• 제목/요약/키워드: experimental device

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보이스 코일 모터를 이용한 미세 하중 및 위치 결정 기구의 개발 (Development of Small Loading and Positioning Device using VCM)

  • 권기환;오승환;조남규;윤준용
    • 한국정밀공학회지
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    • 제20권12호
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    • pp.64-72
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    • 2003
  • This paper presents a small loading and positioning device using VCM (voice coil motor). The developed device consists of a VCM-based linear actuating system, a capacitance displacement sensor and a cantilever deflection sensing system. The trust force of the VCM proportional to applied current moves the column supported on two pairs of parallel leaf springs. The infinitesimal displacement of moved column is detected by capacitance displacement sensor with a resolution of 0.1nm and a repeatability of 1nm. Also, a micro cantilever with known stiffness (200N/m), which is mounted on the end of the column, is used as a force sensor to detect the load applied to a specimen. After the cantilever contacts with the specimen, the deflection of cantilever and the load applied to the specimen are measured by using an optical lever system which consists of a diode laser, a mirror and a PSD (position sensitive detector). In this paper, an experimental system was constructed and its actuator and sensing parts were tested and calibrated. Also, the constructed system was applied to the indentation experiment and the load-displacement curve of aluminum was obtained. Experimental results showed that the developed device can be applied for performing nano indentation.

직접반사형 포토센서를 이용한 스톨 사육 모돈의 인공수정적기 예측 장치 개발 (Development of a Device for Estimating the Optimal Artificial Insemination Time of Individually Stalled Sows Using Direct-reflex Photo-sensors)

  • 김동주;연성찬;장홍희
    • Journal of Biosystems Engineering
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    • 제29권6호
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    • pp.515-520
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    • 2004
  • A device far estimating the optimal artificial insemination time consisted of a computer, RS module, and six direct-reflex photo-sensors. Program was written in LabWindows CVI. In order to establish references for estimating optimal artificial insemination time, lying rate of the thirty three $Berkshire{\times}Hampshire crossbred sows (parity 5 to 6) was recorded from 2 days after moving into stalls to artificial insemination using a time lapse VCR and was measured every hour with one minute interval using the scan point sampling method. Twenty low hours in a day were divided into three comparing periods : 21:00 to 06:59, 07:00 to 13:59, and 14:00 to 20:59. If sum of the percentages of tying during a comparing period was less than the reference value, the starting hour of the comparing period was considered as onset of estrus and the optimal artificial insemination time was estimated at 20 to 24 hours after onset of estrus. The experimental device was evaluated with twenty five $Berkshire{\times}Hampshire$ crossbred sows (parity 2 to 7) and 23 of 25 sows $(92\%)$ were pregnant. This result suggests that the experimental device is excellent in performance for estimating optimal artificial insemination time.

혈관 내 폐 보조장치에서의 산소전달속도 예측에 관한 연구 (A Study of Prediction of Gas Transfer rate in Intravascular Lung Assist Device)

  • 김기범;나도춘;김성종;정인수;정경락;권대규
    • 멤브레인
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    • 제14권1호
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    • pp.18-25
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    • 2004
  • 본 연구의 목적은 정맥 내 폐 보조장치 설계에 있어서 기체전달을 예측하기 위하여 혈관 내 폐 보조장치를 정맥 내에 삽입하기 전, 여러 가지 설계조건에서 실험적 모델링을 통하여 예측식을 찾고자 시도하였다. 실험결과 중공사 충진율의 함수에 따라 기체전달을 예측할 수 있었다. 실험에 의하여 얻어진 기체전달은 예측식에 의한 기체전달과 유사하여, 식에 대한 신뢰성을 얻을 수 있었다. 그러므로, 중공사의 충진율의 함수에 따라 기체전달을 예측할 수 있으며, 혈관 내 폐 보조장치의 기체전달을 예측하는데 매우 유용하였다.

포고억제장치(PSD) 동특성 모델링에 관한 연구 (Study on Dynamics Modeling of Pogo Suppression Device (PSD))

  • 이준경
    • 한국추진공학회지
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    • 제11권5호
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    • pp.23-30
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    • 2007
  • PSD(pogo suppression device)는 액체 추진 로켓의 추진제 공급부를 모사한 배관 시스템에 대한 기존의 실험 연구를 통해 배관 시스템의 동특성을 변화시킬 수 있음을 확인할 수 있었다. 본 연구에서는, PSD에 대한 수학적 모델을 만들고, 각 변수에 대한 값을 결정하는 과정에서 이론적으로 구하기 힘든 변수를 파악하여, 이를 기존의 실험 결과로부터 구하고자 하였다. 그를 위해, 선형화된 전달함수를 만들어 전체 시스템에 대한 불안정성을 판단하는 방법에 대해, PSD를 유체 섭동에 대한 연속 방정식 등의 지배 방정식을 이용하여, 제작된 PSD의 실제 적용시 중요한 이너턴스, 컴플라이언스, 레지스턴스 등의 변수를 수식화하고, 실험 결과를 이용하여 이를 정량화 하는 방법을 제시하였다.

Experimental investigation of a new steel friction device with link element for seismic strengthening of structures

  • Papadopoulos, Panikos K.;Salonikios, Thomas N.;Dimitrakis, Stergios A.;Papadopoulos, Alkis P.
    • Structural Engineering and Mechanics
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    • 제46권4호
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    • pp.487-504
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    • 2013
  • In the present work a new friction device, with a set of single or double rotational friction flanges and a link element, is described and tested. The mechanism may be applied for the strengthening of existing r/c or steel buildings as well as in new constructed buildings. The device has selectable variable behavior in different levels of displacement and an interlock mechanism that is provided by the link element. The link element may be designed to lock at preselected level of displacement, offering in this way an extra safety reserve against strong earthquakes. A summary of the existing literature about other similar mechanisms is initially presented in this paper. The proposed mechanism is presented and described in details. Laboratory experiments are presented in detail and the resulted response that proves the efficiency of the mechanism at selectable levels of strength capacity is discussed. Drawings of the mechanism attached to a r/c frame with connection details are also included. Finally a dynamic analysis of two r/c frames, with and without the proposed mechanism attached, is performed and the resulted response is given. The main conclusion is that the proposed mechanism is a cheap and efficient devise for the improvement of the performance of new or existing framed buildings to seismic loads.

CHARACTERISTICS OF THE HETEROEPITAXIAL Si1-xGex FILMS GROWN BY RTCVD METHOD

  • Chung, W.J.;Kwon, Y.K.;Bae, Y.H.;Kim, K.I.;Kang, B.K.;Sohn, B.K.
    • 한국진공학회지
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    • 제4권S2호
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    • pp.84-89
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    • 1995
  • The growth and the film characteristics of heteroepitaxial $Si_{1-x}Ge_x$ films growth by the Rapid Thermal Chemical Vapor Deposition(RTCVD)method are described. For the growth of $Si_{1-x}Ge_x$ heteroepitaxial layers, $SiH_4/GeH_4/H_2$gas mixtures are used. The growth conditions are varied to investigate their effects on the Si/Ge composition ratios, the interface abruptness and crystalline properties. The Si/Ge composition ratios are analyzed with the RBS and the SIMS techniques, and the interface abruptness are deduced from these data. The crystalline properties are analyzed from TEM pictures. The experimental data shows that the crystalline perfection is excellent at the growth temperature of as low as $650^{\circ}C$, and the composition ratios change linearly with $SiH_4/GeT_$$ gas mixing ratios in our experimental ranges. Boron doping experiments are also performed using 200 ppm $B_2H_6$ source gas. The doping profiles are measured with SIMS technique. The SIMS data shows that the doping abruptness can be controlled within about 200$\AA$/decade.

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OWC형 파력발전 공기챔버의 공기감쇠력 실험연구 (An Experimental Study of Pneumatic Damping at the Air Chamber for OWC type Wave Energy Device)

  • 최학선;류재문;홍석원;김진하
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2004년도 학술대회지
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    • pp.138-144
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    • 2004
  • Pneumatic damping through a orifice type duct for OWC type wave energy device is studied experimentally. Forced oscillation tests are made to measure chamber pressure and velocity of air flaw through orifice. Pneumatic damping coefficient are deducted from the experimental research, and discussion are made far the influence of frequency, heave amplitude, and orifice size. Finally two formula are proposed for the estimation of non-dimensional pneumatic damping coefficient by regression analysis. The proposed formula proves to be a reliable method far practical application.

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Effect of Wavy Flow of Vertical Falling Film on the Absorption Performance

  • Kim, Jung-Kuk;Cho, Keum-Nam
    • International Journal of Air-Conditioning and Refrigeration
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    • 제13권3호
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    • pp.158-166
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    • 2005
  • The present study investigated experimentally and numerically the enhancement of absorption performance due to the waviness of falling film in the vertical absorber tube. The momentum, energy and mass diffusion equations were utilized to find out temperature and concentration profiles at both the interfaces of liquid solution and refrigerant vapor and the wall. Flow visualization was performed to find out the wetting characteristics of the falling film. The maximum heat transfer coefficient was obtained for the wavy flow using spring as an insert device through both numerical and experimental studies. Based on the numerical and experimental results, the maximum absorption rate was found for the wavy-flow using spring as the insert device. The differences between experimental and analytical results ranged from $5.0\;to\;25\%\;when\;Re_j>100$.

OWC형 파력발전 공기챔버의 공기감쇠력 실험 연구 (An Experimental Study of Pneumatic Damping at the Air Chamber for an OWC-type Wave Energy Device)

  • 최학선;홍석원;김진하;류재문
    • 한국해양공학회지
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    • 제18권4호
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    • pp.8-14
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    • 2004
  • Pneumatic damping through an orifice-type duct for an OWC-type wave energy device is studied experimentally. Forced oscillation tests are used to measure chamber pressure and velocity of air-flow through an orifice. Pneumatic damping coefficients are deducted from the experimental research, and the influence of frequency, heave amplitude, and orifice size are discussed. Finally, two formulas are proposed for the estimation of non-dimensional pneumatic damping coefficient by regression analysis. The proposed formula proves to be a reliable method for practical application.

다공질 공기 베어링의 강성 특성에 관한 실험 연구 (An Experimental Study on Porous Air Bearing Stiffness Characteristics)

  • 정순철;이성혁;이재응;지홍규;이동진;류제형;최형길;김혁
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 추계학술대회논문집
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    • pp.75-78
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    • 2005
  • In this paper, an experimental study on porous air bearing stiffness for ultra precision positioning system was performed. In general manufacturer provide bearing stiffness under specific air pressure, but the air pressure used in the field is different. Therefore it is necessary to know the stiffness of air bearing under the pressure used in the field. In order to know that, experimental device which can realize actual operating conditions was made. Using this device, static and dynamic stiffness of air bearing can be obtained. As a result, displacement error occurred around 1 $\mu$m at recommended load.

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