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Estimation of spatial evapotranspiration using Terra MODIS satellite image and SEBAL model in mixed forest and rice paddy area (SEBAL 모형과 Terra MODIS 영상을 이용한 혼효림, 논 지역에서의 공간증발산량 산정 연구)

  • Lee, Yong Gwan;Jung, Chung Gil;Ahn, So Ra;Kim, Seong Joon
    • Journal of Korea Water Resources Association
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    • v.49 no.3
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    • pp.227-239
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    • 2016
  • This study is to estimate Surface Energy Balance Algorithm for Land (SEBAL) daily spatial evapotranspiration (ET) comparing with eddy covariance flux tower ET in Seolmacheon mixed forest (SMK) and Cheongmicheon rice paddy (CFK). The SEBAL input data of Albedo, Land Surface Temperature (LST), Normalized Difference Vegetation Index (NDVI) from Terra MODIS products and the meteorological data of wind speed, and solar radiation were prepared for 2 years (2012-2013). For the annual average flux tower ET of 302.8 mm in SMK and 482.0 mm in CFK, the SEBAL ETs were 183.3 mm and 371.5 mm respectively. The determination coefficients ($R^2$) of SEBAL ET versus flux tower ET for total periods were 0.54 in SMK and 0.79 in CFK respectively. The main reason of SEBAL ET underestimation for both sites was from the determination of hot pixel and cold pixel of the day and affected to the overestimation of sensible heat flux.

A comparative study for reconstructing a high-quality NDVI time series data derived from MODIS surface reflectance (MODIS 지표 분광반사도 자료를 이용한 고품질 NDVI 시계열 자료 생성의 기법 비교 연구)

  • Lee, Jihye;Kang, Sinkyu;Jang, Keunchang;Hong, Suk Young
    • Korean Journal of Remote Sensing
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    • v.31 no.2
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    • pp.149-160
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    • 2015
  • A comparative study was conducted for alternative consecutive procedures of detection of cloud-contaminated pixels and gap-filling and smoothing of time-series data to produce high-quality gapless satellite vegetation index (i.e. Normalized Difference Vegetation Index, NDVI). Performances of five alternative methods for detecting cloud contaminations were tested with ground-observed cloudiness data. The data gap was filled with a simple linear interpolation and then, it was applied two alternative smoothing methods (i.e. Savitzky-Golay and Wavelet transform). Moderate resolution imaging spectroradiometer (MODIS) data were used in this study. Among the alternative cloud detection methods, a criterion of MODIS Band 3 reflectance over 10% showed best accuracy with an agreement rate of 85%, which was followed by criteria of MODIS Quality assessment (82%) and Band 3 reflectance over 20% (81%), respectively. In smoothing process, the Savitzky-Golay filter was better performed to retain original NDVI patterns than the wavelet transform. This study demonstrated an operational framework of gapdetection, filling, and smoothing to produce high-quality satellite vegetation index.

The Effects of distilled Rehmannia glutinosa Herbal Acupuncture on the Heart Rate Variability(HRV) (생지황 약침이 정상인의 심박변이도(HRV)에 미치는 영향)

  • Shin, Jin-Cheol;Kim, Lak-Hyung;Song, Beom-Yong;Yook, Tae-Han
    • Journal of Pharmacopuncture
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    • v.11 no.1
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    • pp.83-97
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    • 2008
  • Objectives : We investigated the effects of distilled Rehmannia glutinosa Herbal Acupuncture on autonomic nervous system with the Heart Rate Variability(HRV) in adult man. as well as we tried to observe how distilled Rehmannia glutinosa Herbal Acupuncture on the balance of the autonomic nervous system. Methods : We investigated on 58 healthy volunteers consisted of 28 subjects in experiment(distilled Rehmannia glutinosa Herbal Acupuncture) group and 30 subjects in control(Normal Saline) group. Study form was a randomized, placebo-controlled, double-blind clinical trial. 28 subjects in experiment group were injected distilled Rehmannia glutinosa Herbal Acupuncture at $GB_{21}$(Kyonjong) and 30 subjects in control group were injected Normal Saline at $G_{21}$(Kyonjong). except of 2 subjects(in control group) who can't be measured and 6 subjects(2 in experiment group and 4 in control group) who move or make unforceable error during measuring. Finally 26 subject in experiment group and 24 subject in control group are studied. We measured HRV by PolyG-I on 7 times : before and after injection per 5 minutes during 30 minutes. The SPSS 10.0 for windows was used to analyze the data and the paired t-test(in group) and Student t-test(between two groups) were used to verify the result. Results : 1. After distilled Rehmannia glutinosa Herbal Acupuncture injection, Mean HRV is significantly low only for first 5 minute, SDNN is significantly high after 5 minute, Complexity is significantly low only from 20 minute to 25 minute. HRV index is significantly high for first 5minute and from 10 minute to after 10 minute. 2. HRV index of distilled Rehmannia glutinosa Herbal Acupuncture Group significantly increased from 25 minute to 30 minute, and pNN50 of Rehmannia glutinosa Herbal Acupuncture Group significantly decreased from 20 minute to 30 minute compared with those of Normal Saline group. 3. After distilled Rehmannia glutinosa Herbal Acupuncture injection, Ln(TP) and Ln(VLF) are significantly high after injection. Normalized LF is significantly high from 5 minute to 20 minute and from 25 minute and 30 minute. Normalized HF is significantly low from 5minute to 20 minute and from 25 minute and 30 minute. 4. Ln(TP) and Ln(VLF) of distilled Rehmannia glutinosa Herbal Acupuncture Group significantly increased from 20 minute to 25 minute compared with those of Normal Saline group. Conclusions : The results suggest that Rehmannia glutinosa Herbal Acupuncture in healthy adult man tend to activate the autonomic nervous system and parasympathetic nervous system compared to Normal Saline within normal range.

Influence of stress and pure tone audiometry on noise-exposed dental laboratory technicians by dental instrument (치과기공 소음 노출이 치기공과 학생의 스트레스와 순음청력에 미치는 영향)

  • Yon, Jung-Min;Lee, Ju-Hee;Kim, Dae-Hyun;Lee, Og-Kyoung
    • Journal of Digital Convergence
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    • v.14 no.4
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    • pp.363-370
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    • 2016
  • Noise is unwanted sound that is the reason of the stress and hearing loss. The current study attempted to estimate whether the noise of dental laboratory affected stress and pure tone audiometry (PTA) of dental laboratory technicians (DLTs) using heart rate variability, air and bone conduction audiometry. The age, heights, and weights of DLTs were resembled control. Standard deviation of normal to normal interval such as stress resistance and normalized HF of DLTs were significantly decreased, but heart rates, normalized LF, and LF/HF ratio of DLTs were significantly increased compared with control. In air conduction audiometry of DLTs, significant increments of thresholds encountered in 125, 250, 500, 1000, 2000, 3000, 4000, and 6000 Hz in the right ears and 125, 250, 500, 1000, and 2000 Hz in the left ears. Thresholds of bone conduction audiometry in both ears were significantly increased in 250, 500, 1000, 2000, and 4000 Hz. The findings in this study provide that stress and hearing loss observed in noise-exposed DLTs at dental laboratory. Therefore, proper safety precautions should be carried out at dental laboratory.

The Effect of Dry Cupping Treatment Applied to Back-shu Points on the Autonomic Nervous System through HRV (흉배부(胸背部)에 시행한 부항요법(附缸療法)이 자율신경계에 미치는 영향 - 심박변이도 측정을 통한 연구 -)

  • Hwang, Eun-Mi;Wang, Kai-Hsia;Bae, Jae-Ik;Keum, Dong-Ho
    • Journal of Korean Medicine Rehabilitation
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    • v.23 no.1
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    • pp.51-64
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    • 2013
  • Objectives : This study was performed to evaluate the effect of dry cupping treatment applied to back-shu points on the autonomic nervous system. Methods : Two groups of sympathicotonia and normal with each 30 volunteers were set up for this experiment. The sympathicotonia group was selected by the criterion for sympathicotonia by the questionnaire composed of 11 items. After 10 minutes for environmental adaptation, the first HRV(heart rate variability) test was conducted, and then, dry cupping therapy was applied to back-shu points for 5 minutes to stimulate sympathetic ganglia lying along the spine. The second HRV test was carried out just after the cupping therapy under the same condition and then, the third test was repeated after two hours based on the first test time. Results : 1. In sympathicotonia group, SDNN(standard deviation of all normal R-R intervals), RMSSD(the square root of the mean of the sum of the squares of differences between adjacent normal R-R intervals), Ln(HF)(high frequency power), nmHF(normalized high frequency power) increased and mHR(mean heart rate), nmLF(normalized low frequency power) decreased significantly right after dry cupping therapy which means dry cupping affects on autonomic nervous system. The effect lasts in these items of nmLF, Ln(HF), nmHF, rLHF(rate ratio of LF/HF). 2. In normal group, SDNN, RMSSD increased and mHR decreased significantly right after dry cupping therapy, too. But, Ln(LF)(low frequency power), nmLF, rLHF unexpectedly increased and nmLF, rLHF stay increased up to 2 hours. Conclusions : The results suggest that the dry cupping therapy has effect on the autonomic nervous system. It is effective to stabilize hyper-sympathetic tone of people diagnosed as Sympathicotonia and activate parasympathetic tone.

Analysis of Spatial Precipitation Field Using Downscaling on the Korean Peninsula (상세화 기법을 통한 한반도 공간 강우장 분석)

  • Cho, Herin;Hwang, Seokhwan;Cho, Yongsik;Choi, Minha
    • Journal of Korea Water Resources Association
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    • v.46 no.11
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    • pp.1129-1140
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    • 2013
  • Precipitation is one of the important factors in the hydrological cycle. It needs to understand accurate of spatial precipitation field because it has large spatio-temporal variability. Precipitation data obtained through the Tropical Rainfall Monitoring Mission (TRMM) 3B43 product is inaccurate because it has 25 km space scale. Downscaling of TRMM 3B43 product can increase the accuracy of spatial precipitation field from 25 km to 1 km scale. The relationship between precipitation and the normalized difference vegetation index(NDVI) (1 km space scale) which is obtained from the Moderate Resolution Imaging Spectroradiometers (MODIS) sensor loaded in Terra satellite is variable at different scales. Therefore regression equations were established and these equations apply to downscaling. Two renormalization strategies, Geographical Difference Analysis (GDA) and Geographical Ratio Analysis (GRA) are implemented for correcting the differences between remote sensing-derived and rain gauge data. As for considering the GDA method results, biases, the root mean-squared error (RMSE), MAE and Index of agreement (IOA) is equal to 4.26 mm, 172.16 mm, 141.95 mm, 0.64 in 2009 and 17.21 mm, 253.43 mm, 310.56 mm, 0.62 in 2011. In this study, we can see the 1km spatial precipitation field map over Korea. It will be possible to get more accurate spatial analysis of the precipitation field through using the additional rain gauges or radar data.

Multi-sensor Image Registration Using Normalized Mutual Information and Gradient Orientation (정규 상호정보와 기울기 방향 정보를 이용한 다중센서 영상 정합 알고리즘)

  • Ju, Jae-Yong;Kim, Min-Jae;Ku, Bon-Hwa;Ko, Han-Seok
    • Journal of the Korea Society of Computer and Information
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    • v.17 no.6
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    • pp.37-48
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    • 2012
  • Image registration is a process to establish the spatial correspondence between the images of same scene, which are acquired at different view points, at different times, or by different sensors. In this paper, we propose an effective registration method for images acquired by multi-sensors, such as EO (electro-optic) and IR (infrared) sensors. Image registration is achieved by extracting features and finding the correspondence between features in each input images. In the recent research, the multi-sensor image registration method that finds corresponding features by exploiting NMI (Normalized Mutual Information) was proposed. Conventional NMI-based image registration methods assume that the statistical correlation between two images should be global, however images from EO and IR sensors often cannot satisfy this assumption. Therefore the registration performance of conventional method may not be sufficient for some practical applications because of the low accuracy of corresponding feature points. The proposed method improves the accuracy of corresponding feature points by combining the gradient orientation as spatial information along with NMI attributes and provides more accurate and robust registration performance. Representative experimental results prove the effectiveness of the proposed method.

Adaptive Digital Predistorter Using the NLMS Algorithm for the Nonlinear Compensation of the OFDM Communication System (OFDM통신시스템의 비선형 왜곡 보상을 위한 NLMS 알고리즘 방식의 디지털 적응 전치 왜곡기)

  • Kim Sang-Woo;Hieu Nguyen Thanh;Kang Byoung-Moo;Ryu Heung-Gyoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.4 s.95
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    • pp.389-396
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    • 2005
  • In this paper, we propose a pre-distortion method using the NLMS(Normalized Least Mean Square) algorithm to cope with hish PAPR(Peak to Average Power Ratio) problem in OFDM communication system. This proposed scheme estimates the distortion characteristics of HPA, and changes the characteristic against the distortion. Therefore, it can be shown that the adaptive characteristic of the NLMS pre-distorter is good to track the various nonlinear characteristic of HPA, even though HPA characteristic is changed by temperature variation or aging. From the performance analysis, SNR efficiency of NLMS pre-distorter is about $0.5\;\cal{dB}$ less than that of common numerical non-adaptive pre-distorter, when IBO(Input Back Off) is $0\;\cal{dB}$. However, the NLMS pre-distorter is better than the common numerical pre-distorter, because these two pre-distorters have similar performance in higher than $3\;\cal{dB}$ IBO, and the NLMS pre-distorter maintains the constant performance even though characteristic of HPA is changed.

The Effects of distilled Astragali Radix Herbal Acupuncture on the Heart Rate Variability(HRV) (황인 약침이 정산인의 심박변이도(HRV)에 미치는 영향)

  • Lim, Sung-Taek;Kim, Lak-Hyung;Song, Beom-Yong;Yook, Tae-Han
    • Journal of Oriental Neuropsychiatry
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    • v.19 no.1
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    • pp.107-124
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    • 2008
  • We investigated the effects of distilled Astragali Radix Herbal Acupuncture on autonomic nervous system with the Heart Rate Variability(HRV) in adult man. as well as we tried to observe how distilled Astragali Radix Herbal Acupuncture on the balance of the autonomic nervous system. Methods : We investigated on 61 healthy volunteers consisted of 31 subjects in experiment(distilled Astragali Radix Herbal Acupuncture) group and 30 subjects in control(Normal Saline) group. Study form was a randomized, placebo-controlled, double-blind clinical trial. 31 subjects in experiment group were injected distilled Astragali Radix Herbal Acupuncture at GB21(Kyonjong) and 30 subjects in control group were injected Normal Saline at GB21(Kyonjong). except of 2 subjects(in control group) who can't be measured and 10 subjects(6 in experiment group and 4 in control group) who move or make unforceable error during measuring. Finally 25 subject in experiment group and 24 subject in control group are studied. We measured HRV by PolyG-I on 7 times : before and after injection per 5 minutes during 30 minutes. The SPSS 10.0 for windows was used to analyze the data and the paired t test(in group) and Student t test(between two groups) were used to verify the result. Results : I. After distilled Astragali Radix Herbal Acupuncture injection, SDNN is significantly high from 5 minute to 10 minute and from 15 minute to 30 minute, Complexity is significantly low from 20 minute to 30minute. HRV index is significantly mgb for first 20 minute and from 25 minute to 30 minute, RMSSD is significantly high only from 15 minute to 20 minute. 2. HRV index of distilled Astragali Radix Herbal Acupuncture Group significantly increased from 25 minute to 30 minute, pNN50 of distilled Astragali Radix Herbal Acupuncture Group significantly decreased from 25 minute to 30 minute and RMSSD of distilled Astragali Radix Herbal Acupuncture Group significantly increased from 25 minute to 30 minute compared with those of Normal Saline group. 3. After distilled Astragali Radix Herbal Acupuncture injection, Ln(TP) is significantly high from 5 minute to 10 minute and from 15 minute to 30 minute. Ln(VLF) is significantly high after 5 minute, Ln(LF) is significantly high after 15 minute and Ln(HF) is significantly high from 5 minute to 10 minute and 25 minute to 30 minute, but significantly low for first 5 minute and from 10 minute to 20 minute. Normalized LF is significantly high after 20 minute and Normalized LF is significantly low after 20 minute. Conclusions : The results suggest that distilled Astragali Radix Herbal Acupuncture in healthy adult man tend to activate the autonomic nervous system within normal range. This result is derived from that parasympathetic nervous system was continuously activated and sympathetic nervous system was activated a little later.

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Dependences of Ultrasonic Parameters for Osteoporosis Diagnosis on Bone Mineral Density (골다공증 진단을 위한 초음파 변수의 골밀도에 대한 의존성)

  • Hwang, Kyo Seung;Kim, Yoon Mi;Park, Jong Chan;Choi, Min Joo;Lee, Kang Il
    • Journal of the Korean Society for Nondestructive Testing
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    • v.32 no.5
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    • pp.502-508
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    • 2012
  • Quantitative ultrasound technologies for osteoporosis diagnosis measure ultrasonic parameters such as speed of sound(SOS) and normalized broadband ultrasound attenuation(nBUA) in the calcaneus (heel bone). In the present study, the dependences of SOS and nBUA on bone mineral density in the proximal femur with high risk of fracture were investigated by using 20 trabecular bone samples extracted from bovine femurs. SOS and nBUA in the femoral trabecular bone samples were measured by using a transverse transmission method with one matched pair of ultrasonic transducers with a center frequency of 1.0 MHz. SOS and nBUA measured in the 20 trabecular bone samples exhibited high Pearson's correlation coefficients (r) of r = 0.83 and 0.72 with apparent bone density, respectively. The multiple regression analysis with SOS and nBUA as independent variables and apparent bone density as a dependent variable showed that the correlation coefficient r = 0.85 of the multiple linear regression model was higher than those of the simple linear regression model with either parameter SOS or nBUA as an independent variable. These high linear correlations between the ultrasonic parameters and the bone density suggest that the ultrasonic parameters measured in the femur can be useful for predicting the femoral bone mineral density.