• Title, Summary, Keyword: End effect

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Detection of Microphytobenthos Using Spectral Unmixing Method in the Saemangeum Tidal Flat, Korea

  • Lee, Y.K.;Won, J.S.;Ryu, J.H.
    • Proceedings of the KSRS Conference
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    • pp.853-855
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    • 2003
  • Microphytobenthos that supply nutrients to the intertidal ecosystem play an important part as a primary producer. If we estimate distribution and density of microphytobenthos, we can possibly calculate a volume of primary product in the tidal flat and its effect to the intertidal ecosystem. To estimate the portion of microphytobenthos, we used a linear spectral unmixing (LSU) method. LSU is a tool for inference the proportions of the pure components (or end-members) in a mixed pixel. The selection of end-members is critical to LSU. The end-members can be selected either from spectral libraries built from field surveys or from a remotely sensed image. We compared the two approaches of end-member selection, and the preliminary results showed end-members from from spectral library are as effective as those from image itself.

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Prediction of Surface Roughness of Al7075 on End-Milling Working Conditions by Non-linear Regression Analysis (비선형 회귀분석에 의한 엔드밀 가공조건에 따른 Al7075의 표면정도 예측)

  • Cho, Yon-Sang;Park, Heung-Sik
    • Tribology and Lubricants
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    • v.26 no.6
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    • pp.329-335
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    • 2010
  • Recently, the End-milling processing is needed the high-precise technique to get a good surface roughness and rapid time in manufacturing of precision machine parts and electronic parts. The optimum surface roughness has an effect on end-milling working condition such as, cutting direction, spindle speed, feed rate and depth of cut, and so on. It needs to form the correlation of working conditions and surface roughness. Therefore this study was carried out to presume of surface roughness on end-milling working condition of Al7075 by regression analysis. The results was shown that the coefficient of determination($R^2$) of regression equation had a fine reliability of 87.5% and nonlinear regression equation of surface rough was made by multiple regression analysis.

Technology of Remote Bundle Welding for CANDU Fuels (중수로 연료용 원격다발 용접기술)

  • Kim, S.S.;Lee, J.W.;Park, G.I.;Koh, J.H.
    • Proceedings of the KWS Conference
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    • pp.33-33
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    • 2009
  • This study is to develop the resistance welding apparatus and investigate the welding characteristics of Zircaloy-4 end-plate of fuel bundle in the cases of the resistance welding and the laser beam welding. The welding parameters which affect the weld nugget and the torque values have been also compared. The effect of the torque strength of end-plate welding using by the resistance welding and the laser beam welding has been studied and optimum conditions of Zircaloy-4 end-plate welding have been found. Futhermore, micro-structures and micro-hardness of the resistance welded specimens have been also compared.

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Analysis on the Precision Machining in End Milling Operation by Simulating Surface Generation (엔드밀 가공시 표면형성 예측을 통한 정밀가공에 관한 연구)

  • Lee, Sang-Kyu;Ko, Sung-Lim
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.4
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    • pp.229-236
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    • 1999
  • The surface, generated by end milling operation, is deteriorated by tool runout, vibration, tool wear and tool deflection, etc. Among them, the effect of tool deflection on surface accuracy is analyzed. Surface generation model for the prediction of the topography of machined srufaces has been developed based on cutting mechanism and cutting tool geometry. This model accounts for not only the ideal geometrical surface, but also the deflection of tool due to cutting force. For the more accurate prediction of cutting force, flexible end mill model is used to simulate cutting process. Computer simulation has shown the feasibility of the surface generation system. Using developed simulation system, the relations between the shape of end mill and cutting conditions are analyzed.

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A Consideration of Open End & Step Discontinuity Effects for Suspended Strip Line (Suspended Strip Line의 Open End 및 Step 불연속 효과에 대한 고찰)

  • Jeon, Yong-Ku;Yang, Seung-In
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.45 no.12
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    • pp.146-151
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    • 2008
  • The equivalent circuits of Open End and Step discontinuity effects for Suspended Strip line are obtained. The circuit parameters for each discontinuity effect are represented by equations after optimization based on EM analysis results, and the coefficients of the equations are obtained by curve fitting for all impedance cases.

Quantitative Analysis and Mathematical Model for Spindle Vibration of the End-Milling by Design of Experiment (실험계획법을 이용한 엔드밀 가공시 주축 진동에 대한 정량적 분석 및 수학적 모형)

  • Park, Heung-Sik;Lee, Sang-Jae;Bae, Hyo-Jun;Jin, Dong-Kyu;Kim, Young-Hee
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.3 no.4
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    • pp.37-42
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    • 2004
  • End-milling have been widely used in aircraft, automobile part and moulding industry. However, various working factors such as spindle speed, feed rate and depth of cut in end-milling have an effect on spindle vibration. There it is demanded the quantitative analysis of spindle vibration in order to get the optimum surface roughness. This study was carried out to analyze an influence of working factors on spindle vibration by design of Experiment. The results are shown that mathematical model of regression equation for an influence of working factors on vibration acceleration of spindle in end-milling by regression analysis is presented.

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Steady-State Performance Analysis of an Integrated Wind Turbine Generating System in a DC Transmission System with Power Compensation System

  • Yamashita, Ken-Ichiro;Nishikata, Shoji
    • Journal of international Conference on Electrical Machines and Systems
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    • v.1 no.1
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    • pp.121-127
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    • 2012
  • An electric power compensation system for a DC transmission system with an integrated wind turbine generator is proposed. The proposed compensation system consists of a synchronous generator and a duplex reactor. This apparatus is connected to the sending-end circuit of the DC transmission system. A set of steady-state equations of the system is first derived. Then, the effect of the duplex reactor, which can eliminate the sending-end grid current distortion due to commutation of the converter, is explored. The relationships among power at the sending-end circuit are also revealed. It is shown that fluctuations in the sending-end grid power due to changes in wind velocities are compensated with the proposed system. Finally, the effects of the sending-end grid conditions on the steady-state characteristics of the system are studied.

Ginsenoside Rg3 protects against iE-DAP-induced endothelial-to-mesenchymal transition by regulating the miR-139-5p-NF-κB axis

  • Lee, Aram;Yun, Eunsik;Chang, Woochul;Kim, Jongmin
    • Journal of Ginseng Research
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    • v.44 no.2
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    • pp.300-307
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    • 2020
  • Background: Emerging evidence suggests that endothelial-to-mesenchymal transition (EndMT) in endothelial dysfunction due to persistent inflammation is a key component and emerging concept in the pathogenesis of vascular diseases. Ginsenoside Rg3 (Rg3), an active compound from red ginseng, has been known to be important for vascular homeostasis. However, the effect of Rg3 on inflammation-induced EndMT has never been reported. Here, we hypothesize that Rg3 might reverse the inflammation-induced EndMT and serve as a novel therapeutic strategy for vascular diseases. Methods: EndMT was examined under an inflammatory condition mediated by the NOD1 agonist, γ-d-glutamyl-meso-diaminopimelic acid (iE-DAP), treatment in human umbilical vein endothelial cells. The expression of EndMT markers was determined by Western blot analysis, real-time polymerase chain reaction, and immunocytochemistry. The underlying mechanisms of Rg3-mediated EndMT regulation were investigated by modulating the microRNA expression. Results: The NOD1 agonist, iE-DAP, led to a fibroblast-like morphology change with a decrease in the expression of endothelial markers and an increase in the expression of the mesenchymal marker, namely EndMT. On the other hand, Rg3 markedly attenuated the iE-DAP-induced EndMT and preserved the endothelial phenotype. Mechanically, miR-139 was downregulated in cells with iE-DAP-induced EndMT and partly reversed in response to Rg3 via the regulation of NF-κB signaling, suggesting that the Rg3-miR-139-5p-NF-κB axis is a key mediator in iE-DAP-induced EndMT. Conclusion: These results suggest, for the first time, that Rg3 can be used to inhibit inflammation-induced EndMT and may be a novel therapeutic option against EndMT-associated vascular diseases.