• Journal of the Semiconductor & Display Technology
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• v.17 no.2
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• pp.41-46
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• 2018

This paper proposes a new method for the number recognition on dot matrix LED display. The proposed method uses morphological processing that dilates dots of numbers and connects the dots into strokes. The size of numbers is normalized using horizontal projection because the gaps of dots are different according to the size of numbers. The numbers are segmented by connected component analysis and finally, template matching method recognizes the segmented numbers. The proposed method is implemented using C language in Raspberry Pi system with a camera module for a real-time image processing. Experiments were conducted by using various dot matrix LED displays. The results show that the proposed method is successful for the number recognition on dot matrix LED display.

• Proceedings of the KAIS Fall Conference
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• 2007.11a
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• pp.159-161
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• 2007

본 논문에서는 버스에 장착되는 LED 번호판의 효율적인 설계에 관한 연구를 보여준다. LED 번호판은 16X16 LED Dot Matrix(LDM)을 사용하여 버스 구간을 번호로 표시하기 위한 것으로 기존의 플라스틱 판을 LDM을 사용하여 표시한 것이다. 본 논문에서는 LDM을 사용하여 효율적인 번호판 설계를 보여주고, 실제 시작품을 버스에 장착하여 그의 타당성을 확인하였다.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2048-2050
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• 2001

기존의 생산관리 현황반, 각종 산업용 판넬의 Faul Indicator, 각종 기계의 상태표시, 엘리베이터 정보출력장치, 주차타워 안내표시, 버스 행선지 안내표시, 병원, 은행 등 각종 광고용에서 사용되는 정보표시장치를 휘도와 안정성이 우수한 40mm 3 Color LED Dot Matrix Module을 이용한 Message 표시장치로서, 각종 Panel 및 기계 장치에 부착되거나 단독 설치되어 Parallel 또는 Serial Port로 입력을 받아 그 입력에 해당되는 Message를 출력 하며 User에 의해 제작되는 Graphic과 Text 형태가 있으며 외부입력에 의해 선택되는 Text Message와 출력 형태는 User에 의해 제작되는 Program에 의해 출력되는 방식으로 구현하여 영문, 숫자는 물론 한글 및 한자 표현도 가능 하도록 하여, 문자의 크기가 5${\times}$7 LED Dot Matrix에 비해 상대적으로 크고 미려하여 현장에서 상황의 인지도를 높이고 ASC-II 및 KS-5601의 Hex Code 입력방식보다 일반사용자가 Programming 하기 쉬우며 Message를 Graphic Symbol형태 및 문자로 작성하여 Message출력 형태를 선택할 수 있는 Mode Programming방식을 적용해 사용자의 용이이성이 배가 되도륵 하여 비교 검토한 결과 사용에 있어 편리성을 입증할 수 있었다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.11a
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• pp.197-198
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• 2016

최근 RGB LED 조명은 다양한 장점으로 이를 활용한 연구가 진행되고 있으며 단순 조명이 아닌 정보전달 및 공간연출의 디자인적 요소의 역할을 이행하기도 한다. RGB의 혼합으로 다양한 색상이 표현 가능한 LED를 사용하여 개별적으로 LED를 제어해 여러 가지 색상 및 모양이 표현 가능한 LED 도트 매트릭스를 제작하였으며, 이를 활용해 다양한 콘텐츠를 출력하고자 한다. 다양한 모양의 콘텐츠에선 개별적으로 LED를 제어하고, 그 외의 콘텐츠에선 원하는 LED를 그룹지어 제어한다. 본 논문에서 제작한 LED 도트 매트릭스는 많은 정보를 전달 할 수 있으며, 다양한 콘텐츠 제공으로 인한 상업화 및 효율성의 확대를 꾀할 수 있다.

• Korean Journal of Materials Research
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• v.20 no.11
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• pp.606-610
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• 2010

Films consisting of a silicon quantum dot superlattice were fabricated by alternating deposition of silicon rich silicon nitride and $Si_3N_4$ layers using an rf magnetron co-sputtering system. In order to use the silicon quantum dot super lattice structure for third generation multi junction solar cell applications, it is important to control the dot size. Moreover, silicon quantum dots have to be in a regularly spaced array in the dielectric matrix material for in order to allow for effective carrier transport. In this study, therefore, we fabricated silicon quantum dot superlattice films under various conditions and investigated crystallization behavior of the silicon quantum dot super lattice structure. Fourier transform infrared spectroscopy (FTIR) spectra showed an increased intensity of the $840\;cm^{-1}$ peak with increasing annealing temperature due to the increase in the number of Si-N bonds. A more conspicuous characteristic of this process is the increased intensity of the $1100\;cm^{-1}$ peak. This peak was attributed to annealing induced reordering in the films that led to increased Si-$N_4$ bonding. X-ray photoelectron spectroscopy (XPS) analysis showed that peak position was shifted to higher bonding energy as silicon 2p bonding energy changed. This transition is related to the formation of silicon quantum dots. Transmission electron microscopy (TEM) and electron spin resonance (ESR) analysis also confirmed the formation of silicon quantum dots. This study revealed that post annealing at $1100^{\circ}C$ for at least one hour is necessary to precipitate the silicon quantum dots in the $SiN_x$ matrix.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.6
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• pp.329-336
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• 2016

In the outdoor advertising and industrial sites, are trying to implement the LED electric bulletin board system that is based on image processing in order to express a variety of intention in real time. Recently, in various field, rather than simple text representation, the importance of intuitive communication using images is increasing. Thus, instead of outputting the simple input information for communication, a system that can output a real-time information being sought. Therefore, the system is directed to overcoming by converting the problem of mapping an image on a variety of conventional LED display that can not be output images, the possible image output formats. Using an LED of low power, it has developed to output the efficient messages and images within a limited resources. This paper provides a system capable of managing the LED display on the wireless network. Atmega2560, Wi-Fi module, using the server and Android applications client, rather than printing a text only, it is a system to reduce the load generated image output character output in to the conversion process as can be managed by the server.

• Current Optics and Photonics
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• v.3 no.6
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• pp.590-596
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• 2019

To improve the color gamut of a liquid-crystal display (LCD), we propose a bandpass filter that is added to the backlight unit to optimize the backlight spectrum. The bandpass filter can only transmit red, green and blue light in the visible range, while reflecting the unwanted light. We study the optical properties of the bandpass filter using the transfer-matrix method, and the effect of the bandpass filter on the color gamuts of LCDs is also investigated. When a bandpass filter based on a 5-layer configuration comprising low and high refractive indices ((HL)²H) is used in phosphor-converted white-light-emitting diode (pc-WLED), K₂SiF₆:Mn⁴⁺ (KSF-LED), and quantum-dot (QD) backlights, the color gamuts of the LCDs improve from 72% to 95.3% of NTSC, from 92% to 106.7% of NTSC, and from 104.3% to 112.2% of NTSC respectively. When the incident angle of light increases to 30°, the color gamuts of LCDs with pc-WLED and KSF-LED backlights decrease by 2.9% and 1% respectively. For the QD backlight, the color gamut almost does not change. When the (HL)²H structure is coated on the diffusion film, the color gamut can be improved to 92.6% of NTSC (pc-WLED), 105.6% of NTSC (KSF-LED), and 111.9% of NTSC (QD). The diffusion film has no obvious effect on the color gamut. The results have an important potential application in wide-color-gamut LCDs.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.8 s.338
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• pp.27-34
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• 2005

In this paper, FPGA It/w and S/W Embedded system for LDM remote control is implemented. XScale CPU is used on developed system and in communcation ethenet and serial is used. CPU interface with H/W LDM rotation and to drive LDM FPGA logic is implemented, to transmit LDM data from long distance command packet is composed, for S/W Embedded linux is used to design linux device driver and linux application program. This S/W is run by module so by loading this module to linu)( file system it can do any movement. Also by compiling Embedded linux to the system it can lower the price of the system. By using this H/W and S/W theory it can be used on any other embedded system.