• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.12
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• pp.17-24
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• 2005

Traditional Internet applications such as FIP and E-mail are increasingly sharing bandwidth with newer, more demanding applications such as Web browsing, IP telephony, video conference and online games. These new applications require Quality of Service (QoS), in terms of delay, loss and throughput that are different from QoS requirements of traditional applications. Unfortunately, current Active Queue Management (AQM) approaches offer monolithic best-effort service to all Internet applications regardless of the current QoS requirements. This paper proposes and evaluates a new AQM technique, called MCDT that provides dynamic and separated buffer threshold for each Applications, those are FTP and e-mail on TCP traffic, streaming services on tagged UDP traffic, and the other services on untagged UDP traffic. Using a new QoS metric, our simulations demonstrate that MCDT yields higher QoS in terms of the delay variation and a packet loss than RED when there are heavy UDP traffics that include streaming applications and data applications. MCDT fits the current best-effort Internet environment without high complexity.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9A
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• pp.1431-1440
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• 2000

In order to support efficiently the multimedia applications, such as virtual classroom, video conferencing and tele-medical, the efficient multipoint-to-multipoint(MP-to-MP) connection management function is essential. Shared tree is reported as the most useful method for this purpose. In this paper we propose a new MP-to-MP connection setup & management scheme, called CIMA(Cell Interleaved Multiplexing on ATM) scheme,which is a VC merging method for MP-to-MP communication using shared tree. In the CIMA scheme,MRM cell delivers the cell merging information to the next node. The receiving node can identfy cells which arrived through a channel using the same VPI/VCI by the merging information in the MRM cell. Therefore the CIMA scheme can solve easily the Cell Interleaving Problem(CIP) that happens in VC merging. We analyzed the overhead of the proposed CIMA by mathematical analysis,and simulated the buffer usage of CIMA with OPNET. As the result of analysis,we found that the CIMA scheme has acceptable merging overhead and doesn't cause the buffer scare problem.

• Journal of the Korea Convergence Society
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• v.11 no.9
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• pp.125-134
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• 2020

This study analyzed the cases of online art museum education based on the core competency of Jenkins' new media literacy to supplement the limitations of online art museum education programs. The core competency of media education suggested by Jenkins can serve as a reference point for an online art museum content. For the case analysis, 4 museums were selected as the domestic art museum, and 4 as the overseas art museum. The results of analysis based on new media literacy are as follows. In the case of overseas art museums, content for mutual communication such as video conferencing and commenting at the bottom of the site page was constructed, but domestic online art museums lacked these elements. Therefore, there is a need to improve core competency of appropriation, networking, negotiation, distributed cognition, and collective intelligence by organizing communication content.

• The Transactions of the Korea Information Processing Society
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• v.5 no.3
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• pp.606-619
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• 1998

In this paper, we have tfesigned and ihlplemented ACE(Application sharing Collaboration Engine) which is pessible an application sharing to collaborate among peoples who are geographically dispersed. The application sharing is a technology whereby two or more users collaborate to share the output of single application running on one computer system to the other users, and to provide input to the applications. We defined ASO(Applicatio!1 Sharing Object) object and its behavior to share applications in real time and ACE processes a sharing using ASO object among the distributed systems. ASO is classified into activateASO, updateASO, inputASO, and controlASO. The each ASO's behavior involves both events which occur at specific moments such as keystrokes and mouse clicks and more persistent status which can be observed at any time such as the image on the screen. The implemented ACE can be applied to the data conferencing, distance education, and project collaboration for engineer in distributed environments.

• The Transactions of the Korea Information Processing Society
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• v.4 no.11
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• pp.2801-2811
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• 1997

This thesis Proposes a media synchronization mechanism for video conferencing system by analyzing a variation of the delay time of media. Using this mechanism, this thesis analyzes the media traffics and determines the values of external variables important on waiting time. This system uses some dummy streams to get the time. When two hosts are initially connected, they change the dummy streams by which a logical time of the sender may be extracted. The time presenting a media stream is a sum of base time, logical time and the waiting time. At this time, for the purpose of optimally adjusting the waiting time, this mechanism uses the rate of updating the waiting time and the sampling unit of media. These values are acquired by analyzing the waiting times, the delay rates and the delayed arrival times.

• Journal of Internet Computing and Services
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• v.4 no.5
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• pp.77-86
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• 2003

This paper introduces the extension of SIP protocol for Multiparty Conference and the implementation of IP-based Multi-Conference. SIP protocol is a signaling protocol for initiating, modifying and terminating interactive sessions (voice, video, text, application). Multiparty conference system is implemented by RTP protocol for real time transmission and by H.323 for call setup. As H.323 fits into PSTN, it has some problems (call setup delay, hard implementation) for IP applications. IETF developed SIP protocol used for signaling in IP networks. However this SIP protocol doesn't explain signal protocol about multimedia conference, which is different from the existing H.323. So this paper describes the extension of SIP according to SIP Specification and case study for the multimedia conference.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.5
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• pp.605-614
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• 2005

In this paper, we present the design and implementation of an agent knowledge and QoS tuning methodology to improve the flexibility of agent-based flexible video-conference system. In order to improve the flexibility during video-conferencing, we propose a new T-INTER(Tuning-INTER) architecture of knowledge part in video-conference manager (VCM) agent in which an automatic QoS parameter tuning method is imbedded. The flexible video-conference system structured based on the proposed architecture can cope with the changes in service quality required by users. The VCM agent cooperates with other agents by protocols and executes the automatic QoS parameter tuning task whenever needed. By the tuned parameters, the system is able to flexibly cope with the internal or external changes and the burden of users can be decreased. In the experimental section, it is shown that our proposed system outperforms the existing system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.11
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• pp.2179-2184
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• 2007

The Intelligent Space(ISpace) provides challenging research fields for surveillance, human-computer interfacing, networked camera conferencing, industrial monitoring or service and training applications. ISpace is the space where many intelligent devices, such as computers and sensors, are distributed. According to the cooperation of many intelligent devices, the environment, it is very important that the system knows the location information to offer the useful services. In order to achieve these goals, we present a method for representing, tracking and human following by fusing distributed multiple vision systems in ISpace, with application to pedestrian tracking in a crowd. This paper described appearance based unknown object tracking with the distributed vision system in intelligent space. First, we discuss how object color information is obtained and how the color appearance based model is constructed from this data. Then, we discuss the global color model based on the local color information. The process of learning within global model and the experimental results are also presented.

• Journal of the Korea Society of Computer and Information
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• v.17 no.2
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• pp.177-185
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• 2012

In this paper, we developed the composition system that it can efficiently edit camera recording data, images, office document such as powerpoint data, MS word data etc in real-time and broadcasting system that the file is made by the composition system. In this Study, we developed two kinds of algorithm; Approximate Composition for Optimization (ACFO) and Sequence Composition using Memory Que (SCUMQ). Especially, the system is inexpensive and useful because the system is based on mobile devices and PCs when lectures hope to make video institutional contents. Therefore, it can be contributed for e-learning and m-learning. In addition, the system can be applied to various fields, different kinds of multimedia creation, remote conferencing, and e-commerce.

• Journal of the Korean Society of School Health
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• v.9 no.1
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• pp.31-41
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• 1996

School health promotion is related to reinforce on various roles of school health teachers including health instruction, health services, healthful school living. In this aspects, there would be necessory for qualified continous education proceed to activate roles of school health teachers. So the objectives of this study are first, to develop curriculum framework for inservice training of health school nurses, second, to descrive of curriculum objectives, third, to state of curriculum objectives and learning methods. There were used study methods as literature review, expert conferencing and workshop. Major results are as follows; 1. Curriculum framework for inservice training of health school nurses was constitute of major variables of health care model and direct services role of school health teacher such as health service, health instruction and healthful environment area. 2. The curriculum for health instruction were different from elementary school and middle school. 3. Time distribution for curriculum was composed of that health service is 12hours, health instruction is 96 hours and healthful environment is 12 hours. 4. The learning methods for inservice training were suggested to intensify positive attitude through the discussion and practical exercise. 5. The curriculum objectives were classified by total, area and a course of study and time summary table was suggested. In conclusion, the developed curriculum would be contribute to improve of practical ability for school health teachers. And to increase of inservice training effect, there should be operate in order to participate trainees activately and to be educate concurrently. Also, there are necessary for execute in series of the program such as standized text developing by course, evaluation index developing and instructor education etc.