• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.2
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• pp.135-143
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• 1990

In this paper, a new motion detection method using an order-statistic filter is proposed to improve the image quality when the QT subsampling structure is used for reduction of bandwidth of high-resolution TV signals. This new method is applicable to the MUSE system of HDTV and various schemes using the multiple subasmpling with frame-offset for the reduction of bandwidth in highresolution TV signals.

• Electronics and Telecommunications Trends
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• v.24 no.1
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• pp.75-89
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• 2009

세계 주요 나라에서 HDTV 방송이 서비스되고 있으며, 현재는 아날로그와 디지털 방송이 동시 송출되고 있으나, 2010년대 초기에 디지털 전환을 완료할 예정이다. 방송서비스는 기술개발, 표준 제정 및 법제 정비 등 많은 개발 및 준비기간을 필요로 하므로, 세계 주요 국가들은 HDTV 이후의 방송 서비스를 위한 준비 작업들을 진행하고 있다. HDTV 이후의 차세대 방송을 UHDTV라고 하며, 가정에서 70 mm 영화보다 뛰어난 화질(비디오 해상도 $7680{\times}4320$, HD 화면 16배 크기에 해당)과 다채널(${\sim}22.2ch$) 음질로 극장급의 초고품질 서비스를 제공하여 소비자의 품질 욕구를 만족시킬 수 있는 TV를 목표로 한다. 본 고에서는 UHDTV 서비스에 필요한 관련 기술 동향과 표준화 동향 및 기술 개발시 선행적으로 필요로 하는 특허 동향에 대해서 설명한다.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.8
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• pp.109-118
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• 1994

We proposed new field/frame mode selection quantization and buffer control strategy for interlaced digital HDTV image coding system. The field/frame mode selection is performed based on the mean square error and number of generated bits for each superblock. The quantization factor for each superblock is determined by the characteristics of human visual system and buffer status. The statistical characteristics of the number of generated bits for basis block and the prediction of buffer status are used for buffer control. Simulation results show that the proposed field/frame mode selection and rate buffer control. Simulation results show that the proposed field/frame mode selection and rate buffer control strategy have good subjective image quality and have stable buffer status.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.7
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• pp.1777-1786
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• 1996

This paper describes theories and implementation techniques of a digital high-definition television(HDTV) modem based on 32-QAM for terrestrial broadcasting. We proposed a digital demodulation scheme and a symbol timing recovery structure based on the band edge component maximization(BECM) method. The adaptive equalizer has 256 complex taps to remove the multipath of delays ranging from -2.mu.s~+24.mu.s with a new T/2-spaced blind equalization algorithm. computer simulation results reveal that the proposed algorithm outperforms other conventional blind equalization algorithm a digital HDTV modem with 4.91MHz symobol rate is implemented by utilizing the proposed algorithms. All processings for modem operations such as demodulation, estimation of symbol timing phase error, adaptive equalization, and carrier recovery except IF signal processing and sampling phase control part of the AD converter are done in digital domain. Especially, the carrier recovery loop can track a carrier offset of upto .+-.350KHz.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2424-2426
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• 1998

We propose a robust equalization algorithm to improve the performance of airplane flutter casuing dynamic ghosts. The algorithm is an augumentation of the DFE with training sequence(DFE-TS) with the Modified Stop-and-Go Algorithm(MSGA) based on DFE structure, which is called a DFE-TS/MSGA. This will allow the equalizer to switch itself back to blind mode almost instantaneously when drastic and sudden changes in the channel occur. Test results based on the 8-VSB HDTV receiver show that the proposed algorithm is robust against dynamic ghosts and outperforms the conventional DFE-TS in reducing the intersymbol interference.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.624-626
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• 1998

Adaptive channel equalization accomplished without resorting to a training sequence is known as blind equalization. In this paper, we present a auto-switching blind, equalization for 8-VSB HDTV receiver. The scheme operate in two mode : blind equalization mode and decision-directed equalization mode. This proposed scheme changes from the blind equalization mode at high error levels to the decision-directed equalization mode at lower error levels smoothly and automatically. Manual switch from the blind equalization mode to the decision-directed mode is not necessary.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3187-3189
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• 1999

A novel wide-tunable quadratic gamma corrector for HDTV camera applications is proposed. The new gamma corrector controls gamma value in a wide range by simple electrical adjustment of multipliers' gain. It has wide signal bandwidth of 30MHz sufficient for HDTV applications. It also simplifies the circuit design, resulting in a compact surface mounting board implementation with reduced power consumption. Simulation and experimental results confirm these characteristics.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3190-3192
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• 1999

A Novel wide-band wide-tunable current-mode (CM) gamma corrector for HDTV camera applications is proposed. The gamma corrector provides accurate gamma control in a wide range by simple electrical adjustment of weighting amplifiers' gain. It has wide signal bandwidth more than 40MHz sufficient for HDTV video signal processing and is implementable with simple integrated circuit with low power dissipation of 125mW.

• Journal of Broadcast Engineering
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• v.16 no.1
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• pp.96-107
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• 2011

Recently, studies of 3D HDTV broadcasting technology have been processed actively. Korea is making efforts to modify Advanced Television Systems Committee (ATSC) 8-Vestigial Side Band (8-VSB) systems for terrestrial 3D HDTV broadcasting services. We intend to adopt a new frame structure to use PN (Pseudo-Noise) sequence as frame header, and VSB modulation. PN sequence is used to recover carrier freqeuncy offset, carrier phase error. In this paper, we will describe this system as the modified ATSC systems. The receiver of the modified ATSC system should be able to estimate and recover carrier frequency offset exactly. A existing ATSC systems inserts pilot to recover carrier frequency offset, on the other hand the modified ATSC systems use PN sequence to recovery carrier frequency offset without the use of pilot. In this paper, we introduce carrier frequency recovery (CFR) scheme for the modified ATSC systems. The proposed CFR scheme is composed of coarse CFR scheme using Fitz algorithm and fine CFR scheme using a simple PN sequence correlation algorithm. And, the symbol information of QAM modulated signal is contained in both In-phase (I)channel and Quadrature-phase (Q)channel. However the symbol information of VSB modulated signal is contained in I channel, and Q channel is just Hilbert transform of I channel. For the reason, VSB modulated symbols can not have fixed phase like QAM modulated symbols, and VSB modulated symbols is more sensitive to carrier frequency offset. Therefore we perform phase correction of received PN sequence to improve performance.

• Product Safety
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• no.4 s.160
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• pp.54-57
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• 2007

tele는 그리스어로 '멀리', vision은 라틴어로‘본다’는 뜻이다. 1931년 미국에서 첫 시험방송이 시작되었고, 1937년에 영국의 BBC 방송국이 세계 최초로 흑백텔레비전 방송을 시작하였다. 한국은 1956년 5월 12일 세계에서 15번째로 TV전파를 발사하였다. 이러한 흑백텔레비전을 시작으로 예전과는 달리 요즘 가정에서는 대다수가 컬러텔레비전(color television)을 시청한다. 이번에는 몇 호에 걸쳐서 이러한 컬러텔레비전의 구조 및 원리 등에 대하여 알아볼까 한다. 먼저 발광의 원리, 방송의 구성, 수상기 및 튜너 등에 대하여 알아보고, 더 나아가 HDTV(High Definition Television : HDTV) 의 구조 및 원리에 대해서도 알아보도록 하겠다.