• Title/Summary/Keyword: Dae-Yong Hong

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MECHANICAL POWER SYSTEM OF TONGCHEON-UI, AN ASTRONOMICAL CLOCK MADE BY HONG, DAE-YONG (홍대용이 제작한 천문시계 통천의의 기계동력시스템)

  • MIHN, BYEONG-HEE;YUN, YONG-HYUN;KIM, SANG HYUK;KI, HO CHUL
    • Publications of The Korean Astronomical Society
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    • v.35 no.3
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    • pp.43-57
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    • 2020

  • Hong, Dae-Yong manufactured the Tongcheon-ui (Pan-celestial Armillary Sphere) with cooperating clock researcher Na, Kyeong-Jeok, and its craftsman An, Cheo-In, in Naju of Jeolla Province in 1760 ~ 1762. Tongcheon-ui is a kind of astronomical clock with an armillary sphere which is rotated by the force generated by a lantern clock's weight. In our study, we examine the lantern clock model of Tongcheon-ui through its description of the articles written by Hong himself. As his description, however, did not explain the detail of the mechanical process of the lantern clock, we investigate the remains of lantern clocks in the possession of Korea University Museum and Seoul National University Museum. Comparing with the clocks of these museums, we designed the lantern clock model of Tongcheon-ui which measures 115 mm (L) × 115 mm (W) × 307 mm (H). This model has used the structure of the striking train imitated from the Korea University Museum artifact and is also regulated by a foliot escapement which is connected to a going train for timekeeping. The orientation of the rotation of the going train and the striking train of our model makes a difference with the remains of both university museums. That is, on the rotation axis of the first gear set of Tongcheon-ui's lantern clock, the going and the striking trains take on a counterclockwise and clockwise direction, respectively. The weight of 6.4 kg makes a force driving these two trains to stick to the pulley on the twine pulling across two spike gears corresponding to the going train and the striking train. This weight below the pulley may travel down about 560 mm per day. We conclude that the mechanical system of Tongcheon-ui's lantern clock is slightly different from the Japanese style.

  • https://doi.org/10.5303/PKAS.2020.35.3.043 인용 PDF KSCI

Improvement Effect on Design Parameters by Pressure Grouting Applied on Micro-piling for Slope Reinforcement (가압식 마이크로파일로 보강된 사면의 설계인자 개량효과)

  • Hong, Won-Pyo;Han, Hyun-Hee;Choi, Yong-Ki;Hong, Ik-Pyo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.163-170
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    • 2005

  • In this paper, the rock bolts, soil nails with filling grout and the micro-piling with injecting grout by pressure were applied for the stabilization of the cut slopes consisting of sedimentary rocks, igneous rocks and metamorphic rocks respectively. The field measurements and 3-D FEM analyses to find out mobilized tensile stresses of the grouted-reinforcing members installed in the drilled holes were executed on each site. With assuming the increments of the cohesive strength in the improved ground, the back analysis using direct calibration approach of changing the elastic modulus of the ground was used to find out the improved elastic modulus which yields the same tensile stresses from field measurements. The results of back analysis show that the elastic modulus of the improved ground were 4 to 6 times as large as the elastic modulus of original ground. Consequently, the design for slope reinforcement to be more rational, it is proposed that not only the improved cohesive strength is to be used in the incremental ranges on well-known previous proposed data, but also the increased elastic modulus which is about 5 times as large as the original elastic modulus is to be considered in design.

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