• 제목/요약/키워드: spectral

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비선형 요소가 결합된 선형역학시스템의 해석에의 Fourier 스펙트럼 해석기법의 응용 (An application of fourier spectral analysis to the analysis of linear dynamic systems coupled with nonlinear elements)

  • 성단근
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
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    • pp.61-64
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    • 1986
  • The Fourier Spectral Analysis has been widely utilized in the analysis of linear dynamic systems. However, it may not be generaly extended to analyze nonlinear systems. In this paper, a linear underlying dynamic structure coupled with nonlinear elements is analyzed by using newly derived equations of motion after the linear dynamic structure is characterized by the Fourier spectral analysis.

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Wideband spectral histogram 분석에 의한 회전기계 요소의 결함탐지 (Fault detection of rotating machine elements by wideband spectral histogram analysis)

  • 정완섭;은희준;임병덕
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
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    • pp.123-127
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    • 1986
  • The use of vibration signal for fault detection inside a machine (or its part) is not new, and a number of signal processing techniques are available at the moment. A common problem for all such techniques is the high level of background signals which often made it very difficult to distinguish the desired signals. We developed a new algorithm to detect the minute faults of rotating part based on spectral histogram analysis. The technique has subsequently been applied to the bearings and has proved to be useful.

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Ocean Scanning Muti-spectral Imager (OSMI) 발사전 태양광 보정의 복사 응답 분석 (Ocean Scanning Muti-spectral Imager (OSMI) Pre-Launch Solar Calibration Radiometric Response Analysis)

  • 조영민
    • 한국광학회:학술대회논문집
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    • 한국광학회 2000년도 제11회 정기총회 및 00년 동계학술발표회 논문집
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    • pp.198-199
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    • 2000
  • 다목적 실용위성 (KOMPSAT) 1호기에 탑재되는 해양관측카메라 Ocean Scanning Multi-spectral Imager (OSMI)는 해양 결상계의 노화에 따른 성능 변화 감지 및 보정을 위해 태양광 보정을 궤도운영 중 수행한다. 태양광 보정의 구조 및 광학적 특성을 분석하고 OSMI 주요 관측파장대역별로 태양광 보정계의 출력신호량을 예측하였다. 이 분석은 OSMI 센서보정 계획 및 영상 품질 이해에 유용할 것이다. (중략)

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순환 근사 과결정 ARMA 스펙트럼 추정 (Recursive approximate overdetermined ARMA spectral estimation)

  • 이철희;이석원;양흥석
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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    • pp.446-450
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    • 1987
  • In this paper, overdetermined method is used for high resolution spectral estimation in case of short data record length. To reduce the computational effort and to obtain recursive form of estimation algorithm, we modify data matrix to have near-Toeplitz structure. Then, new recursive algorithm is derived in the form of fast Kalman algorithm. Two stage procedure is used for the estimation of ARMA parameters. First AR parameters are estimated by using overdetermined modified Yule-walker equation, and then MA parameters are implicitly estimated by estimating numerator spectral coefficients(NS).

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전력밀도 스펙트럼을 이용한 반복적 영상 신호 복원 알고리즘 (Iterative Image Restoration Algorithm Using Power Spectral Density)

  • 임영석;이문호
    • 대한전자공학회논문지
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    • 제24권4호
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    • pp.713-718
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    • 1987
  • In this paper, an iterative restoration algorithm from power spectral density with 1 bit sign information of real part of two dimensional Fourier transform of image corrupted by additive white Gaussian noise is proposed. This method is a modified version of image reconstruction algorithm from power spectral density. From the results of computer simulation with original 32 gray level imgae of 64x64 pixels, we can find that restorated image after each iteration converge to original image very fast, and SNR gain be at least 8[dB] after 10th iteration for corrupted image with additive white Gaussian noise.

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삼각필터를 이용한 Spectral 포락변경에 관한 연구 (A Study on Spectral Envelope Modification using Triangular Filter)

  • 최성은;김동현;홍광석
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
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    • pp.2415-2418
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    • 2003
  • In this paper, we present a new filter to adjust formant information. Spectral envelope in speech analysis shows information about characteristics of speech and formant information determines speech timbre. So, if formant position is adjusted, we can verify adjusted speech timbre. A presented filter is to adjust this formant. This filter is composed of triangular filters. Using this filter we could locate the formant frequency at target position.

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반구면경을 이용한 스펙트럼 방사율 측정법 (Measurement Method of the Spectral Emissivity by Using Hemispherical Mirror)

  • 배신철;오기수
    • 대한기계학회논문집B
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    • 제27권6호
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    • pp.789-795
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    • 2003
  • It is studied that the measuring method of the spectral emissivity by using hemispherical mirror with an inclined observation hole. The in-service calibration method of mirror reflectivity is also dealed with. It is possible to apply this method on measuring emissivity of conductor or non-conductor.

ANALYSIS OF THE BEHAVIOR OF LIMITING SPECTRAL DENSITY FUNCTION OF LARGE DIMENSIONAL RANDOM MATRICES

  • Choi, Sang-Il
    • Journal of applied mathematics & informatics
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    • 제16권1_2호
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    • pp.483-488
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    • 2004
  • Results on the analytic behavior of the limiting spectral distribution of large dimensional random matrices, studied in Marcenko and Pastur [2], are derived. Using the Stieltjes transform, it is shown that the limiting distribution has a continuous derivative away from zero, the derivative being analytic whenever it is positive [3]. In the present paper, it is derived that the behavior of it resembles the behavior of a square root function near the boundary of its support.

A Note on the Spectral Mapping Theorem

  • Jung, Il Bong;Ko, Eungil;Pearcy, Carl
    • Kyungpook Mathematical Journal
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    • 제47권1호
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    • pp.77-79
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    • 2007
  • In this note we point out how a theorem of Gamelin and Garnett from function theory can be used to establish a spectral mapping theorem for an arbitrary contraction and an associated class of $H^{\infty}$-functions.

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