• Wind and Structures
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• 제15권4호
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• pp.345-354
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• 2012

This work discusses the wind stability requirements specified by UN Reg. 27 on emergency car warning triangles, which are of mandatory use in many countries. Wind tunnel experiments have been carried out in order to determine aerodynamic coefficients of commercial warning triangles and the friction coefficients between the triangle legs and an asphalt base that fulfils the roughness requirements stated by Reg. 27 for wind stability certification. The wind stability specifications for warning triangles are reviewed, compared with pressure field measurements and discussed. Results of wind tunnel tests and comparison with field measurements reported in the literature show that the requirements could be excessively conservative.

• 사물인터넷융복합논문지
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• 제4권1호
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• pp.37-41
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• 2018

본 논문은 도로에서 발생하는 2차 사고를 예방하기 위한 스마트 안전 삼각대를 연구한다. 도로에서 교통사고 후, 사고를 알리기 위해 안전 삼각대를 설치해야 된다. 그러나 안전 삼각대 설치 중 2차 사고를 유발할 수 있다. 이러한 문제를 해결하기 위해 스마트 안전 삼각대를 제안하고 구현하였다. 스마트 안전 삼각대는 충격을 감지하면 로고 라이트을 통해 삼각대의 역할을 수행한다. 아두이노를 이용하여 충격 감지, 로고 라이트 기능을 수행한다. 제안된 스마트 안전 삼각대는 조명의 밝기 등이 보완되면 안전 삼각대로의 역할을 수행하여 2차 사고 예방에 도움이 될 것으로 기대한다.

• 건축역사연구
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• 제1권1호
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• pp.205-217
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• 1992

For all the variety of past studies on the pyramids of Old Kingdom of Egypt, they still basically remain in 'enigma and mystery' as Giedion rightly puts in. This paper deals directly with the three most obvious facts about the pyramids : their cardinal orientation, the varying slopes, and above all, their magnitude. The prominent triangles of their once polished faces were there to be seen from the Nile valley as they shined or shaded under the Sun. The northern faces, especially, went in and out of the Sun in accordence with the seasonal variation of the solar declination, The steeper northern faces which turned into shade in high summer noon could have been warning signs of oncoming inundation of Nile, and the milder slopes that suddenly began to shine in some early spring noons could have been the vernal alarms to awaken the peasants to their timely toil on the fresh land. Dates and hours of insolation on the northern faces of pyramids are graphically and numerically computed.