• ETRI Journal
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• v.41 no.1
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• pp.32-41
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• 2019

We propose a speckle reduction technique in electronic holographic display systems, where digital micro-mirror array devices are used as spatial light modulators. By adopting a programmable filtration in a general 4-f optic configuration, it is shown that the signal spectrum components in the frequency domain of a viewing-window-based holographic display system can be selectively filtered. Compared to the widely utilized single-sideband filtration techniques in electronic holographic display systems, our proposed programmable filtration can be utilized to effectively reduce the speckles in the reconstruction of point-cloud-based computer-generated holograms. Experimental results are presented to verify our proposed concept.

• Journal of Broadcast Engineering
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• v.8 no.4
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• pp.465-472
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• 2003

In this paper we propose the structure of MPEG-4 multimedia player platform for Terrestrial Digital Multimedia Broadcasting (DMB) Service. Korea will launch DMB service at next 2004 you based on Eureka-147 Digital Audio Broadcasting (DAB) Service System. This new mobile multimedia broadcasting services provide not only high quality digital audio broadcasting services, but also various multimedia data broadcasting services including high quality video. For the sake of MPEG-4 Systems technologies, it will provide an interactive service to users in the near future. Therefore it terminal shall have various functionalities as well as playing audio-visual contents. However there is no precedence standard for such mobile interactive multimedia broadcasting system. Therefore it is very import to provide the multimedia player platform of DMB service for accelerating the development process of commercial terminal and providing a direction of next DMB terminal structure.

• ETRI Journal
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• v.26 no.6
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• pp.653-656
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• 2004

This paper presents an effective algorithm for inserting an MPEG-2 transport stream (TS) into a Digital Audio Broadcasting (DAB) ensemble without any bandwidth waste in a Digital Multimedia Broadcasting (DMB) transmission system. The key technologies of this algorithm include packet rate control and program clock reference correction, which are important for TS processing. The proposed algorithms are applied to the various DMB transmission systems based on Eureka-147, and the performance of the proposed algorithm is confirmed through the experimental DMB broadcasting.

• ETRI Journal
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• v.26 no.4
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• pp.367-370
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• 2004

A new transmission system is necessary for the Digital Multimedia Broadcasting (DMB) service in Korea. Therefore, in this paper, we propose a new architecture for the implementation of a DMB transmission system based on Eureka-147. We describe the design and implementation of the Ensemble remultiplexer, which is essential to the proposed system for remultiplexing ETI frames and MPEG-2 transport streams. The proposed system provides a solution with high flexibility and low cost for multimedia broadcasting service. The functions of this transmission system have been verified by using our DMB receiver and other related systems.

• Convergence Security Journal
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• v.8 no.2
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• pp.15-25
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• 2008

In today's broadcasting and communication systems, many applications are converged information in a complicated manner by interworking with various networks such as satellite networks. Specifically, as broadcasting and communication systems have become more advanced in terms of technology and capacity, the increase in information assets has created new types of threats and vulnerabilities that we're not previously apparent. This paper has proposed the following methodologies for analyzing the risks and estimating the economical that could arise in broadcasting and communication convergence systems. First, the assets are prioritized by grading them according to confidentiality(copyrights), integrity, and availability. Based on such an analysis, this paper presents a model that can be used for verifying the risk variables caused by changing threats and vulnerabilities. Second, this paper presents a method for quantitatively estimating the economical caused by countermeasure costs for each time period.

• Journal of Broadcast Engineering
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• v.20 no.1
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• pp.3-15
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• 2015

Recently terrestrial digital broadcasting systems have experienced a growth with the demand of high data rate. In order to meet such demand, the MIMO technology has received a wide attention. This paper proposes a pre-coding method, which provides high space channel correlation for the improved performance over terrestrial broadcasting channels when the polarized $2{\times}2$ MIMO SM is adopted for DVB-NGH systems. When signals with two different modulation orders are transmitted through two antennas, a method that is based on non-uniform power is also proposed for improved reception performance. To optimize the proposed method, phase shifting values for the pre-coding method and appropriate unequal power ratio are obtained. These obtained parameters are applied to a terrestrial broadcasting system, and then the performance improvement over the conventional SM is shown through computer simulations.

• Journal of Broadcast Engineering
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• v.20 no.2
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• pp.310-339
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• 2015

In this paper, the possibility of a terrestrial fixed 4K UHD (Ultra High Definition) and mobile HD (High Definition) convergence broadcasting service through a single channel employing the FEF (Future Extension Frame) multiplexing technique in DVB (Digital Video Broadcasting)-T2 (Second Generation Terrestrial) systems is examined. The performance of such a service is also investigated. FEF multiplexing technology can be used to adjust the FFT (fast Fourier transform) and CP (cyclic prefix) size for each layer, whereas M-PLP (Multiple-Physical Layer Pipe) multiplexing technology in DVB-T2 systems cannot. The convergence broadcasting service scenario, which can provide fixed 4K UHD and mobile HD broadcasting through a single terrestrial channel, is described, and transmission requirements of the SHVC (Scalable High Efficiency Video Coding) technique are predicted. A convergence broadcasting transmission system structure is described by employing FEF and transmission technologies in DVB-T2 systems. Optimized transmission parameters are drawn to transmit 4K UHD and HD convergence broadcasting by employing a convergence broadcasting transmission structure, and the reception performance of the optimized transmission parameters under AWGN (additive white Gaussian noise), static Brazil-D, and time-varying TU (Typical Urban)-6 channels is examined using computer simulations to find the TOV (threshold of visibility). From the results, for the 6 and 8 MHz bandwidths, reliable reception of both fixed 4K UHD and mobile HD layer data can be achieved under a static fixed and very fast fading multipath channel.

• Journal of Broadcast Engineering
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• v.10 no.2
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• pp.221-237
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• 2005

This paper presents and analyzes field test results of Equalization Digital On-Channel Repeater (EDOCR) using ATSC(Advanced Television Systems Committee) terrestrial digital TV broadcasting system. In the field test, according to EDOCR On/Off, types of antennas and receivers we measured reception possibility, C/N(Carrier to Noise Ratio), reception power, noise and input margin at each test point. By the field test results, the reception rate of the receiver manufactured in 2004 was $33\%$ when EDOCR is off and directional antenna is used. However, the reception rate was $100\%$ when EDOCR is on. In addition, the noise margin, which determines reception quality was increased at least 6 dB, so that it is capable of constructing SFN(Single Frequency Network) using the EDOCR.

• JSTS:Journal of Semiconductor Technology and Science
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• v.7 no.4
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• pp.267-273
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• 2007

A fractional-N frequency synthesizer supports quadruple bands and multiple standards for mobile broadcasting systems. A novel linearized coarse tuned VCO adopting a pseudo-exponential capacitor bank structure is proposed to cover the wide bandwidth of 65%. The proposed technique successfully reduces the variations of KVCO and per-code frequency step by 3.2 and 2.7 times, respectively. For the divider and prescaler circuits, TSPC (true single-phase clock) logic is extensively utilized for high speed operation, low power consumption, and small silicon area. Implemented in $0.18-{\mu}m$ CMOS, the PLL covers $154{\sim}303$ MHz (VHF-III), $462{\sim}911$ MHz (UHF), and $1441{\sim}1887$ MHz (L1, L2) with two VCO's while dissipating 23 mA from 1.8 V supply. The integrated phase noise is 0.598 and 0.812 degree for the integer-N and fractional-N modes, respectively, at 750 MHz output frequency. The in-band noise at 10 kHz offset is -96 dBc/Hz for the integer-N mode and degraded only by 3 dB for the fractional-N mode.

• The Journal of the Korea Contents Association
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• v.21 no.6
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• pp.155-164
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• 2021

The purpose of this study investigates how the audience evaluation on independency of broadcasting and news credibility of KBS and MBC affect their channel brand equity(cognition, image, loyalty, and quality). The results indicate that the audience evaluation on news credibility of KBS and MBC has stronger influence on channel brand equity than the one of independency of broadcasting. On ages, the older generation group has more positive perception on channel image and loyalty of KBS than the college student group and the college student group has more positive perception on channel cognition and quality of MBC than the older generation group. On political traits, the politically conservative groups of both KBS and MBC have more positive perception on independency of broadcasting, news credibility, and channel brand equity than the other groups. Consequently, public broadcasting systems should improve the credibility of news for securing independency of broadcasting. These systems make audience change their perception toward public broadcasting as recovering integrity of news and improving professionalism of news. Public broadcasting systems should conduct a further research to improve the management of channel brand equity by studying audiences' age and political traits.