• Journal of Korea Multimedia Society
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• v.6 no.2
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• pp.340-351
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• 2003

We introduce our experiences of the design and implementation of the Page Together system that has expanded hyperlink metaphor to utilize human resources in the web. This system supports that a user connects with others in the web, communicates through video/audio channel, navigates same web pages simultaneously and cooperates some work on Internet. For these functions, it comprises Collaborative Browsing Module (CBM), Multimedia Conferencing Module(MCM) Data Conferencing Module(I)CM) and Multi Protocol Interface(MPI). We adopted three standard protocols, IEC, H.323 and T.120 for each nodule and it allows developers to use them easily. We also defined MPI to synchronize information of session among modules. Each module exchanges information each other in session creating process and session terminating process. After a session is created once, each module works independently as its won protocol. Interferences among modules are reduced as minimizing to exchange information. We also introduce a web site that provides web board service based on the Page Together system. A user may post a notice with a link to himself/herself on our web board. After then, if someone read that notice and has any question about it, he or she can try to connect to the writer as clicking the link in that notice and communicate each other. This service site shows that our system can be applied to diverse internet services such as distance teaming and distance conference.

• Journal of Korea Multimedia Society
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• v.7 no.8
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• pp.1097-1106
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• 2004

The typical web cluster architecture consists of replicated real servers and a virtual server that routes client requests among the real servers. In this paper, we proposed an efficient dynamic load distribution method with load prediction for the web cluster systems. The virtual server transmit status request message to real servers in other to get load states. However the load states dose not accurate during load distribution, thus the virtual server predict the load status of real servers and assign a request of the client to the minimum loaded real server. The proposed distribution methods works not related to partial breakdown of real servers, thus the system works with high availability. We also show that the proposed distribution method preserve scalable property and improve the throughput through a set of simulations.

• Journal of Korea Multimedia Society
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• v.12 no.9
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• pp.1323-1332
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• 2009

In this paper, we analyze security weakness of 4-Way Handshake in IEEE 802.11i and propose fast and secure 2-Way Handshake mechanism. Compute PTK(Pairwise Transient Key) using sequence number instead of random numbers in order to protect Replay attack and DoS attack. Also, proposed 2-Way Handshake mechanism can mutual authenticate between mobile station and access point and derive PTK using modified Re-association Request and Re-association Response frames. And, compare with others which are fast and secure Handoff mechanisms.

• Journal of Korea Multimedia Society
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• v.11 no.7
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• pp.977-985
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• 2008

This paper is concerned with automatic telemetering system which reads the consumed quantity of electricity, gas, and piped water. The existing metering method such that a meterman visits households and directly reads meters can cause several problems, including violation of privacy and the possibility of criminal accident, as well the inefficiency in viewpoint of system operation and rate notification. In this paper, we propose a new automatic telemetering and rate notification system, in which the system reads several meters at remote locations and notifies the rates to the customer's cellular phone with short message service(SMS). The proposed system has been developed by using CDMA mobile communication modules and personal computers. This system can operate only with cellular communication network even without wired-internet facilities. In particular, the developed system can provide home security and convenience as well as cost reduction, and thus be applied to intelligent home networks.

• Proceedings of the Korea Contents Association Conference
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• 2004.05a
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• pp.342-347
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• 2004

The VoIP(Voice over Internet Protocol) technology which is able to use a voice service through internet is more cheaper then existing telephone charges, and is easily accept the various of multimedia services from internet. Previous connection method of VoIP used H.323 protocol, but it is very complex to connection establishment. so, the SIP(Session Initiation Protocol) protocol that propose in SIP-Working Group Is in use recently. Therefore, we need new interworking methodology between H.323 and SW products. In this thesis, the progress interworking method between H.323 and SIP are propose, then interpret unnecessary packet delay for call setup and improved feature of message exchange.

• Journal of Broadcast Engineering
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• v.10 no.2
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• pp.190-201
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• 2005

MPEG-21 has identified the need fur Event Reporting in its vision for an interoperable multimedia framework. Event Reporting is required within the MPEG-21 multimedia framework in order to provide a standardized means for sharing information about Events amongst Peers and Users. Such Events relate to Digital Items and/or Peers that interact with them. Arising from an each Event, there is the opportunity to describe what occurred. However, there are a number of difficulties in providing an accurate report about an Event. Different observers of the Event may have vastly different perspectives, needs, and focuses. They may emphasize certain elements to the detriment of others, or they may describe an Event in a way that others may find confusing. In this paper, we design how to express Event Reporting message structure and system architecture in compliance with ISO/IEC 21000-15. And we implement the system for MPEG-21 Event Reporting service.

• Journal of Korea Multimedia Society
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• v.16 no.3
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• pp.342-353
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• 2013

The Internet has become a part of our lives. As the number of devices with Internet accessibility increases, users can use web services with those devices anytime, anywhere. Web contents on the web page can be delivered to user in various forms for various devices and users want to use seamlessly the contents with an appropriate device. Web browser extension is function to add features that are not supported by default browser. All browsers support extensions that provide the same services for cross-browser. In this paper, We proposed object migration architecture between heterogeneous browsers by expanding our proposed mechanism that identifies objects and the information of those objects to be migrated in the web page, extracts the object and creates object after migration. For this purpose, we analyzed the extension architecture of representative browsers and investigated necessary files to develop objects migration extension. In addition, We investigated how to send and receive message among files in each browser extension and the interaction mechanism among those files. Finally, We implemented the object migration mechanisms between heterogeneous browsers.

• Journal of the Korea Computer Industry Society
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• v.5 no.9
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• pp.1017-1024
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• 2004

In this paper, we propose the progressed interworking method between H.323 and SlP, then explain the improved property. The VolP(Voice over Internet Protocol) technology which is able to use a voice service through internet is more cheaper then existing telephone charges, and is easil)· accept the various of multimedia services from internet. Previous connectionmethod of VoIP used H.323 protocol, but it is very complex to connection establishment. so, the SIP(Session Initiation Protocol) protocol that propose in SIP-Working Group is in use recently. Therefore, we need new interworking methodology between H.323 and SIP Products. In this thesis, the progress interworking method between H.323 and SIP are Propose, then interpret unnecessary packet delay for call setup and improved feature of message exchange.

• The KIPS Transactions:PartC
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• v.16C no.4
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• pp.527-534
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• 2009

Almost every mobile phone supports MMS to send and receive multimedia messages among users. MMS is suitable for different types of mobile phones and effectively operates in wireless environments. So the mobile content delivery method using MMS can be efficient. However, there would be some problems if a mobile service provider tries to deliver mobile content to subscribers by using the existing MMS. In this paper, we propose an improved data transmission and control scheme for MMS. Our scheme assists mobile service providers to deliver mobile contents easily by modifying the MMS system software. By using our scheme, mobile service providers are able to manage mobile contents stored in mobile devices. Therefore, they can provide various services such as mobile daily news service, automatic software upgrade service, mobile advertising service, etc. We verify the possibility of the proposed scheme through simulation.

• The KIPS Transactions:PartA
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• v.14A no.5
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• pp.295-300
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• 2007

The Linux-based embedded systems such as mobile telephones. PDAs and MP3 players are widely in use. USB(Universal Serial Bus) is the interface for data communication between the computers and these peripheral devices. Some embedded systems like intelligent home networking and multimedia streaming require guaranteed QoS(Quality of Service), which is needed for real time transmission of UDP/IP messages through USB. Although USB Ethernet driver is supported by USB Gadget API in Linux, it is unable to provide the desirable QoS required by each type or small embedded systems due to the unpredictability or TCP/IP Stack in Linux. This paper proposes IP-Over-USB to improve QoS of UDP/IP message transmission in the embedded systems using USB in Linux system.