• 방송공학회논문지
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• 제25권1호
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• pp.13-24
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• 2020

한국에는 전력 분배를 위하여 약 9백만 개의 전신주와 1.3백만 킬로미터의 송전선이 있다. 이러한 많은 전력 설비의 유지보수를 위해서는 많은 인력과 시간이 소요된다. 최근 인공지능을 사용한 여러 고장진단 기술들이 연구되어 오고 있기 때문에 본 논문에서는 송전선의 여러 요인으로 인한 늘어짐을 감지하기 위해 기존의 현장에서의 검증 방법이 아닌 카메라 시스템으로 촬영한 영상에서의 인공 지능 기술을 활용한 송전선 늘어짐 감지 시스템을 제안한다. 제안하는 시스템은 (i) 객체 탐지 시스템을 이용한 송전탑 감지 (ii) 동영상 촬영 데이터의 화질 저하 문제를 해결하기 위한 히스토그램 평활화 기법 (iii) 송전선 전체를 파악하기 위한 파노라마 영상 스티칭(iv) 송전선 탐지 알고리즘 적용 후 파노라마 영상 스티칭 기술을 이용한 늘어짐 판단 과정으로 진행된다. 본 논문에서는 각각의 과정들에 대한 설명 및 실험 결과를 보인다.

• 기술사
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• 제15권4호
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• pp.12-24
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• 1982

East Parts of Bangladesh have been benifited by low cost energy generated by domestic natural gas but West parts where energy generated by imported fuel. Bangladesh Government authority has very much concerned to transmit the low cost electricity to the West from the East for past several years. To solve such concerns, cross-country 230kv double circuits Power transmission line was proposed, however there was a big obstacle for the realization of this line to cross the Jamuna river which has 12 km long width with a deep muddy river bed. A consultant engineering firm named Merz-Mclellan anyway finalized this plan and a world-wide bid was announced on June 31, 1979. Due to the expected difficulty to construct the towers on sea like area, only three construction groups have participated. including a Korean joint venture organization of Samsung-Korean Developement corporation-Kolon Electric Machinery company. After 3 months bid evaluation, contract was awarded to Korean Consosium and KEM Co was in charge of designing steel towers with anchor bolts and base plates beside to electrical engineering field. Then KEM Co have faced and over-comed many unenpected technical difficulties such as forced eccentricity joint on base plate, distorsion issue of 60mm thick plates welding, threading anchor bolts, tad heat treatment of some anchor bolts, disagreement from Consultant Engineer on multiplying factor of leg stresses for 45$^{\circ}$ wind and on reducing O.L.F for wind loads on cables for such 1220km long spans. After spending two years long period for designing and engineering towers, base plates, and anchor bolts, first shipment of tower was finally realized on Nov. 8, 1981 and on the other hand KDD has proceeded concrete caisson work on schedule at Jamuna river site and expected to complete tower erection and stringing of cables within this year of 1982 which was original completion target.

• Geomechanics and Engineering
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• 제11권1호
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• pp.141-160
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• 2016

This study elucidates the uplift behaviors of the straight-sided and belled shafts. The field uplift load tests were carried out on 18 straight-sided and 15 belled shafts at the three collapsible loess sites under an arid environment on the Loess Plateau in Northwest China. Both the site conditions and the load tests were documented comprehensively. In general, the uplift load-displacement curves of the straight-sided and belled shafts approximately exhibited an initial linear, a curvilinear transition, and a final linear region, but did not provide a well defined peak or asymptotic value of the load, and therefore their uplift resistances should be interpreted from the load test results using an appropriate criterion. Nine representative uplift resistance interpretation criteria were used to define the "interpreted failure load" for each of the load tests, and all of these interpreted uplift resistances were normalized by the failure threshold, $T_{L2}$, obtained using the $L_1-L_2$ method. These load test data were compared statistically and graphically. For the straight-sided and belled shafts, the normalized uplift load-displacement curves were respectively established by the plots that related the mean interpreted uplift resistance ratio against the mean displacement at the corresponding interpreted criteria, and the comparisons of the normalized load-displacement curves were made. Specific recommendations for the designs of uplift belled and straight-sided shafts in the loess were given, in terms of both capacity and displacement.

• 한국측량학회지
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• 제36권3호
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• pp.127-134
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• 2018

Electric transmission towers are facilities to transport electrical power from a plant to an electrical substation. The towers are connected using power lines that are installed with a proper sag by loosening the cable to lower the tension and to secure the sufficient clearance from the ground or nearby objects. The power line sag may extend over the tolerance due to the weather such as strong winds, temperature changes, and a heavy snowfall. Therefore the periodical mapping of the power lines is required but the poor accessibility to the power lines limit the work because most power lines are placed at the mountain area. In addition, the manual mapping of the power lines is also time-consuming either using the terrestrial surveying or the aerial surveying. Therefore we utilized multiple overlapping images acquired from a low-cost drone to automatically reconstruct the power lines in the object space. Two overlapping images are selected for epipolar image resampling, followed by the line extraction for the resampled images and the redundant images. The extracted lines from the epipolar images are matched together and reconstructed for the power lines primitive that are noisy because of the multiple line matches. They are filtered using the extracted line information from the redundant images for final power lines points. The experiment result showed that the proposed method successfully generated parabolic curves of power lines by interpolating the power lines points though the line extraction and reconstruction were not complete in some part due to the lack of the image contrast.

• KEPCO Journal on Electric Power and Energy
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• 제5권4호
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• pp.257-262
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• 2019

Lattice steel towers for overhead transmission lines have been replaced by tubular steel poles due to the visual impact of large and complex shape of truss type. Demand for tubular steel poles consisting of a single frame member continues to grow because of its advantages such as visual minimization, architectural appeal and minimal site consumptions. However, there are some constraints on the transportation and construction. As the diameter of tower base has been enlarged, it may exceed minimum height limit required to pass the tunnel in case of land transportation. Also, in a narrow place where it is not easy to secure the installation areas such as mountainous places, there might be some areas wherein it must secure a wide working space so that large vehicles and working cranes will be allowed to enter. In this paper, we presented a vertical separated tubular steel pole, which is a new type of support that can be implemented for general purpose such as mountainous areas or narrow areas to improve the issues raised by breaking away from the conventional design and fabrication methods. Technical approaches for overcoming the limit of the cross-sectional size is to separate and modularize the cross-section of the tubular steel pole designed with a size that cannot be carried or assembled, and to lighten it with a weight capable of being transported and assembled in a narrow space or mountainous area. As a result of this research, it will be possible to enter small and medium sized vehicles in locations where it is restricted to transport by large-sized vehicles. In the case of mountainous areas, it will be possible to divide it into a weight capable of being carried by a helicopter and it will be easy to adjust and fabricate it with individual modules. Furthermore, in order to break away from the traditional construction method, we proposed the equipment that can be applied to the assembly of Tubular Steel Pole without using a large crane in locations where there is no accessible road or in locations wherein large cranes cannot enter. In particular, this paper shows the movable assembling equipment and some methods that are specialized for vertical separated tubular steel pole consisting of members with reduced weight. The proposed assembly equipment is a device for assembling the body of the Tubular Steel Poles. It will be installed inside the support and the modules can be lifted by using the support itself.

• 한국지반공학회논문집
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• 제23권2호
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• pp.61-69
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• 2007

본 연구에서는 현장타설말뚝을 대상으로 지반조건 및 말뚝형태에 따른 수평지지력과 수평거동에 대하여 실험적 분석을 실시하였다. 이를 위해 가압토조실험을 수행하였으며 상대밀도와 지반응력의 변화를 고려하여 원통형과 테이퍼형 말뚝에 대해 재하시험을 수행하였다. 토조실험결과, 수직응력과 수평응력은 모두 말뚝의 수평거동 및 극한수평 지지력에 영향을 나타내는 것으로 관찰되고 있으나, 수평응력의 영향이 보다 더 크게 작용하고 있음을 알 수 있다. 상대밀도 또한 수평거동 및 지지력에 상당한 영향을 미치고 있는 것으로 나타나고 있었다. 수평거동에 대한 말뚝형태의 영향은 지반상태에 따라 다소간의 차이가 보이고 있으나, 전반적으로 지반응렬이나 상대밀도와 같은 지반특성치에 의한 영향에 비해서는 작게 나타나고 있었다. 기존 예측식을 이용한 비교분석 결과, 기존의 예측식에 의해 산정된 결과는 실측된 결과와 상당한 차이를 보이고 있었으며, 이는 지지력 산정시 수평응력의 변화량이 고려되어 있지 않았기 때문임을 알 수 있었다.