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Park, S.S.;Kim, D.K.;Yoo, H.R.;Cho, S.H.;Park, D.J.;Koo, S.J.;Rho, Y.W.;Lee, J.G.;Hong, H.S.;Seo, J.W.;Park, C.G.
- Proceedings of the KSME Conference
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- 2001.06b
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- pp.222-227
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- 2001
This paper introduces the spring-mounted odometer system which maintains the correct contact with the pipe wall and measures the distance along the pipe. The odometer wheel is designed to keep contact to the pipelines inner wall and to generate fifty rectangular pulses per one turn(l59.5681mm) during pigging. The pipeline has the defects in various types such as buckles, winkles, cracks, dents, welding point and so on. Specially, girth welding points which exist each 12m of the pipeline, much affects the operational environment of the odometer. The measurement error of the distance along the pipe is accumulated, for the measurement error of wheel's circumference and the pipeline inner environment. So, this paper proposes the method for the error compensation based on the analysis of the odometer's behavior around the girth welding point of pipe. The experimental results show that developed odometer system can be used for the intelligent pig with good performances.
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J.W. Ahn;I.H. Song;K.S. Kim;K.Y. Kim;I.S. Moon
- Journal of the Society of Naval Architects of Korea
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- v.37 no.2
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- pp.14-21
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- 2000
The cavitation noise of 2-D hydrofoils is measured a cavitation tunnel. A new experimental method was developed for the noise measurement of 2-D hydrofoil. Three hydrofoils with the span of 600mm are designed and manufactured to investigate cavitation behavior and noise characteristics. The experimental results show the noise characteristics of various cavitation patterns and the noise performance of the three foils very well. This suggests that low-noise propeller blade section can be developed using the present experimental method.
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Choi, Seung-Man;Kim, Min-Joo;Choi, Young-Ho;Ahn, Ho-Jung;Yun, Yeo-Pyo
- YAKHAK HOEJI
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- v.42 no.1
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- pp.89-94
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- 1998
Propionibacterium acnes is the pharmacological target site of antiacne drugs. We have examined the antiacne activity of ninety seven natural products which have been used as Korean traditional medicines in various skin disorders. The antibacterial activity of extracts from the natural products were evaluated against P. acnes ATCC 9616 by disc method. Twelve natural products showed the potent antibacterial activity against P. acnes, and were, selected for the minimal inhibitory concentration(MC) against P. acnes. MICs of nine extracts were below 0.3% (w/v) and Sophora flavescens showed the most potent activity with a MIC of less than 0.008%(w/v) against P. acnes. Thus, the results suggest that nine natural products including S. flavescens can be developed as sources of promising potent antiacne agents.
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곽영주;장용구;김상석;강인준
- Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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- 2004.11a
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- pp.99-104
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- 2004
Recently, the old surveying method for acquiring surveying-geo information results had a low economic efficiency and a low dependence of precision because it took much times and high costs. So, we acquired law data by execution of control surveying through Static positioning of DGPS(Ashtech). It is computed plainmetric(X, Y) positioning through postprocessing by Prism S/W. And we computed height(Z) through control surveying by ring-closed leveling surveying. After control surveying execution, we built DEM(Digital Elevation Model) using LDT S/W and accuracy 3D detail surveying by EDM(Electronic Distance Measurement) surveying. The purpose of this study was to yield automated digital mapping and the automated amount of materials using ahead data. The conclusions were as follows; First, we built the automated amount of materials system and got high efficiency about personnel, times and precision. Second, when, people precisely positioned on railroads of a high-speed railroad and used GPS surveying, the result was permitted. Finally, it was possible to draw automated profile and cross-section using the 3D terrain model build with the DEM technique.
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Lee, S.N.;Baek, S.W.
- 한국전산유체공학회:학술대회논문집
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- 2008.03b
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- pp.547-550
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- 2008
A solid rocket motor has quite complex physical condition such exothermal chemical reaction in subsonic area and supersonic ex pansion in a converging-diverging nozzle. To introduce a simulation tool for compressible flow in supersonic range as well as incompressible chemical reaction zone in a whole rocket nozzle is a essential demand. Since the flow vary subsonic to super sonic, the convergence in computation becomes very low and unstable in a whole domain of rocket motor. This paper reports the 2-D Axisymmetric and simple 3-D solid propellant combustion and flow of gases in rocket motor by using a precondi tioning, shear stress turbulence modeling, AUSM(p). To simulate the simplified combustion process, Double base solid propellant is used to calculate reaction of solid propellant.
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