• Proceedings of the IEEK Conference
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• 2002.06c
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• pp.75-78
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• 2002

In this paper, we present the design and implementation of a Fault Tolerant VOD system. The system uses the double striping policy that a original file is sequentially striped to multiple streaming server with constant data block size and the data block of one streaming server is re-striped to the other streaming server. When a fault occurs in one streaming server, automatically the other streaming server will service.

• Proceedings of the IEEK Conference
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• 2003.11b
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• pp.73-76
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• 2003

Current web-server deals a multimedia data as well as text data. But dealing a multimedia data is high burden to web-server. So it can degrade web-server response. We introduce H/W feature CDA (Contents Delivery Accelerator). Main function of this H/W is transferring data between SCSI disk and NIC by direct path, and TCP offloading. These 2 functions can accelerate web-server performance. In this paper we will explain problem of current web-server and suggest our new architecture and say various implementation issues.

• Proceedings of the Korea Multimedia Society Conference
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• 2000.11a
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• pp.31-36
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• 2000

인터넷의 서비스개선으로 사용자의 수는 기하급수적으로 늘어나고 있으며, 이러한 경향에 발맞추어 홈페이지의 수도 날로 늘어가고 있는 추세이다. 홈페이지를 만드는데 있어서 필수적인 것이 바로 Web Server라고 한 수 있으며, 현재 Web Server에 대한 연구가 계속되고 있는 추세이다. 본 논문에서는 현재 사용되고 있는 Web Server보다 좀더 개선된 Server 시스템을 제안하였으며, 이 Server 시스템은 OS에 독립적일 뿐만 아니라 사용자에 대한 서비스 시간과 사용 자원을 줄일 수 있다.

• Journal of the Korea Computer Industry Society
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• v.5 no.9
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• pp.1063-1068
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• 2004

A log file in web server stores various information of web server. The web server information is good reference information to improve web service quality. Also if web server occurs any fault, log file information is important information to find out occurred error. Currently, many of web server manager that they have wire have disadvantages in mobility. In order to solve above problem, this paper represent web server manager based mobile. Incase web server manager based mobile, it can immediately know recent log information accessing real-rime as also anytime, anywhere

• Journal of the Korean Operations Research and Management Science Society
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• v.18 no.3
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• pp.51-63
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• 1993

We consider a cyclid server system under N-policy. This system consists of multiple queues served in a cyclic order by a single server. In this paper, we consider the following control policy. Every time server polls one queue, the server inspects the state of the queue. If the total number of units is found to have reached or exceeded a pre-specified value, the server begins to serve the queue until it is empty. As soon as the queue becomes empty, the server polls next queue. An approximate analysis of this system is presented. Sever vacation model is used as an analytical tool. However, server vacation periods are considered to be dependent on the service times of respective queues. The results obtained from the approximate analysis are ompared with simulation results.

• Journal of Korea Game Society
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• v.2 no.2
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• pp.20-27
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• 2002

In this paper, I tried to propose efficient online game server architecture that decrease server overload. I used replicated distributed sever type together with non-replicated distributed sever type. Replicated distributed sever type has the advantage to maintain efficient distribution of server overload and non-replicated distributed sever type has the advantage to move a game server to a different game server freely in one server group. I used these advantages suitably in this proposal, and I will show the efficiency of online game server architecture.

• Journal of the Korea Society of Computer and Information
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• v.23 no.9
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• pp.73-80
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• 2018

In this paper, we propose a new type of client server environment to improve the architecture vulnerable to hacking in an existing client server environment. On the server side, move the existing Web server to the client side and This is a way for clients to communicate only the data they need and suggests a structure that completely blocks the web attack itself to the server. This can completely prevent a server from being hacked, spreading malicious code and hacking data on a server. It also presents a new paradigm that will not affect servers even if malware is infected with client PCs. This paper validates the proposed environment through BBS (Big Bad Stick) hardware in the form of USB on the client side. This study proof that secure services are provided through encryption communication with server-side security equipment, indicating that this study is a system with new security.

• Korean Journal of Remote Sensing
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• v.31 no.5
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• pp.491-499
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• 2015

In developed countries such as USA and Europe, agricultural monitoring system is developed and utilized in various fields in order to predict crop yield, observe weather conditions and anomaly, categorize crop fields, and calculate areas for each crop. These system is Web Map Service(WMS) which utilizes open source and commercial softwares, and various information collected from remote sensing data are provided. This study will utilize tools such as GeoServer, ArcGIS Server, which are widely used to monitor agricultural production, to publish Map Server and Web Application Server. This enables performance test study for future agricultural production monitoring system by making use of response time and data transfer test. When tested in identical condition GeoServer showed a better result in response time and data transfer for performance test.

• Journal of the Korea Society for Simulation
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• v.18 no.3
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• pp.61-71
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• 2009

The server redirection system replicates contents on replica servers in the distributed network environment. When users make a request for contents, the system can provide the contents much faster than the client-server network system. In the server redirection system, it is the most important to select the optimal replica server with user's information because many replica servers are geographically distributed. And, the system can serve contents to users flexibly if a redirector is well constructed. In this paper, the redirector makes a list of candidates suitable for user conditions by the decision tree method and calculates the availability of each replica server. And, the redirector selects the replica server with the highest availability. This paper also proposes an availability-based server redirection system that predicts the availability of each replica server in order to reduce the workload of replica servers and the repetitive communication messages between a redirector and replica servers. If a user accesses the network path for the replica server selected and noticed by the proposed system, the user can get contents effectively and efficiently.

• Convergence Security Journal
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• v.4 no.3
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• pp.19-25
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• 2004

This research develops an algorithm using image synthesis for a server to authenticate users and implements it. The server creates cards with random dots for users and distribute them to users. The server also manages information of the cards distributed to users. When there is an authentication request from a user, the server creates a server card based on information of the user' s card in real time and send it to the user. Different server card is generated for each authentication. Thus, the server card plays a role of one-time password challenge. The user overlaps his/her card with the server card and read an image(eg. a number with four digits) made up from them and inputs the image to the system. This is the authentication process. Keeping security level high, this paper proposes a technique to generate the image clearly and implements it.