11,000K, and the intensity distribution was even, which were confirmed to be adequate for medical assisting local lighting.