• 한국전자통신학회논문지
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• 제9권9호
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• pp.999-1004
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• 2014

본 논문에서는 초보자들도 건반악기의 연주 방법을 쉽고, 효과적으로 학습할 수 있도록 건반악기 자율 학습 시스템을 개발하였다. 본 연구에서 개발한 지능형 건반악기 자율 학습시스템은 스마트폰 기반의 학습 어플리케이션과 건반악기 보조 모듈로 구성된다. 건반악기 보조 모듈은 스마트폰 어플리케이션과 블루투스 통신을 통하여 악기 연주 정보를 수신한 후, LED에 표시해 줌으로써 초보자도 쉽게 건반과 음계의 상관관계를 숙지할 수 있도록 하였다. 또한 사용자의 연주정보를 저장하고, 분석 정보를 제공하여 효과적인 학습이 가능하도록 구현하였다.

• Journal of the Optical Society of Korea
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• 제13권3호
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• pp.304-309
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• 2009

We tested the feasibility of measuring fat thickness using a miniaturized chip LED sensor module, testing 12 healthy female subjects. The module consisted of a single detector and four sources at four different source-detector distances (SD). A segmental curve-fitting procedure was applied, using an empirical algorithm obtained by Monte-Carlo simulation, and fat thicknesses were estimated. These thicknesses were compared to computed-tomography (CT) results; the correlation coefficient between CT and optical measurements was 0.932 for bicep sites. The mean percentage error between the two measurements was 13.12%. We conclude that fat thickness can be efficiently measured using the simple sensor module.

• International Journal of Internet, Broadcasting and Communication
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• 제7권2호
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• pp.161-167
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• 2015

The performance of high power LEDs highly depends on the junction temperature. Operating at high junction temperature causes elevation of the overall thermal resistance which causes degradation of light intensity and lifetime. Thus, appropriate thermal management is critical for LED packaging. The main goal of this research is to improve thermal resistance by optimizing and comparing nano-pore silicon-based thermal substrate to insulated metal substrate and direct bonded copper thermal substrate. The thermal resistance of the packages are evaluated using computation fluid dynamic approach for 1 W single chip LED module.

• 한국철도학회논문집
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• 제9권4호
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• pp.504-509
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• 2006

Currently, most of TDIS(Train Destination Indicator System) is operated colored-LED type equipment in Korea. This current LED type TDIS equipment has not graceful display and causes passenger's fatigues because of the LED module inherent characteristics as a display light source, high power consumption, high operating and maintenance costs, and et al. To address these several, we are developed new colored-LCD type TDIS equipment. According to our developed new TDIS equipment, we can achieve high resolution and graceful color stone of information display. Thus high graded service are able to provide to passengers. In addition, LCD module decreases power consumption, and it can be used permanently by changing only backlight in comparison with conventional equipment. Therefore we can decrease the maintenance cost and extend durability-period of TDIS equipment using new equipment.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 추계학술대회 논문집
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• pp.274-277
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• 1996

This paper describes the realization of the full-color to the degree of nearest white light by compounding high brightness Red, Green and Blue LEDs with appropriate proportional index. Once these three colors; red, green and blue are mixed, they are genearlly additive mixing and produce white light color contrasted to negative mixing. The luminous efficiency is defined as the product of the efficiency(lm/w), which indicates the degree of perceptual response by the human eye to unit energy(W) of light emitted by an active display devises and as the conversion efficiency of the device from electric power consumed to optical energy produced. We will deduce the each number of LEDs theoretically and design several shapes of LED displays for the full-color. Finally theoretical predictions will be compared with the measured data with different type of display designs.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 추계학술대회
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• pp.139-140
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• 2010

This paper presents an indoor prototype for wireless digital signal transmission using Visible Light Communications (VLC) in which high power Light Emitting Diode (LED) is used. Using low cost and off-the-shelf components, the transmitter module is constructed using an AVR Atmega128 microcontroller and commercial white beam LEDs. Modulating the light intensity of the LED enables digital signals to be transmitted across the optical link. The receiver module employs a high speed PIN photodetector for optical signal detection and a recovery circuit for optical-electro signal conversion. By sending digitalized data via VLC technology, many applications can be realized in the areas of consumer advertising, traffic safety information and disaster control.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.836-841
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• 2004

This paper describes ASIC design for brightness revision control, A LED Pixel Matrix (LPM) design and LPM in natural color LED vision. A designed chip has 256 levels of gradation correspond to each Red, Green, Blue LED pixel respectively, which have received 8bit image data. In order to maintain color uniformity by reducing the original rank error of LED, we adjusted the specific character value 'a' and brightness revision value 'b' to pixel unit, module unit and LED vision respectively by brightness characteristic function with 'Y=aX+b'. In this paper, if designed custom chip and brightness revision control method are applied to manufacturing of natural color LED vision, we can obtain good quality of image. Furthermore, it may decrease the cost for manufacturing LED vision or installing the plants.

• 조명전기설비학회논문지
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• 제27권5호
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• pp.26-32
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• 2013

The LED has the proportional characteristic between the flux of light and its current and has caused voltage-current deviation on production process. Thus the unbalancing of each LED strings current occurred by its characteristic deviation. This unbalancing reduce a uniformity of the flux of light. Therefore, we researched to design method the LED driver based on DSP and the balancing transformer for a LED current balancing. These are applied to 50W LED module consist of 4 parallel strings. We analyzed the reduction of LED currents unbalance by experimental result from each method.

• 조명전기설비학회논문지
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• 제25권7호
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• pp.1-8
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• 2011

The high efficiency tubular LED lamp has been developed. But, it occurs optical losses in consists of LED package, module, diffuser etc.. By Measuring the tubular LED lamp's luminous flux, we compared and analyzed about the effect of optical losses for each component and actually using measured luminous intensity distribution data, illuminance distribution was simulated by Relux. Optical losses are 24[%] from LED package to luminaire and the tubular LED lamp can be replaced with fluorescent lamp. In this paper, we could provide data for optimum lighting design by analyzing the optical characteristics for developing and propagating the tubular LED lamp.

• 한국전기전자재료학회논문지
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• 제26권10호
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• pp.771-777
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• 2013

This paper dealt with the development of a LED floodlight for naval vessels to replace the conventional floodlight using an incandescent and a halogen lamp. We found a technical solution for current problems of conventional lights and also improved optical characteristics by developing a LED floodlight which has a typical long-lived light source with high efficiency. To satisfy the requirements specified in Korea Standard Vessels (KS V), the optical structure was designed with selected LED package and lens. A LED module was composed of 10 LEDs in series for stable luminous output, and an aluminium heat sink was adopted for effective heat-radiation design. The LED floodlight was fabricated as a module type so that it can easily replace the conventional light source. The power consumption of the prototype floodlight was only a tenth of a conventional one with the same optical performance. Also, a test showed the floodlight satisfied the electrical, optical and environmental requirements of the standards.