• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.7
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• pp.1361-1373
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• 2001

In the firewall systems of 3-tier client/server systems, in general, data transmission speed is declined rapidly according to the duplicated proxy services in application server and fire wall server. In this paper, an application server configuration containing the proxy functions of firewall system is proposed so that the high speed data transmission can be achieved. The proposed application server can form the dual-homed gateway by means of the additional network interface card. The screened router of application server forms the screened subnet gateway that can separate the internal network. The proposed server configuration is more effective in traffic control than the traditional firewall systems and provides high speed data transmission with the functions of firewall. It can be also cost-effective alternative to the firewall system.

• Journal of Information Processing Systems
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• v.2 no.2
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• pp.130-134
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• 2006

In the distributed replicating server model, the provision of replicated services will improve the performance of the providing service and efficiency for clients. Efficiently composing the server selection algorithm decreases the retrieval time for replicated data. In this paper, we define the system model that selects and connects the replicated server that provides an optimal service using the server-side downstream measurement and propose a server selection algorithm.

• Proceedings of the Korea Database Society Conference
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• 1999.06a
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• pp.95-102
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• 1999

The web-based group collaborative systems are emerging as enterprise-wide information systems. Since data in group collaborative systems are apt to be shared among multiple concurrent users and modified simutaneously by them, the web-based group collaborative systems must support synchronous collaboration in order to provide users with synchronized and consistent views of shared data. This Paper proposes an active web server which can facilitate synchronous collaboration in web-based group collaborative systems. To accomplish such a goal, the active web server manages dependency relationships between shared data and web browsers referencing them and actively propagates changing details of the shared data to all web browsers referencing them. And, this paper examines usefullness and effectiveness of the active web server to apply it to the ball-bearing design example of concurrent engineering design systems. The prototype system of the active web server is developed on a commercial Object-oriented Database Management System (ODBMS) called OBJECTSTORE using the C＋＋ programming language.

• Journal of the Korean Data and Information Science Society
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• v.17 no.1
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• pp.13-18
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• 2006

The purpose of this paper is to identify optimal designs of server port connections between two server system for 200-300 user group. Given 3 empirical models as user and port parallel server types under some conditions of 100 Mbps and optimal CPU temperature suggested by Lee and Kim(2005), our results are shown; port parallel model was optimal when traffic processing times measured, and 250 traffics was jumping point as a critical point in our cases.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.619-621
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• 2013

This paper is proposing a real-time audio processing system for TCP/IP with server-client. The server sends the audio data packet which is the same size each time while playing the audio data. And the client plays the received audio data from the server. In general, The receiving speed of audio data packet is faster than processing the audio data. So, the unstable playback is occurred when playing the received audio data at the moment. In order to overcome this problem, the double buffering method is proposed.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.465-468
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• 2002

Today large corporations are constructing distributed server environment. Many corporations are respectively operating Web server, FTP server, Mail server and DB server on heterogeneous operation. However, there is the problem that a manager must manage each server individually. In this paper, we present distributed FTP server for log mining system on ACE. Proposed log mining system is based upon ACE (Adaptive Communication Environment) framework and data mining techniques. This system provides a united operation with distributed FTP server.

• Journal of Intelligence and Information Systems
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• v.4 no.2
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• pp.129-139
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• 1998

통계 software에는 data mining에 필요한 다양한 모형과 함수들이 제공되고 있어 이를 이용한 data mining 도구가 소개되고 있다. 본 논문에서는 data mining을 수행하는데 효과적인 환경을 제공하는 S-Plus로 data mining 기법들을 구현하거나 재구성하였으며, StatServer를 이용하여 대용량의 data base를 직접 관리할 수 있게 하고, S-PLUS의 분석기능을 Internet을 통하여 사용할 수 있게 하여 원거리에서 data mining작업을 수행될 수 있도록 구성하였다. 또한 분석자는 찾아낸 모형을 복잡한 프로그래밍 작업 없이 새로운 웹 페이지를 만들 수 있으며, 이를 통해 운영계의 사용자가 최적 모형이 제시하는 결과를 실제 업무에 즉시 이용할 수 있도록 하였다.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.606-608
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• 2005

In this paper, we introduce localization server system calculated real location of objects using raw data of location-awareness from sensor node gateway. The software architecture of localization server system consists of location calculation and actuator control based on location. Also, this system supports for collecting raw data, calculating location of real objects using raw data, correcting error from outer environment, and server for applications based on location.

• 대한공업교육학회지
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• v.33 no.1
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• pp.265-281
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• 2008

The objective of this study is to show practice example let student experience about concurrent servers based multi-processes and multi-thread among the principles of data communication in ICT(information and communications technology). For this, we first implement multi-process server(fork server) and multi-thread server(thread server), and multi-thread client(thread client), Secondly, for experimental environment, we developed small ethernet networks and measure data transfer time with relation to the number of users. Experimental results show that mean transfer time of thread server is less than that of fork server by 20~61 % on average. Furthermore, it is found that the difference of data transfer time between fork server and thread server is proportional to that of the number of users. Main reason of performance difference dues to the difference between process forking time and thread creation time. We can also find that context switching for process and thread affects the load of web server. Our presentation and experimental results can be applied to used as the educational practice materials with which student can experience data communication principles.

• Proceedings of the IEEK Conference
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• 2003.11b
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• pp.231-234
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• 2003

This paper designs and implements fault-tolerant server of meta server for shared filesystem (SANfs) in SAN environment. SANfs is the filesystem that many clients can share data in Network-attached storage in SAN environment and meta server is the server that processes file operation in SANfs. The focus of this paper is the implementation of fault-tolerant server of meta server in SANfs. In the event of a meta server, meta server failovers to a fault-tolerant server where its processing continues seamlessly. If meta server doesn't restore, fault-tolerant server searches reliable client and makes another fault-tolerant server and work as meta server. Heartbeat monitors meta server and shadow server and controls them.