• Title/Summary/Keyword: Electric Displacement

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Comparative field tests on uplift behavior of straight-sided and belled shafts in loess under an arid environment

  • Qian, Zeng-zhen;Lu, Xian-long;Yang, Wen-zhi;Cui, Qiang
    • Geomechanics and Engineering
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    • v.11 no.1
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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.

Development for Life Assessment System for Pipes of Thermal Power Plants

  • Hyun, Jung-Seob;Heo, Jae-Sil;Kim, Doo-Young;Park, Min-Gyu
    • KEPCO Journal on Electric Power and Energy
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    • v.2 no.4
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    • pp.583-588
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    • 2016
  • The high-temperature steam pipes of thermal power plants are subjected to severe conditions such as creep and fatigue due to the power plant frequently being started up and shut down. To prevent critical pipes from serious damage and possible failure, inspection methods such as computational analysis and online piping displacement monitoring have been developed. However, these methods are limited in that they cannot determine the life consumption rate of a critical pipe precisely. Therefore, we set out to develop a life assessment system, based on a three-dimensional piping displacement monitoring system, which is capable of evaluating the life consumption rate of a critical pipe. This system was installed at the "M" thermal power plant in Malaysia, and was shown to operate well in practice. The results of this study are expected to contribute to the increase safety of piping systems by minimizing stress and extending the actual life of critical piping.

A Study on the Optimal Structural Design and Ultra Precision Position Control using FEM for Micro Stage (마이크로 스테이지의 유한요소법을 이용한 최적설계와 초정밀 위치제어에 관한 연구)

  • Kim, J. Y.;Han, J. H.;Kim, H. W.;You, S.;Kwac, L. K.;Song, I. S.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.336-340
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    • 1997
  • For optimal design of micro stage, we were measured to displacement of piezo-electric transducer that was based on voltage value. And then researchers were analyzed to microstage through FEM with displacement data including voltage value of piezo-electric transducer. For verification of analyzing results, we were gauged on displacement by using Laser-interferometer. And researchers were confirmed to propriety of micro stage design with FEM, were obtained error rate that are 3.5% between measurement results and analyzing results.

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Estimation of displacement responses of a suspension bridge by using mode decomposition technique (모드분해기법을 이용한 현수교의 변위응답추정)

  • Chang, Sung-Jin;Kim, Nam-Sik;Kim, Ho-Kyung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2009.04a
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    • pp.320-325
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    • 2009
  • In this study, a method to estimate the suspension bridge deflection is developed using mode decomposition technique. In order to examine the suspension bridge stability against these dynamic loadings, the prediction of displacement response is very important to evaluate bridge stability. However, it is recognized that any measurement of movement for suspension bridges may be difficult for the absence of proper methods to measure the displacement response on site. This study aims at suggesting a method to estimate the displacement response from the measured strain signals in an indirect way to predict the displacement response, not a direct way to measure the displacement response. Additionally, by applying the FBG sensors with multi-point measurements not influenced by electric noise, it can be expected that the technique would be applicable to infrastructures.

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The Shear Behavior of Composite Material for Retaining Wall (옹벽구조물용 복합재료의 전단거동 특성)

  • Oh, Gi-Dae;Kim, Kyung-Yul;Kim, Dae-Hong
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.1359-1364
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    • 2008
  • In these days, the composite material is popular as a material of Retaining wall because of the advantages of economy and construction. In general, retaining wall is not estimated for the stability of structure, but some of retaining walls that are composed of composite materials became thin because of the highly dense materials. So the concern of shear failure for the structure is rising. Because standard test criterion and large scale tests equipment are rarely available, few studies are performed. So, in this study, we performed large scale direct shear tests for various confining stresses(147, 294, 441 kPa), and estimate shear behavior of composite material by the relation of shear stress - displacement and vertical - shear displacement.

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Co-Simulation and Simulation Integration Technology Development for SUV Vehicle Equipped with Electric Power Steering (EPS) (SUV - EPS 차량의 동시 시뮬레이션 기술 개발 및 시뮬레이션 통합 기술 개발)

  • B. C. Jang;Y. K. Eom
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.472-475
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    • 2003
  • Electric Power Steering (EPS) mechanism has become widely equipped in passenger vehicle due to the environmental consciousness and higher fuel efficiency. This paper describes the development of co-simulation technique and simulation integration technique of EPS control system with dynamic vehicle model. A full vehicle model interacted with EPS control algorithm is concurrently simulated on a single bump road condition. Dynamic responses of vehicle chassis and steering system resulting from road surface impact are evaluated and compared with proving ground experimental data. The comparisons will show reasonable agreement on tie-rod load. rack displacement, handle-wheel torque and tire center acceleration. This developed simulation capability can be used for EPS performance evaluation and calibration as well as for vehicle handling performance integration and synthesis.

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The Stress Analysis of the Cross Beam of the Electric Car-body according to the Change of Location and Shape of Circular Hole (원공 위치와 형상 변화에 따른 전동차 크로스 빔의 강도해석)

  • Jeon, Hyung-Yong;Sung, Rak-Won;Han, Geun-Jo
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.9
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    • pp.9-17
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    • 1999
  • This investigation is the result of the structural analysis by finite element method for optimal design of the cross beam with circular holes of the electric car-body. in order to install the air pipe and electric wire pipe that correspond signal between electric machines for the control system and to reduce the weight of the electric car-body, several circular areas from a cross beam should be taken off. What we want to perform is the optimal design of a cross beam with circular holes to posses equal stress in comparison with no hole cross beam. first, no hole cross beam as basic modal be chosen, executing the analysis, reviewing the distribution of stress and displacement at each location. several parameter should be adopted from the cross beam geometry like the location and shape of the hole to affect the maximum stress and displacement. So the analysis was executed by finite element analysis for finding optimal design parameter to the change of the location and shape of the circular hole. finally, the optimal design of the cross beam with circular holes was obtained and the maximum equivalent stress was compared with no hole cross beam at each location.

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The analysis design and operating characteristics of VCM actuator for auto focusing (자동초점 조절용 VCM 액추에이터 구동특성 분석)

  • Park, J.M.;Lim, H.W.;Chae, B.;Kim, D.G.;Kim, P.H.;Cho, G.B.
    • Proceedings of the KIPE Conference
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    • 2007.07a
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    • pp.447-448
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    • 2007
  • Product development is consisting by trend that accommodate almost function digital cam in camera phone that can speak of Mobile appliance, and competition about number of elemental area of image sensor is consisting for market prior occupation between these. Propose in this research and small size camera phone self-focusing adjustment actuator that do city manufacture is similar with general storehouse pickup actuator drive way, but selected in cylindrical to reduce space that lens holder occupies because there is restriction loading of lens and space enemy. Target number of research established that execute drive displacement more than $600{\mu}m$ in 2.75V that is house voltage that is used in Mobile device that is general. Also, described about maximum transfer displacement characteristic, displacement response characteristic, hysteresis, response characteristic, smallest transfer step characteristic, actuator's drive characteristic that is manufactured to examination item of maximum consumption electric power by special quality estimation system that apply laser displacement sensor that produce itself to evaluate city manufactured actuator's special quality.

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$\pi$-A properties of phospholipid monolayers by Maxwell-displacement-current-measuring technique (변위전류법에 의한 지질 단분자막의 $\pi$-A특성)

  • 이경섭;전동규;권영수;국상훈
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1995.05a
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    • pp.120-123
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    • 1995
  • Maxwell-Displacement-Currnt-Measuring Technique(MDCM) is a simple system for displacement current measuring which consist with two electrodes to the electrometer, With this method, the displacement current flow only when the electric flux density change by the displacement of molecules or charge particles of membrance on the water surface. Thus, It is Possible to detect dynamic behavior of molecules of membrane without any electrical contact with molecule membrane. In this paper, We measure surface pressure, displacement current and dipole moment of phospholipid monolayers on the wafer surface with applied pressure by MDCM and We measured DTA(differential thermal analysis).

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A study on the structural of phospholipid membranes by thermally stimulated displacement current method (열자격 변위 전류법에 의한 인지질막의 구조 연구)

  • 이경섭;김우연;권영수;이준응;강도열
    • Electrical & Electronic Materials
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    • v.9 no.7
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    • pp.696-701
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    • 1996
  • In this study, deposited lipid membranes on the electrode and detected thermally stimulated displacement current generated from it. The researchers examined displacement current of electric conduction organic monolayer generated due to orient change of monolayers alkylchain and changed of dipole moment vertical component due to thermally stimulated. We paid attention to the phase transition temperature obtained by the thermally stimulated displacement current of lipid membrane layers this time. We detected the thermally stimulated displacement current peak of layers. From above results the transition temperature dilauroylphosphatidylcholine layers is about 43.deg. C. This study also compared above results with those obtained by differential thermal analysis method.

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