• 방송공학회논문지
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• 제10권2호
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• pp.210-220
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• 2005

본 논문에서는 ATSC(Advanced Television Systems Committee) 지상파 디지털 TV 방송 방식을 사용하는 등화형 동일 채널 중계기(Equalization Digital On-Channel Repeater: EDOCR)에 대한 실험실 테스트 결과를 기술하고, 그 결과를 분석한다. 캐나다 CRC(Communications Research Centre)에서 수행된 EDOCR실험실 테스트는 수신부 테스트, 송신부 테스트, 그리고 EDOCR 송수신 신호의 주파수 일치 여부 테스트로 구분된다. 수신부 테스트는 궤환 신호, 랜덤 잡음, 단일 에코, 다중경로 앙상블, NTSC와 DTV간섭 테스트 등을 포함하며, 송신부 테스트는 대역외 방사, 송신신호의 품질, 위상 잡음 테스트 등을 포함한다. 실험실 테스트 결과에 의하면, EDOCR 수신부는 $0\~11s$ 범위 내의 평균 5.5dB 궤환 또는 단일 에코 신호를 제거할 수 있으며, 랜덤 잡음에 대한 TOV(Threshold of Visibility)는 평균 18.6dB이다. 또한, EDOCR 송신부 출력 신호는 미국의 FCC(Federal Communications Commission) 규격을 만족하며, 송수신 신호의 주파수는 일치한다.

• 한국정보통신학회논문지
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• 제1권1호
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• pp.35-46
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• 1997

이 논문에서는 ATM을 기반으로 하는 B-ISDN을 통하여 기존의 음성, 영상 및 비연결형 데이타 서비스를 각각, 그리고 동시에 지원하는 B-ISDN 정합 장치에 관해 논한다. B-ISDN 정합 장치에서는 ATM망에 N-ISDN 단말기를 정합하고, NTSC 방식의 TV, VTR등을 DS3급의 코덱을 거쳐 ATM망에 정합함으로써 기존의 음성 및 영상을 B-ISDN에서 지원할 수 있도록 하였다. 또한 이더네트 LAN을 ATM망에 정합하여 비연결형 서비스를 제공할 수 있도록 하였고, N-ISDN 및 DS3 트래픽을 실시간으로 처리하기 위해 AAL 1을 사용하고, LAN 트래픽을 처리하기 위해 AAL 3/4 또는 AAL 5를 사용하였다.

• 제어로봇시스템학회논문지
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• 제13권2호
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• pp.121-127
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• 2007

Frequent occurrences of a fire cause tremendous loss of human lives and their property. Recently, in order to cope with such catastrophic accidents, researches on fire-fighting robots are carried out in developed countries. Under the dangerous situations, it is sometimes impossible for fire-fighting men to access the firing place because of explosive materials, smoke, high temperature and so on. In such an environment, fire-fighting robots can be useful to extinguish the fire. It is usually very dangerous place where fire-fighting robots operate. Hence, these robots should be controlled by remote users who are for away from the firing place exploiting remote communication systems. This paper considers the communication systems between fire-fighting robots and remote users. The communication systems consist of two parts; digital packet communication systems and analog image communication systems. Digital packet communication systems transfer data packets in order to control fire-fighting robots and to check the state of the fire-fighting robots. Remote users watch the video around the fire-fighting robots by exploiting the analog image communication systems. In the future, the more prosperous the commercial communication network systems will be, the more evolved the communication systems for fire-fighting robots are.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2005년도 학술대회
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• pp.117-120
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• 2005

A Digital Broadcasting Satellite (DBS) receiver converts digital A/V streams received from a satellite to analog NTSC A,/V signals in real-time. Multi-tasking is an efficient way to improve the utilization of the processor core in real-time applications. In this paper, we propose a hybrid approach with a balanced trade-off between hardware kernel and multi-tasking programming to increase a system throughput. First, the schedulability of the critical hard real-time tass in the DBS receiver is verified by using a simple feasibility test. Then. several soft real-time tasks are thoughtfully programmed to satisfy functional requirements of the system.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 춘계학술대회
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• pp.164-166
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• 1995

The objectives of study are to develop a peripheral device on the endoscopic surgery system. These systems are consist of the following units. They are a color monitor of high resolution, light source, computer system and endoscopic camera with a C-mount head, irrigator, color video printer, Super VHS recorder and a system rack. The color monitor is a NTSC monitor for monitoring the image projected of the surgical section. The lightsource is necessary to irradiate the interior of a body via an optic fiber, The light projector will adapt the brightness in accordance with changing distance from the object. A miniature camera using a color CCD chip and computer system is used to capture and control an image of the surgical section[1]. The video printer is a 300 DPI resolution using thermal sublimation methods, which is developed by Samsung Electronics Co., Ltd. The specification of the endoscopic data management system is consist of storage of a captured image and pathological database of patients [2-4].

• 한국재료학회지
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• 제18권3호
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• pp.159-162
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• 2008

$Eu^{3+}$-activated $R_3GaO_6$ (R = Y, Gd) phosphors were prepared in a conventional solid-state reaction and their optical properties were investigated. These compounds exhibit strong red emission under light excitation at 254 nm. The emission spectra are dominated by peaks appearing around 610-630 nm that are induced by the electric dipole transition of $^5D_0\;{\rightarrow}\;^7F_2$ of $Eu^{3+}$. In addition, the appropriate CIE (Commission Internationale de l'clairage) chromaticity coordinates, (x = 0.656, y = 0.336) for $Y_3GaO_6$ and (x = 0.655, y = 0.334) for $Gd_3GaO_6$, become closer to the NTSC (National Television System Committee) standard values. With the optimized activator concentrations, the maximum emission brightness is approximately 80% of $Y_2O_3$:$Eu^{3+}$ typical red-emitting phosphor with improved color purity under an excitation condition of 254 nm.

• Journal of Electrical Engineering and information Science
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• 제2권5호
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• pp.9-16
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• 1997

This paper describes the design of a multistandard video encoder. The proposed encoder accepts conventional NTSC/PAL video signals, It also processes he PAL-plus video signal which is now popular in Europe. The encoder consists of five major building functions which are letter-box converter, color space converter, digital filters, color modulator and timing generator. In order to support multistandard video signals, a programmable systolic architecture is adopted in designing various digital filters. Interpolation digital filters are also used to enhance signal-to-noise ratio of encoded video signals. The input to the encoder can be either YCbCr signal or RGB signal. The outputs re luminance(Y), chrominance(C), and composite video baseband(Y+C) signals. The architecture of the encoder is defined by using Matlab program and is modelled by using Veriflog-HDL language. The overall operation is verified by using various video signals, such as color bar patterns, ramp signals, and so on. The encoder contains 42K gates and is implemented by using 0.6um CMOS process.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.438-440
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• 2005

At present, characteristic of high color reproduction for LCD TV is needed in Display market according to start mass production of LCD TV. Therefore development target for LCD is focused on improvement of color reproduction. The improving methods of high color reproduction are alteration of color Filter or Red, Green, Blue phosphor alteration of CCFL. But decrease of luminance and panel transmittance is caused by alteration of Color Filter. Accordingly, we completed LCD with high color reproduction by the most suitable emission spectrum of CCFL phosphor at panel with conventional color filter. In this experiment, we knew that LCD applied to CCFL with high color rendering characteristic had color reproduction range of 81% compared with NTSC in CIE color coordinate. According to increase of intensity peak and alteration of Red, Green, Blue phosphor spectrum, we made LCD with high color reproduction characteristic. In conclusion we achieved improvement of color reproduction ratio by alteration of CCFL phosphor without changing color filter.

• 한국전기전자재료학회논문지
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• 제22권2호
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• pp.163-168
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• 2009

Hyperbranched conjugated polymers (p-HPPV and m-HPPV) with para and meta linkages were synthesized from $A_2$ and $B_4$ type monomers through Wittig polycondensation. The synthesized p-HPPV and m-HPPV were completely soluble in common organic solvents such as chloroform, tetrahydrofuran, 1,2-dichloroethane, etc. and thermal gravimetric analyses showed that p-HPPV and m-HPPV are stable up to $350^{\circ}C$. The molecular weights (from GPC), UV-visible, and photoluminescence maximum peaks of p-HPPV and m-HPPV are characterized in detail. The fabricated EL devices using the synthesized hyperbranched polymers, (ITO/(p-HPPV or m-HPPV)/Al), showed EL emission at about 507 nm and 481 nm (681 nm), respectively. Especially, EL device from m-HPPV were found to exhibit nearly white emission with approximate CIE coordinates of (0.31, 0.34) compared with (0.310, 0.316) of NTSC white color at $100\;cd/m^2$. The good photophysical properties combine with good film-form ability could make these hyperbranched polymers to be a potential candidate for the EL materials.

• 대한의용생체공학회:의공학회지
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• 제22권1호
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• pp.81-90
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• 2001

본 연구에서는 디지털 영상 뇌파계(digital video electroencephalogram, Digital VEEG)에서 비디오 영상과 뇌전도 파형의 동기화된 편집 시스템을 구성한다. 이 시스템은 기존 아날로그 영상 뇌파계(analog video electroencephalogram)의 동기화 문제와 디지털 영상 시스템에서의 영상편집 문제를 해결하기 위하여 MPEG-I(이하 MPEG) 고압축 기술을 이용한 MPEG 인코딩 보드(encoding board)와 MPEG 편집 엔진(editing engine)을 각각 사용하였다. 시스템은 디지털 영상뇌파계모듈과 디지털 편집 모듈로 구성되며, 뇌전도모듈에서는 환자에게 연결된 전극을 통해 들어온 뇌파를 생체신호증폭기를 이용하여 증폭한 후 AD 보드(analog to digital board)를 이용 디지털화한다. 디지털 카메라로 촬영된 환자영상의 아날로그 영상신호(NTSC 신호)는 MPEG 인코딩 보드를 이용하여 고압축 디지털화한다. 이후 디지털화된 뇌전도신호와 MPEG 형식의 영상을 시간 동기화하여 두 개의 모니터에 각각보여준다. 편집 모듈에서는 영상신호와 뇌파신호를 어느 부분이든 간단한 조작으로 오려 붙이기(cut and paste) 기능을 이용할 수 있다. 본 시스템은 사용된 데이터 모두 디지털 기술을 이용하여 영상과 뇌파신호의 정확한 동기화 및 각각의 데이터의 오려 붙이기 기능을 가능케 하였으며, 이는 환자의 데이터를 관리 및 보관하는데 있어, 임상의에게 의미 있는 자료만을 모아서 효율적으로 관리할 수 있게 해준다. 이와 같은 장점을 갖는 디지 영상뇌파계 편집시스템을 구현하였다.