• Title/Summary/Keyword: sensing time

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A LIFE PREDICTION OF LDPE DEGRADATION PROCESSING USING PARAMETERS (파라미터를 이용한 LDPE 절연열화 과정의 수면예측)

  • Kim, Sung-Hong;Seo, Jang-Soo
    • Proceedings of the KIEE Conference
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    • 2000.07e
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    • pp.40-43
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    • 2000
  • Our studies diagnose insulation degradation using the method of computer sensing system, which has the advantages of PD(partial discharge) and AE(acoustic emission) sensing system. To use advantages of these two methods can be used effectively to search for treeing location and PD in some materials. In analysis method of degradation, using statically operator such as the center of gravity (G), the gradient of the discharge distribution(C), we have analyzed for the prediction of life which we can be obtained the time, occurred of many pulse of small discharge amplitude.

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Introduce and application of the angular velocity sensing type of wheel flange lubricator for the railways in KOREA (국내 철도차량용 각속도 감지식 도유기의 적용 및 소개)

  • La, Won-Ki;Yang, Bang-Sub;Lee, Won-Sang;Chang, Dae-Sung
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.958-962
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    • 2010
  • Most of operating railways in domestic, it is used to be Wheel flange lubricator system applied liquid spray type. Wheel flange lubricator are reduced the abrasion of wheel flange through spraying in accordance with operating on the curve or operating function of time base and/or distance base. this paper is written to introduce and study the efficiency for the angular velocity sensing type of lubricant systems.

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Wind speed measurement using SODAR and LIDAR (SODAR와 LIDAR를 이용한 풍속 측정)

  • Ji, Young-Mi;Kim, Hyun-Goo;Chung, Chin-Hwa;Han, Kyung-Seop;Park, Hyun-Chul
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.453-455
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    • 2009
  • The wind speed measurement is performed using SODAR and LIDAR to evaluate availability of remote sensing in assessment of wind resource. The intercomparison comprises time series, correlation analysis and recovery rate. It shows that LIDAR is more effective than using SODAR to measure wind speed in ambient disturbance.

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Terrain Matching Technique Using 3-D Terrain Maps (3차원 지형정보를 이용한 지형영상의 정합기법)

  • 김준식;강민석;박래홍;이쾌희
    • Korean Journal of Remote Sensing
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    • v.7 no.1
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    • pp.13-27
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    • 1991
  • DEM(digital elevation map) is a very useful information in various applications. In this paper, we have studied on the terrain matching algorithm using the DEM, which was proposed by Rodriguez and Aggarwal(1990) for an aircraft navigation system. We evaluated its performance using syntactic images. Cliff maps and critical points are used for the reduction of computation time and information size to be processed. The computer simulation shows that though the computational complexity is high, the technique is efficient even to noisy images.

Current trends in force/torque sensing

  • Morris, Keith-A.
    • 제어로봇시스템학회:학술대회논문집
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    • 1989.10a
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    • pp.606-608
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    • 1989
  • Force/torque sensors are now providing widespread practical solutions to manufacturing problems, particularly in the area of automated assembly. The current state of the industry is discussed, including the evolution of transducer and controller design, and the trend of robot manufacturers to integrate force/torque sensors into their robot systems thereby greatly improving cycle time and simplifying the application development task for the end-user. Current and future application areas are discussed as well as the benefits of force/torque sensing.

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Remote Sensing of Nearshore Currents using Coastal Optical Imagery (해안 광학영상 자료를 이용한 쇄파지역 연안류 측정기술)

  • Yoo, Jeseon;Kim, Sun-Sin
    • Ocean and Polar Research
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    • v.37 no.1
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    • pp.11-22
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    • 2015
  • In-situ measurements are labor-intensive, time-consuming, and limited in their ability to observe currents with spatial variations in the surf zone. This paper proposes an optical image-based method of measurement of currents in the surf zone. This method measures nearshore currents by tracking in time wave breaking-induced foam patches from sequential images. Foam patches in images tend to be arrayed with irregular pixel intensity values, which are likely to remain consistent for a short period of time. This irregular intensity feature of a foam patch is characterized and represented as a keypoint using an image-based object recognition method, i.e., Scale Invariant Feature Transform (SIFT). The keypoints identified by the SIFT method are traced from time sequential images to produce instantaneous velocity fields. In order to remove erroneous velocities, the instantaneous velocity fields are filtered by binding them within upper and lower limits, and averaging the velocity data in time and space with a certain interval. The measurements that are obtained by this method are comparable to the results estimated by an existing image-based method of observing currents, named the Optical Current Meter (OCM).

A Study on the Improvement of the Multichannel Sea Surface Temperature(MCSST) Software for Mini-Computer System (소/중형 컴퓨터를 위한 MCSST 소프트웨어 개선에 관한 연구)

  • 심태보;장덕홍
    • Korean Journal of Remote Sensing
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    • v.5 no.1
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    • pp.41-56
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    • 1989
  • Improvement of the multichannel sea surface temperature(MCSST) software, which had been developed for the purpose of operating under mainframe computer system, was seeked in order to operate effectively in a mini computer system. CPU time and processing time, which is not a major factor under mainframe computer system, become a critical factor in real time image processing under mini computer system. Due to fixed kernel size(3$\times$4) of the old MCSST software, high spatial resolution characteristics of the original image received from satellites were apparently degraded when images are transformed into a cartesian coordinate system after geometrical distortions of the image due to earth curvature are removed. CPU and processing time were reduced to 0.13 and 0.15~0.22 comparing with the old MCSST's, respectively, by applying disk block I/O and M/T queue I/O method under VAX-11/750 computer. The high resolution quality (1.1km in AVHRR) of the processed image was guaranted using 2$\times$2 kernel size and applying moving window techniques without sacrificing CPU and processing time much.

Space-Time Quantization and Motion-Aligned Reconstruction for Block-Based Compressive Video Sensing

  • Li, Ran;Liu, Hongbing;He, Wei;Ma, Xingpo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.1
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    • pp.321-340
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    • 2016
  • The Compressive Video Sensing (CVS) is a useful technology for wireless systems requiring simple encoders but handling more complex decoders, and its rate-distortion performance is highly affected by the quantization of measurements and reconstruction of video frame, which motivates us to presents the Space-Time Quantization (ST-Q) and Motion-Aligned Reconstruction (MA-R) in this paper to both improve the performance of CVS system. The ST-Q removes the space-time redundancy in the measurement vector to reduce the amount of bits required to encode the video frame, and it also guarantees a low quantization error due to the fact that the high frequency of small values close to zero in the predictive residuals limits the intensity of quantizing noise. The MA-R constructs the Multi-Hypothesis (MH) matrix by selecting the temporal neighbors along the motion trajectory of current to-be-reconstructed block to improve the accuracy of prediction, and besides it reduces the computational complexity of motion estimation by the extraction of static area and 3-D Recursive Search (3DRS). Extensive experiments validate that the significant improvements is achieved by ST-Q in the rate-distortion as compared with the existing quantization methods, and the MA-R improves both the objective and the subjective quality of the reconstructed video frame. Combined with ST-Q and MA-R, the CVS system obtains a significant rate-distortion performance gain when compared with the existing CS-based video codecs.

The Improvement of the Correlation Method for Shack-Hartmann Wavefront Sensors using Multi-Resolution Method (다중 해상도 중심점 탐색법을 이용한 샥-하트만 센서용 상관관계법의 속도 개선)

  • Yoo, Jae-Eun;Youn, Sung-Kie
    • Korean Journal of Optics and Photonics
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    • v.19 no.1
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    • pp.1-8
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    • 2008
  • Shack-Hartmann sensors are widely employed as a wavefront measuring device in various applications. Adaptive optics is one of the major applications. Since an adaptive optics system should be operated in real-time, high-speed wavefront sensing is essential. In high-speed operation, integration time of an image detector is very short. In this case, noises such as readout noise and photon noise greatly influence the accuracy of wavefront sensing. Therefore a fast and noise-insensitive centroid finding algorithm is required for the real-time wavefront sensing. In this paper, the multi-resolution correlation method is proposed. By employing multi-resolution images, this method greatly reduces the computation time when compared to the fast Fourier transform (FFT) correlation method. The verification is performed through the computational simulation. In this paper, the center of mass method, correlation method and multi-resolution correlation method are employed to compare the measurement accuracy of the centroid finding algorithms. The accuracy of a Shack-Hartmann wavefront sensor using the proposed algorithm is proved to be comparable to that of the conventional correlation method.