• 제목/요약/키워드: spectral

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A Study on Natural Convection from Two Cylinders in a Cavity

  • Mochimaru Yoshihiro;Bae Myung-Whan
    • Journal of Mechanical Science and Technology
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    • v.20 no.10
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    • pp.1773-1778
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    • 2006
  • Steady-state natural convection heat transfer characteristics from cylinders in a multiply-connected bounded region are clarified. A spectral finite difference scheme (spectral decomposition of the system of partial differential equations, semi-implicit time integration) is applied in numerical analysis, with a boundary-fitted conformal coordinate system through a Jacobian elliptic function with a successive transformation to formulate a system of governing equations in terms of a stream function, vorticity and temperature. Multiplicity of the domain is expressed explicitly.

Development of a Portable Colorimeter (소형 칼라미터의 개발에 관한 연구)

  • 김재형;황정연;서대식
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.328-331
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    • 2001
  • Color simulation on a portable colorimeter was performed to distinguish quantitatively a chromaticity coordinates on a color guide of a urine strips by using the spectral power distribution of chip LED, the spectral reflectance of printed objects, and the spectral sensitivity of photodiode. The CIE tristimulus values and chromaticity coordinates realized by a colorimeter were modified to be conformable with real color reactions. Experimental results showed a real color in comparison with those obtained by Colorimeter CM2C(Color Savvy).

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The Compensation of Chromaticily Coordinates on Primary Color Reaction of Urine Strips (요분석 스트립의 정색반응에 대한 색도좌표 보정)

  • 김재형;조진욱;남상희
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.320-323
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    • 2001
  • A computer simulation was performed to distinguish quantitatively a color reaction in a urine analysis systems by using the spectral power distribution of LEDs, the spectral reflectance of a urine strip, and the spectral sensitivity of photodiode. The CIE tristimulus values and CIE chromaticity coordinates ware modified to be conformable with real color reactions in a urine strips. Results on color simulation showed a of real color in comparison with those obtained by Colorimeter CM2C(Color Savvy).

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Frequency Selective Recursive LP of Discrete Harmonic Spectra for Audio Cording

  • Nam, Seung-Hyon
    • The Journal of Engineering Research
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    • v.5 no.1
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    • pp.37-44
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    • 2004
  • n this paper, an efficient LP method for discrete harmonic spectra is proposed and discussed. A new efficient LP method is a combination of recursive and frequency selective LP. While the recursive LP provides better spectral matching in spectral hill, frequency selective LP eliminates numerical instability and improves spectral matching when the harmonics are confined in the low frequency region. The proposed LP method is applied to the HILN coder. Simulation results using a verification model(VM) software for real audio signals show a definite trend of significant improvement.

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Improvement of the ASR Robustness using Combinations of Spectral Subtraction and KLT-based Adaptive Comb-filtering (스펙트럴 서브트렉션과 비동기 KLT 잡음 감소 기법의 조합에 의한 음성 인식 성능 개선)

  • Park Sung-Joon
    • Proceedings of the KSPS conference
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    • 2003.05a
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    • pp.207-210
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    • 2003
  • In this paper, the combinations of speech enhancement techniques are experimented. Specifically, the spectral subtraction, KLT based comb-filtering, and their combinations are applied to the Aurora2 database. The results show that recognition accuracy is improved when KLT based comb-filtering is applied after spectral subtraction.

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Spectral Characteristics Visible and Near-infrared of Metamorphic Rocks (변성암의 분광특성)

  • 조민조;강필종;이봉주
    • Korean Journal of Remote Sensing
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    • v.8 no.1
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    • pp.1-13
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    • 1992
  • The study is to analize the spectral characteristics of metamorphic rocks by their spectral reflectance curves obtained from CARY 17-D Spectrophotometer. Coarse grained rocks generally show strong absorption at 1.4 and 1.9 $\mu\textrm{m}$ due to preserved water inclusion in quartz of feldspar. The basic rocks show a broad absorption due to Fe$^{++}$ ion rich in mafic minerals. Strong absorption near 2.0$^+\mu\textrm{m}$ suggests existence of carbonate or clay minerals.

Control of Free Spectral Range of tong Period Fiber Grating by Cladding Mode Waveguide Dispersion

  • Jeong, H.;Oh, K.
    • Journal of the Optical Society of Korea
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    • v.7 no.2
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    • pp.89-96
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    • 2003
  • A new method to control the free spectral range of a long period fiber grating is proposed and theoretically analyzed. As the refractive index decreases radially outward in the silica cladding due to graded doping of fluorine, waveguide dispersion in the cladding modes was modified to result in the effective indices change and subsequently the phase matching conditions for coupling with the core mode in a long period fiber grating. Enlargement of the free spectral range in a long period fiber grating was theoretically confirmed.

GENERALIZED INTERTWINING LINEAR OPERATORS WITH ISOMETRIES

  • Hyuk Han
    • Journal of the Chungcheong Mathematical Society
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    • v.36 no.1
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    • pp.13-23
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    • 2023
  • In this paper, we show that for an isometry on a Banach space the analytic spectral subspace coincides with the algebraic spectral subspace. Using this result, we have the following result. Let T be a bounded linear operator with property (δ) on a Banach space X. And let S be an isometry on a Banach space Y . Then every generalized intertwining linear operator θ : X → Y for (S, T) is continuous if and only if the pair (S, T) has no critical eigenvalue.

THE SPECTRAL DECOMPOSITION FOR FLOWS ON TVS-CONE METRIC SPACES

  • Lee, Kyung Bok
    • Journal of the Chungcheong Mathematical Society
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    • v.35 no.1
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    • pp.91-101
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    • 2022
  • We study some properties of nonwandering set Ω(𝜙) and chain recurrent set CR(𝜙) for an expansive flow which has the POTP on a compact TVS-cone metric spaces. Moreover we shall prove a spectral decomposition theorem for an expansive flow which has the POTP on TVS-cone metric spaces.