• Title/Summary/Keyword: Spectral Correlation

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Assessment of the Relationship between Air Temperature and TOA Brightness Temperature in Different Seasons Using Landsat-8 TIRS (Landsat-8 위성의 열적외 센서를 활용한 대기온도와 밝기온도의 계절별 상관관계 분석)

  • CHOUNG, Yun-Jae;CHUNG, Youn-In;CHOI, Soo-Young
    • Journal of the Korean Association of Geographic Information Studies
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    • v.21 no.2
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    • pp.68-79
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    • 2018
  • In general, Top Of Atmosphere(TOA) brightness temperature is closely related to air temperature. Brightness temperature can be derived from the Thermal Infra-Red Sensors (TIRS) of the earth observation satellites such as the Landsat series. The TIRS instrument of the Landsat-8 satellite collects the two spectral bands (Bands 10 and 11) that measure brightness temperature. In this research, the relationship between the air temperature data measured by the weather stations in Seoul, South Korea and the brightness temperature data separately derived from Bands 10 and 11 of the Landsat-8 satellite were assessed in the different seasons through the correlation analysis. The statistical results led to the following conclusions. First, brightness temperature is closely related to air temperature in order of Spring, Autumn, Winter and Summer. Second, when air temperature increases, brightness temperature also increases in Spring, Autumn and Winter but decreases in Summer. Third, Band 10 has a closer relationship to air temperature than Band 11.

Prediction of the Digestibility and Energy Value of Corn Silage by Near Infrared Reflectance Spectroscopy (근적외선분광법을 이용한 옥수수 사일리지의 소화율 및 에너지 평가)

  • Park Hyung-Soo;Lee Jong-Kyung;Lee Hyo-Won;Kim Su-Gon;Ha Jong-Kyu
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.26 no.1
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    • pp.45-52
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    • 2006
  • This study was carried out to explore the accuracy of Near Infrared Reflectance Spectroscopy (NIRS) fer the prediction of digestibility and energy value of corn silages. The spectral data were regressed against a range of digestibility and energy parameters using modified partial least squares(MPLS) multivariate analysis in conjunction with first and second order derivatization, with scatter correction procedure(SNV-Detrend) to reduce the effect of extraneous noise. Calibration models for NIRS measurements gave multivariate correlation coefficients of determination$(R^2)$ and standard errors of cross validation of 0.92(SECV 1.73), 0.91(SECV 1.13) and 0.93(SECV 1.74) for in vitro dry matter digestibility(IVDMD), in vitro true digestibility(IVTD), and cellulase dry matter digestibility(CDMD), respectively. The standard error of prediction(SEP) and the multiple correlation coefficient of validation$(R^2v)$ on the validation set(n=39) was used in comparing the prediction accuracy. The SEP value was 0.30(TDN), 0.01(NEL), and 0.01(ME). The relative ability of NIRS to predict digestibility and energy value was very good for CDMD, total digestible nutrients(TDN), net energy fer lactation(NEL) and metabolizable energy(ME). This paper shows the potential of NIRS to predict the digestibility and energy value of con silage as a routine method in feeding programmes and for giving advice to farmers.

DETERMINATION OF SUGARS AND ORGANIC ACIDS IN ORAGE JUICES USING NEAR INFRARED DIFFUSE REFLECTANCE SPECTROSCOPY

  • Tewari, Jagdish;Mehrotra, Ranajana;Gupta, Alka;Varma, S.P.
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1522-1522
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    • 2001
  • Beverages based on fruit juices are among the most popular commercially available drinks. There is an ever-increasing demand for these juices in the market. Orange juice is one of the most common as well as most favorite flavor. The fruit processing industries have a tremendous responsibility of quality control. For quality evaluation estimation of various components of the juice is necessary. Sucrose, glucose, fructose, citric acid and malic acid are the prime components of orange juice. Little information is available on analysis of orange juice. However, conventional and general wet chemistry procedures are currently being used which are no longer desired by the industry owing to the time involved, labor input and harmful chemicals required for each analysis. Need to replace these techniques with new, highly specific and automated sophisticated techniques viz. HPLC and spectroscopy has been realized since long time. Potential of Near Infrared Spectroscopy in quantitative analysis of different components of food samples has also been well established. A rapid, non-destructive and accurate technique based on Near Infrared Spectroscopy for determination of sugars and organic acids in orange juice will be highly useful. The current study is an investigation into the potential of Near Infrared Diffuse Reflectance Spectroscopy for rapid quantitative analysis of sucrose, glucose, fructose citric acid and malic acid in orange juice. All the Near Infrared measurements were peformed on a dispersive NIR spectrophotometer (ELICO 153) in diffuse reflectance mode. The spectral region from 1100 to 2500nm has been explored. The calibration has been performed on synthetic samples that are mixtures of sucrose, glucose, fructose, citric acid and malic acid in different concentration ranges typically encountered real orange juice. These synthetic samples are therefore considered to be representatives of natural juices. All the Near Infrared spectra of synthetic samples were subjected to mathematical analysis using Partial Least Square (PLS) algorithm. After the validation, calibration was applied to commercially available real samples and freshly squeezed natural juice samples. The actual concentrations were compared with those predicted from calibration curve. A good correlation is obtained between actual and predicted values as indicated by correlation coefficient ($R^2$) value, which is close to unity, showing the feasibility of the technique.

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Sensitivity Analysis of Volcanic Ash Inherent Optical Properties to the Remote Sensed Radiation (화산재입자의 고유 광학특성이 원격탐사 복사량에 미치는 민감도 분석)

  • Lee, Kwon-Ho;Jang, Eun-Suk
    • Korean Journal of Remote Sensing
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    • v.30 no.1
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    • pp.47-59
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    • 2014
  • Volcanic ash (VA) can be estimated by remote sensing sensors through their spectral signatures determined by the inherent optical property (IOP) including complex refractive index and the scattering properties. Until now, a very limited range of VA refractive indices has been reported and the VA from each volcanic eruption has a different composition. To improve the robustness of VA remote sensing, there is a need to understanding of VA - radiation interactions. In this study, we calculated extinction coefficient, scattering phase function, asymmetry factor, and single scattering albedo which show different values between andesite and pumice. Then, IOPs were used to analyze the relationship between theoretical remote sensed radiation calculated by radiative transfer model under various aerosol optical thickness (${\tau}$) and sun-sensor geometries and characteristics of VA. It was found that the mean rate of change of radiance at top of atmosphere versus ${\tau}$ is six times larger than in radiance values at 0.55 ${\mu}m$. At the surface, positive correlation dominates when ${\tau}$ <1, but negative correlation dominates when ${\tau}$ >1. However, radiance differences between andesite and pumice at 11 ${\mu}m$ are very small. These differences between two VA types are expressed as the polynomial regression functions and that increase as VA optical thickness increases. Finally, these results would allow VA to be better characterized by remote sensing sensors.

Quenching Curves for VOCs in the Analysis of Groundwater $^{14}C$ using Liquid Scintillation Counter (액체섬광계수기를 이용한 지하수의 $^{14}C$ 측정에서 휘발성유기화합물(VOC)에 대한 소광곡선)

  • Lee, Kil-Yong;Cho, Soo-Young;Yoon, Yoon-Yeol;Ko, Kyung-Seok;Kim, Yong-Je
    • Journal of Soil and Groundwater Environment
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    • v.12 no.6
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    • pp.53-59
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    • 2007
  • Optimal quenching curves have been studied for the accurate analysis of $^{14}C$ in groundwater polluted by reducing efficiency of volatile organic compounds (VOCs) in liquid scintillation counter (LSC). The quenching parameters (SQP(E)) were measured for ten VOCs such as benzene, toluene, ethylbenzene, o-(m-,p-)xylene, trichloroethylene (TCE), tetrachloroethylene(PCE), carbon tetrachloride and chloroform. The quenching curves were plotted using $^{14}C$ standard solution and chloroform as a quenching agent. Optimal plotting conditions were determined for standard solution, LSC measuring time and the concentration of chloroform. The quenching effects of chlorinated organic compounds such as TCE, PCE, carbon tetrachloride and chloroform were greater than those of BTEX (benzene, toluene, ethylbenzene and xylene). Optimum measuring time was 100 minutes far 7,000 dpm/mL standard solution. A few mL of chloroform should be added for good quenching curves. These quenching curves have good correlation coefficients (> 0.99) and the curves could be applied to accurate analysis of $^{14}C$ in groundwater and tap water.

Urbanization and Urban Heat Island Analysis Using LANDSAT Imagery: Sejong City As a Case Study (LANDSAT 영상을 이용한 세종특별자치시의 도시화와 열섬현상 분석)

  • Kim, Mi-Kyeong;Kim, Sang-Pil;Kim, Nam-Hoon;Sohn, Hong-Gyoo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.3
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    • pp.1033-1041
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    • 2014
  • Rapid urbanization of Korea was an unprecedented example in the world and urban population increased significantly. As a result, unbalanced distribution of population is serious problem in Korea because approximately 50% of the population is concentrated in the capital area that is 10% of nation's territory, thereby occurring various urban problems including UHI. Hence, Sejong Special Autonomous City was inaugurated officially on 2 July 2012 in order to decentralize population of capital area and induce more balanced regional development. The Sejong City has been changed drastically over a period of years as developed practically since the late 2000's and is expected to have new problems of urbanization. The land cover change due to urbanization is the main cause of UHI that urban area is significantly warmer than its surrounding areas and UHI is not only affecting urban climate change but also natural environment. So the purpose of this research is to analyze level of urbanization and UHI effect and to provide the correlation analysis between Land Surface Temperature and spectral indices. To achieve this, satellite imagery from LANDSAT were used. NDVI, NDBI, and UI were calculated using red, near-infrared, mid-infrared ($0.63{\mu}m-1.75{\mu}m$) images and LST was retrieved utilizing thermal infrared ($10.4{\mu}m-12.5{\mu}m$) image. Based on each index and LST, Changes of NDVI, UI and UHI through TVI were analyzed in Sejong City. UHI effect increased around newly constructed multi-functional administrative city, the correlation between LST and NDVI was negative and UI was strong positive.

Analysis on Statistical Characteristic Changes due to the Analysis Periods of Non-Tidal Components Data in the East Coast of Korea (분석기간의 길이에 따른 동해안 비조석성분의 통계적 특성변화 분석)

  • Cho, Hong-Yeon;Jeong, Shin-Taek;Cho, Beom-Jun;Yun, Jong-Tae
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.19 no.2
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    • pp.151-161
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    • 2007
  • Statistical characteristic analysis was carried out using the non-tidal components computed by the harmonic analysis of the tidal elevation data in East coast. The tide gauging stations included in this study are the Sokcho, Mukho, Hupo, Pohang, Ulsan and Ulreungdo stations. In this study, the variance and skewness coefficient (SC) information changes, i.e., the max. value, min. value, mean and standard deviation of the variance and SC, are compared and analysed in detail by the various analysis periods increased from one year to the maximum available period. Based on the result of the statistical information (SI) range analysis, the minimum analysis period required in order to satisfy the confidence interval of the ${\pm}5%$ range of the variance and the ${\pm}0.1$ range of the SC is suggested as the 12 years, except the Ulreungdo stations. The auto-correlation and spectral density change patterns show the very similar shapes in every stations even though the absolute values are a little bit different each other.

Determination of Degree of Retrogradation of Cooked Rice by Near-Infrared Reflectance Spectroscopy (근적외 분광분석법에 의한 밥의 노화도측정)

  • Cho, Seung-Yong;Choi, Sung-Gil;Rhee, Chul
    • Korean Journal of Food Science and Technology
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    • v.26 no.5
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    • pp.579-584
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    • 1994
  • Near infrared reflectance(NIR) spectroscopy was used to determine the degree of retrogradation of cooked rice. Cooked rice samples were stored at $4^{\circ}C$ for 120 hours, and the degree of retrogradation was measured at every 6 hour during the storage time. Stored cooked rices were freeze-dried, milled and passed through a 100 mesh sieve. Enzymatic method using glucoamylase was used as reference method for the determination of the degree of retrogradation. Spectral differences due to retrogradation of cooked rice were observed at 1434, 1700, 1928, 2100, 2284 and 2320 nm. 32 samples of which moisture content were below 5% were used for calibration set, and 16 samples were used for validation set. High correlations were achieved between degree of retrogradation determined by conventional enzymatic method and by NIR with multiple correlation coefficient of 0.9753, and a standard error of calibration(SEC) of 3.64%. Comparable results were obtained with 3.91% of standard error of prediction(SEP), when the calibration equation was applied to independent group of samples of which moisture contents were in the range of calibration set. But when the calibration equation was applied to samples of which moisture contents were outer range of calibration set, SEP and bias were increased and correlation coefficient was decreased. The determination of degree of retrogradation was affected by sample moisture content. To determine degree of retrogradation of cooked rice by NIR using this calibration equation, it was suggested that sample moisture content should be controlled to below 5%.

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Multispectral Image Compression Using Classified Interband Bidirectional Prediction and Extended SPHT (영역별 대역간 양방향 예측과 확장된 SPIHT를 이용한 다분광 화상데이터의 압축)

  • Kim, Seung-Jin;Ban, Seong-Won;Kim, Byung-Ju;Park, Kyung-Nam;Kim, Young-Choon;Lee, Kuhn-Il
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.39 no.5
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    • pp.486-493
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    • 2002
  • In this paper, we proposed the effective multispectral image compression method using CIBP(classified interband bidrectional prediction) and extended SPIHT(set partition in hierarchical trees) in wavelet domain. We determine separately feature bands that have the highest correlation with other bands in the visible range and in the infrared range of wavelengths. Feature bands are coded to remove the spatial redundancy with SPIHT in the wavelet domain. Prediction bands that have high correlation with feature bands are wavelet transformed and they are classified into one of three classes considering reflection characteristics of the baseband. For Prediction bands, CIBP is performed to reduce the spectral redundancy. for the difference bands between prediction bands and the predicted bands, They are ordered to upgrade the compression efficiency of extended SPIHT with the largest error magnitude. The arranged bands are coded to compensate the prediction error with extended SPIHT. Experiments are carried out on the multispectral images. The results show that the proposed method reconstructs higher quality images than images reconstructed by the conventional methods at the same bit rate.

Comparing Quantitative EEG and Low Resolution Electromagnetic Tomography Imaging between Deficit Syndrome and Non-Deficit Syndrome of Schizophrenia (정신분열병의 결핍증후군과 비결핍증후군에서 QEEG와 sLORETA를 이용한 비교연구)

  • Lee, Sang-Eun;Yim, Seon-Jin;Lee, Mi-Gyung;Lee, Jae-Won;Han, Kyu-Hee;Lee, Jong-Il;Sim, Min-Young;Yoon, Hai-Joo;Shin, Byoung-Hak
    • Sleep Medicine and Psychophysiology
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    • v.17 no.2
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    • pp.91-99
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    • 2010
  • Objectives: Deficit schizophrenia (DS) constitutes a disease separate from non-deficit schizophrenia (NDS). The aim of the current study was to compare the quantitative EEG and low resolution electromagnetic tomography (LORETA) imaging between DS and NDS. Methods: This study was performed by 32 channels EEG for 42 schizophrenia patients who we categorized into DS and NDS using proxy instrument deficit syndrome (PDS). We performed the absolute power spectral analyses for delta, theta, alpha, low beta and high beta activities. We compared power spectrum between two groups using Independent t-test. Partial correlation test was performed with clinical parameters. Standardized LORETA (sLORETA) was used for comparison of cortical activity, and statistical nonparametric mapping (SnPM) was applied for the statistical analysis. Results: DS showed significantly increased delta and theta absolute power in fontal and parietal region compared with NDS (p<0.05). Power spectrum showed significant correlation with 'anergia' and 'hostility/suspiciousness' subscale of brief psychiatric rating scale (BPRS)(p<0.05). sLORETA found out the source region (anterior cingulate cortex/limbic part) that delta activity was significantly increased in DS (p=0.042). Conclusions: DS showed different cortical activity compared with NDS. Our results may suggest QEEG and LORETA could be the marker in differentiating between DS and NDS.

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