• 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.

• Journal of Korea Multimedia Society
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• v.6 no.3
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• pp.488-495
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• 2003

With the development of networks, multimedia communication has expanded its application field. From the remote control for household electric appliances to medicine, games, video conferencing and multimedia chatting, multimedia communication is being used in all parts of our lives. This multimedia communication requires the transmission of a lot of data at high speed. But if the transmission rate of the communication network exceeds the processing speed of being used in the high speed network environment, a bottleneck occurs in each node and deteriorates the performance of the network. This is the main reason for the slow speed of data transmission and packet loss. In this paper, considering the client's processing performance, reception performance was predicted and the way of flow control was shown. The computing performance of relevant Processor and its performance was estimated through the actual implementation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.12
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• pp.6034-6056
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• 2018

This paper describes two user studies in remote collaboration between two users with a video conferencing system where a remote user can draw annotations on the live video of the local user's workspace. In these two studies, the local user had the control of the view when sharing the first-person view, but our interfaces provided instant control of the shared view to the remote users. The first study investigates methods for assisting drawing annotations. The auto-freeze method, a novel solution for drawing annotations, is compared to a prior solution (manual freeze method) and a baseline (non-freeze) condition. Results show that both local and remote users preferred the auto-freeze method, which is easy to use and allows users to quickly draw annotations. The manual-freeze method supported precise drawing, but was less preferred because of the need for manual input. The second study explores visual notification for better local user awareness. We propose two designs: the red-box and both-freeze notifications, and compare these to the baseline, no notification condition. Users preferred the less obtrusive red-box notification that improved awareness of when annotations were made by remote users, and had a significantly lower level of interruption compared to the both-freeze condition.

• Journal of Korean Physical Therapy Science
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• v.28 no.3
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• pp.1-10
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• 2021

Background: The purpose of this study is to investigate the effect of the online team project based learning on problem-solving, cooperative self-efficacy, and cooperative self-regulation of college students. Design: Single group pre-post design. Methods: The online team project based learning was conducted for a total of 92 college students for 8 weeks. A survey was conducted on problem-solving ability, cooperative self-efficacy, and cooperative self-regulation. In the online team project-based class, two projects were performed. It consists of video lectures and real-time video conferencing. Through the real-time video conference, the project was carried out based on discussion among learners and feedback was provided. Results: There was a significant difference in the change in problem-solving ability compared to before learning (p<0.05). As a result of the evaluation of cooperative self-efficacy, there was a significant difference (p<0.05). There was a significant differences in cooperative self-regulation compared to before learning (p<0.05). Conclusion: The online team project-based learning are effective in improving learners' problem-solving ability, cooperative self-efficacy, and cooperative self-regulation.

• Journal of Korea Multimedia Society
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• v.4 no.4
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• pp.297-305
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• 2001

Recently advances in high-speed networks and multimedia computer technologies allow new types of multimedia applications to manipulate large volumes of multimedia data. However, in the real time and/or the heterogeneous data transmissions, there are many difficulties such as network transmission delay, the implementation difficulties, and so on. To solve these problems, in this paper, we extend the method of the multimedia service design which is proposed by OMG. To do this, we suggest an efficient real time audio/video stream framework, called Smart Explorer, based un CORBA and JMF Java Media API. And we separate the transmission path of control data from that of media data and use RTP/RTCP protocol for efficient real time audio/video transmission. Also we show the appropriate implementation of the audio/video stream system based on our suggested framework Smart Explorer. In the future, we expect our audio/video stream system to be applied to the real time communication software such as broadcasting, distance learning, and video conferencing.

• Journal of the Korea Society of Computer and Information
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• v.16 no.2
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• pp.71-81
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• 2011

In order to easily create video tutorials, the algorithm is needed that video camera recording, white board images, video attachments, and document data are combined in real-time. In this study, we implemented the video lecture content creation system using wavelet-based lossless compression to composite multimedia objects in real-time and reproduce the images. Using commercially available PC can be useful when lecturers want to make video institutional contents, it can be operated easily and fastly. Therefore, it can be very efficient system for e-Learning and m-Learning. In addition, the proposed system including multimedia synthesis technology and real-time lossless compression technology can be applied to various fields, different kinds of multimedia creation, remote conferencing, and e-commerce so there are highly significant.

• Women's Health Nursing
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• v.28 no.4
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• pp.275-285
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• 2022

Purpose: This study explored the experiences of pregnant women with depressed mood participating in a group cognitive behavioral therapy (CBT) program using video communication, based on Beck's cognitive theory. Methods: The participants were six pregnant women out of 13 women who had participated in an 8-session group CBT program using video communication for women with depressed mood (Edinburgh Postnatal Depression score of ≥9). Data were collected from February 20 through March 25, 2021. In-depth individual interviews were conducted through a video conferencing platform at 1 month post-baseline. Thematic analysis was done. Results: Three themes, 10 subthemes, and 38 concepts were derived from experiences of participating in the 4-week group CBT program (twice a week). The first theme, entitled "continuing realization" had subthemes of "a negative and instable self," "a selfish judgment that excludes others," and "a strong belief in self-control." The second theme, entitled "attempt to change for restoration" had subthemes of "shift to rational thinking," "freedom from suppressed beliefs," "tolerance of other people," and "courage for self-expression." The third theme, entitled "departure for a positive life," had subthemes of "emotional healing," "faith in oneself," and "reestablishing the criteria for happiness." Conclusion: Pregnant women with depressed mood expressed that continuing realizations and attempts to change supported their transition toward a positive direction of healing. Thus, they were able to change their distorted thinking into rational thinking through CBT using video communication. These findings support the use of group CBT using video communication with pregnant women who have depressed mood.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.2 no.4
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• pp.81-87
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• 2009

In this paper, the reduction amount of CO2 due to the virtual international video-conference organized by ITU in order to reduce the greenhouse gas (GHG) is calculated. The comparison is made with the case of off-line conference. In the symposium organized by ITU, "The power of ICTs to save The planet", held on September 2009 the participants were highly encouraged to attend the symposium through video-conferencing for the reduction of GHG. As a result, 46 foreign participants and 16 among 170 domestic participants have attended at virtual video-conference, which resulted in about 94.7 ton of CO2 emission reduction. This international symposium firstly tried in conjunction with online and off-line has drawn a big attention in the aspect of global warming. Definitely such ITU's trial will make significant impacts on the holding of other international symposiums and forums.

• Proceedings of the Korea Contents Association Conference
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• 2003.11a
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• pp.347-351
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• 2003

It is important to consider not only audio/video but presentation way, in video conferencing, seminar, lecture based network communication. The method to transmit image of a chalkboard used in traditional seminar, conference, lecture are one of difficulties for remote environment since it requires techniques high-resolution transmission and talking films. In this paper we implemented real-time multimedia shared board system for shared effective multimedia presentation using connection-oriented socket of TCP. In this system, decreasing cost of related system construction, improve of data reliableness and interaction, presentation delay time be able to minimize.