• Journal of the Korean Vacuum Society
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• v.22 no.3
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• pp.150-155
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• 2013

Textured surface has been fabricated to reduce the light reflectance from the solar cells. The textured surface is very suitable for the multi-junction III-V solar cells because it can decrease the light reflectance over a large wavelength range. In this study, we have generated a textured structure on InAlP which is used for the window layer of the multi-junction III-V solar cells. Ultra-thin Pt layer (0.7 nm) has been used for wet etching mask. An array of nanosized pyramid shape formed on InAlP surface dramatically reduces the light reflectance up to 13.7% over a large wavelength range (i.e., $0.3{\sim}1.5{\mu}m$).

• Korean Journal of Materials Research
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• v.23 no.3
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• pp.194-198
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• 2013

In this paper, we studied a p-type reflector based on indium tin oxide (ITO) for vertical-type ultraviolet light-emitting diodes (UV LEDs). We investigated the reflectance properties with different deposition methods. An ITO layer with a thickness of 50 nm was deposited by two different methods, sputtering and e-beam evaporation. From the measurement of the optical reflection, we obtained 70% reflectance at a wavelength of 382 nm by means of sputtering, while only 30% reflectance resulted when using the e-beam evaporation method. Also, the light output power of a $1mm{\times}1mm$ vertical chip created with the sputtering method recorded a twofold increase over a chip created with e-beam evaporation method. From the measurement of the root mean square (RMS), we obtained a RMS value 1.3 nm for the ITO layer using the sputtering method, while this value was 5.6 nm for the ITO layer when using the e-beam evaporation method. These decreases in the reflectance and light output power when using the e-beam evaporation method are thought to stem from the rough surface morphology of the ITO layer, which leads to diffused reflection and the absorption of light. However, the turn-on voltage and operation voltage of the two samples showed identical results of 2.42 V and 3.5 V, respectively. Given these results, we conclude that the two ITO layers created by different deposition methods showed no differences in the electric properties of the ohmic contact and series resistance.

• Journal of Broadcast Engineering
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• v.24 no.4
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• pp.623-632
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• 2019

Many researches have been carried out for brightness and contrast enhancement, illumination reduction and so forth. Recently, the aforementioned hand-crafted approaches have been replaced by artificial neural networks. This paper proposes a convolutional neural network that can replace the method of generating a reflectance image where illumination component is attenuated. Experiments are carried out on 102 low-light images and we validate the feasibility of the replacement by producing satisfactory reflectance images.

• Journal of Marine Bioscience and Biotechnology
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• v.16 no.1
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• pp.19-25
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• 2024

To verify the color change in dried laver postproduction during the heating process, chromaticity elements were compared via a spectrophotometer across various heating conditions within the visible light spectrum. In general, the moisture reduction rate increased with rising temperature and time. Surface image comparisons revealed an expanded area of light reflection on the heat-treated dried laver sample due to surface roughening from shrinkage. No statistically significant differences in chromaticity values were observed in the measurements of brightness (L^*), redness (a^*), and yellowness (b^*). Reflectance spectrum measurements in the visible light region confirmed high reflectance under red wavelength conditions. In particular, a significant increase in reflectance at 700 nm compared with untreated samples was noted. The correlation between the increase in 700 nm reflectance of dried laver samples and heating conditions ranged from 0.7471 to 0.7793, suggesting its potential use as an indicator for comparing color changes in dried laver based on heating conditions.

• Journal of the Optical Society of Korea
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• v.18 no.1
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• pp.9-14
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• 2014

We numerically investigate the effect of sunlight polarization on the absorption efficiency of V-shaped organic solar cells (VOSCs) using the finite element method (FEM). The spectral distribution of absorbance and the spatial distribution of power dissipation are calculated as a function of the folding angle for s-and p-polarized light. The absorption enhancement caused by the light-trapping effect was more pronounced for s-polarized light at folding angles smaller than $20^{\circ}$, where s-polarized light has a relatively larger reflectance than p-polarized light. On the other hand, the absorption efficiency for p-polarized light is relatively larger for folding angles larger than $20^{\circ}$, where the smaller reflectance at the interface of the VOSC is more important in obtaining high absorption efficiency.

• Journal of Korea Multimedia Society
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• v.1 no.1
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• pp.26-36
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• 1998

It is very important study field in computer vision 'How we obtain 3D information from 2D image'. For this purpose, we must know position of camera, direction of light source, and surface reflectance property before we take the image, which are intrinsic information of the object in the scene. Among them, surface reflectance property presents very important clues. Most previous researches assume that objects have only Lambertian reflectance, but many real world objects have Non-Lambertian reflectance property. In this paper the new method for analyzing the properties of surface reflectance and reconstructing the shape of object through estimation of reflectance parameters is proposed. We have interest in Non-Lambertian reflectance surface that has specular reflection and diffuse reflection which can be explained by Torrance-Sparrow model. Photometric matching method proposed in this paper is robust method because it match reference image and object image considering the neighbor brightness distribution. Also in this thesis, the neural network based shaped reconstruction method is proposed, which can be performed in the absence of reflectance information. When brightness obtained by each light is inputted, neural network is trained by surface normal and can determine the surface shape of object.

• Journal of Broadcast Engineering
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• v.24 no.1
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• pp.87-96
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• 2019

Improvement of low-light image mainly focuses on the contrast enhancement. Many researches have been carried out for brightness enhancement, contrast improvement and illumination reduction. Recently, the aforementioned approaches have been replaced by artificial neural networks. This paper proposes a methodology that can replace the Retinex-based reflectance image acquisition by deep neural network. Experiments carried out on 102 low-light images validated the feasibility of the replacement by producing PSNR=30.8682(db) and SSIM=0.4345.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.9
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• pp.1321-1325
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• 2001

Color characteristics of pig ${\times}$ wild boar meat were determined with a fiber-optic spectrophotometer. The spectrophotometric characteristic of reduced-myoglobin observed after cutting immediately changed to the spectrophotometric characteristic of oxymyoglobin after 15 minutes of cutting. The spectrophotometry at 400 to 700 nm after 30, 45, 60, 90 and 120 minutes of cutting changed slightly. Compared with M. longissimus thoracis, M. rhomboideus had higher reflectance around 400 nm and from 650 to 1,100 nm and M. spinalis was lower in the visible light region after 60 minutes of cutting. The pig ${\times}$ wild boar meat was similar in reflectance shape with pork but was lower in intensity. The differences depended on the anatomical location. The M. rhomboideus from pig ${\times}$ wild boar had greatly lower reflectance than that from pig, the M. longissimus thoracis reflectance was lower, but M. spinalis reflectance hardly differed. These results showed that pig ${\times}$ wild boar meat had no special characteristic of blooming but had distinguishing characteristic of meat color among anatomical locations.

• 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 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.