• Journal of Broadcast Engineering
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• v.25 no.4
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• pp.560-568
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• 2020

In recent years, as network technology develops, the usage of streaming services by users is increasing. However, the complexity of streaming services is also increasing due to various terminal environments. Even when streaming the same content, it is necessary to re-encode the content according to the type of service. In order to solve the complexity and latency of the streaming service, Moving Picture Experts Group (MPEG) has standardized the Common Media Application Format (CMAF). In addition, as content transmission using a communication network becomes possible, the Republic of Korea's Ultra High Definition (UHD) broadcasting standard has been enacted as a hybrid standard using a broadcasting network and a communication network. The hybrid service enables various services such as transmitting additional information of contents or providing user-customized contents through a communication network. The Republic of Korea's UHD transmission standard utilizes MPEG Media Transport (MMT), and Mobile MMT is an extension of MMT to provide mobile network-specific functions. This paper proposes a method of inserting CMAF contents suitable for various streaming services using signaling messages of MMT and Mobile MMT. In addition, this paper proposes a model for content insertion system in heterogeneous network environment using broadcasting and communication networks, and verifies the validity of the proposed technology by checking the result of content insertion.

• Macromolecular Research
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• v.16 no.7
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• pp.644-650
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• 2008

This study examined the effect of nanoclays on the shape memory behavior of polyurethane (PU) in fibrous form. A cation was introduced into the PU molecules to disperse the organo-nanoclay (MMT) into poly($\varepsilon$-caprolactone) (PCL)-based PU (PCL-PU). The MMT/PCL-PU nanocomposites were then spun into fibers through melt-processing. The shape memory performance of the spun fibers was examined using a variety of thermo-mechanical tests including a new method to determine the transition temperature of shape memory polymers. The MMTs showed an improved the fixity strain rate of the MMT /PCL- PU fibers but a slight decrease in their recovery strain rate. This was explained by the limited movement of PU molecules due to the presence of nanoclays. The shape memory performance of the MMT/PCL-PU fibers was not enhanced significantly by the nanoclays. However, their recovery power was improved significantly up to a strain of approximately 50%.

• Journal of Broadcast Engineering
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• v.20 no.1
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• pp.40-47
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• 2015

This paper discusses QoS enhancement in the Best-effort services of the service plan provided by MPEG Media Transport (MMT) systems for video streaming applications. Among MMT services, i.e. per-flow, per-class, and best-effort services, the server does not provide guaranteed bandwidth for the best-effort service only. Therefore, in the best-effort services, a bandwidth access priority is defined for various services, where the lowest priority is assigned to the low-level video services. To alleviate the issue of bandwidth limitation in the best-effort services, this paper investigates transmission of low-resolution video with low bitrate and up-sampling. Our experimental results prove the superiority of the proposed method in terms of delivered video quality.

• Journal of the Korea Computer Industry Society
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• v.2 no.8
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• pp.1133-1138
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• 2001

In this paper, we implemented that MMT(Multimedia Terminal) demonstrates spot news, weather forecast, sports news and cultural news employed CDMA mobile communication networks. The MMT displays mobile pictures/joint pictures/on screen ad and to make known Bus stop or Mobile stations. The MMT gives driver's and passenger's safety and valuable information for one's use GPS satellites. We verified to make real time mobile picture transfer use of CDMA2000 1×(IS-95C) network and development the scheduler control each module. This system tested on vehicle that train and bus. MMT was implemented high reliability and stability by the embedded system. The mobile terminal shows reliable data transfer rate about 74Kbps on IS-95C.

• Journal of Broadcast Engineering
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• v.22 no.5
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• pp.570-577
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• 2017

Recently, with the development of broadcasting communication, users expect to receive high quality and various broadcasting services anytime, anywhere. In the case of terrestrial broadcasting, HD broadcasting and mobile broadcasting are provided at different frequencies. In the case of terrestrial UHD, which recently started trial broadcasting, 700MHz frequency is used which is different from the existing one. If the contents of the same contents are transmitted at different frequencies, it can be considered ineffective in terms of the use efficiency of the terrestrial broadcast frequency. As a method to solve this problem, a transmission system model and a service have been proposed for transmitting the hierarchical encoded UHD contents by SHVC on the basis of the multimedia transmission technology MMT in a heterogeneous network environment combining broadcast network and communication network. However, it is still in the initial stage of study the receiving model that can reliably receive various quality UHD contents in various environments such as mobile and fixed environment. Therefore, in this paper, we propose a receive buffer model that can reliably receive UHD contents layered on SHVC based on MMT.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.06a
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• pp.63-65
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• 2016

최근 기술의 발전으로 자연스로운 미디어와 실재감을 제공하는 차세대 3D 기술이 많은 관심을 받고 있다. 그 중 (초)다시점 미디어 기술은 기존의 안경식 3D 미디어 기술을 대체할 수 있는 기술로써 각광받고 있다. (초) 다시점 미디어는 기존의 미디어와 비교하여 많게는 10배가 넘는 시점 정보를 포함하고 있다. 그러므로, 대용량의 (초) 다시점 미디어를 전송하기 위해서는 IP 망에서 실시간성을 고려한 프로토콜 사용이 필요하다. 이를 위하여 본 논문에서는 차세대 미디어 전송 규격인 MPEG MMT를 이용하여 DirectShow를 기반으로 (초) 다시점 미디어를 전송, 재현할 수 있는 스트리밍 시스템을 구현 하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.06a
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• pp.68-69
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• 2016

ISO/IEC 13818-1 MPEG2 시스템의 타이밍 모델은 인코더에 들어간 비디오와 오디오 샘플들이 일정한 딜레이가 지난 후 디코더에서 정확히 한 번씩 나타나는 식으로 구현된다. 해당되는 디코더는 타이밍 모델에 부합하여 대응되는 비트스트림을 전달받는다. 이를 통해서 적절하게 동기화가 이루어진 고품질 오디오와 비디오를 위한 디코더 구현을 쉽게 할 수 있다. 반면에, RTP 타이밍 모델은 실제 프리젠테이션 시간에 관한 타이밍 정보를 가지고 있지 않다. 데이터 패킷의 타임스탬프는 상대적 타이밍을 제공하고, RTCP 송신자는 스트림 간 동기화에 대한 정보를 제공하지만 RTP 수신기에서는 버퍼링의 량이나 패킷의 디코딩 시간에 대한 정보를 주지 않는다. 따라서 RTP는 유동적인 전송 지향적인 타이밍 모델을 가지고 있다. 반면에 MPEG-2 시스템은 정확한 타이밍 모델을 수신측을 위해 제공하고 있다. 본 논문에서는 MPEG-2 시스템과 RTP의 타이밍 모델의 이점을 가져와 MMT 시스템을 위한 타이밍 모델을 제안한다.

• Electronics and Telecommunications Trends
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• v.27 no.6
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• pp.165-181
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• 2012

세계은행의 발표에 따르면 전 세계적으로 개인 간 해외송금 시장의 규모는 지속적으로 성장해 왔으며, 향후에도 지속적으로 성장할 것으로 전망된다. 이러한 글로벌 송금 시장의 확산과 맞물려 이동통신 네트워크의 글로벌화와 스마트폰의 확산 등 통신 기술 및 서비스 진화에 따라 모바일 네트워크를 통해 간편하고 신속하게 송금할 수 있는 모바일 송금 서비스 시장이 국내외에서 급속하게 팽창하고 있다. 이에 세계이동통신사업자협회(Global System for Mobile Communications Association: GSMA)의 MMT(Mobile Money Transfer) 프로그램, 케냐 및 일본의 모바일 송금 서비스 제공 사례를 중심으로 서비스 제공 시스템 및 그 이용에 따른 장 단점, 가치사슬, 서비스 유형 등을 간략하게 살펴보았다. 이를 바탕으로 모바일 송금 서비스 제공 과정에서 나타날 수 있는 규제 이슈들을 분석해 보았다. 그리고, 국내 이동통신 사업자가 MMT 서비스를 본격적으로 제공하는 경우에 고려해야 할 규제 요소들과 안전하고 효율적인 MMT 시장의 활성화를 위해 필요한 규제정책 방향을 검토해 보았다.

• Journal of Broadcast Engineering
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• v.20 no.1
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• pp.16-25
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• 2015

Even if the demands for ultra-high-quality multimedia contents are increasing, it is difficult to produce, encode, play and transport ultra-high-quality contents under the existing broadcasting environment. By the reason, various technologies for the UHD contents have been developed in order to satisfy the user's needs. In this paper, we propose a design methodology of a broadcasting system, which consists of two parts, for UHD services with two parts. At the transmit part of the proposed system can encode a video into several layered-bitstreams hierarchically, and then transport each bitstream over heterogeneous networks. The receiver part can play the received video by composing the separated bitstreams. The proposed system can adaptively provide both HD and UHD contents according to user's reception conditions by using the heterogeneous networks.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.4
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• pp.166-171
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• 2006

In this paper, we have studied for analysis of the partial discharge(PD) signal in underground transmission line. The PD signal has estimated as detected signal accumulation of a PRPDA method by using Labview, and analyzed with fuzzy algorithm. In our algorithm, we developed system configuration that detected accumulating PD signal using by Labview and programmed fuzzy algorithm can be analyzed the PD signal using with Matlab. With practical PD logic implementation of theoretical detected system and hardware implementation, the device for Hipotronics Company's 50kV setup has generated and then has applied with $15k{\sim}17kV$ with 1:1 time probe. It's also used the LDPE 0.27mmt (scratch error 0.05mmt) to sample for making PD. In conclusion, Our new class of PD detected algorithm has also compared with previous PRPDA or Fuzzy algorithm. which has diagnose more conveniently by adding numerical values.