• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.2
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• pp.102-108
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• 2011

The existing vessels lighting control system has several problems, which are complexity of construction and high cost of establishment and maintenance. In this paper, We designed low cost and high performance lighting control system at digital vessel environment. We proposed a system which recognize the user's emotions after obtaining the biological informations about user's bio information(pulse sensor, blood pressure sensor, blood sugar sensor etc) through wireless sensors controls the LED Lights. This system classified emotions using backpropagation algorithm. We chose 3,000 data sets to train the backpropagation algorithm. As a result, obtained about 88.7% accuracy. And the classified emotions find the most appropriate point in the method of controlling the waves or frequencies to the red, green, blue LED Lamp comparing with the 20-color-emotion models in the HP's 'The meaning of color' and control the brightness or contrast of the LED Lamp. In this method, the system saved about 20% of the electricity consumed.

• Journal of Korea Game Society
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• v.17 no.3
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• pp.45-52
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• 2017

This paper proposes a new strategy of emotion-based music visualization. Emotional LED lighting control system is suggested to help audiences enhance the musical experience. In the system, emotion in music is recognized by a proposed algorithm using a dimensional approach. The algorithm used a method of music emotion variation detection to overcome some weaknesses of Thayer's model in detecting emotion in a one-second music segment. In addition, IRI color model is combined with Thayer's model to determine LED light colors corresponding to 36 different music emotions. They are represented on LED lighting control system through colors and animations. The accuracy of music emotion visualization achieved to over 60%.

• Journal of the Korean Institute of Educational Facilities
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• v.18 no.3
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• pp.23-33
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• 2011

This study investigates the evaluation on simple comparison and seeking hidden figures works 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 performance of concentration and visual discrimination by students under three types of LED illumination conditions were analyzed. The 4 kinds of simple tests concerning with concentration and 2 types of tests for visual discrimination were developed, and test results under natural light and LED illumination by 3 types of color temperatures were analyzed. There were differences on concentration as well as visual discrimination performance in most cases by t-test ($p{\leq}0.05$). For further analysis among three types of color temperatures and natural light, ANOVA tests were performed. The test results shows that illumination condition plays an important role when students try to concentrate on simple comparison of characters, figures or colors and seek hidden figures. The experimental results of this study might be applied to designing better luminous environment.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.4
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• pp.42-49
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• 2009

This paper proposes a driving current control method for a back light unit (BLU), consisting of red, green, and blue (RGB) light-emitting diodes (LEDs), whereby an RGB optical sensor is used to check the output color stimulus variation to enable a time-stable color stimulus for light emission by the RGB LED BLU. First, to obtain the present color stimulus information of the RGB LED BLU, an RGB to XYZ transform matrix is derived to enable CIEXYZ values to be calculated for the RGB LED BLU from the output values of an RGB optical sensor. The elements of the RGB to XYZ transform matrix are polynomial coefficients resulting from a polynomial regression. Next, to obtain the proper duty control values for the current supplied to the RGB LEDs, an XYZ to Duty transform matrix is derived to calculate the duty control values for the RGB LEDs from the target CIEXYZ values. The data used to derive the XYZ to Duty transform matrix are the CIEXYZ values for the RGB LED BLU estimated from the output values of the RGB optical sensor and corresponding duty control values applied to the RGB LEDs for the present, first preceding, and second preceding sequential check points. With every fixed-interval check of the color stimulus of the RGB LED BLU, the XYZ to Duty transform matrix changes adaptively according to the present lighting condition of the RGB LED BLU, thereby allowing the RGB LED BLU to emit the target color stimulus in a time-stable format regardless of changes in the lighting condition of the RGB LEDs.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.204-207
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• 2009

LED 광원의 광학적 성능이 발전함에 따라 광원으로서의 광학효율이 기존 광원을 대체할 정도의 수준을 만족하고 있으며, 이에 의해 실내 조명광원으로서 활용도가 점차 증가하고 있다. 하지만, LED 광원의 경우 기존 광원과는 판이한 분광분포를 가지고 있으며, 소형 광원의 군집체로서 조명기구를 형성하기 때문에 이를 이용하는 사용자들에게 이전의 조명기구와는 크게 다른 느낌, 분위기 등을 가질 수가 있다. 본 연구에서는 기존광원과 LED 광원과의 차이점을 분석하고 이러한 차이점 즉, 분광분포 및 조명기구의 구성 형태 등에 따른 피험자들이 느끼는 색 편차, 조명 분위기의 변화 등을 평가 시험할 수 있는 실험실의 구성안을 제시하였다.

• KIEAE Journal
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• v.15 no.2
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• pp.37-43
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• 2015

Purpose: It is crucially important that indoor luminous conditions of built environments be carefully studied so as to promote comfort and occupants' well-being. Method: The current study therefore focuses on the lit aspect of an enclosed space considered to be a resting room ($4.5m{\times}6.32m{\times}2.5m$). Particularly, on the effect that light levels and light color temperatures have on the physiological and psychological responses of resting occupants. To do so, a questionnaire survey was carried out on 50 subjects. The independent variables for the experiment included 9 different luminous environment conditions setup using 3 different levels of illuminance (50 lx, 150 lx, 300 lx) and 3 different color temperatures (2000 K, 3800 K, 5600 K). A questionnaire was utilized in determining which conditions were preferred by occupants. Result: As it turns out, indoor luminous environment designed for relaxation purposes should display luminance levels of at least 150 lx and 3800 K of color temperature in order to provide a visually comfortable environment suitable for the occupant's relaxation while at the same time promoting the psychological and HRV well-being of resting occupants.

• Journal of the Korean Institute of Rural Architecture
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• v.10 no.3
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• pp.27-34
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• 2008

Recently, the outdoor lighting of architectural Facade has increased for the improvement of night-scape in urban and coastal resort. The purpose of this research is to analyze lighting characteristics; Luminance, Illuminance, Color Temperature, Chromaticity in Gyengpo Park of Eastern famous coastal resort. The result of this paper is as follows: 1) The Luminance ratio was measured that compare to the 1:10 criterion(IESNA) was in excess to the most building except "K". Because of these condition, Luminance environments was injurious to visual health the overuse of the outdoor lighting or glare to the eyes. 2) The level of vertical Illuminance value was insufficient 33.3% among the cases of survey with 4Lux standard of CIE. 3) The kinds of outdoor lighting of BLDG were increased lighting emitting diode(LED), metal halide(MH) instead of reduction trend of neon, fluorescent light, halogen. As the crisis of Energy resources we will be investigate adapt method of outdoor lighting, which design is based on economical efficiency by the use of optimum lighting.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.1
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• pp.28-34
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• 2010

The pulse width modulation(PWM) method has been generally used as conventional method controlling luminance of LED(light emitting diode). PWM method as analog method with a relation that duty ratio of LED be proportional to luminance has weak point that it is not compatible with digital method of communication etc. In this paper, a experiment is conducted which the luminance of RGB LED be controlled by digital method. For this, the LED digital control system is developed which consist of LED driving circuits and digital logic circuits. By controlling the number of pluses on RGB LED versus digital input, various lighting colors is implemented and digital codes are optimized in order that measured x, y chromaticity coordinates of lighting colors are comprised in the CIE chromaticity coordinates area of targeted lighting colors. The result of this study can be utilized usefully in research on implementing full color by using remote control of LED lamp with digital communication.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.1
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• pp.57-63
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• 2015

Recently, LED is widely used in the kinds of display devices or lighting. In this paper, we fabricated LED chamber light for naval vessels to replace to conventional chamber light using incandescent lamp. The LED package of chamber light was designed with luminous intensity of 5.5 cd, color temperature of $6,000{\pm}500K$, forward voltage of 3~3.2 V and input current of 60 mA. A LED module was composed of 36 LED packages and metal PCB. The VF and luminous intensity of LED package were getting down when temperature increased. The temperature of LED chamber light was measured by changing the number of LED package and applied current for one hour when an electric current flow. The heat transfer capability have been improved by using metal PCB. The power consumption of LED chamber light reduced by 86% compared to the conventional chamber light using incandescent lamp.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.7
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• pp.778-784
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• 2012

In comparison with some other light sources, LED has merits such as increased life expectancy, fast response, pollution free, and high energy efficiency. Lately, due to development of LED with high brightness and capacity, LED has widely used in many industrial fields such as automotive, aviation, display, transportation and special lighting applications. Since the high heat generation of LED chips can cause a reduction in lifetime, degradation of luminous efficiency, and variation of color temperature, studies have been carried out on the optimization of LED packaging and heat sinks. In this study, experiments on measuring the heat generation rate of LED and the cooling performance of a heat sink were carried for analyzing the thermal characteristics of LED lighting system in free convection. From the results, dimensionless correlation on the cooling performance of heat sink in natural convection was proposed with Nusselt number and Rayleigh number as a guideline for designing cooling device of LED lightings.