• Title/Summary/Keyword: Absolute measurement

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Development of 3-dimensional measuring robot cell (3차원 측정 로보트 셀 개발)

  • Park, Kang;Cho, Koung-Rae;Shin, Hyun-Oh;Kim, Mun-Sang
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10a
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    • pp.1139-1143
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    • 1991
  • Using industrial robots and sensors, we developed an inline car body inspection system which proposes high flexibility and sufficient accuracy. Car Body Inspection(CBI) cell consists of two industrial robots, two corresponding carriages, camera vision system, a process computer with multi-tasking ability and several LDS's. As industrial robots guarantee sufficient repeatabilities, the CBI cell adopts the concept of relative measurement instead of that of absolute measurement. By comparing the actual measured data with reference data, the dimensional errors of the corresponding points can be calculated. The length of the robot arms changes according to ambient temperature and it affects the measuring accuracy. To compensate this error, a robot arm calibration process was realized. By measuring a reference jig, the differential changes of the robot arms due to temperature fluctuation can be calculated and compensated.

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The Absolute Rate Measurement by Light Modulation-ESR Technique (Light Modulation-전자상자성공명법을 이용한 절대속도상수의 결정)

  • Choo Kwang Yul;Gaspar Peter P.
    • Journal of the Korean Chemical Society
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    • v.21 no.4
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    • pp.270-275
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    • 1977
  • A rate constant is deduced for the reaction of tert-butoxy radicals and trimethylsilane from the measurement of the phase shift between the modulated light source and the ESR signal of trimethylsilyl radical. The rate constant was found to $3{\times}10^{-2}M^{-1}{\cdot}sec^{-1}$ at $-50^{\circ}C$.

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Measurement of Spatial Coherence Function of laser beam by using a Sagnac Interferometer (샤냑간섭계를 이용한 레이져빔의 Spatial Coherence Function 측정)

  • Lee, Chang-Hyouck;Kang, Yoon-Shik;Sung, Yu-Gene;Noh, Jae-Woo
    • Proceedings of the Optical Society of Korea Conference
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    • 2007.07a
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    • pp.111-112
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    • 2007
  • The spatial coherence function of laser beam was measured by using a Sagnac interferometer and self referencing technique. For laser beam passing through a narrow slit, absolute value of measured spatial coherence function becomes more symmetric as the slit size is reduced. For diverging beams, the spatial coherence function shows fast oscillations in its real and imaginary parts. We explain this by using a Gaussian Schell-model. One can use this measurement method to study and characterize the property of light field coming out of small sample.

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Techniques of deformations measurement in Electric Power structure by using Close Range Photogrammetry (근거리사진측량을 이용한 전력구조물의 미소변위 측정기법)

  • 김감래;김명배
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.12 no.1
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    • pp.77-87
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    • 1994
  • One of the often espoused merits of close-range photogrammetry is the effectiveness of the method for measuring non-accessible objects of unusual and complex shape. In this study, techniques of deformation measurement using close-range photogrammetry for electric power structures were developed. Absolute deformation could be found efficiently through close-range photogrammetry in the structure deformation analysis based on time variation. Also, feasibility of the structures management system was presented based on this study.

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Absolute Measurement of the Quantum Efficiency of Photodetectors Using Correlated Photon Pairs (광자쌍을 이용한 광검출기의 양자효율 절대측정)

  • 안경진
    • Korean Journal of Optics and Photonics
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    • v.4 no.4
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    • pp.452-456
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    • 1993
  • The quantum efficiencies of photomultiplier tubes were measured by counting the coincidence photon pairs generated in the process of spontaneous parametric down-conversion. They were measured within 3% accuracy over the range of wavelength from 560 to 850 nm without any standard light source or detector. The values for 633 nm correspond to those obtained with a calibrated laser power meter within the measurement error.

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VISUAL MEASUREMENT METHOD USING A CIRCULAR GROOVE IMAGE FOR MEASURING INTERNAL DEFECTS OF PIPES IN NUCLEAR POWER PLANT

  • Choi, Young-Soo;Jeong, Kyung-Min;Lee, Sung-Uk;Jung, Seung-Ho
    • Nuclear Engineering and Technology
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    • v.40 no.5
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    • pp.419-428
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    • 2008
  • During the overhaul period of nuclear power plants in Korea, an ROV(Remotely Operated Vehicle) enters the cold-leg pipes connected with the reactor to examine the state of the thermal sleeves and their positions in the safety injection nozzles. To measure the positions of the thermal sleeves or scratches with video images recorded during the examination, time-varying camera parameters should be known, such as the focal length and principal points used for the capturing each video image. In this paper, we propose a camera calibration and measurement scheme by using a single image containing two circular grooves of a cylindrical nozzle whose radius and distance are known.

Measurement of Spatial Coherence Function of Laser Beam by using a Sagnac Interferometer

  • Lee, Chang-Hyouck;Kang, Yoon-Shik;Sung, Yu-Gene;Noh, Jae-Woo
    • Journal of the Optical Society of Korea
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    • v.11 no.2
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    • pp.71-75
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    • 2007
  • The spatial coherence function of a laser beam was measured by using a Sagnac interferometer and self referencing technique. For a laser beam passing through a narrow slit, the absolute value of the measured spatial coherence function becomes more symmetric as the slit size is reduced. For diverging beams, the spatial coherence function shows fast oscillations in its real and imaginary parts. We explain this by using a Gaussian Schell-model. One can use this measurement method to study and characterize the property of the light field coming out of a small sample.

Electrical Safety Inspection for Empty Houses Using Leakage Current Measurement (누설전류 측정을 이용한 부재수용가의 전기안전 점검)

  • Lim, Young-Bae;Jung, Jong-Wook;Jung, Jin-Soo;Cho, Seong-Won
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2006.05a
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    • pp.260-263
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    • 2006
  • The number of empty houses during normal working hours is rising. As a result, the number of uninspected electric installations for general use is increasing. To define the potential risk of the electric installation, measurement of leakage current has been getting considered but because the measured leakage current value also contained leakage current by capacitance, the measured value can not be adapted to absolute reference to the installation. Therefore in this paper, the correlation between the condition of electric installation and leakage current were analyzed.

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Noise Criteria for the Calculation of Response Spectra (응답스펙트럼 계산을 위한 잡음기준)

  • 노명현;최강룡;윤철호
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.03a
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    • pp.238-246
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    • 2003
  • By using simulated ground motions, which is sum of earthquake signals and noise, we measured the distortion of response spectra due to noise. We found that the distortion is more closely related to the signal-to-noise (S/N) ratio of root-mean-square (RMS) measurement than that of conventional peak measurement. Given a S/M ratio, the distortion of absolute acceleration response spectra is independent on the earthquake magnitude, while that of relative displacement response spectra has a strong dependence on the earthquake magnitude. This means that, when we calculate response spectra from time histories, we can efficiently predict the distortion of acceleration response spectra simply by measuring the RMS SJN ratios, or the distortion of displacement response spectra by combining the RMS S/N ratios and the earthquake magnitudes.

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Characteristics and Dynamic Compensation Modeling of Liquid-Based Tilt Sensor (액체저항경사계의 특성과 동적모델링)

  • Song, Mu-Seok;Ahn, Ja-Il
    • Journal of the Society of Naval Architects of Korea
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    • v.42 no.2 s.140
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    • pp.73-79
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    • 2005
  • The characteristics of a tilt sensor utilizing the resistance change of an electrolyte associated with inclination is investigated, and a dynamic compensation modeling is proposed to make the real-time measurement of the absolute slope possible even with sporadically dynamic motion. Although the proposed system is small, economical and accurate for quasi-steady slope measurement, since it contains a freesurface the evolution of the liquid surface that has no direct relation to the real slope must be excluded for any rapid rotations or translations. For various artificial motions the response of the sensor is analyzed and simplified modeling equations are proposed.