• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1998.11a
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• pp.520-524
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• 1998

인터넷상에서 실시간 영상회의 시스템을 구축하기 위해 MBone망을 구성하고 RTP에 의해 영상 및 음성정보의 고속전송이 가능하게 하였다. 이를 기반으로 멀티미디어 영상회의 프로토콜인 H.323을 탑재하여 다자간 회의 시스템을 구현하고, 더불어 영상사서함 기능을 부가하여 녹화, 재생이 가능하게 한다. 구현결과 기존의 시스템보다 속도가 향상됨을 확인했다.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.617-619
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• 1999

본 논문에서는 H.263과 G.723.1을 이용한 인터넷 화상회의 시스템의 구현을 기술한다. 시스템은 회의요청자의 요구에 대한 처리를 담당하는 프로세스와 미디어를 압축하여 전송하는 송신부, 그리고 상대방이 전송한 미디어를 복원하여 재생하는 수신부로 구성된다. 비디오와 오디오의 엔코더 및 디코더 모듈들은 소프트웨어 콤포넌트로 구현되어 다양한 스트리밍 시스템의 개발에 사용될 수 있다. 또한 IP 멀티캐스트, TCP/UDP 등의 프로토콜을 지원하여 다양한 형태의 회의를 가능하게 한다.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.11
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• pp.48-51
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• 1996

We developed a multimedia monitoring system for patients at home, equipped with video and audio-conferencing capabilities. It can also monitor biological signals in real-time with vital signs. The system has an extensible architecture to accommodate probable future needs easily.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.130-132
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• 2003

화상회의 시스템에서 원활한 동영상의 전달을 위해서는 주어지는 처리시간에 대하여 그에 상응하는 품질을 보장하는 프레임 스케줄링 방법이 필수적이다 영상 복원 작업에 주어지는 처리시간이 증가함에 따라 그 실행 결과로 얻어지는 영상의 품질이 함께 증가할 것이 요구된다. 본 논문에서는 영상회의 시스템에서의 압축된 영상의 복원 과정에서 프로세서의 처리시간에 따르는 결과 영상의 품질에 대한 QoS함수를 도출하고 이를 IRIS 스케줄링 방안에 적용하는 온-라인 스케줄링 알고리즘을 제안한다. 본 논문에서 제시하는 알고리즘에 대한 모의실험의 결과는 주어진 시스템 성능에 H하여 영상회의에 참여한 모든 화자 영상의 총체적 화질을 향상시킬 수 있음을 보여준다.

• Journal of Broadcast Engineering
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• v.3 no.1
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• pp.100-109
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• 1998

The coding of video sequences has been the focus of research in recent years. High Definition TV(HDTV), video conferencing and video on demand(VOD) are some of the well known applications. In the moving picture compression, motion estimation algorithm plays a very important role, but due to its high computational complexity, there has been many approaches to overcome this difficulty. We propose a new block matching criterion that uses modified cost functions. This new block matching criterion classifies pixels into 2-levels, 4-levels and 8-levels with a suitable thresholding method. We also show that our new proposed algorithms can easily be combined with many other fast motion estimation algorithms with good performance.

• Smart Media Journal
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• v.4 no.1
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• pp.9-15
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• 2015

Nonverbal communications such as eye gazing, posture, and gestures send forceful messages. In regard to nonverbal communication, eye gazing is one of the most strong forms that an individual can use. However, lack of mutual gazing occurs when we use video conferencing system. The displacement between locations of the eyes and a camera gets in the way of eye contact. The lack of eye gazing can give unapproachable and unpleasant feeling. In this paper, we propose an eye gazing correction for video conferencing. We use two cameras installed at the top and the bottom of the television. The captured two images are rendered with 2D warping at virtual position. We implement view morphing to the detected face, and synthesize the face and the warped image. The result shows that eye gazing is corrected and correctly preserved and the image was synthesized seamlessly.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.1
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• pp.209-219
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• 2011

Most of the computer-based distance learning systems are asynchronous ones that allow students to download from the server the lecture previously given by a lecturer. While these asynchronous systems has the advantage that enable students to view the lecture with no time restriction, the study may not be effective due to the lack of support for real-time interaction between students and lecturers. Based on the student-lecturer-collaboration session model, this paper presents a collaboration session-centric synchronous distance learning system that supports real-time interaction between students and teachers, awareness information during lecture, and feedback from students. Basic feature of the proposed system include audio and video conferencing, text-based chat, and shared slide with annotation support.

• The Journal of Korean Association of Computer Education
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• v.12 no.3
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• pp.31-40
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• 2009

English education taken with native English speakers is very effective, but it is hard to obtain English education with native English speakers in rural schools. In this study, therefore, we supported English education with on-line content and video conferencing with native English speakers. This study worked with one hundred fifty students from six elementary and middle schools equally distributed by city size over three months. This study performed experimental research by T-test comparing of pre- and post-tests of the hybrid model. In our results, the upper group showed greater improvement in understanding while the lower group showed more improvement in writing. In addition, the lower group showed more improvement than the upper group in overall English accomplishment.

• ETRI Journal
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• v.27 no.1
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• pp.13-21
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• 2005

Many multicast applications, such as video-on-demand and video conferencing, desire quality of service (QoS) support from an underlying network. The differentiated services (DiffServ) approach will bring benefits for theses applications. However, difficulties arise while integrating native IP multicasting with DiffServ, such as multicast group states in the core routers and a heterogeneous QoS requirement within the same multicast group. In addition, a missing per-flow reservation in DiffServ and a dynamic join/leave in the group introduce heavier and uncontrollable traffic in a network. In this paper, we propose a distributed and stateless admission control in the edge routers. We also use a mobile agents-based approach for dynamic resource availability checking. In this approach, mobile agents act in a parallel and distributed fashion and cooperate with each other in order to construct the multicast tree satisfying the QoS requirements.

• Journal of the Korea Society of Computer and Information
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• v.19 no.10
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• pp.159-168
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• 2014

The Web is a way to share documents and communicate. However, voice and video data can be transmission in real time and currently being developed by the objects and the objects that interact to further develop the Internet. Existing video and audio programs to transmission data to the interface of different types of systems a lot of constraint condition on the cost of the interface, extensibility. In this paper, voice and audio transmission system a different operating system, improve the constraints of the ERP system compatibility and extensibility is a open source based system developed by the research. The program is different types of systems and interface, extensibility with program design and development methodologies, and open source-based system composed This system is good for cost saving and extensibility. Therefore, systems research and development, Extensibility and excellent on the interface, system design and development methodologies, such as real-time video conferencing, HMI, and take advantage of your video available from SNS.