• Title/Summary/Keyword: Correlation identification

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Time Series Analysis of SPOT VEGETATION Instrument Data for Identifying Agricultural Pattern of Irrigated and Non-irrigated Rice cultivation in Suphanburi Province, Thailand

  • Kamthonkiat, Daroonwan;Kiyoshi, Honda;Hugh, Turral;Tripathi, Nitin K.;Wuwongse, Vilas
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.952-954
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    • 2003
  • In this paper, we present the different characteristics of NDVI fluctuation pattern between irrigated and non-irrigated area in Suphanburi province, in Central Thailand. For non-irrigated rice cultivation area, there is a strong correlation between NDVI fluctuation and peak rainfall, while there is a lower correlation with irrigated area. In this study, the 'peak detector' classifier was developed to identify the area of non-irrigated and irrigated cropping and its cropping intensity (number of crops per year). This classifier was created based on cropping characteristics such as number of crops, time or planting period of each crop and its relationship with the peak of rainfall. The classified result showed good accuracy in identification irrigated and nonirrigated rice cultivation areas.

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Measurement of the Velocity field of Rotor-Stator in a Centrifugal Turbine Pump by Using PIV (PIV를 이용한 터빈펌프의 동${\cdot}$정익 속도장 계측)

  • Im, Yu-Cheong;Seo, Min-Sik;Lee, Young-Ho
    • 유체기계공업학회:학술대회논문집
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    • 1998.12a
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    • pp.11-18
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    • 1998
  • The present experimental study is focused on the application of multi-point simultaneous measurement by PIV(Particle Image Velocimetry) to rotor-stator region within centrifugal turbine pump. Six different kinds of rpm(120, 500, 1000, 1500, 2000 and 2500) are selected as experimental condition. Optimized cross correlation identification to obtain velocity vectors is implemented by direct calculation of correlation coefficients. Fine optical setup deeply concerned with PIV performance is arranged for accurate PIV measurement of high-speed complex flow. The instantaneous and time-mean velocity distribution and velocity profile are represented quantitatively at the rotor and stator region.

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A Study on Flow and Efficiency Characteristics in Guide Vane of Diffuser Pump Using PIV Measurement (PIV 계측을 이용한 디퓨져펌프의 정익에서의 성능과 유동특성에 관한 연구)

  • Kim, J. H.;Choi, M. S.;Kim, J. G.;Lee, Young-Ho
    • 유체기계공업학회:학술대회논문집
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    • 2000.12a
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    • pp.29-35
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    • 2000
  • The present experimental study is focused on the application of multi-point simultaneous measurement by PIV(Particle Image Velocimetry) to guide vane region within diffuser pump. Various different kinds of rotational velocity were selected as experimental condition. Optimized cross correlation identification to obtain velocity vectors is implemented with direct calculation of correlation coefficients. Fine optical setup concerned with PIV performance is arranged for the accurate PIV measurement of high-speed complex flow. Variable flow pattern are represented quantitatively at the stator region.

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Flow Characteristics of Guide Vane of Diffuser Pump by PIV Measurement (PIV계측에 의한 디퓨져펌프 안내깃에서의 유동특성)

  • Kim, J.H.;Choi, J.W.;Kim, M.Y.;Lee, H.;Lee, Young-Ho
    • Proceedings of the KSME Conference
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    • 2000.11b
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    • pp.391-396
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    • 2000
  • The present experimental study is focused on the application of multi-point simultaneous measurement by PIV(Particle Image Velocimetry) to guide vane region within a diffuser pump. Various different kinds of clearance were selected as experimental conditions. Optimized cross correlation identification to obtain velocity vectors was implemented with direct calculation of correlation coefficients. Fine optical setup important in PIV performance is arranged for the accurate PIV measurement of high-speed complex flow. Various flow patterns are represented quantitatively at the stator passages.

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A PIV Measurement on Flow Characteristics inner Diffuser Pump Using High Resolution CCD Camera (고해상도 CCD 카메라를 이용한 디퓨져펌프 내부 유동특성에 대한 PIV 계측)

  • 김성윤;김범석;김정환;김유택;이영호
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2002.05a
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    • pp.161-166
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    • 2002
  • The resent experimental study is focused on the application of multi-point simultaneous measurement by PIV Particle Image Velocimetry) to guide vane region within diffuser pump. Various different kinds of rotational veto ity and changing clearance between Guide Vane and Impeller were selected as experimental condition. Optimized ross correlation identification to obtain velocity vectors is implemented with direct calculation of correlation coeffi cients. Fine optical setup concerned with PW performance is arranged for the accurate PW measurement of high peed complex flow. Variable flow pattern are represented quantitatively at the stator region.

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Measurement of Flow Field in a Domestic Boiler Circulation Pump by PIV (PIV에 의한 가정용보일러용 순환펌프의 내부 유동장 계측)

  • Im, Y.C.;Kim, J.H.;Choi, M.S.;Lee, Y.H.
    • Journal of Power System Engineering
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    • v.3 no.2
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    • pp.13-19
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    • 1999
  • The purpose of the present experimental study is to apply multi-point simultaneous measurement by PIV(Particle Image Velocimetry) to high-speed flow region within a domestic boiler circulation pump. Two different kinds of flow rate($27{\ell}/min,\;19{\ell}/min$)are selected as experimental condition. A volute casing and Impeller made of transparent Polycarbonate were made for the easy access of the illumination laser via fiber optical line and cylinder lens assembly to the measuring region. A CCD camera is syncronized with AOM to acquire clear original particle images. Optimized cross correlation identification to obtain velocity vectors is implemented by direct calculation of correlation coefficients. The instantaneous and time-mean velocity distribution, velocity profile and kinetic energy are represented quantitatively at the full-scale region for the deeper understanding of the unsteady flow characteristics in a commercial circulation pump.

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Implementation of a Touch Panel System using Accelerometers (가속도센서를 이용한 터치패널시스템 구현)

  • Lee, Young-Sup;Kim, Dong-Il;Kang, Min-Su
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.12
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    • pp.1194-1202
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    • 2011
  • A touch panel system has been one of the most widely used input devices. In this study, a touch panel embedded system using accelerometers is considered in order to make commercial white-boards or plates into touch panels. Three accelerometers are located at different positions on such a white board, so that touch points on the board can be identified using the sensors. For the identification of touch points, a TDOA (Time Difference of Arrivals) technique is applied in the algorithm which was implemented in a DSP board (TI 6713 DSK), which can provide a precise touch location by using the cross-correlation function of measured signals from the three accelerometers. Experiment results show that the touch panel system with accelerometers could provide the exact touch location. Thus a novel approach using such accelerometers could be applied to a new touch panel system.

Analysis on Cold Air Circulation of a Domestic Refrigerator Freezer by PIV Animation (PIV 애니메이션에 의한 가정용 냉장고 냉동실의 냉기 순환 해석)

  • Kim, J.Y.;Yang, C.J.;Kim, J.H.;Lee, Y.H.
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.686-691
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    • 2000
  • Animation technique from the PIV database is particularly emphasized to give macroscopic and Quantitative description of complex flow fields. As an example, an experimental study was carried out investigate the fundamental (low characteristics of the freezer with the domestic refrigerator. Optimized cross correlation identification to obtain velocity vectors is implemented by direct calculation of correlation coefficients. Image intensifier CCD camera to cope with illumination problem is arranged for the accurate PIV measurement of large flow field. As a results, continuous pictures of the spatial distribution of the instantaneous and time-mean velocity distribution are displayed in real-time sense.

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Measurement of the Velocity Field of Rotor-Stator in a Centrifugal Turbine Pump Using PIV (PIV를 이용한 터빈펌프의 동${\cdot}$정익 속도장 계측)

  • Im, Yu-Cheong;Seo, Min-Sik;Lee, Young-Ho
    • The KSFM Journal of Fluid Machinery
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    • v.2 no.1 s.2
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    • pp.35-42
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    • 1999
  • The present experimental study is focused on the application of multi-point simultaneous measurement by PIV(Particle Image Velocimetry) to rotor-stater region within centrifugal turbine pump. Six different kinds of rpm(120, 500, 1000, 1500, 2000 and 2500) are selected as experimental condition. Optimized cross correlation identification to obtain velocity vectors is implemented with direct calculation of correlation coefficients. Fine optical setup concerned with PIV performance is arranged for the accurate PIV measurement of high-speed complex flow. The instantaneous and time-mean velocity distribution and velocity profile are represented quantitatively at the rotor and stator region.

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Identification of Dynamic Characteristics of Gimbals for Line-of-Sight Stabilization Using Signal Compression Method (신호 압축법을 이용한 시선안정화 제어용 짐벌의 동특성 규명)

  • Kim, Moon-Sik;Yoo, Gi-Sung;Yun, Jung-Joo;Lee, Min-Cheol
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.7
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    • pp.72-78
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    • 2008
  • The line-of-sight(LOS) stabilization system is a precision electro-mechanical gimbals assembly for suppressing vibration due to its environment and tracking the target in a desired direction. This paper describes the design of gimbals system to reject the disturbance and to improve stabilization. The controller consists of a DSP with transducer and actuator interfaces. Unknown parameters of the gimbals are estimated by the signal compression method. The cross-correlation coefficient between the impulse response from the assumed model and the one from model of the gimbals is used to obtain the better estimation. The quasi-impulse response through linear element included in the gimbals could be obtained by the signal compression method. The unknown parameter of the linear element could be estimated as comparing the bode plots for impulse response from gimbals with them from model's response.