• Journal of Broadcast Engineering
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• v.15 no.4
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• pp.563-581
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• 2010

In this paper, we perform subjective visual quality assessments on UHD video for UHD TV services and analyze the assessment results. Demands for video services have been increased with availabilities of DTV, Internet and personal media equipments. With this trend, the demands for high definition video have also been increasing. Currently, 2K-HD ($1920{\times}1080$) video have been widely consumed over DTV, DVD, digital camcoders, security cameras and other multimedia terminals in various types, and recently digital cinema contents of 4K-UHD($3840{\times}2160$) have been popularly produced and the cameras, beam projects, display panels that support for 4K-UHD video start to come out into multimedia markets. Also it is expected that 4K-UHD service will appear soon in broadcasting and telecommunications environments. Therefore, in this paper, subjective assessments of visual quality on resolutions, color formats, frame rates and compression rates have been carried to provide basis information for standardization of signal specification of UHD video and viewing environments for future UHDTV. As the analysis on the assessments, UHD video exhibits better subjective visual quality than HD by the evaluators. Also, the 4K-UHD test sequences in YUV444 shows better subjective visual quality than the 4K-UHD test sequences in YUV422 and YUV420, but there is little perceptual difference on 4K-UHD test sequences between YUV422 and YUV420 formats. For the comparison between different frame rates, 4K-UHD test sequences of 60fps gives better subjective visual quality than those of 30fps. For bit-depth comparison, HD test sequences in 10-bit depth were little differentiated from those in 8-bit depth in subject visual quality assessment. Lastly, the larger the PSNR values of the reconstructed 4K-UHD test sequences are, the higher the subjective visual quality is. Against the viewing distances, the differences among encoded 4K-UHD test sequences were less distinguished in longer distances from the display.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2005.11a
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• pp.77-80
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• 2005

본 논문에서는 ATSC 지상파 디지털 TV 방송방식을 사용하는 등화형 동일채널 중계기(Equalization Digital On-Channel Repeater: EDOCR)에서의 신호처리 시간지연을 최소화하기 위한 전치등화 방법에 대하여 기술하고 결과를 다양한 각도에서 분석한다. 제안된 전치등화 방법은 기준신호인 기저대역 신호와 복조된 중계기 출력신호를 이용하여 전치등화필터계수를 계산하고 펄스성형필터계수와의 컨볼루션을 통해 얻어진 새로운 펄스성형필터를 이용하는 것이다. 새로운 펄스성형필터의 전치 탭 수를 조절함으로써 시간지연을 최소화하고, 마스크필터에 의한 선형왜곡을 보상할 뿐 아니라, 원래 펄스성형필터의 대역 외 방사 특성의 열화를 최소화할 수 있다. 이를 컴퓨터 시뮬레이션 및 제작된 전치등화기를 이용하여 검증하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.701-704
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• 2005

In this paper, we looked into the feature of a transmission system of the terrestrial digital broadcasting system and considered a ATSC 8-VSB transmission standard. Also, we analyzed the performance with the influence of an interchannel interference by the ATSC standard. As a result, the case not to consider Rician fading, The influence of the interfere did not exist if Frequency interval fell off over the 20MHz. The case to consider Rician fading, the system had the degradation of the performance.

• Journal of Advanced Navigation Technology
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• v.17 no.3
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• pp.298-305
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• 2013

In this paper, we propose simple combining schemes for sensing ATSC digital television signals with spectral correlation density (SCD). The detection algorithms exploiting the cyclostationarity exhibited by the pilot of ATSC digital television signals usually use the SCD value at a given particular frequency. However, we found that non-zero SCDs are found to be distributed over a certain range of frequencies in multipath fading environment. To utilize a set of non-zero SCD values computed in the vicinity of the pilot location, we formulate a class of combining methods in analogy with the maximal ratio combining, the square law combining and the equal gain combining. We show that the proposed simple combining schemes improve the detection performance by 0.5~1.0dB under multipath fading environments.

• Journal of the Korea Society of Computer and Information
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• v.14 no.1
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• pp.91-97
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• 2009

This paper proposes novel FE-CBIRS that finds best position of a cut to be retrieved based on color feature distribution in digital contents of IPTV. Conventional CBIRS have used a method that utilizes both color and shape information together to classify images, as well as a method that utilizes both feature information of the entire region and feature information of a partial region that is extracted by segmentation for searching. Also, in the algorithm, average, standard deviation and skewness values are used in case of color features for each hue, saturation and intensity values respectively. Furthermore, in case of using partial regions, only a few major colors are used and in case of shape features, the invariant moment is mainly used on the extracted partial regions. Due to these reasons, some problems have been issued in CBIRS in processing time and accuracy so far. Therefore, in order to tackle these problems, this paper proposes the FE-CBIRS that makes searching speed faster by classifying and indexing the extracted color information by each class and by using several cuts that are restricted in range as comparative images.

• Journal of Broadcast Engineering
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• v.14 no.3
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• pp.311-321
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• 2009

In a single frequency network (SFN) for Advanced Television Systems Committee (ATSC) terrestrial digital television (DTV) system, the interference due to the use of same frequency among multiple transmitters or repeaters is inevitable for receivers. This problem can be solved by adjusting transmit power and time of each transmitter and repeater. To adjust SFNs, the ATSC recommended practice (RP) introduces a transmitter identification (TxID) signal which is embedded in a signal from each transmitter or repeater. This paper proposes an efficient method to estimate the individual reception power from each transmitter or repeater based on the channel profile of SFN and the total reception power. Moreover, field test results are provided to evaluate the performance of the proposed method.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2008.11a
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• pp.7-10
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• 2008

본 논문에서는 국내에서 DTV 전환에 대비한 기술적 보호조치 방안 마련을 위하여 기술적 보호조치의 방법들에 대하여 간략히 살펴보고 이를 바탕으로 유통활성화를 도모하기 위한 기술적 보호조치 방법을 제안하였다. 디지털 방송프로그램을 보호하기 위한 기술적 보호조치는 인터넷을 통한 불법유통을 방지하여 저작권자의 이익을 도모하려는 목적이나, 이로 인하여 방송프로그램 유통의 지나친 억제는 저작권자의 권익보호를 위하여 바람직하지 않다. 따라서 사용자가 보다 편리하고 저렴한 비용으로 방송프로그램을 재시청 및 재활용할 수 있도록 방송프로그램의 기술적 보호조치를 마련하는 것이 저작권자의 권익을 극대화 할 수 있다. 이러한 방법의 하나로 방송프로그램에 콘텐츠 보호선호 및 콘텐츠의 이용을 위한 연결정보를 포함하여 송출하고 방송수선단말에서 사적이용범위 내에서는 방송프로그램을 자유롭게 녹화 및 복사하여 시청할 수 있지만, 사적이용범위 밖으로 복사/전송 시에는 콘텐츠 연결정보만을 복사하고, 이를 재생할 때는 콘텐츠 연결정보를 이용하여 방송프로그램 유통서버로 연결하며, 유통서버와의 통신을 통하여 저렴하고 편리하게 방송프로그램을 사용할 수 있는 기술적 보호조치의 한 방법을 제안하였다.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.217-218
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• 2008

Since the digital TV signal band is very wide ($54{\sim}806MHz$), the VCO used in the frequency synthesizer must also have a wide frequency tuning range. Multiple LC VCOs have been used to cover such wide frequency band. However, the chip area increases due to the increased number of integrated inductors. A general method for achieving both reduced VCO gain(Kvco) and wide frequency band is to use the switched-capacitor bank LC VCO. In this paper, a scheme is proposed to cover the full band using only one VCO. The RF VCO block designed using a 0.18um CMOS process consists of a wideband LC VCO with reduced variation of VCO gain and frequency steps. Buffers, divide-by-2 circuits and control logics the simulation results show that the designed circuit has a phase noise at 100kHz better than -106dBc/Hz throughout the signal band and consumes $9.5{\sim}13mA$ from a 1.8V supply.

• Journal of Broadcast Engineering
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• v.18 no.4
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• pp.572-588
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• 2013

In this paper, 4K-UHDTV or 8K-UHDTV and UHD-3DTV that the next generation broadcasting implementation and the possibility of direct receiving environment construction is analyzed on the terrestrial broadcasting. Particularly, we investigated the possibility by analyzing the previous and related works with regard to UHDTV transmission by DVB-T2 that is one of the best commercialized transmission mode. In order that the UHDTV broadcasting succeeds once again after completion of digital terrestrial switch over at the end of 2012, the ultra high resolution image transfer is important. However, the direct, the indoor and ubiquitous receiving environment is important in not only TV but also the personal type multimedia terminal in the sense of UHDTV service penetration. Therefore, in this paper, by using SFN and high error-correcting mode in DVB-T2 standard, the efficient frequency utilization and effective reception environment construction is illustrated. Particularly, SFN network constitution by 2 mutually different frequencies including the VHF bandwidth and UHF band, and etc. is shown. And the method that builds the free wireless receive environment by using SFN low power radio repeater and for home use gap filler is proposed. And the effect and frequency amount required are presented, when UHDTV broadcasting use 10MHz bandwidth.

• Journal of KIISE:Software and Applications
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• v.37 no.1
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• pp.39-50
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• 2010

Interactive broadcasting service using wired/wireless Internet return channel has strong ripple effect. It allows the audiences to participate actively to the program they are watching, and communicating. This paper develops an authoring tool that makes an object-formed interactive advertisement from extracted areas of the advertising object the user specified in TV programs. In the authoring tool, the advertisement producer specifies the target object subjectively and the selected object keeps moving here and there repeatedly. Therefore, it is hard to make an object-formed interactive advertisement with existing tools. This paper suggests sketch-based interface technique for extracting advertising objects, and also provide evaluation functions to correct any sketch error. This paper also converts the area of object into MPEG-4 BIFS codes for authoring the object-formed interactive advertisement.