• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.159-162
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• 2003

This paper presents a novel heuristic mechanism, Dynamic-network Adapted Cost selection (DAC-selection), which has higher backup path sharing rate, lower number of blocked channel requests and number of used wavelengths fer reservation of working path and backup path by using unique cost function than that of widely used random selection (R-selection) mechanism and Combined Min-cost selection (CMC-selection) mechanism proposed by Lo, while maintaining 100% restoration capability.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.5
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• pp.854-859
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• 2010

Distribution Automation System(DAS) is designed to improve operational efficiency by acquisition and control of remote data using its components such as central computation units, communication network and feeder remote terminal units. A conventional human machine interface of the DAS adopts a schematic diagram which is made by drawing power equipments on the geographic information system map. The single line diagram is more useful than the schematic diagram for the main tasks of distribution system operation such as protective relay coordination, service restoration and loss minimization. Since the configuration of the distribution line is changed according to the relocation of the open tie switches, the auto-drawing algorithm based on the connection between the sections and the switches is an essential technique. This paper proposes a new auto-drawing algorithm for a single line diagram of distribution systems based on tertiary tree and collision avoidance method. The feasibility of the proposed algorithm has been testified for various cases using practical distribution system with 12 feeders.

• Atmosphere
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• v.16 no.4
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• pp.343-350
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• 2006

The rainfall amount measured by Chugugi at Gongju was found in "Gaksadeungnok". Gaksadeungnok is ancient documents from governmental offices in Joseon dynasty. Rainfall data at Gongju are restored for 18 years of 19th century. In 1871, total rainfall amount is 1,338 mm. It is different by about 11% in the amount compared with Seoul Chugugi rainfall in 1871 and Daejeon modern raingauge measurement result during the 30 years (1971-2000). Annual march of monthly rainfall data at Gongju is similar with that of Seoul. Based on the results, restored rainfall at Gongju is consistent with Seoul Chugugi rainfall data. The rainfall amount restored in this study is measured by Chugugi which was installed at Gongju, in Chung-Cheong province. Furthermore, Gaksadeungnok includes rainfall amount reports by agricultural tool measurement in addition to Chugugi measurement. These facts prove a network of rain gauge in Joseon dynasty.

• Proceedings of the Korea Contents Association Conference
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• 2005.05a
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• pp.329-332
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• 2005

The Internet advances and the documents of existing Is provided on web. An amount of data is increased through amendment and addition of information. The web is wide and is used and to follow the users of the majority which acquires information depend in web, the necessity of the data management by web is increasing. The sudden system failure frequently occurs from network environment, we must protect data from this danger. In this paper, we present data management system, which is composed of backup and restoration. This system provides systematic, efficient and stable data management on web.

• International Journal of Fluid Machinery and Systems
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• v.10 no.3
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• pp.296-306
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• 2017

Hydropower is now changing its role from the energy generator into the most powerful and reliable tool for stabilizing the electrical network, especially under the increase of intermittent power sources like wind-power and solar-power. Although the hydropower plants are the most robust generating facilities, they are not immune from unexpected severe incidents having long downtime, considerable restoration cost and sometimes fatalities. The present paper provides some study results about severe incidents in the conventional hydropower plants, mainly about the flood, fire and electro-mechanical troubles, except for the incidents of civil facilities. It also provides some possible scenarios which may lead some measures how to avoid such incidents. Finally, it provides some comprehensible recommendations to avoid severe incidents based on experiences.

• Journal of Korean Foot and Ankle Society
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• v.20 no.3
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• pp.106-111
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• 2016

The Lisfranc joint complex is an anatomical association of many bones and articulation, restrained by an even more complex network of ligaments, capsules, and fascia, which must work in concert to provide normal and painless motion. Careful diagnostic workup with high-quality radiographs and computed tomography of the foot are used to diagnose injuries and fractures of this complex. We have to understand the normal anatomy and injury mechanism in order to appropriately treat Lisfranc injuries. Good results have been associated with anatomic reductions of all bones, which was achieved with restoration of proper alignment.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.436-438
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• 2001

광 네트워크상의 SONET계층에서 수행되었던 망의 고장에 대한 복구 등의 요구사항은 Generalized Multiprotocol Lambda Switching (GMPLS)에서 해결해야 할 가장 중요한 문제중의 하나이다. GMPLS망 구현 시 고려되어야 할 사항중의 하나는 중단 없는 서비스를 제공하고 망의 효율을 극대화하기 위하여 망의 고장이나 성능의 저하를 대응하기 위한 관리 방안이다. 신뢰성 있는 망 서비스를 제공하기 위한 망 복구 기능에 있어서 주요 과제는 복구의 대상으로 하는 작업 경로에 대한 대체경로를 설정하는 것이다. 본 논문은 GMPLS를 이용하여 광 네트워크에서 최소한의 링크 정보로 망 자원의 효율성을 증가시키는 동시에 모든 작업 경로와 대체 경로의 경로 구성 정보를 이용하여 정확한 대역 공유가 가능한 경로 자동 복구 기법을 제안한다. 본 메커니 즘의 경우 확장된 CR-LDP프로토콜을 이용하게 되므로 망의 변형을 최소화하는 동시에 효율성 면에서 매우 뛰어난 메커니즘이라 할수 있다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.457-459
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• 2001

오늘날 MPLS 망에서의 제어 부분(control plane)을 다양한 장치의 스위칭(switching)과 포워딩(forwarding) 기술 및 계층을 포함할 수 있도록 확장하기 위해서 IETF에서 GMPLS 망이 제안되고 있다. 그리고 망은 보호(protection)와 복구(restoration)를 통해서 망의 생존성(survivability)을 지원해야만 한다. 망은 어떤 장애에서도 서비스가 제공될 수 있어야 한다. 본 논문은 Kini에 의해서 제안된[5] MPLS망에서 망의 장애 시에 망의 생존성과 효율성을 고려해서 복구하기 위해서, 백업 패스(Backup Path)를 설정하는 방법을 GMPLS에서 적용하려고 한다. 즉, GMPLS 망에서 망에 장애가 발생했을 때 효율적으로 복구하기 위해서, RSVF-TE(resource Reservation Protocol with Traffic Engineering)를 이용해서 백업 패스를 잡는다.

• Journal of the Korea Society of Computer and Information
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• v.20 no.7
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• pp.49-56
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• 2015

In this paper, we introduce recent cloud system security technologies categorizing them according to Reliability, Availability, Serviceability, Integrity, and Security (RASIS), terms that evaluate robustness of the computer system. Then we describe examples of security attacks and corresponding security technologies for each of them. We introduce security technologies based on Software Defined Network (SDN) for Reliability, security technologies based on hypervisor and virtualization for Availability, disaster restoration systems for Serviceability, authorization and access control technologies for Integrity, and encryption algorithms for Security. We believe that this paper provide wise view and necessary information for recent cloud system security technologies.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.10C
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• pp.933-936
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• 2002

One of the problems of a Gigabit-Ethernet system for installation in telecom networks is its relative low reliability compared with SONET, the major telecom network system, which restores from fault within 50 msec. In this study, an optics layer protection for the Gigabit-Ethernet system is proposed. It monitors optical signal quality by comparing the signal level with a calibrated window, and switchs fibers within a time comparable to SONET.