• Aerospace Engineering and Technology
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• v.12 no.2
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• pp.156-162
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• 2013

In the communication between satellite and ground station, data rate can be determined from the data volume and required transmission time. Increasing data rate can be limited according to the available bandwidth. For the reason, it has been popularly studying on high spectral-efficient modulation scheme in large volume data application such as digital video broadcasting service. This paper presents the conceptual design of UHRIT broadcasting in GEO-KOMPSAT-2A (GK2A) mission by using DVB-S2 standard. Based on the recently determined data rate, UHRIT bandwidth was calculated at the various modulation schemes and code rates of DVB-S2 standard. Receiving performance of global user station was also evaluated thorough link analysis by considering that user station is located at the edge of beam coverage. Finally, maximum data rate was analyzed in a situation that COMS HRIT bandwidth should be alternatively applied for UHRIT downlink.

• Convergence Security Journal
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• v.21 no.3
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• pp.67-73
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• 2021

According to a survey by the Korea Tourism Organization in 2018 and 2019, traveling to places recorded in TV programs or influential videos has become an important travel trend and several studies show that watching a travel program improves the intention to visit the places featured on the program. This study designed a travel program-linked data service that provides additional information on the places and events to the viewers of the travel program. Specifically, the additional information of the travel program was defined in a formal manner by dividing it into places and events, and a method of exposure of the additional information conformed to the contents of the program was designed. We also devised an international standard DVB-based data transmission method that provides the additional information to data services appropriately in time for program broadcasting. This study is significant in that it tested new applications of data services for travel programs.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.73-80
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• 2020

The OECD surveys the questionnaire on the background of ICT every three years since 2003. In this study, we compare and analyze the changes in ICT accessibility and ICT usability of Korean students in 2015 and 2018 using the ICT background data of OECD PISA. ICT accessibility refers to the degree of access to ICT equipment at school or at home. There are 10 items of accessibility surveys at schools used by PISA, and 11 items at home. ICT usability refers to how much ICT equipment is used at or outside of school for learning or non-learning purposes. There are ten items for surveying usability at school, and twenty-four items for surveying usability outside of school. In the analysis of this study, the arithmetic mean of the items is used. As a result, Korean students' accessibility at school improved from 25.48% in 2015 to 40.40% in 2018, and from the lowest group in 2015 to below-average group in 2018. In terms of students' usability at school, we analyzed the percentage of students who use the ICT equipment 'almost every day' and the students who use it 'everyday'. Both 2015 and 2018 are among the lowest. Accessibility at home is higher in 2018 than in 2015, and belongs to the average group of OECD countries in 2018. ICT Usability for learning purposes outside of school is the lowest group in both 2015 and 2018. ICT Usability outside of school for non-learning purposes is in the average group of OECD countries. As a result of this study, we can see that Korea's digital literacy education is weak compared to other OECD countries. Prior to education about the Fourth Industrial Revolution, investment in digital literacy education is needed.

• Journal of Digital Contents Society
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• v.11 no.3
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• pp.291-298
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• 2010

Although searching service is popularized in the PC-based internet environment, it is not (or rarely) supported on TV, which is the major multimedia equipment in the living room. Several trials are made to port established PC-based searching systems onto TV-set but failed to get popularity among viewers as they did not consider the viewers' modality. Operating the searching system should not disturb viewers in watching TV (for example, TV screen should not be (even partially) covered by the searching system's graphics) and the number of pushing the remote controller's buttons should be minimized so that viewers can keep watching TV without glancing at the searching system's graphics. In this paper, the author introduces a new searching system running on TV-set, which is designed to reflect properly the viewers' modality. The searching system is also compatible with the data service standard adopted by the domestic broadcasting networks so that it can be easily implemented by them.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.7A
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• pp.529-536
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• 2003

In this Paper, a new DCT HLMS DFE(Discrete Cosine Transform Hierarchical Least Mean Square Decision Feedback Equalizer) algorithm is proposed to improve the convergence speed and MSE(Mean Square Error) performance of a receive channel equalizer in ATSC(Advanced Television System Committee) 8VSB(Vestigial Side Band) digital terrestrial TV system. The proposed algorithm reduces the eigenvalue range of input data autocorrelation by transforming LMS (Least Mean Square) DFE into the subfilter of hierarchical structure. Moreover, the use of DCT and power estimation algorithm makes it possible to reduce the eigenvalue deviation of input data which results from distortion and delay of the receive signal in the miulti-path environment. Simulation results show that proposed DCT HLMS DFE has SNR improvement of approximately 3.8dB, 5dB and 2dB as compared to LMS DFE when the equalized symbol error rate is 0.2 in ATTC defined digital terrestrial TV broadcasting channels A, B and F, respectively.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.4
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• pp.123-128
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• 2020

Technology in digital video has changed the functions of the digital video field based on various platforms, including streaming, on-demand, interactive, and data-based services. The displays that provide the visual representations of these digital video contents have also been improving with various changes. There is a variety of display screen ratios currently available, with the ratio of the display screen being based on the intended purpose. This study conducted a psychophysics experiment to examine the correlation between colour properties and shape ratio based on the display screen ratio, and then analysed the results. The colours used in the experiment were visual perception-based Munsell colours, and the hue, brightness, and chroma attributes were analysed according to the shape ratio to examine colour properties. The analysis of the results of this study defined the significance of the study as basic data for future studies on colour property changes based on shape ratio, and suggested directions for future studies.

• Journal of Communications and Networks
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• v.12 no.6
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• pp.568-576
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• 2010

The paper presents a control architecture aimed at implementing bandwidth optimization combined with call admission control (CAC) over a digital video broadcasting (DVB) return channel satellite terminal (RCST) under quality of service (QoS) constraints. The approach can be applied in all cases where traffic flows, coming from a terrestrial portion of the network, are merged together within a single DVB flow, which is then forwarded over the satellite channel. The paper introduces the architecture of data and control plane of the RCST at layer 2. The data plane is composed of a set of traffic buffers served with a given bandwidth. The control plane proposed in this paper includes a layer 2 resource manager (L2RM), which is structured into decision makers (DM), one for each traffic buffer of the data plane. Each DM contains a virtual queue, which exactly duplicates the corresponding traffic buffer and performs the actions to compute the minimum bandwidth need to assure the QoS constraints. After computing the minimum bandwidth through a given algorithm (in this view the paper reports some schemes taken in the literature which may be applied), each DM communicates this bandwidth value to the L2RM, which allocates bandwidth to traffic buffers at the data plane. Real bandwidth allocations are driven by the information provided by the DMs. Bandwidth control is linked to a CAC scheme, which uses current bandwidth allocations and peak bandwidth of the call entering the network to decide admission. The performance evaluation is dedicated to show the efficiency of the proposed combined bandwidth allocation and CAC.

• Journal of Broadcast Engineering
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• v.7 no.2
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• pp.88-95
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• 2002

According to an evolution of digital broadcasting, it is possible that terrestrial and satellite broadcasting media provide multi-channel services. CATV and satellite media have been also extended to hundreds of channels. As the result of channel expanding, viewers came to select lots of channels. But it is difficult that they select the favorite channel among hundreds of channels. In this paper, we propose an efficient automatic method to recommend channels and programs on a viewer's preference in a multi-channel broadcasting receiver like a Set ToP Box(STB). The proposed algorithm selects channels based on the following method. It makes and saves user history data by using MPEG-7 MDS based on the program information a viewer had watched. It recommends programs similar to a viewer's preference based on user history data. It selects the channel in the recommended genre based on the viewer's channel preference. The experimental result shows that the proposed scheme is efficient to select the user preference channel.

• Convergence Security Journal
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• v.12 no.6
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• pp.19-24
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• 2012

As the representative of the convergence of broadcasting and communication, the data service was expected to be a new profit source of the related industries. The data service, however, has not satisfied the expectation due to the short of killer services that make it popular with the viewers. According to the several survey reports, a lot of viewers do internet-searching using the key-words related to the TV program they are watching and, with the faith in the survey results, several trials has been performed to port established PC-based searching systems onto TV-set only to fail to get popularity among viewers. The failures are mainly caused that they did not sufficiently consider the viewers' modality that viewers seriously want not to be obstructed by anything when they are absorbed in a program. This paper proposes an MHP-based searching data service designed to minimally interrupt the viewers watching a TV program and to be synchronized with a TV program by using the searching key-words relative to it, the content of which changes as time goes on.

• Convergence Security Journal
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• v.22 no.4
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• pp.119-127
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• 2022

A movie information program has a positive effect on the viewer's intention to watch the movie by providing an indirect experience of the movie based on trust. In order to increase the effectiveness of a movie information program, a data service that provides the additional information on the movies introduced in a movie information program has been studied. However, since the study limited the data service to one movie information program, it was difficult to apply it to the actual environment of general cable broadcasting companies or satellite broadcasting companies that transmit multiple movie information programs. Therefore, this study expanded the existing research limited to one movie information program to provide additional information of several movie information programs. This study is meaningful in that it suggests a data service that can be operated in the realistic environment of a broadcaster that actually transmits several movie information programs.