• Proceedings of the Korea Contents Association Conference
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• 2006.05a
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• pp.189-192
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• 2006

An important application domain for online services is an interactive, multiplayer game. in recent, many increase of users that use on-line services through networks have caused a heavy load to the server. In this paper, we propose a MMORPG distributed game server using 2Layer-Virtual Cell. Our method provides more effective solution of MMORPG distributed game server for large numbers of users.

• Journal of Digital Contents Society
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• v.9 no.4
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• pp.533-541
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• 2008

In distributed mobile systems, the congestion control and disconnection problems are current major issues. This paper proposes a grouping-based fuzzy reference streaming method to improve the performance of systems supporting distributed mobile transactions. The proposed method resolves transaction requests issued by mobile clients using the GS interface. In the paper disconnection problems are resolved efficiently using transaction read and update for improved streaming service. Experimental results show that the proposed method outperforms the other existing methods significantly.

• International Journal of Contents
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• v.2 no.1
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• pp.39-44
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• 2006

Load sharing is a critical resource in computer system. In sender-initiated load sharing algorithms, the sender continues to send unnecessary request messages for load transfer until a receiver is found while the system load is heavy. Meanwhile, in the receiver initiated load sharing algorithms, the receiver continues to send an unnecessary request message for load acquisition until a sender is found while the system load is light. These unnecessary request messages result in inefficient communications, low CPU utilization, and low system throughput in distributed systems. To solve these problems, we propose a genetic algorithm based approach for improved sender-initiated and receiver-initiated load sharing in distributed systems. And we expand this algorithm to an adaptive load sharing algorithm. Compared with the conventional sender-initiated and receiver-initiated algorithms, the proposed algorithm decreases the response time and task processing time.

• Proceedings of the Korea Contents Association Conference
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• 2004.05a
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• pp.497-502
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• 2004

OCSP has specific characters which can suspend, close, and correct in real time. But, as more clients use the OCSP server verification, more updated information is needed, which can lead to jamming in the OCSP server. To apply this technique of Distributed OCSP server so as to reduce the certificate verification OCSP from jamming. Also, the Distributed OCSP server will solve the problems of the intensive central structure.

• Journal of Digital Contents Society
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• v.16 no.1
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• pp.123-126
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• 2015

This paper described fault tolerance system running on distributed multimedia. We implemented the error manager service so that the users participated in distribute multimedia collaborative work may refer synchronized error objects as the same view to others. distributed multimedia environment are based on IP-USN(Internet Protocol - Ubiquitous Sensor Network) and M2M(Machine to machine). This is a system that is suitable for detecting, sharing and recovering software error in distribute multimedia CSCW(Computer Supportes Cooperated Work) environment. With error synchronization system, a group cooperating users can synchronize error applications.

• Journal of Digital Contents Society
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• v.8 no.1
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• pp.27-33
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• 2007

Grid is a distributed computing model for next to the WWW computing model. Java language is developed for distributed computing and is being commonly used for WWW applications. Java can also be used for designing and implementing Grid systems. We introduced the basic concepts of Grid and implemented a new computing grid system. We test proper distributed applications on the multimedia grid system and analyzed the execution results. The execution results showed that the grid performance was much better than the legacy systems.

• Journal of Digital Contents Society
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• v.9 no.1
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• pp.125-130
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• 2008

User web service is increasing by development of internet technology. Quantity of encrypted data that transmitted through the network are increasing by development of encipherment technology. We have many problems; it is caused by technical development and service increase of user requests. It is like that, we have reliability of contents and illegality copy problem of internet contents in web application system. It is contents protection skills in web that encipherment technology, authentication and digital signature. We need message encoding and secret key for solve vulnerability of encipherment in web application system. In this paper, we propose a distributed secure system that can data confidentiality and user authentication. It prevent performance degradation from bottle neck in encipherment server, and improve service quality.

• The Journal of the Korea Contents Association
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• v.16 no.7
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• pp.667-680
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• 2016

As distributed computing platforms like Hadoop MapReduce have been developed, it is necessary to perform the conventional query processing techniques, which have been executed in a single computing machine, in distributed computing environments efficiently. Especially, studies on similarity join query processing in distributed computing environments have been done where similarity join means retrieving all data pairs with high similarity between given two data sets. But the existing similarity join query processing schemes for distributed computing environments have a problem of skewed computing load balance between clusters because they consider only the data transmission cost. In this paper, we propose Matrix-based Load-balancing Algorithm for efficient similarity join query processing in distributed computing environment. In order to uniform load balancing of clusters, the proposed algorithm estimates expected computing cost by using matrix and generates partitions based on the estimated cost. In addition, it can reduce computing loads by filtering out data which are not used in query processing in clusters. Finally, it is shown from our performance evaluation that the proposed algorithm is better on query processing performance than the existing one.

• The Journal of the Korea Contents Association
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• v.6 no.5
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• pp.113-121
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• 2006

As Internet evolves, web sites are becoming more and more complex, and it costs a lot of time and money to update web sites. The explosive growth of a large amount of content has resulted in an excessive server load and high network traffic, and thus it decreases the quality of service. In this research, we designed and implemented an integrated content management system which can be constructed and managed the content easily, and which is combined a merchant system with a personal information system based on the distributed content gathering and searching in order to optimize the utilization of the content itself.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.611-614
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• 2007

The IEEE 802.11 Task Group E has worked to enhance the legacy 802.11 MAC to expand support for applications with QoS requirements. EDCF(Enhanced Distributed Coordination Function) of IEEE 802.11e is enhanced from DCF(Distributed Coordination Function) of 802.11 and It has differential AC(Access Category). In this paper, we change parameters(AIFS, CWmax) and make an analysis of network performance. We use NS-2 to verify change of network performance.