• Title/Summary/Keyword: Energy measurement

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Measurement of Crack Length by Ultrasonic Attenuation Coefficient (초음파 감쇠계수에 의한 균열길이의 측정)

  • Chung, Nam-Yong;Park, Sung-Il
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.340-345
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    • 2003
  • In this paper, the ultrasonic attenuation coefficient was measured by variation of crack length for double-cantilever beam(DCB) specimen. The energy release rate, G, was obtained by the experimental measurement of compliance. The experimental results represents that the relation between crack length for the ultrasonic attenuation coefficient and energy release rate is increased proportionally. From the results of experiments, the measurement method of crack length by the ultrasonic attenuation coefficient was proposed and discussed.

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Microprocessor based welding power meter (마이크로 프로세서를 이용한 용접전력 측정에 관한 연구)

  • 노창주;박상길
    • Journal of Advanced Marine Engineering and Technology
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    • v.11 no.4
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    • pp.33-40
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    • 1987
  • Arc power is consumed energy per unit time between welding electrodes. The relations between consumed energy and electrode distance, current, voltage are nonlinear characteristics. Therefore commercial A.C. wattmeter cannot be used for measurement of the arc power. Most of arc energy measuring systems are developed for relay contact arc measurement. Relaly arc requires integrated instantaneous power because relay arc finishes in a short instant. But most of welding powers are continually consumed powers, therefore instantaneous power must be continually indicated in the form of averagy value. The author propose a new measurement method of power in which the current and voltage of welding electrode is multiplied and the resultant signal is passed to low pass filter in order to remove higher order frequency components. After integrating, the signal is devided by the integral interval and the results are stored in a computer memory.

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Accurate Measurement of Twist Angle for Analysis of Azimuthal Anchoring Energy and Rubbing Direction of LC Panels of IPS Mode

  • Baek, S.H.;Rho, B.G.;Oh, J.M.;Dong, W.S.;Yang, B.K.;Kim, J.S.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.531-533
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    • 2007
  • A new method is developed for the measurement of twist angles of LC molecules in an LC panel with angular resolution of 0.01degree, which allows measurement of LC panels with small twist angles. The method is based on the analysis of the change in polarization state of a light beam as it passes through the LC panel in test is rotated in-plane. Compared to other traditional method, including the analysis of transmittance change, our method is more sensitive and more precise. This method allows accurate determination of anchoring energy and close analysis of the rubbing process in the fabrication of IPS mode LC panels.

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Application of the Through-Transmitted Ultrasonic Signal for the Identification of Two-Phase Flow Patterns in a Simulated High Temperature Vertical Channel

  • Chu In-Cheol;Song Chul-Hwa;Baek Won-Pil
    • Nuclear Engineering and Technology
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    • v.36 no.1
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    • pp.12-23
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    • 2004
  • In the present study a new measurement technique has been developed, which uses an ultrasonic transmission signal in order to identify the vertical two phase flow pattern. The ultrasonic measurement system developed in the present study not only provides the information required for the identification of vertical two phase flow patterns but also makes real time identification possible. Various vertical two phase flow patterns such as bubbly, slug, churn, annular flow etc. have been accurately identified with the present ultrasonic measurement system under atmospheric condition. In addition, the present test apparatus can practically simulate the ultrasonic propagation characteristics under high temperature and high pressure systems. Therefore, it is expected that the present ultrasonic flow pattern identification technique could be applicable to the vertical two phase flow systems under high temperature and high pressure conditions.