• FLOWER RESEARCH JOURNAL
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• v.17 no.4
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• pp.279-284
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• 2009

In order to recover fertility from sterile interspecific OA-1 $F_1$ hybrid (Oriental hybrid 'Mero Star' ${\times}$ Asiatic hybrid 'Connecticut King'), various concentrations (0.1, 0.3 and 0.5%) of caffeine were injected directly into flower buds and then confirmed the viability of OA-1 $F_1$ hybrid at the flowering time. After the caffeine treatment, fertilized $F_1$ hybrids were crossed as female with Asiatic hybrid 'Lanzarote' as male. Five plantlets were obtained from seven embryos of 16 pollinated flowers at 0.3% treatment of caffeine while 0.5% treatment of caffeine obtained one plant let and 0.1 % treatment of caffeine plantlet did not produce at all. Thus 0.3% of caffeine treatment was considered as optimum concentration to produce subsequent progenies and the OA-l $F_1$ hybrid treated with caffeine produced 51% of putative 2n gametes. Pollen germination of OA-2 ('Romero Star' ${\times}$ 'Lady Rosa') and OA-3 ('Expression' ${\times}$ 'Lady Rosa') was not differ between temperature treatment alone and in combination with caffeine and temperature treatment. In the reciprocal crosses of OA-1 and Asiatic hybrid 'Lanzarote' or Oriental hybrid 'Sorbonne', A ('Lanzarote') ${\times}$ OA-1 or OA-1 ${\times}$ A crosses showed better results than O ('Sorbonne') ${\times}$ OA-1 or OA-1 ${\times}$ a crosses in plant obtaining. All progenies obtained from A ${\times}$ OA-1 or OA-1 ${\times}$ A crosses were confirmed as triploids by GISH analysis.

• Journal of Korean Elementary Science Education
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• v.27 no.1
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• pp.1-8
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• 2008

The purpose of this study was to analyze students', preservice teachers and inservice teachers' images of scientists. For the purpose of this study, we selected 711 people. The results generally was showed the students, preservice teachers and inservice teachers have the stereotyped image of scientists. When we group the subject of investigation as elementary-school students, middle-school students, high-school students, preservice teachers, inservice elementary-school teachers, and looked into whether there were meaningful differences among them by the method of ANOVA, we could see the meaningful differences (p<0.05). And also elementary-school students showed the meaningful difference from other groups when examined on the $Scheff{\acute{e}}$ test.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.4
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• pp.491-497
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• 2018

Most of the applications for distribution system operation highly rely on the voltage and current managements from the field devices. Voltage from the remote controlled switch contains unacceptably large measurement error due to the nonlinear characteristics of the bushing potential transformer. This paper proposes a new voltage magnitude estimation method by calculating voltage drop using current measurement, line impedance and loads deployment data. Contract demand power and pole transformer capacity managed by NDIS are used as a key element to improve accuracy of the proposed method. Various case studies using Matlab simulation have been performed to verify feasibility of the propose voltage estimation method.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.30 no.2
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• pp.43-48
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• 2016

Operational applications such as service restoration, voltage control and protection coordination are calculated based on the active and reactive power loading of the sections in the distribution networks. Loadings of the sections are estimated using the voltage and current measured from the automatic switches deployed along the primary feeders. But, due to the characteristics of the potential transformer attached to the switches, accuracy of the voltage magnitude is not acceptable to be used for section loading calculation. This paper proposes a new accurate section loading estimation method through voltage measurement error compensation by calculating voltage drop of the distribution line. In order to establish feasibility of the proposed method, various case studies based on Matlab simulation have been performed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.3
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• pp.327-335
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• 2008

As communication is becoming increasingly prevalent and especially communication architecture is more relying on the open standard communication protocols, the security issues become major concerns. In this paper we consider possible cyber attacks in the applications based on the current distribution communication architecture, and then derive the security goals. Next we propose how the security algorithms can be adapted to achieve these security goals. We intend to adapt the most efficient ways of secure message exchange, taking the resource-constrained FRTUs into account Finally we show some experiments to validate the protocols.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.156-157
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• 2011

본 논문은 방사상으로 운용중인 배전계통에 1선 지락 고장시 퍼지 로직 알고리즘을 이용하여 고장구간을 판단하는 기법에 대해 제안하고 있다. 배전계통에 1선 지락 고장 발생 시 선로불평형 전류에 의해 고장구간 이후의 자동화개폐기에서 고장표시기가 오동작을 한다. 이로 인해 고장구간을 잘못 판단하여 수용가에 전력공급의 신뢰성이 줄어든다. PSCAD/EMTDC라는 전력해석용 툴을 이용하여 배전계통 모델링과 시뮬레이션을 하였고, 개폐기의 영상전류 크기를 통해 퍼지 로직이라는 인공지능기법을 이용하여 정확한 고장구간을 판단하는 기법을 제안한다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.3
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• pp.506-514
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• 2010

Defense systems are needed to prevent catastrophic failures of a power grid due to cascaded events. Cascaded events can be occurred by power flow overload. Especially, it is the most dangerous problem that overload line is outage, because it can make the power system face danger of cascaded. In this paper, vulnerability evaluation for monitoring wide are outage is proposed using by configuration information of transmission systems. This method of vulnerability evaluation is considered direct effect and indirect effect of power flow, especially overload. What is more, it can be used when the configuration of power system changes, as simple fault occurs or maintenance of facility. In the case studies, the estimation and simulation network have been testified and analysed in PSSE and C programming.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.175-177
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• 2008

본 논문에서는 I-PIU를 통해 등기화된 데이터를 취득 이용하여 실시간 계통 감시는 물론 광역정전방지에 대한 방법을 제안하고 있다. 또한 민감도 지수(Sensitivity Factor)를 이용한 취약도 지수(Vulnerability Index)와 실시간 데이터를 이용한 거리계전기 동작을 예측 알고리즘을 적용하여 실시간 계통의 상황감시는 물론 계통의 위험 정도를 미리 알리는 거리 계전기 모니터링 시스템을 설계하였다 이는 운영자로 하여금 개통의 위험 요소를 적절한 조치를 취해 제거함으로써 치명적인 광역 정전 사태의 방지와 효율적 계통관리를 기대 할 수 있다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.10
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• pp.1633-1638
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• 2016

Loop system arrangement in the primary distribution system has been increased for higher reliability of power supply to the customer. This paper presents a new fault calculation method for the loop structured unbalanced distribution feeders. Mathematical modeling method of the distribution system and superposition principal based fault calculation procedures are provided. In order to establish feasibility of the proposed method, various case studies have been performed using Matlab power system toolbox.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.10
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• pp.1460-1465
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• 2017

Outage areas can be transferred to adjacent feeders to restore power supply in case of the fault on the distribution system. Feeders in the small island or mountain area may not have backup feeders due to the low density of load. In this weakly meshed open loop system, BESS can be used as a backup feeder to improve reliability of power supply. This paper proposes a new network reconfiguration method for BESS based service restoration. Fuzzy decision making technique is adopted to deal with fuzziness of service restoration planning rules. Case studies using KEPCO real distribution system have been performed to verify feasibility of the proposed method.