• 대한전기학회논문지:전력기술부문A
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• 제51권1호
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• pp.23-28
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• 2002

In order to survey the radiation characteristics of pure line noise of unwanted noise from overhead high voltage AC transmission lines, a disk type gap noise generator was manufactured. Disk size which decides capacitance between the noise generator and earth was selected through preliminary indoor experiments and analysis by using surface charge method. The capacitance is one of principal parameters related to the injection of a proper noise current into lines. On the basis of the capacitance obtained from calculation, 5mm of space was given to the gap of the noise generator to be installed o test line and an aluminum disk of 60cm radius was made. The field experiments were performed with the noise generator hung on the Kochang 765 kV full scale test line. As the results, the useful data which can be used to analysis the radiation characteristics of noise from transmission lines were obtained. Those are the directivity of antenna toward the line, lateral profiles, frequency spectra, height pattern and so on.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(2)
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• pp.104-107
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• 2000

We designed and implemented the RFIC(RF front-end IC) for DTV(Digital TV) tuner. The DTV tuner RF front-end consists of low noise IF amplifier fur the amplification of 900 MHz RF signal and down conversion mixer for the RF signal to 44MHz IF conversion. The RFIC is implemented on ETRI 0.8u high resistive (2㎘ -cm) and evaluated by on wafer, packaged chip test. The gain and IIP3 of IF amplifier are 15㏈ and -6.6㏈m respectively. For the down conversion mixer gain and IIP3 are 13㏈ and -6.5㏈m. Operating voltage of the IF amplifier and the down mixer is 5V, current consumption are 13㎃ and 26㎃ respectively.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제6권2호
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• pp.9-24
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• 2002

Total Variation(TV) regularization method is effective for reconstructing "blocky", discontinuous images from contaminated image with noise. But TV is represented by highly nonlinear integro-differential equation that is hard to solve. There have been much effort to obtain stable and fast methods. C. Vogel introduced "the Fixed Point Lagged Diffusivity Iteration", which solves the nonlinear equation by linearizing. In this paper, we apply multigrid(MG) method for cell centered finite difference (CCFD) to solve system arise at each step of this fixed point iteration. In numerical simulation, we test various images varying noises and regularization parameter $\alpha$ and smoothness $\beta$ which appear in TV method. Numerical tests show that the parameter ${\beta}$ does not affect the solution if it is sufficiently small. We compute optimal $\alpha$ that minimizes the error with respect to $L^2$ norm and $H^1$ norm and compare reconstructed images.

• 한국통신학회논문지
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• 제37권8A호
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• pp.679-688
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• 2012

본 논문에서는 3D 워핑(warping) 기법을 이용하여 가상시점 영상생성 시 화질 개선을 위하여 경계 잡음(boundary noise)을 제거하고 홀(hole) 채움을 하는 새로운 기법을 제안한다. 경계 잡음은 가상시점 영상 합성 시기준 시점 영상과 깊이 영상 내 객체의 경계 불일치로 발생되며 홀은 기준시점 영상에서 보상할 수 없는 가려짐 영역(occlusion)으로 정의된다. 제안하는 기법에서는 경계 잡음 제거를 위해 먼저 배경 화소들의 평균과 절대 값 비교를 통해 경계 잡음에 해당되는 화소를 검출하고 검출된 화소를 홀 영역으로 확장한다. 경계 잡음 영역이 포함된 확장된 홀 영역은 나선형 가중 평균(spiral weighted average) 기법과 기울기 탐색(gradient searching) 기법을 혼용하여 채우게 된다. 나선형 가중 평균 기법은 깊이 정보를 사용함으로 객체 정보를 최소로 사용하지만 결과 영상이 번지는 단점이 있다. 기울기 탐색 기법은 영상의 기울기를 이용하여 세밀한 부분을 보존할 수 있는 장점이 있다. 따라서 각각의 결과를 ${\alpha}$ 가중치로 조합하여 생성된 가상 시점은 두 기법의 장점을 동시에 적용하기 때문에 좋은 화질을 얻을 수 있다. 실험을 통해 제안하는 기법의 성능이 기존의 다른 기법보다 우수하다는 것을 확인하였다.

• 전기학회논문지
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• 제59권7호
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• pp.1340-1345
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• 2010

FRC(Frame Rate Control) has been applied to the monitor and TV product as part of cost-saving in many flat panel display manufacturers. As FRC can represent the same number of gray scale level with bits of a smaller amount than bits of the input image data, it is widely used. However, FRC causes visual artifacts by using repeatedly pre-designed the FRC unit size of block pattern in display devices. Therefore, this paper analyzes the cause of the visual artifacts. And in order to improve them, it proposed the pattern arrangement of FRC unit blocks through frame rolling method as analytic solution for the first time. So, we could embody causes of FRC noise. Using the proposed structure, more robust pattern to FRC noise will be designed.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.57-60
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• 2001

CATV is the abbreviation for Cable Television. General CATV is a way of multi-channel sending images, voices and music including stillness image as well as characters to public receivers through electrical cable communication system. In the beginning, master antennas were people can not receive TV signal well. TV programs were received from master antennas to TVs in each house. Ground connection began by experimenting lightning with the use of a kite and it means electric appliances, communication equipments, measuring instruments and so on connecting the Earth in order to flow away overcharged electricity. There are two kinds of earth connection: Power Ground and Signal Ground. Power Ground is for preventing an electric shock and in general there's no current in the connector. However in an accident, there's a quick flow of electricity out to the Earth. Signal Ground is not only for the safety of appliances but also for the safety of equipment operation. This paper is about connection for noise and interference reduce in order to prevent wrong operation and distortion of signal in the electrical appliances which can take place in CATV.

• JSTS:Journal of Semiconductor Technology and Science
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• 제15권3호
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• pp.381-389
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• 2015

A fully integrated multistandard multiband CMOS mobile TV tuner with small silicon area and low power consumption is proposed for receiving multiple mobile digital TV signals and FM signal. In order to reduce the silicon area of the multistandard multiband receiver, other RF front-end circuits except LNAs are shared and a local oscillator (LO) signal generation architecture with a single VCO for a frequency synthesizer is proposed. To reduce the low frequency noise and the power consumption, a vertical NPN BJT is used in an analog baseband circuits. The RF tuner IC is implemented in a $0.18-{\mu}m$ CMOS technology. The RF tuner IC satisfies all specifications for DVB-H/T, T-DMB, and ISDB-T with a sufficient margin and a successful demonstration has been carried out for DVB-H/T, T-DMB, and ISDB-T with a digital demodulator.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.57-60
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• 2001

CATV is the abbreviation for Cable Television. General CATV is a way of multi-channel sending images, voices and music including stillness image as well as characters to public receivers through electrical cable communication system. In the beginning, master antennas were people can not receive TV signal well. TV programs were received from master antennas to TVs in each house. Ground connection began by experimenting lightning with the use of a kite and it means electric appliances, communication equipments, measuring instruments and so on connecting the Earth in order to flow away overcharged electricity. There are two kinds of earth connection: Power Ground and Signal Ground. Power Ground is for preventing an electric shock and in general there's no current in the connector. However in an accident, there's a quick flow of electricity out to the Earth. Signal Ground is not only for the safety of appliances but also for the safety of equipment operation. This paper is about connection for noise and interference reduce in order to prevent wrong operation and distortion of signal in the electrical appliances which can take place in CATV.

• 방송공학회논문지
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• 제8권2호
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• pp.109-115
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• 2003

본 논문에서는 미국식(ATSC) 지상파 디지털 TV 방송을 단일 주파수 망을 통해 서비스하기 위해 필요한 기술적인 사항에 대하여 고찰하고 ATSC 방송방식에서 단일 주파수 망을 구성하기 위한 방법을 제안한다. 제안한 방법은 기존의 8-VSB 방송시스템에 적용된 트렐리스 부호기의 메모리를 주기적으로 초기화함으로써 동일한 입력이 복수의 송신기에 인가될 경우 언제나 동일한 출력이 나오도록 한다. 제안방식을 적용한 8-VSB 시스템은 기존의 시스템에 비해 최대 0.1dB의 성능 저하가 발생하였으나 이러한 성능 저하는 트렐리스 부호부의 초기화 주기를 늘림으로서 무시할 정도로 줄일 수 있으며, 최소한의 하드웨어 변경을 통해 SFN을 구성할 수 있다.

• 한국전자파학회논문지
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• 제23권7호
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• pp.805-814
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• 2012

무선기기의 간헐적인 신호 또는 높고 낮은 진폭의 주기적인 신호 전송은 오디오 주파수에 간섭 신호를 발생시켜 근접 거리에 설치된 음향 기기에 잡음을 발생시킨다. 최근 이와 관련하여 Global system for Mobile Communication(GSM) 폰과 유사하게 간헐적인 신호 전송을 하는 Long Term Evolution(LTE) 폰에 의한 오디오 잡음현상이 보고되었다. 현재 국내 KN20 규격에서는 잡음에 대한 내성 능력을 확보하기 위하여 음향 및 TV 방송수신기의 내성 시험 기준 신호로 변조 주파수 1 kHz Amplitude Modulation(AM) 80 %와 Code Division Multiple Access(CDMA) 신호를 이용하고 있다. 본 논문에서는 LTE 폰의 출시에 따라 기존의 내성 기준 신호 AM과 CDMA를 GSM과 LTE 폰이 발생시키는 오디오 잡음의 수준과 비교한 후, 국내 음향 기기에 대한 내성 기준 신호의 개선을 제안한다. CDMA 신호는 음향 기기에 간섭을 거의 일으키지 않는 것으로 여겨지므로 시험 항목에서 삭제해도 무방할 것으로 판단된다. 반면, LTE는 많은 사용자가 이용하고 있으며, 음향 기기 등에 무시할 수 없는 간섭을 발생시킬 것으로 분석되므로 CDMA 신호를 대신하여 음향 기기 및 TV 방송 수신기의 내성 시험을 위한 시험 기준 신호로 규정하는 것이 바람직할 것으로 사료된다.