• Journal of the Semiconductor & Display Technology
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• v.21 no.4
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• pp.1-5
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• 2022

We presented a micro hemi-sphere structure flexible film to improve the external quantum efficiency (EQE) in OLEDs. The micro hemi-sphere flexible film was fabricated with breath figure (BF) method and replica process. At 45 mg/mL of concentration, the size of the hemi-spheres was approximately 6.2 ㎛ were obtained which are the most circular shape. So, it was possible to yield the best performance with an improvement of 33 % in the EQE and the widest viewing angle ranging from 0° to 70°. As a result, the hemi-sphere film's size and distribution seem to play important roles in enhancing the EQE in OLEDs. Furthermore, the flexible hemi-sphere film based on polymeric materials could offer an effective, large-scale, mass-produced product and a simple process and approach to achieve high efficiency in flexible OLEDs.

• Journal of the Korean Applied Science and Technology
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• v.30 no.3
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• pp.518-527
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• 2013

5,6-dihydroxyindole was easily oxidation with air and light Conditions. Availability of 5,6-dihydroxyindole was studied for hair dye as a precursor of melanin. This study used wet and dry coating process to stabilize 5,6-dihydroxyindole. In wet process used dimethicone and cyclometicone, the 5,6-dihydroxyindole had darkened through the drying process at $58^{\circ}C$. Wet coating process was inappropriate to stabilize the coating. In dry coating process, shea butter coating was stable until 3 days. Dextrin palmitate was most efficient ingredient to prevent oxidation by sun light and air until 7days. Oxidation test with 1.0% and 1.5% of dextrin palmitate was not different under conditions of sun light and air and was not dependent on contents. Vitamin E acetate under conditions of sun light and air, there were no significant effect in preventing oxidation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.5-6
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• 2006

• Journal of Environmental Science International
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• v.11 no.7
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• pp.705-711
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• 2002

In order to determine the factors causing Microcystis spp. bloom in the lower Nakdong River (Mulgum), we prepared wide ranges of pH, nutrient(N, P) concentration and the light through an enclosure experiment far 10days (pH gradient. 6.5, 7.5, 8.5, 9.5; gradient of N, P: ${\frac{1}{2}}DW+{\frac{1}{2}}River$ Water (RW), RW only; four different levels of nutrient addition/day; light: 100, 85, 60, 30, 15% of full sun light). From three days, the difference of Microcystis density in each enclosures was observed. The high density of Microcystis was maintained in the treatments over pH 9.5 and 85% of full sun light. However, in all nutrient treatments, relatively lower cell density than that of pH and light treatments was observed. These results suggested that pH and light input may play more important roles than nutrients in the early development of Microcystis bloom in the eutrophic lower Nakdong River.

• The International Journal of Costume Culture
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• v.3 no.3
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• pp.212-222
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• 2000

This study intends to observe how the essential elements of art have changed Human's sense of beauty extending over the whole lives as well as fashion through the investigation of Light and Rays which have played a important role in giving birthe to the new trend of art within the upheaval age of various cultures. The peculiarities of which Futurism of Italy and Rayonism of Russia including Impressionism have a great role in giving birth to a new trend of art by means of the development of science technology are like these. Impressionists looked for the origin of the subtle harmony in nature within changes of sun-rays. The special feature of Impressionism paintings was to express the line of vision diversely according to changes of light rather than to focus on the line of vision with clear outlines. Henceforth, Neo-Impressionism which developed Impressionism more systematically leaded changes of Light and Rays more systematically and scientifically and maintained Divisionnisme techniques which extends to lead towards color and light through dividing and juxtaposing color. In the early 20th century Futurists tried to express dynamism through the interpenetration of light and revive color and light through the division techniques of color and persist an artificial light like eletricity rather than a natural light. Rayonism of Russia which was ifluenced from Impressionism and Futurism maintained intersection of reflecting rays which emerges from an object of things more deeply. This pursuit of light and rays also light and rays also appears as it is in modern fashion. First, it is the fashion which applied sun-rays persisted by Impressionists and expressed colors which show differently according to direction of light. Second, it is the fashion design which re-analyzed what Futurists expressed artificial light and rays. Third, it is the design which expressed Divisionnisme theory persisted by Impressionists and Futurists into fashion as it is and was made of being divided the form of glittering light into small dots. Fourth, it is the fashion design which applied Rayonists'work which applied intersection of reflected rays. Like this, it is aproved that the pursuit of light and rays expresses as it is in modern fashion of the 21st.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.8
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• pp.799-804
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• 2011

The LFLP (Linear Fresnel Light Pipe) system uses a linear Fresnel lens to follow the sun and concentrates the parallel sunlight into a line. A LFLP daylighting system has been developed and updated to a DBLP (Double Blind Light Pipe) daylighting system to improve the overall system efficiency in the morning and afternoon. The new design consists of a double-blind style with a cone-shaped light transformer. The blinds are used to collect the sun's altitude and azimuth movements through the day. Behind the two sets of blinds is the light transformer, which is based on a parabolic-shaped light concentrator. The light transformer is designed to efficiently deliver light within a thirty-degree radial spread so that the light pipe can internally reflect the light. The results of scale-model tests are encouraging, and the efficiency is three times higher than that of the previous LFLP system.

• Journal of the Korean Society of Costume
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• v.61 no.3
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• pp.122-138
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• 2011

The present research aims to consider the real remains of 2 suits of Kasaya owned by the Hwaeom Temple(華嚴寺) based on research results about Kasaya in the meanwhile. The present research on 2 suits of remains which are Royal gifts given to monk soldiers in case of a national crisis of the Joseon Dynasty has a big meaning in examining characteristics of Kasaya and grasping characteristics and structure of the 17th century's Kasaya of the Joseon Dynasty through dense survey and analysis according to components. If examining characteristics of Kasaya, the Kasaya of the Great Monk Seo San(西山) is composed on the basis of an initial form of Sun and Moon Light Patch's generation and the Kasaya of the Great Monk Byeok Am(碧巖) has a form that is separately attached through production of embroidery patch as a process of being settled down. If examining what surrounds gold thread in the girth and expression of Sumeru and Chaeunmun(彩雲紋), the composition of a form similar to an insignia badge, so because this is a Royal gift, this can be estimated as being analyzed in a Buddhism aspect by devising a design from the insignia badge at the time, with a meaning like an official uniform given to a monk. Although the insignia badge is a square, it seems that the Sun and Moon Light Patch is made as a rectangular form corresponding to the structure of Kasaya. In addition, it is thought that what the Samjoko(三足烏) idea which is a symbol of the Sun based on Buddhism and Taoism is used together with Yijoko(二足烏) even in expression of the Sun and Moon Light Patch in the Joseon Dynasty which was a Confucian country has a relationship with what a bird was expressed in the insignia badge of winged animals.

• Journal of Korea Foresty Energy
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• v.21 no.3
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• pp.46-53
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• 2002

The study was carried out to determine the growth and biomass production of deciduous trees including Betula pendula, Fraxinus rhynchophylla, Cornus controversa subjected to artificial shade treatment of three levels in nursery field. The results were as follows; The height growth of seedlings was no difference subjected to artificial shade treatment. The root collar diameters of the relative growth rates of seedlings grown in full sun showed 29-32% as compared with those subjected to the shade treatment of 7-10% light intensities of full sun. Corrus controversa of the root collar diameters of the relative growth rates were better in the seedlings grown in 26-34% light intensities of full sun. Total dry mass including the dry mass of leaves, shoot and root were as a whole decreased with shade treatment. The ratio of the dry mass of leaves and stem increased the dry mass of root. T/R ratio of the seedlings increased by decreasing the relative light intensity. And the T/R ratio of 7-10% light intensities of full sun was ranged from 1.00~2.27 were greater in the full sun light was ranged from 0.51~l.13. Light intensity by artificial shade treatment decreased in deciduous trees when compared on the whole, it showed tendency that SLA increases, increased that seeing resemblant tendency in LAR and LWR and changed of light intensity is strong, it increased that showed difference as statistical.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.3
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• pp.230-236
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• 2016

This research attempted simplifications to the LED street light for price competitiveness. The street light was simplified by replacing the SMPS with an IC driver on the PCB using an AC-type LED. The optical element that shape of a line-shaped lens covered LED crowded. Thus, this study aims to improve LED efficiency by using the minimum optical system. In order to satisfy the M3 regulation of street lighting at grade, the lens was divided into two parts depending on the forward direction of the light. Further, the changes in the number of LEDs located on part 1 and part 2 of the lens were analyzed. Through simulation, we determined the proper light distribution that meets M3 regulation of street lighting.

• Journal of the Korean Solar Energy Society
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• v.31 no.2
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• pp.31-36
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• 2011

LED is expected as an environmentally friendly next generation light source with its good reliability and long lifetime. The light sources for illumination have a variety of applications in the indoor and outdoor, and the variation of optical power and color rendering of the light source limits their applications. Therefore, it is necessary to research the LED lamp and its luminaire to minimize the variation of dynamic characteristics and to improve the color rendering due to that illuminating environment. Daylight is very good light source to human and can be used as primary or a secondary light source with benefits of energy, productivity and health.This paper presents the design method of LED lighting system to improve poor property in terms of CR(color redering) characteristic to use daylight effectively.