• 정보과학회 논문지
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• 제43권9호
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• pp.1052-1059
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• 2016

클라우드 컴퓨팅 시스템의 주요 역할은 신뢰받지 않은 클라우드 서버의 데이터베이스 실행이 키 관리의 복잡성을 요구하기 때문에 중요한 이슈가 되고 있다. 본 연구는 키 실행을 최소화하는 셀프 프락시 서버를 사용한 키 관리 시스템을 제안하고, 사용자가 암호화된 데이터베이스에 질의할 때 데이터 소유자가 관련키에 직접적으로 관여하지 않는 셀프 생성 알고리즘을 생성하여 클라우드 서비스 성능을 개선한다. 셀프 프락시 서버는 클라우드 키 서버에 문제가 발생했을 때와 효율적인 클라우드 키 관리를 위하여, 이를 대신한 분산 서버로서 능동적이고 자율적인 키 관리를 지원한다. 따라서 제안한 키 관리 시스템은 클라우드 서버 데이터베이스의 기밀성 지원으로 안전한 클라우드 서비스를 제공한다.

• 한국정보통신학회논문지
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• 제10권6호
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• pp.1106-1118
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• 2006

인터넷은 우리에게 많은 정보를 제공해 주는 중요한 수단이 되었다. 그리고 정보 제공을 위해 인터넷의 서버 시스템들은 대용량의 정보를 처리하여 다양한 서비스를 제공함과 동시에 이들의 네트워크 구조는 더욱 더 복잡해지고 있다. 따라서 서버 시스템들에 대한 신속하고 지속적인 관리가 중요시 되고 있다. 그러나 대부분의 서버 시스템들은 방화벽 내부에 위치하여 제한된 접근만을 허용하며 또한 각 서버 시스템들의 서로 다른 운영체제와 서로 다른 관리 방법으로 인해 효율적인 서버 시스템 관리가 이루어지고 있지 않다. 즉 서버 관리자들은 제한된 공간에서 로컬 또는 소켓 기반의 단일 접속 애플리케이션을 이용하여 다양한 형태의 서버들을 직접 관리해야만 한다. 따라서 본 논문은 CORBA, Java RMI, DCOM등의 분산 객체 기술을 가지면서 플랫폼이나 개발언어에 제약을 받지 않는 XML(extensible Markup Language) 기반의 웹서비스 기술(Web Services Architecture)을 이용하여 다수의 서버 시스템들을 통합적으로 관리 할 수 있는 미들웨어 시스템을 설계하고 구현하였다. 시스템은 위치 투명성 및 단말기 독립성을 제공하며 서버 시스템 관리 명령을 호출하여 시스템 관리가 가능하다.

• Journal of Information Technology Applications and Management
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• 제14권4호
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• pp.31-41
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• 2007

In order to keep global competitiveness, most of small and medium size manufacturing companies require to equip a product information management system which collects and analyzes the data generated at the manufacturing lines and then provides information for manager or worker to make a decision. However, these companies have a cost problem for adopting the enterprise resource planning system mostly used in large companies. To overcome this problem, we suggest an IOCP-based server for the product information management system suitable for small and medium size manufacturing companies. The basic concept of suggested server is that it is possible to process concurrently the connection requests coming from data collector and client by using the facility of asynchronous notification of OS and protect a server against overload by using the thread pool.

• 한국정보통신학회논문지
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• 제8권2호
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• pp.394-406
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• 2004

웹 서버에서 제공하는 문서 자원들은 URL/URI 형식으로 표현되고 있지만, 동적인 서버 환경의 변화로 인해 반드시 해당 자원이 서버에 존재하고 있는 것을 보장할 수 없다. 따라서 본 논문에서는 자원에 대한 신뢰성을 보장하고, 동적인 서버 자원 관리 및 클라이언트의 요청을 처리하기 위해 XML-RPC를 이용한 통합문서 관리 시스템을 제안하고 모델링 한다. 제안한 시스템은 동적인 서버 자원을 관리하는 미들웨어 시스템과 클라이언트가 서버에 저장시킨 문서에 대한 갱신 정보를 서버에서 미들웨어 시스템으로 통보하는 서버시스템으로 구성된다. 모델링 결과, 분산된 서버에 있는 동적으로 변하는 문서들을 효과적으로 저장 관리할 수 있었으며, 현재 운영되고 있는 웹 서버에 적용시킬 수 있어 새로운 웹 서버 구축비용을 절감할 수 있고, XML-RPC 프로토콜을 사용하기 때문에 플랫폼 독립적이고 또한 데이터 관리가 효율적임을 알 수 있었다.

• 디지털산업정보학회논문지
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• 제6권4호
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• pp.95-105
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• 2010

DNS(Domain Name System) is a huge distributed database that converts host name to IP address. We are expecting the importance of DNS is more increased because many Internet application services appear according to the continuous increase of Internet users and nearly all the Internet application services use DNS. To prevent the interruption of DNS service, DNS server is configured with primary DNS server and a secondary DNS server which takes the place of primary DNS server in case of the service interruption. But this scheme is difficult for providing DNS service constantly in case of DDoS attack, which brings about much network load or network problems in DNS server group. Therefore, This paper proposed the scheme to locally distribute load of DNS server, and the use of address system to group the distributed DNS servers. Also, it proposed the authentication scheme of the correspondent server in case the server is changed in DNS server group having grouping address. In this paper, it is shown that the prosed scheme guarantees the improved service reliability with maintaining the present service performance through the evaluation. Through this, we can expect the high improved DNS service can be provided in the Internet environment in the future.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2008년도 정기 학술대회
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• pp.458-463
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• 2008

An IFC Server is a database management system that stores data complying with a standard data format, called IFC, and keeps track of data transactions, modifications, and deletions. It plays a role as an information hub for storing and sharing information between various parties involved in construction projects. There have been several efforts to develop an IFC Server, however, they suffered from slow performance and long transaction time due to a complex mapping process between IFC files and relational database structures. In this study, we aim to develop an IFC Server using an object-relational database system. Since IFC has an object-flavored data structure, we expect to have a simpler and faster mapping process from IFC to the IFC Server. This paper reviews existing studies and describes the overall framework of the OR-IFC Server.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(3)
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• pp.233-236
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• 2001

When we execute a online game in the network, a lots of game informations and user informations are transfered between game server and game clients. This information has deferent data structure and communication protocol. So, game developers will be design the communication protocols and packet structures after analyze the game. And, they will be design the database for user management. It will be lots of overload to the game developers. From a user point of view, they must be register to each game server to use several games. It is a undesible operation for the game users. This problems are solved by using the communication server which operates commonly with several game servers. Game providers can get the benefit of multiple access of users and get freedom from user management. Game users can access the several games which connected to communication server by register the communication server only. In this paper we design the communication packet and propose a communication protocol which operates on the communication server described previous.

• 한국디지털정책학회:학술대회논문집
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• 한국디지털정책학회 2004년도 International Conference on Digital Policy & Management
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• pp.211-219
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• 2004

Due to rapid increases in Internet users, it becomes essential to provide well-established web services and monitor web server's load for the sake of reliable web server management. The existing web server load monitoring has been based on such cable methods as RPC, RMI, CORBA and etc. But it has the limitation in bringing information both anywhere and anytime over the Internet. This thesis is aimed to realize real-time wireless web server monitoring system based on Wireless Application Protocol (WAP). As any user can log on wirelessly to the Internet at any time through wireless terminals like PDA, the realization will make possible instant and real-time web server monitoring.

• 경영과학
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• 제19권1호
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• pp.29-38
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• 2002

Due to the rapid increase In the Internet traffic volume, ISPs are faced with the definite need of the expansion of server capacity. In order to Provide prompt services for customers and still prevent excessive facility cost, it is critical to determine the optimum level of internet server capacity. The purpose of this Paper is to provide a simple but effective strategy on the expansion of servers capacity according to the increase in internet traffic. We model an internet server as an M/G/m/m queueing system and derive an efficient method to compute the loss probability which, In turn, Is used as a basis to determine proper server capacity. The Process of estimating the traffic parameter values at each server based on log data analysis is also given. All the procedures are numerically demonstrated through the process of analyzing actual log data collected from a game company.

• 한국시뮬레이션학회논문지
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• 제13권1호
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• pp.41-50
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• 2004

The purpose of this paper is to analyse the manager's policy to maximize the profit in a multiple-server queueing facility with a limited queue capacity. We assume that the level of advertizing effects on the arrival rate of customers to the facility. The model without ‘word of mouth effect’ is assumed that the arrival rate is independent on the qualify of service level. We estimate the service quality by the balking rate of customers from system. We extend this to the model with ‘word of mouth effect’. To achieve the maximum profit, the most important factor is the considerably high utilization of facility for both models. Given service rate, we should maintain an effective arrival rate to some extent. To this end, among the available options, an increase of advertizing effort is more desirable than reducing the fee if the service value of customers remains unchanged. We also investigate whether the variability of service time has a significant impact on determining the optimal policy. The cost of service variability is not so expensive as that in a single server model due to the reduced variability of service times in a multiple-server model.