• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 학술대회 논문집 정보 및 제어부문
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• pp.405-406
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• 2008

To maintain reliable and stable power grid the Power Dispatch Center consists of two sections, primary and backup centers. It is necessary that the Backup Dispatch Center stay away from the primary center in case of emergency like terror and natural disaster. The Backup Dispatch Center operates transmission lines outside of Seoul metropolitan area and could perform main center's role when primary center lose control Without building a duplex Power IT system, it would be doubtful to operate both centers efficiently. This paper deals with primary and backup Power IT systems which run two Dispatch Centers and focuses on expectation effects of its duplex system and transferring the Backup system.

• Journal of Information Technology Applications and Management
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• 제10권1호
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• pp.71-89
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• 2003

This paper firstly introduces a classification model for designing the architecture of backup centers in terms of business continuity management. We propose that the replication solution, the level of disaster recovery, and the outsourcing style as three important factors that help explain the architecture of backup centers. We provide the details of each factor of the model and apply them to the real world cases of backup centers in Korea. We conclude that the model is well fitted to many cases of currently available backup centers and can provide backup center architects with a well classified architecture model with specific guidelines.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권12호
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• pp.5116-5134
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• 2015

In this paper, due to the network security defense is mainly static defense, a dynamic classification network security defense strategy model is proposed by analyzing the security situation of complex computer network. According to the network security impact parameters, eight security elements and classification standard are obtained. At the same time, the dynamic classification algorithm based on fuzzy theory is also presented. The experimental analysis results show that the proposed model and algorithm are feasible and effective. The model is a good way to solve a safety problem that the static defense cannot cope with tactics and lack of dynamic change.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제9권4호
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• pp.455-469
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• 2003

최근 SAN과 NAS 같은 기술의 발전과 함께 대용량의 데이타를 효과적으로 백업하기 위한 요구들이 증가되고 있다. 본 논문에서는 네트웍 기반의 백업을 위해 제안된 개방형 표준 프로토콜인 NDMP를 이용하여 SAN 환경에 적합한 백업 소프트웨어를 설계하고 구현한다. 제안하는 백업 소프트웨어는 SAN을 기반으로 한 LAN-free 백업을 지원한다. 또한 사용자의 스케줄링에 의한 자동 백업과 다양한 유형의 백업 및 복구 타입을 지원한다. 파일 시스템, 원시 장치 그리고 데이타베이스에 대한 백업 및 복구를 수행한다. 향후 제안하는 백업 소프트웨어는 백업 센터로 사용한 수 있다.

• Journal of Communications and Networks
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• 제16권3호
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• pp.258-263
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• 2014

A hierarchical identity-based broadcast encryption (H-IBBE) scheme is an identity-based broadcast encryption (IBBE) scheme in a hierarchical environment. In order to obtain secure H-IBBE schemes in the quantum era, we propose an H-IBBE scheme based on the learning with errors problemassumption.Our scheme achieves indistinguishability from random under adaptive chosen-plaintext and chosen-identity attacks in the random oracle model.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.307-308
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• 2008

This paper presents the effects of operating Backup Dispatch Center as a System Dispatch Center(SDC). SDC operates the 154kV transmission lines outside of Seoul metropolitan area, and acts as the backup dispatch center in case of central dispatch center's failure. With SDC, it became possible not only to divide operation of Korean transmission lines to separate control centers according to voltage and region, but to clear faults faster and more accurately. It has paved the way to improve power system reliability and advance the power system operation in general.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 제7회 압연 심포지엄
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• pp.13-16
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• 2009

In order to investigate the effects of geometry factors such as a roil diameter ratio and backup roll crown of the stress concentration factor on the edge of backup roil end, 3-dimensional FEM analyses of stress at the contact of backup roll and work roll assembled in a 4-high strip mill were carried out, It was made clear that the peak stress at the edge is about 2 to 3 times of that at the longitudinal center of the roll barrel and the peak stress proportionally increase with decreasing the ratio of backup roll diameter to work roll diameter Furthermore a crowning on the backup roll is effective to decrease the maximum edge stress.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권5호
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• pp.1291-1312
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• 2013

Cloud computing changes the service models of information systems and accelerates the pace of technological innovation of consumer electronics. However, it also brings new security issues. As one of the important foundations of various cloud security solutions, entity authentication is attracting increasing interest of many researchers. This article proposes a layered security architecture to provide a trust transmission mechanism among cloud systems maintained by different organizations. Based on the security architecture, four protocols are proposed to implement mutual authentication, data sharing and secure data transmission in federated cloud systems. The protocols not only can ensure the confidentiality of the data transferred, but also resist man-in-the-middle attacks and masquerading attacks. Additionally, the security properties of the four protocols have been proved by S-pi calculus formal verification. Finally, the performance of the protocols is investigated in a lab environment and the feasibility of the security architecture has been verified under a hybrid cloud system.

• 대한기계학회논문집A
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• 제35권9호
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• pp.977-982
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• 2011

보강롤 구동 4 단 냉간압연기에서 작업롤과 보강롤 사이의 접촉력으로 인해 발생된 작업롤의 수평력을 고찰하였다. 본 수평력은 작업롤을 수평방향으로 휘게하고 롤갭 형상을 그 만큼 변화시킨다. 본 논문에서는 압연을 정상상태라고 가정하여 작업롤의 수평력을 예측할 수 있는 수식모델을 제시하였다. 해석에 사용된 소재는 고-실리콘(약 3%) 강판이었다. 수평력의 비-정상거동을 고찰하기 위해서 삼차원 유한요소모델을 채용하였다. 두 가지 모델을 이용하여 작업롤의 수평력은 보강롤의 중심으로부터 작업롤의 중심이 벗어난 길이에 따라 변한다는 결과를 얻었다. 그리고 작업롤의 수평력을 최소화 시킬 수 있는 작업롤의 최적 중심이탈 길이를 도출하였다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2012년도 제38회 춘계학술대회논문집
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• pp.468-471
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• 2012

본 논문은 우주발사체에 사용되는 추진기관의 성능평가를 수행하기 위한 지상연소시험설비의 이중화 또는 삼중화 제어시스템의 구축 방안을 다루고 있다. 이중화된 제어시스템의 경우 수동제어 콘솔을 설치하여 삼중화 제어시스템을 모사할 수 있었고, 운용자들의 무분별한 조작을 통제하기 위한 제어실 내 제어 콘솔의 배치 안을 제시하였다.