• Title/Summary/Keyword: spatial resolution improvement

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A Study on Improvement of MUAP Resolution using Spatial Filter (공간필터에 의한 운동단위 활동전위의 분해능 향상에 관한 연구)

  • Yang, Duck-Jin;Jun, Chang-Ik;Lee, Young-Suk;Lee, Jin;Kim, Sung-Hwan
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.53 no.1
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    • pp.55-64
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    • 2004
  • Conventional bipolar surface electromyography(EMG) technique detects only the superimposed electromyographic activity of a large number of motor units due to its low spatial resolution. For the diagnosis of neuromuscular disorder, the information of single MU is required. In this paper, 9 channel array surface electrode system was as designed and MLoG filter was proposed. Also the MCPT(modified convolution processing technique)method was proposed for the improvement of MUAP resolution. For performance evaluation, power spectrum analysis of random data and raw EMG signal comparison of MUAP shape and quantitative estimation of SNR were executed. As a result, the MUAP resolution improvement of 32% was obtained from the standpoint of the signal-to-noise ratio(SNR).

Spatial Resolution Improvement of landsat TM Images Using a SPOT PAN Image Data Based on the New Generalized Inverse Matrix Method (새로운 일반화 역행렬법에 의한 SPOT PAN 화상 데이터를 이용한 Landsat TM 화상이 공간해상도 개선)

  • 서용수;이건일
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.31B no.8
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    • pp.147-159
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    • 1994
  • The performance of the improvement method of spatial resolution for satellite images based on the generalized inverse matrix is superior to the conventional methods. But, this method calculates the coefficient values for extracting the spatial information from the relation between a small pixel and large pixels. Accordingly it has the problem of remaining the blocky patterns at the result image. In this paper, a new generalized inverse matrix method is proposed which is different in the calculation method of coefficient values for extracting the spatial information. In this proposed metod, it calculates the coefficient values for extracting the spatial information from the relation between a small pixel and small pixels. Consequently it can improve the spatial resolution more efficiently without remaining the blocky patterns at the result image. The effectiveness of the proposed method is varified by simulation experiments with real TM image data.

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Numerical Study on Atmospheric Flow Variation Associated With the Resolution of Topography (지형자료 해상도에 따른 대기 유동장 변화에 관한 수치 연구)

  • Lee, Soon-Hwan;Kim, Sun-Hee;Ryu, Chan-Su
    • Journal of Environmental Science International
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    • v.15 no.12
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    • pp.1141-1154
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    • 2006
  • Orographic effect is one of the important factors to induce Local circulations and to make atmospheric turbulence, so it is necessary to use the exact topographic data for prediction of local circulations. In order to clarify the sensitivity of the spatial resolution of topography data, numerical simulations using several topography data with different spatial resolution are carried out under stable and unstable synoptic conditions. The results are as follows: 1) Influence of topographic data resolution on local circulation tends to be stronger at simulation with fine grid than that with coarse grid. 2) The hight of mountains in numerical model become mote reasonable with high resolution topographic data, so the orographic effect is also emphasized and clarified when the topographic data resolution is higher. 2) The higher the topographic resolution is, the stronger the mountain effect is. When used topographic data resolution become fine, topography in numerical model becomes closer to real topography. 3) The topographic effect tends to be stronger when atmospheric stability is strong stable. 4) Although spatial resolution of topographic data is not fundamental factor for dramatic improvement of weather prediction accuracy, some influence on small scale circulation can be recognized, especially in fluid dynamic simulation.

Ensemble Downscaling of Soil Moisture Data Using BMA and ATPRK

  • Youn, Youjeong;Kim, Kwangjin;Chung, Chu-Yong;Park, No-Wook;Lee, Yangwon
    • Korean Journal of Remote Sensing
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    • v.36 no.4
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    • pp.587-607
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    • 2020
  • Soil moisture is essential information for meteorological and hydrological analyses. To date, many efforts have been made to achieve the two goals for soil moisture data, i.e., the improvement of accuracy and resolution, which is very challenging. We presented an ensemble downscaling method for quality improvement of gridded soil moisture data in terms of the accuracy and the spatial resolution by the integration of BMA (Bayesian model averaging) and ATPRK (area-to-point regression kriging). In the experiments, the BMA ensemble showed a 22% better accuracy than the data sets from ESA CCI (European Space Agency-Climate Change Initiative), ERA5 (ECMWF Reanalysis 5), and GLDAS (Global Land Data Assimilation System) in terms of RMSE (root mean square error). Also, the ATPRK downscaling could enhance the spatial resolution from 0.25° to 0.05° while preserving the improved accuracy and the spatial pattern of the BMA ensemble, without under- or over-estimation. The quality-improved data sets can contribute to a variety of local and regional applications related to soil moisture, such as agriculture, forest, hydrology, and meteorology. Because the ensemble downscaling method can be applied to the other land surface variables such as temperature, humidity, precipitation, and evapotranspiration, it can be a viable option to complement the accuracy and the spatial resolution of satellite images and numerical models.

On the Improvement of Bearing Estimation Algorithm Using Automatic Tracking Window (자동 추적 윈도우를 이용한 방위각 추정 알고리즘에 개선에 관하여)

  • 윤병우;신윤기
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.12
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    • pp.1800-1809
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    • 1990
  • This paper proposed a preprocessing algorithm which is named Automatic Tracking Window (ATW), which eliminates the effects of noises at spatial signals and spurious peaks at high-resolution algorithm in bearing estimation algorithm. This method estimates spatial spectrum by periodogram algorisdthm and hihg-resolution algorithm after preprocessing of spatial signal by automatically tracked window.

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A Study on the Improvement of Image Fusion Accuracy Using Smoothing Filter-based Replacement Method (SFR 기법을 이용한 영상 융합의 정확도 향상에 관한 연구)

  • Yun Kong-Hyun;Sohn Hong-Gyoo
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2006.04a
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    • pp.187-192
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    • 2006
  • Image fusion techniques are widely used to integrate a lower spatial resolution multispectral image with a higher spatial resolution panchromatic image. However, the existing techniques either cannot avoid distorting the image spectral properties or involve complicated and time-consuming decomposition and reconstruction processing in the case of wavelet transform-based fusion. In this study a simple spectral preserve fusion technique: the Smoothing Filter-based Replacement(SFR) is proposed based on a simplified solar radiation and land surface reflection model. By using a ratio between a higher resolution image and its low pass filtered (with a smoothing filter) image, spatial details can be injected to a co-registered lower resolution multispectral image minimizing its spectral properties and contrast. The technique can be applied to improve spatial resolution for either colour composites or individual bands. The fidelity to spectral property and the spatial quality of SFM are convincingly demonstrated by an image fusion experiment using IKONOS panchromatic and multispectral images. The visual evaluation and statistical analysis compared with other image fusion techniques confirmed that SFR is a better fusion technique for preserving spectral information.

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Recognition resolution enhancement of ultrasonic sensors via multiple steps of transmitter voltages

  • Na, Seung-You;Park, Min-Sang
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10a
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    • pp.409-412
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    • 1996
  • Ultrasonic sensors are widely used in various applications due to advantages of low cost, simplicity in construction, mechanical robustness, and little environmental restriction in usage. But the main purposes of the noncontact sensing are rather narrowly confined within object detection and distance measurement. For the application of object recognition, ultrasonic sensors exhibit several shortcomings of poor directionality which results in low spatial resolution of objects, and specularity which gives frequent erroneous range readings. To resolve these problems in object recognition, an array of the sensor has been used. To improve the spatial resolution, more number of sensors are used in essence throughout the various devices of the sensor arrays. Under the disguise of a fixed number of the sensors, the array can be shifted mechanically in several steps. In this paper we propose a practical sensor resolution enhancement method using an electronic circuit accompanying the sensor array. The circuit changes the transmitter output voltage in several steps. Using the known sensor characteristics, a set of different return echo signals provide enhanced spatial resolution. The improvement is obtained with neither the cost of the increased number of the sensors nor extra mechanical devices.

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Laser Generation of Focused Lamb Waves

  • Jhang, Kyung-Young;Kim, Hong-Joon;Kim, Hyun-Mook;Ha, Job
    • Journal of the Korean Society for Nondestructive Testing
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    • v.22 no.6
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    • pp.637-642
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    • 2002
  • An arc-shaped line array slit has been used for the laser generation of focused Lamb waves. The spatially expanded Nd:YAG pulse laser was illuminated through the arc-shaped line array slit on the surface of a sample plate to generate the Lamb waves of the same pattern as the slit. Then the generated Lamb waves were focused at the focal point of which distance from the slit position is dependent on the curvature of slit arc. The proposed method showed better spatial resolution than the conventional linear array slit in the detection of laser machined linear defect and drill machined circular defect on aluminum plates of 2mm thickness. Using the focused waves, we could detect the linear defect and the circular defect with the improvement of spatial resolution. The method can also be combined with the scanning mechanism to get an image just like by the scanning acoustic microscope(SAM).

A Study on the Improvement of Image Fusion Accuracy Using Smoothing Filter-based Replacement Method (SFR기법을 이용한 영상 융합의 정확도 향상에 관한 연구)

  • Yun Kong-Hyun
    • Spatial Information Research
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    • v.14 no.1 s.36
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    • pp.85-94
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    • 2006
  • Image fusion techniques are widely used to integrate a lower spatial resolution multispectral image with a higher spatial resolution panchromatic image. However, the existing techniques either cannot avoid distorting the image spectral properties or involve complicated and time-consuming decomposition and reconstruction processing in the case of wavelet transform-based fusion. In this study a simple spectral preserve fusion technique: the Smoothing Filter-based Replacement(SFR) is proposed based on a simplified solar radiation and land surface reflection model. By using a ratio between a higher resolution image and its low pass filtered (with a smoothing filter) image, spatial details can be injected to a co-registered lower resolution multispectral image minimizing its spectral properties and contrast. The technique can be applied to improve spatial resolution for either colour composites or individual bands. The fidelity to spectral property and the spatial quality of SFM are convincingly demonstrated by an image fusion experiment using IKONOS panchromatic and multispectral images. The visual evaluation and statistical analysis compared with other image fusion techniques confirmed that SFR is a better fusion technique for preserving spectral information.

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Development of Solenoid RF coil for 4.7 T Magnetic Resonance Velocimeter to Improve Resolution (해상도 향상을 위한 4.7 T 자기공명유속계 용 솔레노이드 RF 코일 개발)

  • Yang, Byungkuen;Cho, Jee-Hyun;Song, Simon
    • Journal of the Korean Society of Visualization
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    • v.14 no.2
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    • pp.40-45
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    • 2016
  • Magnetic resonance velocimeter (MRV) is a powerful tool to non-invasively measure the velocity of a fluid flow in various fields ranging from medicine to engineering. However, since the demands for accurate measurement in the solid/liquid interface for cardiovascular diseases and porous media increase, the improvement of spatial resolution is required. In this study, a solenoid RF coil is developed for high spatial resolution measurement. The signal-to-noise ratio in solenoid RF coil is increased seventeen times better than that in commercial coil. Moreover, the velocity distribution of Hagen-Poiseuille flow is measured with in-plane resolution of $36{\mu}m$ by $36{\mu}m$ and the accuracy of the measured velocity is compared with theoretical distribution of the laminar flow. Flow rate calculated by MRV is estimated with the flow rate injected by syringe pump.