• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.265-267
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• 2002

In this paper, the communication between Over-Current Relay agents is realized using DNP(Distributed Network Protocol), which is the standard communication protocol of distribution automation system in KEPKO. The key words in OCR agent communication are defined and represented by use of DNP application function code. And the DNP index for OCR agent is defined. The proposed communication scheme is tested by use of Communication Test Harness, a test tool for DNP protocol to show its soundness.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.125-127
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• 1999

We generally use Yes-No algorithms for feeder automation algorithm. This logic determines the faulty section by fault current detection information of the fault indicators of each switches in distribution feeder. This paper presents the data acquisition method such as breaker's open status in fault and the determination method of faulty section using fault indicator's information of each switches.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.267-269
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• 1999

One of the main jobs of the operators is to make it sure to have a service continuity in a fault situation. This paper proposes a restoration index which indicates the restoration capability of the feeder in case of a fault. A necessary and sufficient condition for a feeder to have 100% restoration of the outage is also described.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.303-305
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• 1999

This paper introduces the MMI software for Central Control System in the Distribution Automation System. It provides remote monitoring and real-time control of distribution through the use of remote terminal units(RTUs) graphically. Our MMI software for distribution automation displays a circuit operating map based on the distribution automation database, and overlays it with outage information from the feeder Automation software.

• Journal of the Korean Society of Earth Science Education
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• v.5 no.2
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• pp.166-174
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• 2012

This study is purposed to survey on astronomical observation experiences of elementary students and teachers. Survey samples are 182 elementary students and 51 elementary teachers, and 8 students and 2 teachers among them are interviewed. The results of this study show that most elementary students are not interested in observing constellations, planets, and moon. Also most elementary students and teachers are not taught to observe astronomical objects. Finally, regarding the difficulty of astronomical practice, teachers pointed out that lack of knowledge about astronomy.

• Journal of Sericultural and Entomological Science
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• v.42 no.2
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• pp.67-72
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• 2000

Autotetraploid 'Sawonppong 26'was induced by dropping clochicine solution in growing point of Keomseolppong which is of high rootability and some agronomic charactelistics are as follows. Sawonppong 26 is a tetraploid of Keomseolppong with 56 of the chromosome number. Its fertlization percent was 59.4% and the germination percent of sank seed was normal. Sugar degree of mulberry fruit was 13.3% and total acidity was 0.69%. Single fruit weight of Sawonppong 26 was increased by 79%, as compared to that of Keomseolppong. Even though percent of survival of hard wood cutting was 94%, number of rootings was less and diameter of root was slender, it is expectedly a promising variety to be used for a breeding parent from the aspect of rootability.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.2
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• pp.103-106
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• 2000

ZnO is a wide-bandgap II-IV semiconductor and has a variety of potnetial applications. ZnO exhibits good piezoelectric, photoelectric and optical properties, and is a good candidate for an electroluminescence device. ZnO films have been deposited on (001) sapphire by PLD technique. Nd:YAG pulsed laser was operated at a wavelength of $\lambda=355nm$. The ZnO films were deposited at oxygen pressures from base to 500 mTorr. The substrate temperatures was increased from $200^{\circ}C\; to\;700^{\circ}C$ films showed strong UV emission by increasing the partial oxygen pressure. We have investigated the relationship between partial oxygen pressure and the intensity of UV emission.

• Proceedings of the Safety Management and Science Conference
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• 2012.04a
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• pp.205-220
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• 2012

The construction industry in Korea after the Korean-war has evolved until these days. But the construction industry accident severity rate and frequency is over then the All industry rate. This study analyzed the 'Disaster Statistical Yearbook' of the Korea Occupational Safety and Health Agency, based on the factors that affect construction accidents that is selected and fined the some factors the construction Disaster Prevention Factors. This study will develop the methodology for analyzes that the national qualification is effected to the construction industrial machine disaster prevention status. It suggest two ways to the establishment of disaster trends. First way is the disaster quantitative analysis and second way is comparing the statistical data and the analysis of expert opinion.

• Journal of the Korea Safety Management & Science
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• v.14 no.2
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• pp.103-112
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• 2012

The construction industry in Korea after the Korean-war has evolved until these days. But the construction industry accident severity rate and frequency is over then the All industry rate. This study analyzed the 'Disaster Statistical Yearbook' of the Korea Occupational Safety and Health Agency, based on the factors that affect construction accidents that is selected and fined the some factors the construction Disaster Prevention Factors. This study will develop the methodology for analyzes that the national qualification is effected to the construction industrial machine disaster prevention status. It suggest two ways to the establishment of disaster trends. First way is the disaster quantitative analysis and second way is comparing the statistical data and the analysis of expert opinion.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.11
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• pp.1547-1553
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• 2017

Due to the high penetration ratio of dispersed generations, overvoltage problem of the feeder has become more an important issue in distribution system operation. This paper proposes a new method for the smart inverter to control reactive power to mitigate voltage rise by the reverse power flow from the DGs. The proposed method controls reactive power based on current measurement while conventional methods use voltage measurement which include unacceptably large errors. Various case studies using MATLAB simulation have been performed to verify effectiveness of proposed method.