• Title/Summary/Keyword: Media transport

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Finite element solutions of natural convection in porous media under the freezing process (동결과정을 포함한 다공층에서 자연대류에 대한 유한요소 해석)

  • Lee, Moon-Hee;Choi, Chong-Wook;Seo, Suk-Jin;Park, Chan-Guk
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.51-56
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    • 2000
  • The Finite Element Solutions Is reported on solid-liquid phase change in porous media with natural convection including freezing. The model is based on volume averaged transport equations, while phase change is assumed to occur over a small temperature range. The FEM (Finite Element Method) algorithm used in this study is 3-step time-splitting method which requires much less execution time and computer storage the velocity-pressure integrated method and the penalty method. And the explicit Lax-Wendroff scheme is applied to nonlinear convective term in the energy equation. For natural convection including melting and solidification the numerical results show reasonable agreement with FDM (Finite Difference Method) results.

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Measurements of Optical Constants of Biomedical Media Based on Time-Resolved Reflectance (시간 분해 반사율 측정에 의한 다중산란 매질의 광학 계수 측정)

  • Jeon, K.J.;Park, S.H.;Kim, U.;Yoon, K.W.;Kim, W.K.
    • Proceedings of the KOSOMBE Conference
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    • v.1996 no.05
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    • pp.235-239
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    • 1996
  • In recent years, the optical properties of multiple-scattering media like tissue have been studied for their potential applications in medicine. In this work the optical properties of multiple scattering media were investigated using the time-resolved reflectance measurement. The reflected light was measured by time-correlated single photon counting system. The transport scattering and absorption coefficient are related to the initial rapid decay and the subsequent decay in reflected light, respectively. Also the optical properties of the samples were measured by conventional method, ie., using continuous wave light. When the distance between the light source and the detector is over 8mm, the optical coefficient can be measured accurately using the suggested method.

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Adaptive Wireless Sensor Network Technology for Ubiquitous Container Logistics Development

  • Chai, Bee-Lie;Yeoh, Chee-Min;Kwon, Tae-Hong;Lee, Ki-Won;Lim, Hyotaek;Kwark, Gwang-Hoon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.05a
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    • pp.317-320
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    • 2009
  • At the present day, the use of containers crisscrossing seven seas and intercontinental transport has significantly increased and bringing the change on the shape of the world economy which we cannot be neglected. Additionally, with the recent technological advances in wireless sensor network (WSN) technologies, has providing an economically feasible monitoring solution to diverse application that allow us to envision the intelligent containers represent the next evolutionary development step in order to increase the efficiency, productivity, utilities, security and safe of containerized cargo shipping. This paper we present a comprehensive containerized cargo monitoring system which has adaptively embedded WSN technology into cargo logistic technology. We share the basic requirement for an autonomous logistic network that could provide optimum performance and a suite of algorithms for self-organization and bi-directional communication of a scalable large number of sensor node apply on container regardless inland and maritime transportation.

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A Study on the Characteristics of Urban Public Transportation Information Services Use (도시 대중교통정보 이용 행동 특성 연구)

  • Joh, Chang-Hyeon;Lee, Back-Jin;Bin, Mi-Young
    • Journal of the Economic Geographical Society of Korea
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    • v.12 no.1
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    • pp.56-66
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    • 2009
  • As the amount of information is rapidly growing, and the ubiquitous urban environments are emerging, the question which information type to provide and which communication media to support is a major challenge for commercial and public travel-information service providers. The current research reports the first findings of analyses of recent data, collected in metropolitan Seoul, about the acquisition of travel information and the communication media used. The study is based on the assumption that information acquisition and choice of communication medium is strongly context-driven. The study applies CHAID analysis to find homogeneous segments in information acquisition and use of communication media. Findings indicate that transport mode and activity are important determinant of information acquisition and choice of media. The type of travel information acquired co-varies strongly with transport mode and activity. In addition, we found evidence of time of day effects. Similarly, the choice of communication medium depends on the type of travel information searched for, transport mode and activity. The results suggest important implications of managerial and policy measures, in particular the dynamic, contextual market segmentation.

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Multiplexing of UHDTV Based on MPEG-2 TS (MPEG-2 TS 기반의 UHDTV 다중화)

  • Jang, Euy-Doc;Park, Dong-Il;Kim, Jae-Gon;Lee, Eung-Don;Cho, Suk-Hee;Choi, Jin-Soo
    • Journal of Broadcast Engineering
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    • v.15 no.2
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    • pp.205-216
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    • 2010
  • In this paper, a method of MPEG-2 Transport Stream (TS) multiplexing for Ultra HDTV (UHDTV) and its design and implementation as a SW tool is described. In practice, UHD video may be divided into several HD videos and each video is encoded in parallel. Therefore, it is necessary to synchronize and multiplex multiple bitstreams encoding each HD video for transmitting and storing UHD video. In this paper, it is assumed that 4 HD videos partitioning a UHD spatially are encoded as H.264/AVC and two 5.0 channel audios are encoded by AC-3. Therefore, 4 H.264/AVC elementary streams (ESs) and 2 AC-3 ESs is mainly considered in the TS multiplexing of UHD. For the carriage of H.264/AVC and AC-3 over MPEG-2 TS, PES packetization and TS multiplexing are designed and implemented based on the extended specification of the MPEG-2 Systems and ATSC (Digital audio compressed standard), respectively. The implemented UHD TS multiplexing tool emulates real time HW operation in the time unit corresponding to the duration of one TS packet transmission in a given TS rate. In particular, in order to satisfy the timing model, the buffers defined in the TS System Target Decoder (T-STD) are monitored and their statuses are considered in the scheduling of TS multiplexing. For UHD multiplexing, two kinds of multiplexing structures, which are UHD re-multiplexing and UHD program multiplexing, are implemented and their strength and weakness are investigated. The developed UHD TS multiplexing tool is tested and verified in terms of the syntax and semantics conformance and functionalities by using a commercial analyzer and real-time presentation tools.

Analysis of Flexible Media: I. Static and Dynamic Analysis (유연매체의 거동해석: I. 정.동적 거동해석)

  • Jee, Jung-Geun;Jang, Yong-Hoon;Park, No-Cheol;Park, Young-Pil
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.1253-1258
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    • 2007
  • The media transport systems, such as printers, copy machines, facsimiles, ATMs, cameras, etc. have been widely used and being developed rapidly. In the development of those sheet-handling machineries, it is important to predict the static and dynamic behavior of the sheet with a high degree of reliability because the sheets are fed and stacked at such a high speed. Flexible media are very thin, light and flexible, so they behave in geometric nonlinearity with large displacement and large rotation but small strain. In the flexible media analysis, aerodynamic effect from the surrounding air must be included because any small force can make large deformation. In this paper, only the flexible media analysis is performed as early stage of analysis including aerodynamic effect. Through formulations and simulations for total Lagrangian(TL), updated Lagrangian (UL) and co-rotational(CR) method which are widely used for geometric nonlinear analysis, usefulness and reliability of each methods are investigated.

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Design and Implementation of a Content Manager in the Multimedia Steaming Framework (멀티미디어 스트리밍 프레임워크에서 컨텐츠 관리자의 설계 및 구현)

  • Hong, Yeong-Rae;Kim, Hyeong-Il;Lee, Seung-Ryong;Jeong, Byeong-Su;Yun, Seok-Hwan;Jeong, Chan-Geun
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.2S
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    • pp.733-743
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    • 2000
  • This paper describes design and implementation of a content manager in the Integrated Steaming Framework Architecture (ISSA) that is proposed by the authors. The ISSA can provide an environment to develop multimedia streaming applications under heterogeneous distributed systems. The goal of ISSA is to extend the limitations of existing streaming systems. It can support diverse media formats and high level programming environment for streaming application developers. Moreover, it is independent from underlying networks and operating systems, and compatible with the global real-time multimedia database system(BeeHive) so that streaming media is efficiently retrieved, stored, and serviced. The role of a content manager is important in the ISSA environment since it manages an information of media that are provided by the server, and allow users to access media more easily by means of conveying that information to the streaming server, Web server, and client efficiently. The proposed content manager is not only to meed these requirements, but also to provide streaming information to media source and transport manager in order to be an efficient streaming. Furthermore, it supports database transaction processing by using the database connector.

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Transmission system design for synchronized data service on digital data broadcasting environment (디지털 데이터 방송 환경에서 동기화 데이터 서비스를 위한 전송 시스템 설계)

  • Lee Yong Ju;Park Min Sik;Choi Ji Hoon;Choi Jin Soo
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2003.11a
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    • pp.201-204
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    • 2003
  • 본 논문에서는 디지털 데이터 방송에서 동기화 데이터 서비스를 제공하기 위한 전송 시스템과 이를 이용한 동기화 데이터 서비스 방법을 제안한다. 데이터 방송을 통해 전송되는 부가 데이터는 그 특징에 따라 비동기, 동기, 동기화 데이터로 구분된다. 이들 중 동기화 데이터는 사용자의 선택에 의해 데이터 방송 수신기에서 재생되는 비동기 데이터와는 달리 비디오 또는 오디오의 특정 장면에 통기되어 재생될 수 있는 데이터고서, 데이터를 전송하는 단계에서 데이터가 재생되어야 하는 시전의 시간 정보인 재생시각이 함께 전송되는 특징이 있다. 동기화 데이터의 이와 같은 특징으로 인해 현재 대부분의 데이터 방송에 사용되고 있는 비동기 데이터 서비스를 위한 전송 시스템은 동기화 데이터의 전송에는 부적합하며, 동기화 데이터 서비스를 위해서는 새로운 전송 시스템에 대한 연구가 필요하다. 본 논문에서는 데이터 방송을 동해 동기화 데이터 서비스를 제공하기 위해 기존의 비동기 데이터 전송 시스템에 MPEG-2 오디오/비디오 TS(Transport Stream)를 출력하는 장치와 동기화 데이터를 다중화 하는 장치를 추가한 새로운 동기화 데이터 전송 시스템과 이를 이용한 동기화 데이터 서비스 방법을 제안한다

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Commercial 4K UHD Streaming Device over 5G Mobile Communication Network (5G 이동통신망을 통한 상용 4K UHD 스트리밍 장치)

  • Junghoon, Paik;Yongsuk, Kim
    • Journal of Broadcast Engineering
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    • v.27 no.6
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    • pp.914-922
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    • 2022
  • In this paper, we construct a commercial 4K UHD(Ultra High Definition) streaming device that utilizes a 5G mobile communication network as a transport channel and conduct a streaming performance test. It uses RTP(Realtime Transport Protocol) which has transmission quality monitoring capability as a transmission protocol to apply adaptive streaming. In addition, it provides the function to adjust the encoding rate of the video signal so that encoding can be optimized for the change in the bandwidth of the transmission channel. Through the performance test, it is confirmed that the H.265 encoding rate for 4K UHD signal is 48.69Mbps, the average glass-to-glass delay time is 293.60ms, and the average time difference between video and audio for lip sync is 120ms. With the result of performance test, it is shown that the streaming device is applied to 4K UHD Streaming device over 5G mobile communication network.

Adaptive QoS Study for Video Streaming Service In MMT Protocol (비디오 스트리밍 서비스를 위한 MMT 기반 적응적 QoS 연구)

  • Jo, Bokyun;Lee, Doohyun;Suh, Doug Young
    • 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.