• Title/Summary/Keyword: metrology

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Measurements of the Benzene Absorption Cross Section in the Range of Ultra Violet (UV) (UV 영역에서 벤젠의 흡수 단면적의 측정)

  • Lee, J.S.;Ryu, S.Y.;Kim, H.H.;Woo, J.C.;Kim, K.B.
    • Journal of Korean Society for Atmospheric Environment
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    • v.22 no.6
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    • pp.922-928
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    • 2006

  • An absolute absorption cross section of benzene was measured with a spectrometer system including a mono-chrometer and a grating in the wavelength region of $240{\sim}280nm$ under the atmospheric pressure and room temperature in the laboratory. A certificated reference benzene gas ($98{\mu}mol/mol$ in $N_2$) was used to measure its absorption cross section. A 710 mm cell with a quartz window and a 150 W Xe arc lamp were employed. The magnitude of absorption cross section of $1.41{\times}10^{-18}cm^2$ was lower than that of the reference spectra ($2.5{\times}10^{-18}cm^2$) of high resolution spectrometer, Total measurement uncertainty was estimated to be 4.0%.

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RF and Microwave Power Standards from 10 MHz to 40 GHz over Decades

  • Kang, Tae-Weon;Kwon, Jae-Yong;Park, Jeong-Il;Kang, No-Weon
    • Journal of electromagnetic engineering and science
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    • v.18 no.2
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    • pp.88-93
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    • 2018

  • Radio frequency (RF) and microwave power is one of the key quantities in the framework of electromagnetic measurement standards. Therefore, the stability of the power standard is essential to users' reliable measurements in various areas. Coaxial and waveguide thermistor mounts are used as transfer standards of RF and microwave power. Over decades, the effective efficiencies of thermistor mounts have been measured using coaxial and waveguide microcalorimeters in the frequency range of 10 MHz-40 GHz. The measurement uncertainty of the effective efficiency is evaluated. Results show that the power standards have been well maintained within the measurement uncertainty.

  • https://doi.org/10.26866/jees.2018.18.2.88 인용 PDF KSCI

Active cancellation of phase noise induced by an optical fiber for delivery of optical frequency standard (광섬유를 통한 광 주파수 전송에서 광 위상 잡음의 능동 제거)

  • Lee, Won-Kyu;Kim, Jae-Wan;Ryu, Han-Young;Kim, Eok-Bong
    • Korean Journal of Optics and Photonics
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    • v.18 no.1
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    • pp.44-49
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    • 2007

  • We have transferred a narrow-linewidth $1.5{\mu}m$ laser beam through a 525 m fiber network with excellent transfer stability. The fiber-induced optical phase noise during the fiber transmission is cancelled by configuring a noise-canceling servo. The transfer instability was $2{\times}10^{-17}$ at 1 s of averaging time. We quantitatively analyzed the transferred optical frequency in the frequency domain and in the time domain.

  • https://doi.org/10.3807/HKH.2007.18.1.044 인용 PDF KSCI

Fabrication of a Single Molecule Detection System and Its Application: Connection between Ensemble and Single Molecule Measurements

  • Park, Mira;Lee, Heung Soon;Kim, DongHo;Song, Nam Woong
    • Journal of Photoscience
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    • v.11 no.32
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    • pp.47-53
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    • 2004

  • A laser scanning fluorescence microscope system has been fabricated for single molecule detection (SMD). Problems associated with the system set-up have been discussed along with proper suggestions. Based on the SMD results obtained by using the apparatus, a statistical method has been suggested to determine the minimum number of required molecules to form a group of uniform average in a selected error range.

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