• 제목/요약/키워드: cross-correlation method

검색결과 865건 처리시간 0.022초

NOAA/AVHRR 자료를 이용한 일 최고기온 추정에 관한 연구 (Estimation of daily maximum air temperature using NOAA/AVHRR data)

  • 변민정;한영호;김영섭
    • 한국GIS학회:학술대회논문집
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    • 한국GIS학회 2003년도 공동 춘계학술대회 논문집
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    • pp.291-296
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    • 2003
  • This study estimated surface temperature by using split-window technique and NOAA/AVHRR data was used. For surface monitoring, cloud masking procedure was carried out using threshold algorithm. The daily maximum air temperature is estimated by multiple regression method using independent variables such as satellite-derived surface temperature, EDD, and latitude. When the EDD data added, the highest correlation shown. This indicates that EDD data is the necessary element for estimation of the daily maximum air temperature. We derived correlation and experience equation by three approaching method to estimate daily maximum air temperature. 1) non-considering landcover method as season, 2) considering landcover method as season, and 3) just method as landcover. The last approaching method shows the highest correlation. So cross-validation procedure was used in third method for validation of the estimated value. For all landcover type 5, the results using the cross-validation procedure show reasonable agreement with measured values(slope=0.97, intercept=-0.30, R$^2$=0.84, RMSE=4.24$^{\circ}C$). Also, for all landcover type 7, the results using the cross-validation procedure show reasonable agreement with measured values(slope=0.993, Intercept=0.062, R$^2$=0.84, RMSE=4.43$^{\circ}C$).

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상호상관관계를 이용한 방위탐지기의 확률적 모델 (Stochastic Model of the Bearing Estimator Using Cross-Correlation Method)

  • 박상배;류존하;이균경
    • 전자공학회논문지B
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    • 제31B권1호
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    • pp.23-33
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    • 1994
  • In this paper, we propose a probabilistic model appropriate for the bearing estimator which uses cross-correlation method following a close investigation on real underwater acoustic bearing data. The well-known JPDA(Joint Probabilistic Data Association) filter is tuned to the underwater acoustic bearing estimation based on the result that the reliability of the bearing measurement is related to the amplitude of the cross-correlation peak. The proposed probabilistic model is shown to be adequate by presenting the results of the improved tracking performance of the modified filter for various real bearing data as well as artificially generated ones.

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소음 신호의 웨이블렛 변환 및 상호상관 함수를 이용한 고장 검출 및 위치 판별 (Fault Detection and Localization using Wavelet Transform and Cross-correlation of Audio Signal)

  • 지효근;김정현
    • 한국정밀공학회지
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    • 제31권4호
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    • pp.327-334
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    • 2014
  • This paper presents a method of fault detection and fault localization from acoustic noise measurements. In order to detect the presence of noise sources wavelet transform is applied to acoustic signal. In addition, a cross correlation based method is proposed to calculate the exact location of the noise allowing the user to quickly diagnose and resolve the source of the noise. The fault detection system is implemented using two microphones and a computer system. Experimental results show that the system can detect faults due to artifacts accidentally inserted during the manufacturing process and estimate the location of the fault with approximately 1 cm precision.

진행파를 이용한 송전선로의 고장점 표정 알고리즘 (A Fault Location Algorithm for a Transmission Line Using Travelling Waves)

  • 강상희;김진한
    • 대한전기학회논문지:전력기술부문A
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    • 제53권10호
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    • pp.542-549
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    • 2004
  • The conventional fault location algorithms based on the travelling waves have an inherent problem. In cases of the close-up faults occurring near the relaying point and of the faults having zero degree inception angle of voltage signals, the conventional algorithms can not estimate an accurate fault distance. It is because the shapes of travelling waves are near sinusoidal in those cases. A new method solving this problem is presented in this paper. An FIR(Finite Impulse response) filter which makes high frequency components prominent and makes the power frequency component and dc-offset attenuated is used. With this method, the cross-correlation peak is to be very clear when a close-up fault or a fault having near zero-degree inception angle occurs. The cross-correlation peaks can be clearly distinguished and accurate fault location is practically possible consequently. A series of simulation studies using EMTP(Electromagnetic Transients Program) show that the proposed algorithm can calculate an accurate fault distance having maximum 2% or less error.

Cross-Correlation Measurements of Phase Noise Induced by Relative Intensity Noise in Photodetectors

  • Cao, Zhewei;Yang, Chun;Zhou, Zhenghua
    • Journal of the Optical Society of Korea
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    • 제20권6호
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    • pp.694-697
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    • 2016
  • Up-converted phase noise, which is induced by the low-frequency relative intensity noise (RIN) of a laser through AM-PM conversion within a photodetector (PD), is first measured here by means of a cross-correlation method. Our proposed measurement system can isolate the RIN-induced phase noise from noise contributions of other components, such as amplifiers, modulators, and mixers. In particular, shot noise and thermal noise generated from the PD are also suppressed by this method, so that standalone characteristics of the RIN-induced phase noise can be obtained. Experimental results clearly show the quantitative relationship between the RIN-induced phase noise and the incident optical power of the PD. Our findings indicate that the least RIN-induced phase noise appeared at the saturation point of the PD, which is about -162 dBc/Hz at 10 kHz offset.

멀티미디어 대응 상용 PIV의 국산화개발에 관한 연구 (A Study on Development of Commercial PIV Utilizing Multimedia)

  • 최장운
    • Journal of Advanced Marine Engineering and Technology
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    • 제22권5호
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    • pp.652-659
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    • 1998
  • The present study is aimed to develop a new PIV operating software through optimization of vector tracking identification including versatile pre-processings and post-processing techniques. And the result exhibits an improved version corresponding various input and output multimedia compared to previous commercial software developed by other makers. An upgraded identification method called grey-level cross correlation coefficient method by direct calculation is suggested and related user-friendly pop-up menu are also represented. Post-processings comprising turbulence statistics are also introduced with graphic output functions.

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통계적 기법을 이용한 국지성집중호우의 이동경로 분석 (Rainstorm Tracking Using Statistical Analysis Method)

  • 김수영;남우성;허준행
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2005년도 학술발표회 논문집
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    • pp.194-198
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    • 2005
  • Although the rainstorm causes local damage on large scale, it is difficult to predict the movement of the rainstorm exactly. In order to reduce the rainstorm damage of the rainstorm, it is necessary to analyze the path of the rainstorm using various statistical methods. In addition, efficient time interval of rainfall observation for the analysis of the rainstorm movement can be derived by applying various statistical methods to rainfall data. In this study, the rainstorm tracking using statistical method is performed for various types of rainfall data. For the tracking of the rainstorm, the methods of temporal distribution, inclined Plane equations, and cross correlation were applied for various types of data including electromagnetic rainfall gauge data and AWS data. The speed and direction of each method were compared with those of real rainfall movement. In addition, the effective time interval of rainfall observation for the analysis of the rainstorm movement was also investigated for the selected time intervals 10, 20, 30, 40, 50, and 60 minutes. As a result, the absolute relative errors of the method of inclined plane equations are smaller than those of other methods in case of electromagnetic rainfall gauges data. The absolute relative errors of the method of cross correlation are smaller than those of other methods in case of AWS data. The absolute relative errors of 30 minutes or less than 30 minutes are smaller than those of other time intervals.

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히스토그램 기반 상관성을 이용한 모양영상 인식 (Shape Image Recognition by Using Histogram-based Correlation)

  • 조용현
    • 한국지능시스템학회논문지
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    • 제20권4호
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    • pp.548-553
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    • 2010
  • 본 논문에서는 4차원의 히스토그램 기반 상관성을 이용한 효과적인 모양영상의 인식방법을 제안하였다. 여기서 히스토그램 기반 상관성은 4개 방향을 고려한 계산으로 얻어지며, 이는 영상 사이에 대응하는 차원의 위치를 비교함으로써 유사성을 좀 더 정확하게 반영하기 위함이다. 또한 상관성 척도로 정규화된 상호상관계수를 이용함으로써 모양, 위치, 크기, 회전과 같은 기하학적 변화에 강건한 인식성능을 얻기 위함이다. 제안된 방법을 8개의 $64\times64$ 픽셀의 모양영상과 30개의 $256\times256$ 픽셀의 모양영상을 대상으로 실험한 결과, 영상의 속성을 잘 반영하는 우수한 인식성능이 있음을 확인하였다.

제곱합과 교차곱합의 특성을 이용한 표본분산과 상관계수의 계산 (Updating Sample Variance and Correlation Using Sum of Squares and Sum of Cross product)

  • 조태경;신미영
    • 한국수학교육학회지시리즈A:수학교육
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    • 제45권3호
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    • pp.315-318
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    • 2006
  • In this paper we present the simple updating formulas for a sum of product and a sum of cross product when a new value is added on or a specific value is eliminated from the original data. The sample variance and correlation for the new data set are derived by new computing formulas. Any statistic which is a function of the sum of product and a sum of cross product also can be updated by proposed method even though the original data is not available.

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한 변조 직교수열에 알맞은 부호만들기 (Generation of codes for a modulated orthogonal sequence)

  • 박성일;박정순;김홍길;박소령;송익호
    • 한국통신학회논문지
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    • 제23권4호
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    • pp.926-931
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    • 1998
  • 이 논문에서는 직교수열의 하나인 수에히로 수열을 만드는 방법을 하나 제안한다. 이 방법에서는 정수합과 나머지방법만으로 부호수열을 만든다. 이 방법으로 만든 수열의 자기상관과 교차상관 특성을 살펴본다. 제안한 방법으로 만든 수열은 직교성을 가지며 교차상관의 수학적 하한을 만족시킨다.

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