• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1677-1680
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• 2003

In this paper, we propose the multimedia tutoring system that provides multimedia learning contents for english Loaming on mobile environment. In order to design and implement the system, we have developed mobile multimedia contents from contents modeling based on the types of item, but also mobile interface to provide learning contents for learners effectively under limitation of mobile environment. The contents server in this system creates multimedia learning contents as XML document for each learner and provides those to learners through mobile interface using Wireless Application Protocol at anytime and anyplace.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.577-580
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• 2006

The rapidly growth of Internet is main factor that activates the Digital Contents market. However imprudent Digital Contents market could be shrunk by imprudent illegal copy and delivery. MPEG(Moving Picture Experts Group) proposed MPEG-21 Multimedia frameworks in order to solve these problem. IPMP is parts of MPEG-21 Multimedia Frameworks, when Digital Contents goes through production delivery consumption, which defines standard to keep the Digital Contents in safety. Currently IPMP defined by FCD(Final Committee Draft) level. Therefore development of system which applied to latest standard to protect and manage the Digital Contents is required. and the system consists of fourth organizations which means Metadata Production server, Tool server, License server, Consumption server. In this Paper, we made production server to parse REL(Rights Expression Language) document that has right information for content from license server, and create metadata based on MPEG-21 IPMP about the content that applied to watermark. then, after it do remuxing, transmit the protected data to consumption server.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.808-810
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• 2005

본 논문은 공개소스 기반의 WAS 구성의 핵심인 Tomcat, JBoss, PostgreSQL, Apache 등을 한국형 공개SW 표준 플랫폼 BOOYO 상에 효과적으로 탑재하고 SPECjAppServer2004 벤치마크를 실시하여 외산 제품과 성능을 비교 한다. 벤치마크 결과 부하가 증가할수록 성능 측정단위인 JOPS가 기존의 공개SW플랫폼에 비하여 현저히 덜 하락하는 결과를 보이며 비교적 우수한 결과를 나타내었다. 본 논문에서는 이러한 벤치마크를 실시하기 위하여 구축한 시험용 WAS의 구성 내용과 아울러 그 결과를 보다 상세히 기술한다.

• Journal of Korea Multimedia Society
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• v.18 no.5
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• pp.620-630
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• 2015

This research suggests a load balancing method for a volume rendering system which supports concurrent users. When concurrent users use a volume rendering server system, the computational resources are occupied by a particular user by turns because each process consumes the computational resources as much as possible. In this case, the previous method shows acceptable throughput but the latency is increased for each user. In this research, we suggest a method to improve the latency without performance degradation. Each process makes concessions for taking the resources according to the number of users connected to the system. And we propose a load balancing method in the dynamic situation in which the number of users can vary. Using our methods, we can improve the latency time for each user.

• Journal of Internet Computing and Services
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• v.2 no.5
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• pp.93-104
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• 2001

In this paper. we analyze networks in accordance with topology which consists of ATM-LAN in order to enhance performance in multimedia environment, We analyze job processing time of Email, FTP and Http server for variance of node in star, ring and mesh topology, We analyze a load factor of Email, FTP and Http server and variance of sending/receiving rate for various topology, We examined that the constituent networks in this paper can minimize load of server in any other topology.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.503-505
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• 2006

In this paper we introduce a design and implementation of an agent for multimedia retrieval and personalized broadcasting service. It is compliant with TV Anytime Forum specifications and supports searching location resolving, storing and streaming of remote multimedia contents. For this service, we implemented a contents server, a 메타데이터 database server, a location resolution server and a client terminal is implemented The Client terminal gathers content information by SOAP of operation, and it has a user preference module and usage history module that make user information. The personalize service agent recommends suitable contents to user by similarity algorithm.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.624-629
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• 2007

Digital Multimedia Broadcasting (DMB) is a digital radio transmission system for sending multimedia such as radio, TV, and data casting to mobile devices. Nowadays, DMB specifications are the major standard for digital broadcasting and have been establishing for bidirectional service using MPEG-4 system. But there has been only some simple demonstrated system for this bidirectional services. In this paper, we introduce bidirectional DMB data service system that provides the interaction between the user and DMB server without any additional equipment such as web server. The proposed bidirectional DMB system can capture and send user interaction information and response through the existing DMB transmission channel, finally update the original contents. The action event from the user is the most important thing in developing the bidirectional DMB system. Therefor, capturing the event data from the user is the first step we need to do for the bidirectional DMB service. In this paper, we propose an interaction manager module for the user events. This system will extract the user events and make a plan to update the original scene with the server's reaction information.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.3
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• pp.171-179
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• 2014

Among the P2P based multimedia streaming architecture, multiple chain architecture has advantage in adapting to dynamically changing network topology simply and rapidly, so this architecture is used for UCC broadcasting system. In UCC broadcasting system, general peer involved in DSLAM becomes UCC server rather than broadcasting system that transfers data from ISP servers. Therefore UCC data generated from UCC server peers is transmitted to peers through DSLAM, and this transmission uses uplink bandwidth of DSLAM. In this paper, I propose an efficient management method of DSLAM uplink bandwidths through negotiating tracker and UCC server peer or head peers of DSLAM. I propose the method that tracker restricts a bitrate of uplink stream of UCC servers when used uplink bandwidth of DSLAM exceeds a certain point of maximum uplink bandwidths. I will show the improved performance of proposed scheme rather than general method with respect to the uplink bandwidth of DSLAM by numerical analysis and simulation.

• Journal of Communications and Networks
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• v.9 no.1
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• pp.43-49
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• 2007

The implementation of client polling as a weak cache coherence mechanism has two major drawbacks: Firstly, the cache may return a stale copy if the object is changed in the origin server while the cached copy is considered valid. Secondly, the cache can invalidate a cached copy that is still valid in the server. Therefore, we propose a multilevel pre-fetching (MLP) in conjunction with the client polling to refine these drawbacks. MLP is introduced to improve the level of freshness among the cached objects. The simulation results presented in this paper show that the proposed MLP significantly minimizes the number of stale objects and reduces the invalidation messages sent out to the server, i.e., increase the cache HIT rate.

• Journal of Korea Multimedia Society
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• v.25 no.8
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• pp.1136-1140
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• 2022

This paper is a method for efficient traffic prediction in mobile edge computing, where many studies have recently been conducted. For distributed processing in mobile edge computing, tasks offloading from each mobile edge must be processed within the limited computing power of the edge. As a result, in the mobile nodes, it is necessary to efficiently select the surrounding edge server in consideration of performance dynamically. This paper aims to suggest the efficient clustering method by selecting edges in a cloud environment and predicting mobile traffic. Then, our dynamic clustering method is to reduce offloading overload to the edge server when offloading required by mobile terminals affects the performance of the edge server compared with the existing offloading schemes.