• Computational Structural Engineering
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• v.28 no.4
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• pp.30-37
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• 2015

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.4
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• pp.515-522
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• 2021

In this paper, we present and analyze a method of applying a machine learning to ultrasonic test signals for constant monitoring of the welding faults in a tubular steel tower. For the machine learning, feature selection based on genetic algorithm and fault signal classification using a support vector machine have been used. In the feature selection, the peak value, histogram lower bound, and normal negative log-likelihood from 30 features are selected. Those features clearly indicate the difference of signals according to the depth of faults. In addition, as a result of applying the selected features to the support vector machine, it has been possible to perfectly distinguish between the regions with and without faults. Hence, it is expected that the results of this study will be useful in the development of an early detection system for fault growth based on ultrasonic signals and in the energy transmission related industries in the future.

• 전기의세계
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• v.18 no.3
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• pp.24-27
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• 1969

이글은 이시리즈의 마지막으로 끝으로 언급하고 싶은 것은 초고압선로의 선로정전용량의 영향이 크므로 선로충전시 또는 경부하시 발전기의 자기려자현상이 발생하지 않도록 병렬 reactor를 설치하거나 또는 발전기대수를 규정수이하로 줄이지 않도록 유의해야 한다는 점이다. 이상으로서 우선 345KV 초고려송전선의 특성일부 그리고 철탑설계에 필요한 자료의 계산등에 관한 일차적 검토를 끝마치고저 한다.

• 한국가스학회:학술대회논문집
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• 2001.10a
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• pp.103-107
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• 2001

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.670-671
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• 2013

• 전기의세계
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• v.43 no.8
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• pp.40-47
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• 1994

본고에서는 주로 계통절연이 받는 스트레스의 해석방법과 그 결과에 대하여 기술하고 절연강도에 대한 부분은 외국의 실험결과를 이용하였으나 우리 나라에서도 공기절연에 대한 실증시험을 지지물 발주이전에 완료하여 우리고유의 철탑모델에 대한 절연 신뢰도를 확인할 계획으로 연구를 추진중에 있다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.178-188
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• 2007

In this paper, a half-scaled substructure test was performed to evaluate the buckling and structural safety of an existing transmission tower subjected to wind load. A loading scheme was devised to reproduce the dead and wind loads of a prototype transmission tower, which uses a triangular jig that is mounted on the reduced model to which the similarity law of a half length was applied. As a result of the preliminary numerical analysis carried out to evaluate the stability of a specimen for the design load, it was confirmed that the calculated axial forces of tower leg members were distributed to $80{\sim}90%$ of an admissible buckling load. When the substructured transmission tower was loaded by 270% of its maximum admissible buckling load, it was failed due to the local buckling that is occurred in joints with weak constraints for out-of-plane behavior of leg members. By inspection of load-displacement curves, displacements and strains of members, it is considered that this local buckling was due to additional eccentric force by unbalanced deformation because the time that is reached to yielding stress due to the bending moment is different at each point of a same section.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.6
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• pp.22-28
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• 2005

The electrical characterstic of earth is the most dominant factor for grounding design and an earth is typically represented by a uniform medium with the specific earth resistivity, which is unique for a specific site. For a hand-working grounding design using a specific earth resistivity requires a process converting a real earth of complex medium into a simple uniform medium In this paper, we suggest a procedure to convert a multi-layered earth s into a simpler uniform earth for grounding design of Myanmar 500[kV] transmission towers.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.7 s.124
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• pp.649-661
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• 2007

Friction-type reinforcing members(FRM) to enhance the resistance to wind loads of a transmission tower through both stiffness strengthening and damping increase are energy dissipation devices that utilize bending deflection of a tower leg. In this paper, the hysteretic behavior of the transmission tower structure with FRMs was experimentally investigated through cyclic loading tests on a half scale substructure model. Firstly, the variation of friction forces and durability of the FRM depending on the type of friction-inducing materials used in the FRM were examined by performing the cyclic loading tests on the FRM. Secondly, cyclic loading tests of a half-scale two-dimensional substructure model of a transmission tower with FRMs were conducted. Test results show that the FRM, of which desired maximum friction force is easily regulated by adjusting the amplitude of the torque applied to the bolts, have stable hysteretic behaviors and it is found that there exists the optimum torque depending on a design load by investigating the amount of energy dissipation of the FRMs according to the increase of torque.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.452-453
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• 2008

본 논문에서는 송전철탑에 작용하는 설계하중으로서 [송전철탑 설계풍속에 관한 연구]에 근거하여 1987년 6월 제정된 지역별설계 풍하중기준의 개정을 위한 연구결과를 수록하였다. 당시 제정된 송전설계기준은 이전에 전국적으로 통일시켜 적용되던 풍속압($76kg/m^2$)을 지역별 풍속을 구분하여 그 차이에 따라 I, II, III, 지역 및 울릉도로 구분하여 차등 적용하였으며, 본 연구에서는 국내 기상청이 생긴 이래 2005년까지 누적된 기상 DB의 분석을 통하여 최근의 기상 현상을 반영한 보다 현실적인 설계기준 개정과정을 수록하였다. 본 논문에서는 1980년대 후반부터 약 20년간의 기상청의 풍향, 풍속자료를 추가로 확보하여 이를 분석하고 재현기간을 반영한 지역별 설계하중을 재산정하여 최근의 기상자료를 포함하여 보다 정확한 분석을 도모하고, 사회 환경의 급변함에 따라 우려되는 기상이변 등을 고려한 안전성과 경제성이 향상된 설계기준의 산정과정을 고찰하고자 한다.