• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.11A
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• pp.1908-1924
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• 2001

Interoperability and inter-working in the various network and media environment with different technology background is very important to enlarge the opportunity of service access and to increase the competitive power of service. The ITU-T and advanced counties are planning ahead for provision of GII enabling user to access advanced global communication services supporting multimedia communication applications, embracing all modes of information. In this paper, we especially forced the heterogeneity of end user applications for multimedia networking. The heterogeneity has several technical aspects, like different medium access methods, heterogeneous coding algorithms for audio-visual data and so on. Among these elements, we have been itemized bit rate shaping algorithm on the compressed moving video. Previous manipulations of video has been done on the uncompressed signal domain. That is, compressed video should be converted to linear PCM signal. To do such a procedures, we should decode, manipulate and then encode the video to compressed signal once again. The traditional approach for processing the video signa1 has several critical weak points, requiring complexity to implement, degradation of image quality and large processing delay. The bit rate shaping algorithm proposed in this paper process the manipulation of moving video on the completely compressed domain to cope with above deficit. With this algorithms. we could realized efficient video bit rate shaping and the result of software simulation shows that this method has significant advantage than that of pixel oriented algorithms.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.1
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• pp.39-44
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• 2009

The advance of communication and networking technology enables high bandwidth multimedia data transmission. The development of high performance compression technology such as H.264 also encourages high quality video and audio data transmission. The trend requires efficient protection system for digital media rights. We propose an efficient digital media protection system using elliptic curve cryptography. Only key parameters are encrypted to reduce the burden of complex encryption and decryption in the proposed system, and the digital media are not played back or the quality is degraded if the encrypted information is missing. We need a playback system with an ECC processor to implement the proposed system. We implement an H.264 decoding system with a configurable ECC processor to verify the proposed protection system We verify that the H.264 movie is not decoded without the decrypted information.

• The Journal of the Korea Contents Association
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• v.7 no.5
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• pp.110-117
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• 2007

The recent developments of audio/video technology in the ubiquitous media have resulted in a variety of formal feature such as screen sizes for media and the new viewing environment can alter television viewers' experience of mediated communication. So the concern about formal feature of media itself is increasing in the recent media effects studies. From this point of view, this study is conducted to test the effect of the different monitor size of DMB Phone(2'1"), PMP(4'3") and PC monitor(19') on the viewers' memory and emotion of content by experimental research. The results showed that the effect by monitor size on the view's memory and emotion is significant. And watching moving image on a bigger monitor resulted in better memory of visual message elements contained in the content and more favorable emotion of the content.

• Journal of Broadcast Engineering
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• v.10 no.3
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• pp.297-312
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• 2005

The multimedia traffic of continuous video and audio data via streaming service accounts for a significant and expanding portion of the Internet traffic. This streaming data delivery is mostly based on RTP with UDP. However, UDP does not support congestion control. For this reason, UDP causes the starvation of congestion controlled TCP traffic which reduces its bandwidth share during overload situation. In this paper, we propose a new TCP-friendly rate control scheme called 'TF-RTP(TCP-Friendly RTP)'. In the congested network state, the TF-RTP exactly estimates the competing TCP's throughput by using the modified parameters. Then, it controls the sending rate of the video streams. Therefore, the TF-RTP adjusts its sending rate to TCP-friendly and fair share with competing TCP traffics. Through the simulation, we prove that the TF-RTP correctly estimates the TCP's throughput and improves the TCP-friendliness and fairness.

• Journal of Broadcast Engineering
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• v.20 no.5
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• pp.667-675
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• 2015

As the interest on the high-definition and high-quality broadcasting is increased, the request on the high quality sound signal is enlarged as well as on the video signal's quality. One factor contributing to the high-quality of audio signal is an expansion of reproduction channels like 10.2channel and 22.2channel, but there is a problem of speaker installation issue of these many channels. One solution to solve this problem, we can use frontal loudspeaker array reproduction technique making virtual surround sound. So in this paper, we introduce theocratical analysis on the Wave Field Synthesis used for speaker array based sound reproduction and also present the result about the subjective listening test of reproduction performance based on this technique to check the perfoemance of this system. As a result, we showed WFS based frontal loudspeaker array reproduction method could provide sufficient performance compared to conventional discrete 5.1 channel reproduction method.

• Journal of Broadcast Engineering
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• v.21 no.3
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• pp.436-449
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• 2016

This paper compares the transport overhead of MMT (MPEG Media Transport) with that of MPEG-2 TS (Transport Stream). MPEG-2 TS is globally used in multiplexing compressed audio and video data in digital broadcast industry, including areas of DTV (Digital Television), IPTV (Internet Protocol Television), and DMB (Digital Multimedia Broadcasting). It was the early 1990s when MPEG-2 TS standard was established. After more than two decades of years since its first establishment, many parts of MPEG-2 TS turned out to be inappropriate to today's broadcast and communication environment. Given the situations, in 2014 MPEG (ISO/IEC JTC 1 SC 29/WG 11) standardized MMT as the next-generation multimedia transport standard hopefully that can replace MPEG-2 TS. In this paper, with assumptions of broadcast service scenarios we applied both MMT and MPEG-2 TS to each scenario and we calculated their transport overheads. We used a software program that counts the transport overhead, which was developed in our laboratory for this paper. And we conducted a comparative analysis based on the calculated result of transport overhead.

• Journal of Korea Multimedia Society
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• v.4 no.5
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• pp.371-376
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• 2001

Since continuous media such as video and audio data are displayed within a certain time constraint, their computation and manipulation should be handled under limited condition. Traditional real-time scheduling algorithms cold be directly applicable, because they are not suitable for multimedia scheduling applications which support many clients at the same time. Rate Regulating Proportional Share Scheduling Algorithm based on the stride scheduler is a scheduling algorithm considered the time constraint of the continuous media. The stride schedulers, which are designed to general tasks, guarantee the fairness of resource allocation and predictability. The key concept of RRPSSA is a rate regulator which prevents tasks from receiving more resource than its share in a given period. But this algorithm loses fairness which is a strong point of the stride schedulers, and does not show graceful degradation of performance under overloaded situation. This paper proposes a new modified algorithm, namely Modified Proportional Share Scheduling Algorithm considering the characteristics of multimedia data such as its continuity and time dependency. Proposed scheduling algorithm shows graceful degradation of performance in overloaded situation and it reduces the scheduling violations up to 70% by maintaining the fair resource allocation. The number of context switching is 8% less than RRPSSA and the overall performance is increased.

• The Journal of the Korean dental association
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• v.57 no.12
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• pp.728-735
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• 2019

Objective: Previous studies suggested the potential influence of YouTube videos regarding dentistry on the mass population. However, there was not any clear investigation for Korean population. We aimed to systemically analyze the type of the dentistry-related videos uploaded on YouTube Korea and the accounts used for uploading, and to assess their effect on the view count of the content. Methods: Classification, type of the accounts, and view count of the videos listed by the keyword 'dentistry' were analyzed, which were uploaded on YouTube Korea platform from September 2017 to April 2019. Kruskal-Wallis test with post hoc analysis was used to assess the effect of the classification of the videos and the type of accounts on the view count. Results: 1.026 videos were enrolled to the analysis. Primary classification of the videos was information/education, advertisement, life, news, child contents, autonomous sensory meridian response, broadcast, cartoon/game, humor, and music. Secondary classification of the videos was dental experience, advertisement, role-playing, information/education., humor, cartoon/game, child contents, life, and broadcast. Type of the accounts was dentistry associates, general public, media company, and government office (sorted by frequency). Subject of the most videos (93.6%) was general public. There was statistically significance in the view count of the videos according to the primary and secondary classifications, the account used for uploading, and target subject of the videos. Conclusion: Dentists and their associates should recognize the importance of YouTube platform and try to monitor and intervene the dentistry-related contents, considering its huge impact on the general public.

• Journal of Broadcast Engineering
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• v.24 no.2
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• pp.329-340
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• 2019

Recently, broadcasting technologies have evolved as high-quality AV services such as domestic terrestrial UHD(Ultra-High Definition) broadcasting have been increasing, and broadcasting standards have been newly defined. Also, as network technology develops, contents are consumed not only in the country but also the world. Accordingly, content insertion technology, which is a method of providing suitable contents in accordance with the national and local environments, will be needed. This paper proposes a content insertion service system model and synchronization scheme using ATSC(Advanced Television Systems Committee) 3.0 Event Signaling standard under heterogeneous network environment of broadcasting network and internet network based on transmission standard DASH(Dynamic Adaptive Streaming over HTTP)/ROUTE(Real time Object delivery Over Unidirectional Transport) and MMT(MPEG Media Transport) of terrestrial UHD broadcasting. It also verifies that the service operates in an environment that meets the broadcast standard.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.983-986
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• 2005

This paper describes a digital convergence platform(DCP) whice is implemented based on the MPEG-21 multimedia framework. The DCP is a newly proposed solution in this research for the convergence service of future home multimedia environment. The DCP is a common platform designed to have the feature of configurability, via means of S/W, which is needed for the convergence service of diverse digital media. A distributed peer to peer service and transaction model is also a new feature realized in the DCP using the MPEG-21 multimedia framework. A prototype DCP is implemented to verify its functions of multimedia service and transactions. The developed DCPs are networked with IP clustering storage systems for the distributed service of multimedia. Successful streaming services of the MPEG-2/4 video and audio are verified with the implemented test-bed system of the DCP.