• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.521-529
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• 2022

This study evaluated the effects of agricultural reflective film and HANSPEK film on the fruit quality attributes and peel color variables of 'Fuji' apples. The reflective films were applied under the tree canopies at 20 and 30 days before harvest (DBH), and a tree with no films was used as the control. Depending on the measurement locations, the light intensity was 7.4 - 14.6% higher in the reflective film treatments than that of the control. However, no difference in the light intensity was observed between the reflective and HASPEK films. In addition, the light intensity was not also different between the 20 and 30 DBH. At harvest, the flesh firmness, fruit weight, soluble solids content, titratable acidity, and internal ethylene concentration were not different regardless of the type of reflective film and treatment time. In addition, the peel color variables were not affected in the equatorial region. However, in the calyx region, the L* and b* values were decreased, and the a* value was increased by the reflective and HANSPEK films compared with the control. Hence, the hue angle was decreased to near 0^o (red), and the peel color was improved. Therefore, this study suggests that the application of the HANSPEK film under a tree canopy could improve the fruit peel color of 'Fuji' apples.

• Journal of the Korean Ceramic Society
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• v.32 no.1
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• pp.57-62
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• 1995

The coating condition of reproducible anti-reflective coating film and the light transmittance characteristics of the prepared anti-reflective coating glass were investigated as a study for the preparation of single-layer anti-reflective coating glasss. In case of coating with the sol in which the solvent was substituted with the ethanol with the addition of 0.1 mol HNO3, the coated glass showed the minimum value of the refractive index of 1.464, light transmittance of 94.2% at 550nm standard wavelength which is 3.2% higher than that of the parent glass, and the reflectance in the entire wave range of visible light. The refractive index represented its minimum at the sol concentration of 1.0 mol per 100mols of water and the higher the sol concentration, the higher the refractive index, resulting in the decrease of the light transmitance. The production condition of the reproducible anti-reflective coating on glass with the maximum transmittance of 94.2% was 4cm/min of withdrawal speed, 40$0^{\circ}C$ and 1 hour of heat treatment temperature and time, resulting in the film thickness of 94nm.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.1
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• pp.65-70
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• 2008

The shape and the material of a reflective sheet affect the amount and the range of retroreflection on incident angle of light, significantly. In this study, the method to determine the shape and the material of the reflective sheet is introduced for the maximum retroreflection. Since the microprism shape with an equilateral triangle base has been used widely, the shape optimization of the microprism shape is carried out. The path of the light within the prism is geometrically calculated to find the relationship between incoming and outgoing light to and from a microprism. The optimal shape of a microprism found by the simulation has almost same figure with the one being used in industry for the maximum retroreflection. It is also found that the refraction index of the reflective sheet is another parameter to control for maximum retroreflection and the range of retroreflection.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1377-1380
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• 2008

A development of low power display is an important problem from a point of reduction in worldwide energy consumption. In this research, we aimed to achieve a high quality and low power paper-like reflective full-color display and investigated the design rules for the light diffusing film, LC-cell structure, front lighting systems based on the diffused light control technology. As a result, we successfully obtained the high quality reflective liquid crystal display with a high reflectivity, a wide color gamut and a high motion picture quality.

• Korean Journal of Environmental Agriculture
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• v.30 no.4
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• pp.414-418
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• 2011

BACKGROUND: Plastic mulches widely used in raised-bed culture mainly to conserve water, control weeds and raise soil temperature. The most widely used plastic mulch colour is black. Reflective red and far-red light can affect on growth and yield of various vegetable crops. Objectives of this study were to investigate the characteristics of reflective light of black and red plastic mulches, and to evaluate the reflective red and far-red light on the quality characteristics and yield of the Oriental melon (Cucumis. Melo L.) and tomato (Lycopersicon esculentum L.). METHODS AND RESULTS: Oriental melon and tomato were cultivated over the reflective red and black plastic mulches in plastic house. Reflected red and far-red light over the red plastic mulch were 2.6 times higher than those of black plastic mulch. Red to F-Red ratio of black plastic mulch, red plastic mulch and sunlight were 1.14, 0.93 and 1.16 respectively. Intensity of reflected red and far-red light over red plastic mulch were highest at surface height of 30 cm. The higher the height of the surface decrease the intensity of far-red light. Accordingly, Red to F-Red ratio were increased. Reflective red plastic mulch increased the weight of fruit and content of sugar in Oriental melon and tomato. CONCLUSION(s): Yield of Oriental melon over reflective red plastic mulch was higher than that of black plastic mulch. These results suggested that reflected red and far-red light over the red plastic mulch affected allocation of photosynthate in growing Oriental melon.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.2
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• pp.131-137
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• 2003

We have performed computer simulation to obtain electro-optic chracteristics of reflective liquid crystal display (LCD) using wide viewing angle LC mode, fringe field switching(FFS). Unlike other reflective LCD modes, in the FFS mode, the LC director in plance so an application to reflective display consisted of polarizer, LC layer and reflector is possible. when an incident light is 550mm, the optimal cell retardation value is 0.1365${\mu}$m and the efficiency of reflectivity is high over 90% with very little wavelength dispersion. Further, we have studied a new reflective display with polarizer, optical compensation film with half plate, LC plus reflector. The display with optimized cell parameters shows high contrast ratio (CR) over 130 with high light efficiency over 90% at normal direction and the CR greater than 5 exists over 60$^{\circ}$ of polar angle in all directions.

• Journal of the Optical Society of Korea
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• v.19 no.1
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• pp.80-83
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• 2015

White reflective patterns are very difficult to fabricate, due to the scattering and reflection of light, especially when the pattern size goes down to micron size. A reflective white barrier structure of height $50{\mu}m$ and width $80{\mu}m$ was fabricated using dry-film resist as an intermediate reverse pattern. The reverse dry-film resist pattern was coated with an $SiO_2$ layer by sputtering, to protect the resist from chemical attack by the radical molecules in UV white resin. The UV white resin was applied on the dry-film resist pattern and then cured with ultraviolet light. The fine three-dimensional reflective patterns were finished by removing the dry-film resist.

• Journal of agricultural medicine and community health
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• v.28 no.2
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• pp.61-70
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• 2003

Objectives: Traffic accidents often occur to power tillers without reflective light in the dawn, evening and night. Because of this reason, there has been a 'campaign to attach reflective lights' to power-tillers in recent years. Therefore, the authors investigated the relationship between reflective light and traffic accidents involving power-tillers. Methods: We defined traffic accidents of power tillers as those cases of rear-end collision by a car in the dawn, evening or night. According to our definition, four cases were confirmed in Hyungok-myeon, Gyeongju and five cases in Gigye-myeon, Pohang. We selected a control group from people in the same village with similar age, sex, driving history and education. Results: The study group contained 9 accidents and 36 non-accidents. Power tillers with reflective light were 32 cases (72.7%) of 44 cases (excluded one case due to death). Of those, the status of reflective light was 'clean' in 18 cases (56.3%). The recognition that reflective light can prevent accidents was 'Yes' in 26 cases of 44 cases (59.1%). The recognition of the 'campaign to attach reflective lights' to power tillers was 'Yes' in 38 cases of 44 cases (86.4%). The recognition about the safety regulation of driving power-tillers was 'Yes' in 32 cases of 44 cases (72.7%). Odds ratio of traffic accidents for no reflective light was 7.00 (95% CI: 1.06-58.37). Conclusions: Although the 'campaign to attach reflective lights' to power tillers are going on, its effectiveness may unknown. Therefore, more extensive epidemiologic study is needed into the relationship between reflective light and power tiller traffic accidents, with effective administration of the government and the attention of medical persons.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.614-615
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• 2009

For the high reflectance under the ambient light condition, a highly efficient diffractive reflector has been proposed, based on a micro grating structure.[1] This reflector was designed to show highly concentrated distribution of the reflected light to the normal direction of the reflector under specific incident conditions of the light. In order to apply a diffractive reflector to a reflective liquid crystal display, the coupling between the viewing angle characteristics of a liquid crystal (LC) cell and the reflective distribution of the reflector should be considered. Under the optimum configuration confirmed through the analysis of the coupling between a LC cell and a reflector, a reflective vertical alignment (VA) cell with a diffractive reflector shows contrast ratio and brightness much higher than that with a conventional bumpy reflector.

• International journal of advanced smart convergence
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• v.10 no.2
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• pp.45-52
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• 2021

The surveillance camera market has developed and plays an important role in the field of video surveillance. However, in recent years, the identification of areas requiring surveillance has been limited by reflective light in the surveillance camera market. Cameras using polarization filters are being developed to reduce reflective light and facilitate identification. Programs are required to automatically adjust polarization filters. In this paper, we proposed an optimal angle extraction method from surveillance cameras using polarization filters through histogram analysis. First of all, transformed to grayscale to analyze the specifications of frames in multiple polarized angle images, reducing computational throughput. Then we generated and analyzed a histogram of the corresponding frame to extract the angle when the highlights are the fewest. Experiments with 0˚ and 90˚ showed high performance in extracting optimal angles. At this point, it is hoped this technology would be used for surveillance cameras in place like beach with a lot of reflective light.