• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.6
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• pp.408-411
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• 2018

We fabricated highly flexible Mn-doped $SnO_2$ (MTO)/Ag/MTO/polydimethylsiloxane (PDMS)/MTO multilayer transparent conducting films. To reduce refractive-index mismatching of the MTO/Ag/MTO/polyethylene terephthalate (PET), index-matching layers were inserted between the oxide-metal-oxide-structured films and the PET substrate. The PDMS layer was deposited by spin-coating after adjusting the mixing ratio of PDMS and hexane. We investigated the effects of the index-matching layer on the color and reflectance differences with different PDMS dilution ratios. As the dilution ratio increased from 1:100 to 1:130, the color difference increased slightly, while the reflectance difference decreased from 0.62 to 0.32. The MTO/Ag/MTO/PDMS/MTO film showed a transmittance of 87.18~87.68% at 550 nm. The highest value of the Haacke figure of merit was $47.54{\times}10^{-3}{\Omega}^{-1}$ for the dilution ratio of 1:130.

• Korean Journal of Agricultural Science
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• v.41 no.3
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• pp.169-175
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• 2014

Objective of this study was to investigate effects of pre-processing method and number of sampling leaves on stability of the reflectance measurement for Chinese cabbage and kale leaves. Chinese cabbage and kale were transplanted and cultivated in a plant factory. Leaf samples of the kale and cabbage were collected at 4 weeks after transplanting of the seedlings. Spectra data were collected with an UV/VIS/NIR spectrometer in the wavelength region from 190 to 1130 nm. All leaves (mature and young leaves) were measured on 9 and 12 points in the blade part in the upper area for kale and cabbage leaves, respectively. To reduce the spectral noise, the raw spectral data were preprocessed by different methods: i) moving average, ii) Savitzky-Golay filter, iii) local regression using weighted linear least squares and a $1^{st}$ degree polynomial model (lowess), iv) local regression using weighted linear least squares and a $2^{nd}$ degree polynomial model (loess), v) a robust version of 'lowess', vi) a robust version of 'loess', with 7, 11, 15 smoothing points. Effects of number of sampling leaves were investigated by reflectance difference (RD) and cross-correlation (CC) methods. Results indicated that the contribution of the spectral data collected at 4 sampling leaves were good for both of the crops for reflectance measurement that does not change stability of measurement much. Furthermore, moving average method with 11 smoothing points was believed to provide reliable pre-processed data for further analysis.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.4
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• pp.314-320
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• 1998

In this study, we have investigated crystallization properties of $Te_x(Sb_{85}Ge_{15})_{100-x}$ (x=0.3, 0.5, 1.0) thin films prepared by thermal evaporation. The change of reflectance according to phase change from amorphous to crystalline phases with annealing and exposure of diode laser is measured b the n&k analyzer and the surface morphology between amorphous and crystalline phase is analyzed by SEM and AFM. The difference in reflectance($\DeltaR$) between amorphous and crystalline phase appears approximately 20% at the diode laser wavelength, 780nm in all prepared films. Especially, the reflectance difference,$\DeltaR$ comes up to about 30% in $Te_{0.5}(Sb_{85}Ge_{15})_{99.5}$ thin film. Also, amorphous-to-crystalline phase change is observed in all prepared films. As a result of the measurement of the reflectance using diode laser, the reflectance is increased in proportion to the laser power and exposure time in all films. As a result of observing each film with the SEM and AFM, the surface morphology of the annealed and the exposed films are evidently increased than those of as-deposited films. The fast crystallization is occurred by increasing in Te content. Therefore, we conclude that the $Te_{0.5}(Sb_{85}Ge_{15})_{99.5}$ and $Te_1(Sb_{85}Ge_{15})_{99}$ thin films can be evaluated as an attractive optical recording medium with high contast ratio and fast erasing time due to crystallization.

• Korean Journal of Remote Sensing
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• v.30 no.5
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• pp.627-639
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• 2014

Accurate correction of surface effect from back scattered solar radiance is one of key issue to retrieve aerosol information from satellite measurements. In this study, two different methods are applied to retrieve surface reflectance by using single visible channel measurement from meteorological imager onboard COMS. The first one is minimum reflectance method, which composes the minimum value among previously measured reflectances at each pixel over a certain search window length. This method assumes that the darkest pixel corresponds to the aerosol-free condition, and deduces surface reflectance by correcting atmospheric scattering from the measured visible reflectance. The second method, named as the "atmospheric correction method" in this study, estimates the result by correcting aerosol and atmospheric scattering with ground-based observation of aerosol optical properties. The purpose of this study is to investigate the retrieval accuracy of the widelyused minimum reflectance method. Also, the retrieval error caused by the loading of background aerosol is mainly estimated. The comparison between surface reflectances retrieved from the two methods shows good agreement with the correlation coefficient of 0.87. However, the results from the minimum reflectance method are slightly overestimated than the values from the atmospheric correction method when surface reflectance is lower than 0.2. The average difference between the two results is 0.012 without the background aerosol correction. By considering the background aerosol effect, however, the difference is reduced to 0.010.

• Economic and Environmental Geology
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• v.32 no.1
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• pp.83-91
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• 1999

Coal properties are controlled by the following two factors : One is the maceral components and the other is the degree of coalification. In other words, even if coals in question indicate the same degree of coalification, their chemical and physical properties considerably vary one another when their maceral components are different. It is well known that virtrinite reflectance is the best single criterion for the degree of coalification covering the whole range of coal rank. Some authors have recently insisted that sporinite fluorescence is more leliable coal rank parameter than vitrinite reflectance in case of low rank coals. In this paper, to examine the relince of sporinite fluorescence as coal rank parameter, fluidity analysis of coals is newly performed and the data are analyzed in comparision with those of virinite reflectance, sporinite fluorescence and maceral components. The results of this study are as follows; 1) Vitrinite reflectance becomes low when degradinite content is high within one columnar samples, and vice versa. 2) variation of vitrinite reflectance depend on degradinite content and on difference of roiginal plant. 3) In dealing with the Japanese paleogene coals, sporinite fluorescence is more reliable parameter indicating the degree of coalification than vitrinite reflectance. 4) Maximum fluidity increases exponetially in proportion to the increases of degradinite content.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.1
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• pp.21-25
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• 2021

We measured the sizes of microstructures and the reflectance of blue feathers in the Common Kingfisher (Alcedo atthis). The colors were mainly produced in the barbs, which were composed of keratin sponge layers with air spaces and melanin rods. The reflectance spectra of back and tail feathers of the Common Kingfisher showed a peak with a broad plateau in the visible wavelength, whereas those of the wing feathers showed peaks in ultraviolet and visible and short-wavelengths. Moreover, the reflectance of back and tail feathers was higher than that of wing feathers. The blue color of the feathers comes from the keratin sponge layer due to coherent scattering. The back and tail feathers are composed of the keratin sponge layer only, and the wing feathers are composed of the keratin sponge layer and the keratin honeycomb structure. Due to the difference in these structures, it supposed that the reflectance is different. Determining why the reflectance spectra of the back and tail feathers were flattened will require further study.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.627-630
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• 2003

This research determined the spectral reflectance characteristics and vegetation indices when intermixed with field crops and soil. Ground-level spectral reflectance were collected in the field experiment containing plots of soybean and other seven crops. The first and second derivative of reflectance spectra showed several peaks that were dependent in different degrees on leaf age and chlorophyll concentration in the crop leaves. This study evaluated a number of spectral indices for estimating chlorophyll concentrations at the leaf scale difference, using samples from field crops at various stages of senescence. Five vegetation indices were evaluated which had advantages over previous techniques. Experimental data recorded on field crops during the growing season are in good agreement with previous theoretical results.

• Fashion & Textile Research Journal
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• v.3 no.4
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• pp.357-361
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• 2001

This paper is concern with the effect of various conditions on mechanical properties of textile fabrics by water soluble resin treatment. Resin treatment of cotton, acetate, viscose rayon, polyester, nylon and acryl fabrics were made by aqueous resin treatment to improve the mechanical properties. The mechanical properties of fabrics, the breaking strength and strain were measured and surface reflectance was measured by color eye. The breaking strength and surface reflectance of fabrics by water soluble resin treatment showed difference by the different treatment concentration. The surface reflectance was increased by water soluble resin treatment. The breaking strength was lower in fabrics with resin treatment than fabrics with none treatment.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1207-1217
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• 2022

Vegetation indices using the reflectance of selected wavelength, associating with the monitoring purpose such as identifying the progress of crop growth, on the vegetation canopy surface is widely used in the digital agriculture technology. However, the surface reflectance anisotropy can distort the true value of vegetation index related to the condition of surface, even though the surface property be unchanged. That causes difficulty to observe accurately crop growth on the monitoring system. In this study, a simple type goniometer was designed to measure the reflectance from the anisotropic surface according to various zeniths and azimuths of sun and viewing sensor in the field. On the tarp like as Lambertian surface, the reflectance of Blue, Green, Red, Near-Infrared band was similar to the tarps' reflectance properties. However, the reflectance was slightly overestimated in the cloudy day. The relative difference values of vegetation indices on grass were overestimated for the forward viewing and underestimated for the backward viewing. In addition, enhanced vegetation index (EVI) showed less sensitive according to the positions of sun and sensor viewing. Field observation with a goniometer will be helpful to understand the anisotropy characteristics on the vegetation surface.

• Korean Journal of Remote Sensing
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• v.34 no.6_1
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• pp.981-996
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• 2018

In agriculture, remote sensing data using earth observation satellites have many advantages over other methods in terms of time, space, and efficiency. This study analyzed the changes of reflectance and vegetation index according to atmospheric correction of images before using satellite images in agriculture. Top OF Atmosphere (TOA) reflectance and surface reflectance through atmospheric correction were calculated to compare the reflectance of each band and Normalized Vegetation difference Index (NDVI). As a result, the NDVI observed from field measurement sensors and satellites showed a higher agreement and correlation than the TOA reflectance calculated from surface reflectance using atmospheric correction. Comparing NDVI before and after atmospheric correction for multi-temporal images, NDVI increased after atmospheric corrected in all images. garlic and onion cultivation area and forest where the vegetation health was high area NDVI increased more 0.1. Because the NIR images are included in the water vapor band, atmospheric correction is greatly affected. Therefore, atmospheric correction is a very important process for NDVI time-series analysis in applying image to agricultural field.