• Textile Coloration and Finishing
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• v.22 no.1
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• pp.28-36
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• 2010

The deep black coloration of polyester fabrics was obtained by the physical properties of color and color mixing system. In this experiment, we have measured the absorbance and the reflectance of various disperse dyes for accomplishing the lowest lightness value and uniform reflectance, and new matching algorithm and computer color matching was made. The matching used both isomeric and metameric matching. The color matching of deep black color represented low lightness. Though actual reflectance of dyed polyester fabrics using these matching results was as high as theoretical one, low lightness value($L^*$) and uniform appearance were achieved.

• Journal of Biosystems Engineering
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• v.17 no.4
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• pp.370-381
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• 1992

Optical properties of fruits can provide information for nondestructive quality evaluation. An attempt is made here to develop an optical method for quality evaluation of apple using the spectral reflectance of its surface. Optical fiber was used to transmit light conveniently from light source to sample and sample to detector. Spectral reflectances of two types of Fuji variety-one of which was exposed to the sunlight directly (non-bagging) and the other was wrapped with bag (bagging) - were investigated from the wavelength ranging of 400nm to 700nm. The relationships between reflectance characteristics and quality indices such as chlorophyll content, anthocyanin content, and soluble solids were analyzed.

• Korean Journal of Optics and Photonics
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• v.9 no.5
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• pp.300-306
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• 1998

We have studied the optical effects in dielectric multilayer due to the interdiffusion formed during the deposition process. We suggest a numerical method to calculate the optical properties of periodical multilayer thin-films with gradient-index profiles. Using this method the spectral transmittance and reflectance were obtained for Fabry-Perot type filters, broad-band total reflectors and antireflection filters with interdiffusion layers. Interdiffusion reduced the spectral band width of high reflectance in total reflectors, and deteriorated the characteristics of multilayer AR-coatings leading to a large variation of reflectance if the number of the layers is large.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.103-109
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• 1998

A technique on atmospheric correction algorithm for a single band (0.76-0.90 $\mu$m) reflective of Landsat TM imagery has been developed using a radiation transfer model simulation. It proceeds in two steps: First, calculation of the surface reflectance of each pixel based on precomputed planetary albedo functions for actual atmospheres(e. g. radiosonde) and two kinds of atmospheric visibility states. Second, approximate correction of the adjacency pixel effect by taking into account the average reflectance in an 7 $\times$ 7 pixel neighbourhood and using appropriate land cover classification in reflectance. The correction functions are provided by MODTRAN model.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.231-235
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• 1998

We have made the cross calibration in terms of space reflectance between POLDER and OCTS sensors on board ADEOS satellite, using the POLDER and OCTS data acquired simultaneously on April 24, 1997. The space reflectance values for the same target computed from the POLDER and OCTS data are in very good agreement, when we adopted the new calibration coefficients of OCTS suggested by the vicarious experiment by NASDA. Then, we estimated aerosol parameters for several target areas (two areas in the Sea of Japan and three in the Pacific Ocean) from ADEOS/POLDER's directional reflectance and polarization data in 760nm and 865nm bands. A single atmospheric layer model with an isotropic Gaussian type ocean surface (Cox-Munk model) was assumed in this study.

• Current Photovoltaic Research
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• v.3 no.3
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• pp.91-96
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• 2015

Optical modeling and characterization of transparent dye-sensitized solar cells (DSC) are presented to design and estimate DSC devices numerically. In order to model the inhomogeneous active layer of DSC, the porous structure of titanium oxide ($TiO_2$) and dye mixture, we prepared films consisting of layer by layer of the DSC's basic materials sequentially, and characterized the optical parameters of the films with the effective refractive index, which was extracted from the transmittance and reflectance measurements in ultra violet to near infra-red range. By using the effective refractive index, we made the optical model for DSC, and demonstrated that the optical model based on effective refractive index can be used to design and evaluate the performance of transparent-type DSC modules.

• Journal of Biosystems Engineering
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• v.22 no.2
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• pp.227-236
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• 1997

Manual grading and sorting of red-ginsengs are inherently unreliable due to its subjective nature. A computerized technique based on optical and geometrical characteristics was studied for the objective quality evalution. Spectral reflectance of three categories of red-ginsengs - "Chunsam", "Chisam", "Yangsam" - were measured and analyzed. Variation of reflectance among parts of a single ginseng was more significant than variation among the quality categories of ginsengs. A PC-based image processing algorithm was developed to extract geometrical features such as length and thickness of body, length and number of roots, position of head and branch point, etc. The algorithm consisted of image segmentation, calculation of Euclidean distance, skeletonization and feature extraction. Performance of the algorithm was evaluated using sample ginseng images and found to be mostly sussessful.

• Journal of the Semiconductor & Display Technology
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• v.11 no.1
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• pp.67-71
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• 2012

The optical properties of PDP, such as the transmittance and reflectance, were analyzed with 3D optical code. Three different ITO-less structures in the front panel are examined. In the assembled panel study, the test 1 structure shows 16.6% and 10.2% higher reflectance than the structures of tests 2 and 3, respectively. In order to check the validation of the simulation result, three 7.5-inch test panels having the same geometry and property are fabricated as simulation models. The calculated reflective properties are compared to the measured data from real panels. The relative difference extracted from the simulation and measurement methods is less than 4.9% and are well matched.

• Journal of the Semiconductor & Display Technology
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• v.10 no.4
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• pp.31-35
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• 2011

For high efficiency of Si-cells, Si wafers were textured by the KOH and NaOH etching solution to decreas the reflectance at surfaces of the cells. The textured surfaces were shown various types such as isotropic and anisotropic depending on the etching solution. The reflectance at sample of an anisotropic form with pyramid type was lower than that of isotropic form. The surface with isotropic form of general tiny circles on the surface increased the efficiency, however, the reflectance of it was increased. The efficiency was increased on surface with low roughness.

• Journal of the Optical Society of Korea
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• v.19 no.6
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• pp.649-657
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• 2015

We present a surface color measurement including quantities of surface color, methods, and uncertainty evaluation. Based on a relation between spectral reflectance and surface color, we study how an uncertainty of spectral reflectance propagates to surface color. In analyzing the uncertainty propagation, we divide the uncertainty into uncorrelated components, fully correlated components, and correlated components with spectrally varying correlations. As an experimental example, we perform spectro-reflectometric measurements for ceramic color plates. With measured spectral reflectance and its uncertainty evaluation, we determine surface color and analyze uncertainties of the ceramic color plates.