• 한국화재소방학회논문지
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• 제23권2호
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• pp.55-61
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• 2009

본 연구에서는 서지나 순간 과전압 등에 의한 과도현상으로부터 보호될 수 있는 높은 신뢰성의 화재수신기가 될 수 있도록 과도현상 보호시스템의 개발에 대한 연구를 수행하였고, 보호시스템의 성능을 시험으로 입증함으로써 과도현상 보호시스템을 개발할 수 있는 기틀을 마련하였다. 과도현상 보호시스템의 개발을 위한 프로세스 정립과 이론을 바탕으로 과도현상으로부터 보호될 수 있는 1단계 및 2단계 보호시스템을 개발하였고, 소방법 및 관련규정에서 제시하는 제반 성능조건으로 시험하고 만족스런 결과를 얻음으로써, 과도현상 보호시스템을 개발할 수 있는 엔지니어링 데이터 구축과 원천기술을 확립하였다.

• 조명전기설비학회논문지
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• 제24권10호
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• pp.73-77
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• 2010

Most accidents occurred in power receiving & transforming facility are ground fault. The quality of power supply is deteriorated since the ground fault is not detected promptly. This paper analyzes the problems about system-grounding type of 2 step power receiving & transforming facility, arrangement of protection relaying scheme and ground-fault protection system of ungrounded system. Then, this paper presents the arranging scheme of system-grounding type to improve power supply reliability.

• 전기학회논문지
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• 제60권1호
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• pp.43-49
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• 2011

A distance relay scheme is commonly used for backup protection. This scheme, called a step distance protection, is comprised of 3 steps for graded zones having different operating time. As for the conventional step distance protection scheme, Zone 2 can exceed the ordinary coverage excessively in case of a transformer protection relay especially. In this case, there can be overlapped protection area from a backup protection relay and, therefore, malfunctions can occur when any fault occurs in the overlapped protection area. Distance relays and overcurrent relays are used for backup protection generally, and both relays have normally this problem, the maloperation, caused by a fault in the overlapped protection area. Corresponding to an IEEE standard, this problem can be solved with the modification of the operating time. On the other hand, in Korea, zones are modified to cope with this problem in some specific conditions. These two methods may not be obvious to handle this problem correctly because these methods, modifying the common rules, can cause another coordination problem. To overcome this problem clearly, this paper describes an improved backup protection coordination scheme using an IEC 61850-based distance relay for transformer backup protection. IEC 61850-based IED(Intelligent Electronic Device) and the network system based on the kernel 2.6 LINUX are realized to verify the proposed method. And laboratory tests to estimate the communication time show that the proposed coordination method is reliable enough for the improved backup protection scheme.

• 전기학회논문지
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• 제61권10호
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• pp.1542-1547
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• 2012

Asynchronous phenomenon occurs on the synchronous generators under power system when a generator's amplitude of electromagnetic force, phase angle, frequency and waveform etc become different from those of other synchronous generators which can follow instantly varying speed of turbine. Because the amplitude of electromagnetic force, phase frequency and waveform differ from those of other generators with which are to be put into parallel operation due to the change of excitation condition for load sharing and the sharing load change, if reactive current in the internal circuit circulates among generators, the efficiency varies and the stator winding of generators are overheated by resistance loss. When calculation method of protection settings and logic for protection of generator asynchronization will be recommended, a distance relay scheme is commonly used for backup protection. This scheme, called a step distance protection, is comprised of 3 steps for graded zones having different operating time. As for the conventional step distance protection scheme, zone 2 can exceed the ordinary coverage excessively in case of a transformer protection relay especially. In this case, there can be overlapped protection area from a backup protection relay and, therefore, malfunctions can occur when any fault occurs in the overlapped protection area. Distance relays and overcurrent relays are used for backup protection generally, and both relays have normally this problem, the maloperation, caused by a fault in the overlapped protection area. Corresponding to an IEEE standard, this problem can be solved with the modification of the operating time. On the other hand, in Korea, zones are modified to cope with this problem in some specific conditions. These two methods may not be obvious to handle this problem correctly because these methods, modifying the common rules, can cause another coordination problem. To overcome asynchronizing protection, this paper describes an improved backup protection coordination scheme using a new logic that will be suggested.

• 전기학회논문지
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• 제60권11호
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• pp.2000-2006
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• 2011

Asynchronous phenomenon occurs on the synchronous generators under power system when a generator's amplitude of electromagnetic force, phase angle, frequency and waveform etc become different from those of other synchronous generators which can follow instantly varying speed of turbine. Because the amplitude of electromagnetic force, phase frequency and waveform differ from those of other generators with which are to be put into parallel operation due to the change of excitation condition for load sharing and the sharing load change, if reactive current in the internal circuit circulates among generators, the efficiency varies and the stator winding of generators are overheated by resistance loss. Where calculation method of protection settings and Logic for Protection of Generator Asynchronization will be recommended, A distance relay scheme is commonly used for backup protection. This scheme, called a step distance protection, is comprised of 3 steps for graded zones having different operating time. As for the conventional step distance protection scheme, Zone 2 can exceed the ordinary coverage excessively in case of a transformer protection relay especially. In this case, there can be overlapped protection area from a backup protection relay and, therefore, malfunctions can occur when any fault occurs in the overlapped protection area. Distance relays and overcurrent relays are used for backup protection generally, and both relays have normally this problem, the maloperation, caused by a fault in the overlapped protection area. Corresponding to an IEEE standard, this problem can be solved with the modification of the operating time. On the other hand, in Korea, zones are modified to cope with this problem in some specific conditions. These two methods may not be obvious to handle this problem correctly because these methods, modifying the common rules, can cause another coordination problem. To overcome asynchronizing protection this paper describes an improved backup protection coordination scheme using a new Logic that will be suggested.

• 한국화재소방학회논문지
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• 제27권2호
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• pp.18-24
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• 2013

대형화, 다양화되고 있는 화재 폭발사고 및 지구온난화와 자연현상에 의한 재난으로부터 인명과 재산손실을 예방하기 위해 정부와 기업은 많은 노력을 기울이고 있다. 그러나 국가의 성장과 더불어 국민의 삶의 질 향상 및 복지증진이라는 국가의 거시적 목표에 부응하되 기업목적인 이윤추구의 달성을 위해 우선시된 경제정책 속에서 앞만 보고 달려온 기업들은 미온적 위험관리의 결과로 소중한 인명과 재산손실을 감내하고 있다. 2007년 소방방재청의 '안전문화 활성화를 위한 국민안전의식조사'에서 국민이 생각하는 우리 사회의 안전불감증은 '심각한 수준'으로 조사된 바, 본 연구에서는 소방안전사고예방과 안전의식수준향상을 위해 위험관리가 가능한 대기업뿐만 아니라 조직과 예산규모가 작아 사고발생의 위험이 큰 중소기업의 현 실태를 평가, 체계적인 안전관리를 통한 소방안전사고예방을 위해 현 실정에 맞는 '단계별 소방안전경영시스템' 구축에 대한 필요성을 조사하였다.

• 정보보호학회논문지
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• 제28권6호
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• pp.1585-1594
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• 2018

데이터 주도 시대가 형성되면서 경제적 활용가치가 높은 정보의 수집과 분석, 생산과 유통에 관한 안전성 확보를 위한 정보보호 관리의 중요성이 날로 높아지고 있다. 이러한 환경에서 기업은 정보보호 관리체계(ISMS) 인증을 통해 정보보안에 대한 신뢰를 보장받고 있으나 관리체계를 구성하는 세부영역에 대한 수준 평가와 활용은 제한적이다. 이에 반해 보안 성숙도 모델은 기업의 정보보호 수준을 단계적으로 진단할 수 있고 시급히 개선해야 할 영역을 판단할 수 있음은 물론 기업의 특성과 수준에 맞는 목표 설정을 지원하는 도구가 된다. 본 논문에서는 성숙도 모델을 바탕으로 정보보호 분야에 특화되어 개발, 활용되고 있는 보안 성숙도 모델의 사례인 C2M2를 국내 ISMS인증과 비교, 분석하여 정보보호 관리 수준을 점검하기 위한 모형을 벤치마크 하고 ISMS인증의 정보보호대책 세부영역을 구성하는 점검항목 간 우선순위를 도출하여 단계적으로 정보보호 관리수준을 점검하고 구축을 지원할 수 있는 방법을 살펴본다.

• 대한기관윤리심의기구협의회지
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• 제2권1호
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• pp.6-22
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• 2020

Purpose: Clinical studies require institutional review board (IRB) approval based on the ethical principle and regulations. While the number of clinical studies has been increased and diversified, duplicated IRB review for multi-center studies has become a major issue. Therefore, single IRB system has been suggested in revised Common Rule. This study aimed to identify and assess the current status of single IRB in Korea and the anticipated needs of single IRB from researchers and IRB member or administrators. Methods: We developed 14 questions including perceived advantages and disadvantages of single IRB, and anticipated problems. The online survey collected opinions on single IRB from researchers, IRB members and IRB administrators. We also interviewed five IRB administrators who have an experience of single IRB. Results: A total of 80 responses were analyzed in this study. Although efficiencies were suggested for the advantages of single IRB in terms of reducing burden of duplicated review, respondents also perceived that the different review criteria between single IRB and each IRB would be a major hurdle for adopting single IRB system. Therefore, the standardization of standard of procedures (SOP) and the standardization of IRB submission materials should be preceded. According to the small group experiences of single IRB in Korea, we also observed the similar anticipated problems of single IRB. Conclusion: Single IRB system has many advantages for conducting multi-center trial. However, many specialists still have a lot of concerns about introducing a single IRB system in Korea. Therefore, a gradual, step-by-step process for conducting a single IRB system in Korea will be needed. Many studies for improving currently suggested single IRB system and the improvement of awareness about the essential of single IRB system would be needed.

• 융합보안논문지
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• 제12권2호
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• pp.107-113
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• 2012

최근 개인정보보호법 제정에 따라 인터넷에서 개인정보를 취급하는 공공기관 및 기업들은 개인정보 보호를 위해 접근제어, 암호화 등 기술적 대책을 강구하고 있다. 개인정보 유출시 공공기관이나 기업은 이미지 훼손뿐만 아니라, 법적책임을 면할 수 없는 실정이다. 그러나, 대용량 데이터베이스 시스템에서 매 접속 시마다 개인정보 항목에 대해 접근제와와 암 복호화를 하도록 하는 것은 성능 저하의 원인이 된다. 본 논문에서는 동시 트랜잭션이 많은 Oracle DBMS 환경에서 JVM(Java Virtual Machine)을 이용한 경량화 시스템을 설계 구현하여 성능에 최소한 영향을 미치면서 개인정보보호법에 정한 요구사항을 효율적이고 안전하게 수행하는 시스템을 제안하였다. 제안 시스템을 A 공공기관 포털 및 인사 시스템 내 개인정보 보호에 적용하여 성능 차이를 검증하였다.

• Journal of Radiation Protection and Research
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• 제46권2호
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• pp.48-57
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• 2021

Background: In this study, the complexities of step-and-shoot intensity-modulated radiation therapy (IMRT) plans in magnetic resonance-guided radiation therapy systems were evaluated. Materials and Methods: Overall, 194 verification plans from the abdomen, prostate, and breast sites were collected using a ⁶⁰Co-based ViewRay radiotherapy system (ViewRay Inc., Cleveland, OH, USA). Various plan complexity metrics (PCMs) were calculated for each verification plan, including the modulation complexity score (MCS), plan-averaged beam area (PA), plan-averaged beam irregularity, plan-averaged edge (PE), plan-averaged beam modulation, number of segments, average area among all segments (AA/Seg), and total beam-on time (TBT). The plan deliverability was quantified in terms of gamma passing rates (GPRs) with a 1 mm/2% criterion, and the Pearson correlation coefficients between GPRs and various PCMs were analyzed. Results and Discussion: For the abdomen, prostate, and breast groups, the average GPRs with the 1 mm/2% criterion were 77.8 ± 6.0%, 79.8 ± 4.9%, and 84.7 ± 7.3%; PCMs were 0.263, 0.271, and 0.386; PAs were 15.001, 18.779, and 35.683; PEs were 1.575, 1.444, and 1.028; AA/Segs were 15.37, 19.89, and 36.64; and TBTs were 18.86, 19.33, and 5.91 minutes, respectively. The various PCMs, i.e., MCS, PA, PE, AA/Seg, and TBT, showed statistically significant Pearson correlation coefficients of 0.416, 0.627, -0.541, 0.635, and -0.397, respectively, with GPRs. Conclusion: The area-related metrics exhibited strong correlations with GPRs. Moreover, the AA/Seg metric can be used to estimate the IMRT plan accuracy without beam delivery in the ⁶⁰Co-based ViewRay radiotherapy system.