• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.4
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• pp.223-229
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• 2022

In this paper, the ignition trans used in boilers was studied. Regardless of the change in the ignition rod length and the ignition rod gap, the output frequency was measured between 59.5 and 61.3 Hz, and it was found that the low frequency circuit operated normally. When the ignition rod gap changed by 2 to 10 mm, the ignition rod length was measured from 2.8A to 3.45A at 30cm. The ignition rod length was measured from 9.37 A to 14.5 A at 500 cm and from 13.2 A to 32.6 A at 1000 cm. As the ignition rod length and the ignition rod gap increased, the current increased. As a result of measuring the secondary coil output voltage. The ignition rod length was measured from AC 0.84 kV to AC 1.75 kV at 30 cm, AC 1.17 kV to AC 1.944 at 500 cm, and AC 1.4 kV to AC 7.18 kV at 1000 cm. As the ignition rod length and the ignition rod gap increased, the output voltage of the secondary coil also increased. As a result of measuring the output voltage of the ignition trans, the ignition rod length was measured from DC 1.11 kV to DC 1.57 kV at 30cm, DC 2.49 kV to DC 3.72 kV at 500cm, and DC 3.78 kV to DC 9.42 kV at 1000cm, and the power voltage increased as the ignition rod length and interval increased.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1893-1894
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• 2006

본 논문은 원자로 제어봉구동장치 각 기구의 동작을 감시하여 이 장치에 의한 제어봉의 이동 여부를 검출하는 방법에 관한 것이다. 제어봉구동장치의 일부에서 전기적, 기계적 결함이 생기면 제어봉의 스텝 이동이 제대로 수행되지 못하고, 결국 해당 제어봉은 원자로의 목표 열적 출력을 위한 바른 위치에 도달하지 못하게 된다. 이렇게 되면 제어봉들 사이에 위치 편차가 발생하여 원하는 원자로 열적 출력을 얻을 수 없게 되므로 제어봉구동장치 각 기구의 동작을 신속하고 정확하게 파악하여 해당 제어봉의 이동 여부를 검출할 수 있어야 한다. 제어봉구동장치의 기구들은 각자의 여자 코일의 전류 파형 변화를 통해 동작 여부를 확인할 수 있는데 본 논문에서는 코일 전류 파형을 분석하기 위하여 국소적인 왜곡 검출 능력이 우수한 웨이블릿 변환 기법을 사용하였다.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.33-39
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• 1998

기존 가압형 경수로에서 전체 반응도가의 상당부분을 제어하고 있는 붕산수를 사용하지 않고 가연성독봉 및 쟤어봉을 확대 사용하는 전략으로 1300MWe급 차세대원자로(KNGR)를 대상으로 무붕산 노심 개념설계를 수행하였다. 가연성독봉으로는 기존 PYREX 독붕의 독물질을 농축한 농축 PYREX 독봉을 도입하여 주기초 반응도 제어효과 및 전 주기동안 평평한 잉여반응도 유지에 매우 효과적인 결과를 도출하였다. 또한, 무붕산 노심이 필연적으로 갖게되는 축방향 출력분포의 노심 하단부치중현상을 제어하기 위하여 부분장 제어봉(Part Length Control Red)을 보조적으로 사용, 매우 간단한 형태의 핵연료집합체 축방향 zoning 설계를 수행하였다. 부분장 제어봉의 사용으로 모든 핵연료집합체를 축방향으로 zoning 하지 않고도 축방향 출력분포를 효과적으로 제어할 수 있었다. 제어봉으로는 큼 제어봉가를 확보하기 위하여 B$_4$C를 재질로하는 Checkerboard 형태의 제어봉 설계를 수행하였고, 효과적인 제어봉 운영을 통하여 무붕산 노심의 잉여반응도 및 출력분포 제어가 가능하였으며 제어봉이 운전중에 상당부분 삽입될지라도 약 7%$\delta$p 의 충분한 운전정지 여유도를 확보할 수 있다는 가능성을 확인할 수 있었다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.10
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• pp.905-913
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• 2017

In this work, a method of size optimization is proposed to maximize the natural frequency of a rod that consists of a hidden shape in one part and an exposed shape in the other. The frequency response function of a rod composed of two parts is predicted by using the frequency response functions of each of the parts instead of the shapes of the parts. The mass and stiffness matrices of the rod are obtained by using the mass and stiffness matrices of the equivalent vibration systems, which are obtained by applying the experimental modal analysis method to the frequency response functions of the parts. Through several numerical examples, the frequency response function obtained by using the proposed method is compared with that of a rod to validate the prediction method based on equivalent vibration systems. A size optimization problem is formulated for maximizing the first natural frequency of a combined rod, which is replaced with an equivalent vibration system, and a rod structure is optimized by using an optimization algorithm.

• Nuclear Engineering and Technology
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• v.28 no.1
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• pp.17-26
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• 1996

The in-reactor fuel rod support conditions against the fretting wear-induced damage can be evaluated by residual spacer grid spring deflection or rod-to-grid gap. In order to evaluate the impact of fuel design parameters on the fretting wear-induced damage, a simulation methodology of the in-reactor fuel rod supporting conditions as a function of burnup has been developed and implemented in the GRIDFORCE program. The simulation methodology takes into account cladding creep rate, initial spring deflection, initial spring force, and spring force relaxation rate as the key fuel design parameters affecting the in-reactor fuel rod supporting conditions. Based on the parametric studies on these key parameters, it is found that the initial spring deflection, the spring force relaxation rate and cladding creepdown rate are in the order of the impact on the in-reactor fuel rod supporting conditions. Application of this simulation methodology to the fretting wear-induced failure experienced in a commercial plant indicates that this methodology can be utilized as an effective tool in evaluating the capability of newly developed cladding materials and/or new spacer grid designs against the fretting wear-induced damage.

• Food Science and Preservation
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• v.15 no.2
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• pp.185-190
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• 2008

We investigated changes in fruit quality of Hallabong tangor (Citrus Kiyomi ${\times}$ ponkan) that was packaged with Si+CaO and LDPE film. The flesh ratio during storage was 74.33% (${\pm}3.66$) to 81.56% (${\pm}1.38$). Firmness of M16A, a variant of Hallabong tangor, was higher 100g-force than that of Hallabong tangor, changes of firmness was not shown among film packages. A fruit juice was $12-14^{\circ}$Brix, and this increased somewhat at the end of storage without film packaging. The titratable acidity of the M16A variety was 0.2% lower than that of the Hallabong tangor. Hallabong and M16A maintained freshness and taste for 120 and 60 days, respectively. The level of reducing sugars in the Hallabong tangor was 1% higher than that of the M16A variety. Reducing sugars increased at room temperature storage without film packaging. Total sugar content was 9.19% (${\pm}2.03$) to 12.78% (${\pm}0.75$). The content of vitamin C declined slowly after 105 days of storage. In conclusion, storage of Hallabong tangor with film packaging coated with Si+CaO was effective for maintaining freshness and quality.

• 월간낙농육우
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• v.37 no.5
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• pp.137-140
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• 2017

충남 당진에는 여성 낙농인으로 구성된 우유사랑봉사회가 있다. 우유사랑봉사회가 주로 하는 활동은 지역에서 생산된 우유와 유가공 제품을 알리고 홍보할 수 있는 곳을 찾아 봉사활동을 펼치며 국산우유와 유제품을 홍보하는 것. 매일 쉴 틈 없이 일하는 낙농인으로서 따로 시간을 내서 봉사한다는 것이 말처럼 쉽진 않지만 우유사랑봉사회는 40명의 회원이 동고동락하며 낙농발전은 물론 지역사람들과의 상생을 향해 아낌없이 헌신하고 있다.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05c
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• pp.476-482
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• 1996

사용후핵연료 관리 및 후행핵연료주기 시설에서 요구되는 사용후핵연료 연료봉 인출기술을 확보하기 위하여 연료봉 인출장치를 제작하였으며, 모의 연료봉을 사용하여 이를 인출하는 실험을 수행하여 장치의 성능을 시험하였다. 인출장치는 컴퓨터로 제어할 수 있도록 함으로서 대부분의 인출공정을 자동으로 수행할 수 있도록 하였다. 실험 결과를 분석하여 장치의 개선점을 제시하였고, 또한 향후 실제 사용후핵연료 시설에 적용할 경우에 대비한 보완책도 제시하였다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.6
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• pp.467-472
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• 2021

In this paper, the ignition trans used in the gas boiler was produced to measure current, power factor, and power consumption. As a result of measuring the power factor, the self-made ignition trans was higher than that of foreign products and the power consumption was lower. The ignition gap was fixed to 2 m, and when the ignition rod length was 30cm, 500cm, and 1000cm, it was measured as 3.45A, 14.5A, and 16.2A. When the ignition gap was fixed to 4mm and the ignition rod length was 30cm, 500cm, and 1000cm, it was measured as 2.8A, 10.1A, and 13.2A. When the ignition gap was fixed at 6mm and the ignition rod length was 30cm, 500cm, and 1000cm, it was measured as 2.73A, 10.2A, and 32.6A. When the ignition gap was fixed at 8 mm and the ignition rod length was 30 cm, 500cm, and 1000cm, it was measured as 3.13A, 9.37A, and 21.4. The ignition gap was fixed at 10 mm, and when the ignition rod length was 30cm, it was measured as 3.4A, 14.4 A, and 25.6A. In conclusion, as the length of the ignition rod increased, the current also increased.

• The Korea Beekeeping Bulletin
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• s.290
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• pp.15-18
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• 2004