• Journal of Biosystems Engineering
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• v.33 no.1
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• pp.63-68
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• 2008

This study was carried out to find a useful method to predict hardness of tomato using optical spectrum data. Optical spectrum of reflectance and transmittance data were collected processed by 9 kind of preprocessing methods-normalizations of mean, maximum and range, SNV (standard normal variate), MSC (multiplicative scatter correction), the first derivative and second derivative of Savitzky-Golay and Norris-Gap. With the preprocessed and non-processed original spectrum data, prediction models of hardness of tomato were developed using analytical tools of PLS (partial least squares) and MLR (multiple linear regression) and tested for their validation. The test of validation resulted that the analytical tools of PLS and MLR output similar performances while the transmittance spectra showed much better result than the reflectance spectra.

• Journal of the Semiconductor & Display Technology
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• v.9 no.3
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• pp.71-74
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• 2010

In this study the optical properties, such as relative transmittance and reflectance of PDP were analyzed with 3D optical code. Because of the electrode structure, the reference model shows 21.3 % higher transmittance than the test model and the reference model shows 16.6 % higher reflectance than the test model. The calculated reflectance of reference and test models is compared to the measured reflectance and the difference between calculation and measurement is 4.9 %.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.4
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• pp.303-307
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• 2016

The fiber optical temperature sensing device was developed by using a Fiber Bragg Grading (FBG) sensor and a linear transmittance optical filter. The temperature change causes change in the FBG sensor reflectance wavelength and the reflectance wavelength from FBG sensor is transmitted to a linear transmittance filter so that the optical signal value is determined by the wavelength. The temperature can be measured by the optical signal value by passing FBG reflectance wavelength to the linear transmittance filter. Using the developed system, temperature ranges from $10^{\circ}C$ to $50^{\circ}C$ were measured and the measured data were almost linear.

• 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.

• Laser Solutions
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• v.11 no.2
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• pp.20-25
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• 2008

Polyimide is one of the useful materials in industry. The surface treatment of polyimide by a femtosecond laser can help accurate and fine fabrication of microstructure. And it can change the transmittance and reflectance of polyimide, too. We put femtosecond laser pulses on polyimide for rectangular or square type surface treaments and observe the change of transmittance and reflectance. Pulsewidth is 172 fs, laser power changes for fabrication are from 5 mW to 20 mW, and transmittance and reflectance are measured under 20m W, 300m W, and 920 mW. Pulse patterning is stable and almost no unwanted surface damage is shown. As power increases, working depth increases but working line width does not increase significantly. As speed changes, they also have same results. It shows the efficiency of a femtosecond laser is good and thermal damage is small for polyimide.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.525-532
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• 2000

A new spectroscopic method for pesticide residues detection on agricultural products was developed. The general determination methods are high performance liquid chromatography (HPLC), gas chromatography (GC) or GC-mass spectrometry. They have provided relatively good detection limit and accuracy with complicated and time-consuming (5hrs above) procedures. In addition freshness is very important for evaluating qualities of agricultural products. This requires a simple and fast method for detection of pesticides. Reflectance, transmittance and fluorescence spectrometry of pesticides were tested using UV range because most of pesticides contain conjugation band in the molecular structures. Fluorescence spectrometry showed better sensitive to detect pesticide residues than did reflectance and transmittance spectrometry. Intensity and shape of fluorescence spectra showed different patterns with different structures of pesticides. Detection limit for fluorescence spectrometry was 0.1 ppm to 10 ppm depending on the structures of pesticides. Application of fluorescence spectrometry appears to be an easy method for detection of pesticide residues on agricultural products.

• 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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.20-22
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• 1997

In ours study, we investigated the various properties in Te-light doped $Sb_{85}$G $e_{15}$ thin films such as the change of reflectance and transmittance according to phase change from amorphous to crystalline states In all films the transmittance was decreased, but the reflectance was increased by annealing. Particularly, the reflectance between as- deposited state and annealed state showed the largest change in the T $e_{0.5}$($Sb_{85}$G $e_{15}$ )$_{99.5}$ thin film at 780nm, which was about 40% in as-deposited state and about 70% in annealed state. Therefore, it might be considered that the T $e_{0.5}$($Sb_{85}$G $e_{15}$ )$_{99.5}$ thin film is recording medium showing to a good optical properties if it is used to optical recording of the phase change type. change type.ype.

• Journal of the Korean Ceramic Society
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• v.42 no.6 s.277
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• pp.399-404
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• 2005

Anti-reflection film was coated by using spherical silica nano colloidal particles and fumed silica particles. Silica colloid sol was reserved between two inclined slide glasses by capillary force, and particles were stacked to form a film onto the substrate as the upper glass was sliding. The deposition processes were studied to enhance the wavelength dependency of the light transmittance and to control the effective refractive index of the film. Both of the spherical and fumed silica particles showed an enhancement of $4.0-4.4\%$ in light transmittance by one step coating. The dependence of the transmittance on wavelength was largely improved at the longer wavelength by partial coating of fumed particles on the film of spherical particles. The effective refractive index of the film was controlled by removing latex particles that were co-deposited with silica particles. Using this process the light reflectance from one side of the glass substrate could be reduced from $4.2\%$ to $0.6\%$ although zero reflectance was not achieved due to the agglomeration of the latex particles.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.7
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• pp.437-442
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• 2018

This work reports the preparation of Al-Ti based oxide thin films and their optical properties. Although the transmittance of a $TiO_2/Al2O_3$ bilayer structure was as high as 90% at wavelengths of 600 nm or larger, the reflectance of the bilayer reached its minimum at wavelengths of around 360 nm. The transmittance of an 89-nm-thick $TiO_2$ thin film rapidly increased and then decreased at a critical wavelength because of destructive interference. The wavelength corresponding to the reflectance minimum increased after an increase in $TiO_2$ film thickness. The smooth surface morphology of the AlTiO thin film was retained up to a film thickness of 65 nm, and the transmittance of the film was inversely proportional to film thickness, in accordance with the general tendency for optical films. The reflectance of the AlTiO film at visible light wavelengths was lower than that of the $TiO_2$ film, which implies that the AlTiO film is suitable for applications as an optical thin film layer in semitransparent solar cells.