• Title/Summary/Keyword: spectral methods

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Selective Histogram Matching of Multi-temporal High Resolution Satellite Images Considering Shadow Effects in Urban Area (도심지역의 그림자 영향을 고려한 다시기 고해상도 위성영상의 선택적 히스토그램 매칭)

  • Yeom, Jun-Ho;Kim, Yong-Il
    • Journal of Korean Society for Geospatial Information Science
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    • v.20 no.2
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    • pp.47-54
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    • 2012
  • Additional high resolution satellite images, other period or site, are essential for efficient city modeling and analysis. However, the same ground objects have a radiometric inconsistency in different satellite images and it debase the quality of image processing and analysis. Moreover, in an urban area, buildings, trees, bridges, and other artificial objects cause shadow effects, which lower the performance of relative radiometric normalization. Therefore, in this study, we exclude shadow areas and suggest the selective histogram matching methods for image based application without supplementary digital elevation model or geometric informations of sun and sensor. We extract the shadow objects first using adjacency informations with the building edge buffer and spatial and spectral attributes derived from the image segmentation. And, Outlier objects like a asphalt roads are removed. Finally, selective histogram matching is performed from the shadow masked multi-temporal Quickbird-2 images.

Phytochemical Constituents of Capsella bursa-pastoris and Their Anti-inflammatory Activity

  • Cha, Joon Min;Kim, Dong Hyun;Lee, Tae Hyun;Subedi, Lalita;Kim, Sun Yeou;Lee, Kang Ro
    • Natural Product Sciences
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    • v.24 no.2
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    • pp.132-138
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    • 2018
  • Phytochemical investigation of 80% MeOH extract of the aerial parts of Capsella bursa-pastoris yielded fourteen compounds (1 - 14). The structures of the compounds were elucidated by spectroscopic methods to be methyl-1-thio-${\beta}$-D-glucopyranosyl disulfide (1), 10-methylsulphinyl-decanenitrile (2), 11-methyl-sulphinyl-undecanenitrile (3), 1-O-(lauroyl)glycerol (4), phytene-1, 2-diol (5), (3S,5R,6S,7E)-5,6-epoxy-3-hydroxy-7-megastigmen-9-one (6), loliolide (7), ${\beta}$-sitosterol (8), 3-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-1-propanone (9), 1-feruloyl-${\beta}$-D-glucopyranoside (10), pinoresinol-4'-O-${\beta}$-D-glucopyranoside (11), luteolin (12), quercetin-3-O-${\beta}$-D-glucopyranoside (13), and luteolin 6-C-${\beta}$-glucopyranoside (14). Although compound 1 was reported as synthetic compound, 1 was first isolated from natural source. NMR spectral data assignments of 1, 2 and 3 were reported for the first time, and compounds 1 - 14 were for the first time reported from this plant source. The anti-inflammatory effects of 1 - 14 were evaluated in lipopolysaccharide (LPS)-stimulated murine microglia BV-2 cells. Compounds 12 exhibited strong inhibitory effects on nitric oxide production in LPS-activated BV-2 cells with $IC_{50}$ values of $9.70{\mu}M$.

Antioxidant and Nitrite Scavenging Effect of Soybean, Meju and Doenjang (대두, 메주 및 된장의 항산화 효과와 아질산염 소거 효과)

  • 최계선;임선영;최재수
    • Journal of Life Science
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    • v.8 no.5
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    • pp.473-478
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    • 1998
  • The radical scavenging activity of the methanol extracts was in the order of doenjang〉 meju〉 soybean. The metha-nol extracts were further fractionated with dichloromethane, ethyl acetate, butanol and water in sequence. Among the solvent fractions of the methanol extracts, the ethyl acetate fraction demonstrated high levels of radical scave-nging activity. On the other hands, the nitrite scavenging activity of the methanol extrats was in the order of doen-jang〉soybean〉meju. All fractions from doenjang were exhibited the strong nitrite scavenging effect. Especially, $H_2O$, EtOAc and BuOH fractions with 6gmg/10$m\ell$ concentration exhibited much stronger nitrite scavenging effect than that of L-ascorbic acid. The ethyl acetate fraction showed remarkable antioxidant and nitrite scavenging effects compared with the other fractions obtained from soybean, meju and doenjang. The ethyl acetate fraction of doenjang was fur-ther purified by repeated chromoatograpic methods and isolated three compounds. There are identified as genistin, dai-dzein and genistein on the basis of spectral data.

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The Effect of Electroacupuncture at Sobu(HT8) on the EEG and HRV (소부(HT8) 전침이 뇌파(EEG)와 심박변이도(HRV)에 미치는 영향)

  • Yoon, Dae Shik;Hong, Seung-Won;Lee, Yong-Sub
    • Korean Journal of Acupuncture
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    • v.30 no.4
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    • pp.305-318
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    • 2013
  • Objectives : The aim of this study was to examine the effect of electroacupuncture(EA) at an acupoint, HT8(Sobu), on normal humans by using power spectral analysis. We examined the effect on the Heart Rate Variability(HRV), and the balance of the autonomic nervous system. Methods : Thirty-two healthy volunteers participated in this study. EEG(Electroencephalogram) power spectrum exhibits site-specific and state-related differences in specific frequency bands. A thirty-two channel EEG study was carried out on thirty-two subjects(14 males; mean age=23.5 years old, 18 females; mean age=21.5 years old). HRV and EEG were simultaneously recorded before and after acupuncture. Results : In the ${\alpha}$(alpha) band, during the HT8-acupoint treatment, the power values in the ${\alpha}$(alpha) band significantly decreased(p<0.05) at 28 channels. In the ${\beta}$(beta) band significantly decreased(p<0.05) at 26 channels. In ${\delta}$(delta) band significantly decreased(p<0.05) at 18 channels. In ${\theta}$(theta) band significantly decreased(p<0.05) at 20 channels. ${\alpha}/{\beta}$ values were increased at 6 channels and decreased at 10 channels.${\beta}/{\theta}$ values were increased at 10 channels and decreased at 19 channels. Mean-RR(RR-interval), Complexity, RMSSD(Root mean square of successive differences), SDSD(Standard deviations differences between adjacent normal R-R intervals), norm HF showed a significantly increased and mean-HRV, norm LF, LHR(LF/HF Ratio) showed a significantly decreased after HT8-acupoint treatment(p<0.05). Conclusions : These results suggest that EA at the HT8 mostly causes significant changes on alpha(28 channels), beta(26 channels), delta(18 channels), theta(20 channels) bands and mean-HRV, mean-RR, complexity, RMSSD, SDSD, norm LF, norm HF and LHR. If practicing EA at the HT8, it will regulate the function of the cerebral cortex, decrease activity of the sympathetic and increase parasympathetic nervous activity.

CYTOTOXICITIES OF GINSENG SAPONINS AND THEIR DEGRADATION PRODUCTS AGAINST SOME CANCER CELL LINES AND STRUCTURE-ACTIVITY RELATIONSHIP (수종의 암세포주에 대한 인삼 사포닌 및 그 분해산물의 구조와 세포독성 관계)

  • Baek N.I.;Kim S.I.;Lee Y.H.;Kim D.S.;Park J.D.;Lee C.B.
    • Proceedings of the Ginseng society Conference
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    • 1993.09a
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    • pp.132-137
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    • 1993
  • Several Prosapogenins and sapogenins obtained by acid hydrolysis or alkaline cleavage of Korean red ginseng saponins were separated and identified by spectral and physical methods. Some of these degradation products showed the cytotoxic activities against various cancer cell lines, that is, A549, SK - OV - 3, L121O, P388 and K562. The significant difference of activity between stereoisooers was not approved and the activity was inversely proportional to the number of sugars binding to sapogenins. It was clear that diol type prosapogenins and sapogenins were more cytotoxic than triol type ones.

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Heart Rate Variability in Obese Climacteric Women in Korea;Relations between Autonomic Nervous System Activity and Obesity (폐경 전과 폐경 후 비만 여성의 심박변이도에 관한 연구)

  • Hwang, Deok-Sang;Hwang, Mi-Ja;Lee, Yoon-Jae;Lee, Kyung-Sub;Song, Mi-Yeon
    • Journal of Korean Medicine for Obesity Research
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    • v.8 no.1
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    • pp.81-88
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    • 2008
  • Objectives To investigate the relationship between Heart Rate Variability and menopause among obese middle-aged women in Korea. Subjects and Methods Forty middle-aged women (age 49.05 $\pm$ 2.64 years) with BMI > $23kg/m^2$ were recruited by local advertisement. Blood profiles of estrogen, FSH, LH, glucose, total cholesterol, HDL-cholesterol, and triglyceride were measured. Autonomic Nervous System (ANS) was estimated by short-term spectral analysis of heart rate variability (HRV). Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were accessed using Computerized Tomography (CT), Bioimpedance Analysis (BIA), and anthropometry. To scrutinize the influence of ANS on obesity-related factors, we divided the subjects into pre- and post-menopausal women. Results The total cholesterol, FSH and LH were significantly higher in post-menopausal obese women group. The estradiol and standard deviation of all normal R-R intervals (SDNN), high-frequency components (HF) of the HRV were significantly lower in postmenopausal obese women group (P<0.05). Adipose tissue distribution and blood profiles were not significantly different between two groups. Conclusion Menopause induced a decrease in SDNN and HF values and increase in total cholesterol level in obese women although the VAT itself was not related with ANS in obese women.

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Nondestructive sensing technologies for food safety

  • Kim, M.S.;Chao, K.;Chan, D.E.;Jun, W.;Lee, K.;Kang, S.;Yang, C.C.;Lefcourt, A.M.
    • 한국환경농학회:학술대회논문집
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    • 2009.07a
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    • pp.119-126
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    • 2009
  • In recent years, research at the Environmental Microbial and Food Safety Laboratory (EMFSL), Agricultural Research Service (ARS) has focused on the development of novel image-based sensing technologies to address agro-food safety concerns, and transformation of these novel technologies into practical instrumentation for industrial implementations. The line-scan-based hyperspectral imaging techniques have often served as a research tool to develop rapid multispectral methods based on only a few spectral bands for rapid online applications. We developed a newer line-scan hyperspectral imaging platform for high-speed inspection on high-throughput processing lines, capable of simultaneous multiple inspection algorithms for different agro-food safety problems such as poultry carcass inspection for wholesomeness and apple inspection for fecal contamination and defect detection. In addition, portable imaging devices were developed for in situ identification of contamination sites and for use by agrofood producer and processor operations for cleaning and sanitation inspection of food processing surfaces. The aim of this presentation is to illustrate recent advances in the above agro.food safety sensing technologies.

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A SEARCH FOR AGN INTRA-DAY VARIABILITY WITH KVN

  • LEE, TAESEOK;TRIPPE, SASCHA;OH, JUNGHWAN;BYUN, DO-YOUNG;SOHN, BONG-WON;LEE, SANG-SUNG
    • Journal of The Korean Astronomical Society
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    • v.48 no.5
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    • pp.313-323
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    • 2015
  • Active galactic nuclei (AGN) are known for irregular variability on all time scales, down to intra-day variability with relative variations of a few percent within minutes to hours. On such short timescales, unexplored territory, such as the possible existence of a shortest characteristic time scale of activity and the shape of the high frequency end of AGN power spectra, still exists. We present the results of AGN single-dish fast photometry performed with the Korean VLBI Network (KVN). Observations were done in a “anti-correlated” mode using two antennas, with always at least one antenna pointing at the target. This results in an effective time resolution of less than three minutes. We used all four KVN frequencies, 22, 43, 86, and 129 GHz, in order to trace spectral variability, if any. We were able to derive high-quality light curves for 3C 111, 3C 454.3, and BL Lacertae at 22 and 43 GHz, and for 3C 279 at 86 GHz, between May 2012 and April 2013. We performed a detailed statistical analysis in order to assess the levels of variability and the corresponding upper limits. We found upper limits on flux variability ranging from ~1.6% to ~7.6%. The upper limits on the derived brightness temperatures exceed the inverse Compton limit by three to six orders of magnitude. From our results, plus comparison with data obtained by the University of Michigan Radio Astronomy Observatory, we conclude that we have not detected source-intrinsic variability which would have to occur at sub-per cent levels.

A Study of the Dynamic Amplification Characteristics of the Domestic Seismic Observation Sites Using Coda Wave (Coda파를 이용한 국내 관측소지반의 동적 증폭특성에 관한 연구)

  • Kim, Junkyoung;Lee, Jundae
    • Journal of the Korean GEO-environmental Society
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    • v.10 no.7
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    • pp.135-141
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    • 2009
  • For more reliable estimation of soil-structure interaction and seismic source and attenuation properties, site amplification function should be considered. This study use the Nakamura's method (1989) for estimating site amplification though various methods for the same purpose have been proposed. This method was originally applied to the surface waves of background noise and therefore there are some limitation for applications to general wave energy. However, recently this method has been extended and applied to the S wave energy successfully. This study applied the method to the coda wave energy which is equivalent to the backscattered S wave energy. We used more than 60 observed ground motions from 5 earthquakes which occurred recently, with magnitude range from 3.6 to 5.1 Each station showed characteristic site amplification property in low-, high- and resonance frequency ranges. In the case of comparing these results to those from S wave energy, lots of information to the site classification work can be gained. Moreover, removal of site amplification can give us more reliable seismic source parameters.

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New method for generation of artificial ground motion by a nonstationary Kanai-Tajimi model and wavelet transform

  • Amiri, G. Ghodrati;Bagheri, A.;Fadavi, M.
    • Structural Engineering and Mechanics
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    • v.26 no.6
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    • pp.709-723
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    • 2007
  • Considering the vast usage of time-history dynamic analyses to calculate structural responses and lack of sufficient and suitable earthquake records, generation of artificial accelerograms is very necessary. The main target of this paper is to present a novel method based on nonstationary Kanai-Tajimi model and wavelet transform to generate more artificial earthquake records, which are compatible with target spectrum. In this regard, the generalized nonstationary Kanai-Tajimi model to include the nonstationary evaluation of amplitude and dominant frequency of ground motion and properties of wavelet transform is used to generate ground acceleration time history. Application of the method for El Centro 1940 earthquake and two Iranian earthquakes (Tabas 1978 and Manjil 1990) is presented. It is shown that the model and identification algorithms are able to accurately capture the nonstationary features of these earthquake accelerograms. The statistical characteristics of the spectral response of the generated accelerograms are compared with those for the actual records to demonstrate the effectiveness of the method. Also, for comparison of the presented method with other methods, the response spectra of the synthetic accelerograms compared with the models of Fan and Ahmadi (1990) and Rofooei et al. (2001) and it is shown that the response spectra of the synthetic accelerograms with the method of this paper are close to those of actual earthquakes.