• Proceedings of the SCSK Conference
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• 1992.09a
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• pp.69-78
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• 1992

It is well hewn that ultraviolet light(UV) penetrates into the skin depends on the wavelength and causes many biochemical reactions in the skin. The enormous amount of information reveals that UV effects sun-burn, sun-tan and photoaging etc. In addition to these, it is now recognized that UV initiates immuno-suppression, and associated with this, skin cancer. In this review, I tried to illuminate the processes of injurious effects of UV on the skin.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.6
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• pp.515-520
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• 2012

A daylighting system includes three parts; light collector, light transformer and light distributor. A DBLP(Double blind light pipe) daylighting system consists of a double blind light collector, a mirror duct type light transformer and a prism film light pipe distributor. The double blinds for a light collection are used to track the sun's altitude and azimuth movements throughout the day. Behind both sets of blinds is the light transformer, which is based on a rectangular cone shaped light duct. The light transformer was designed to efficiently deliver the light into the light pipe within a 30 degree radial spread for the efficient light into the distributor. In this study, DBLP system efficiency was simulated, evaluated and optimized by Tracepro as a popular ray trace light design simulation program. The results indicated that DBLP system efficiency evaluated a maximum 22.4% in case of Spring/Fall season solar noon time. While the overall average system efficiency in the morning and afternoon is evaluated about 10%.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.260-263
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• 2007

The importance of natural light in building is known by all of us who experienced dark rooms. The sunlight system is very important from energy saving and human welfare point of view. The system consists of light-collecting module, light -transporting module and light-emitting module. The light-collection is used light reflection mirror, a prism for lighting bent, and lens for light condensing. The transportation of collected sunlight is used polished duct, tube, pipe and specially used fiber optic cable. This paper investigate research and development trends of sunlight system for advanced product.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.3
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• pp.319-323
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• 2015

This study investigated the effects of the light conditions on the productivity of scenedesmus dimorphus in the continuous mass cultivation system. To compare the algal productivity according to the light conditions, S. dimorphus was cultivated continuously under the wide range of light intensity(200-600 PPFD) and various light wavelength(white light and red-blue mixed light). After 100 days of cultivation under the different light intensity, the productivity of S. dimorphus increased as light intensity decreased. So, the productivity was maximized as 100 mg/L/d when light intensity was 200 PPFD. In case of light wavelength, the productivity of S. dimorphus was enhanced about 20% with the white light compared to that of the red-blue mixed light. Consequently, the optimal light conditions for the continuous mass cultivation of S. dimorphus were 200 PPFD as light intensity and white light as light wavelength.

• Journal of the Korean Society of Costume
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• v.58 no.2
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• pp.120-133
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• 2008

The purpose of this study is to analysis types of light and to find the characteristics of light in contemporary fashion design. In a scientific context, light is electromagnetic radiation of a wavelength that has the characteristics of straightness, reflection, refraction, scattering and diffraction. But in philosophical speculations, light has been used as a metaphor of 'being', 'to-be' or 'enlightenment.' And through the ages, people have tried to represent and apply the light into plastic art like painting and architecture. The types of light in fashion design was categorized as those; reflective light from the surface of clothing which is the result of interaction between illumination and material, representative light as the pattern of light or light effect such as sun or its rays and optical or psychedelic patterns, luminescent light from light emitting material like phosphorescence or LED which combines into fashion design, projective light from a medium to reveal virtual patterns on the surface or a fashion design itself using holography. These lights in fashion design can be considered as reflection of emphasis of sexuality, longing for fantasy and mystique, visualization of interaction and communication and groping for the play.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.3
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• pp.487-492
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• 2012

In this study we researched a spotlight in LED lighting. Ordinary LED spotlight was manufactured with characterized property of traveling straightness of LED light source, but multiple use of shell type LED, a yellow band has formed caused by light source interference between the LED. Also, there was a high miscellaneous light efficiency with losing light source homogeneity and efficiency due to light source control uneasiness. The study uses aspheric reflector and aspheric lens, so we can control the light source of LED spotlight with effectively and we reached surface light source by using COB/COM for LED module. Furthermore it can change its use by a reduced scale of light system. It has been designed to make its various application from low power consumption of bicycle lamp, up to high power consumption of automobile lamps and lighthouse.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.106-113
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• 2023

Plant extracts have been studied due to their potential as photoprotective agents against UV and blue light exposure. Previous studies have revealed that several plant extracts have photoprotection capacities and synergistic effects with synthetic products. However, such results for pu'er tea and Curcuma longa L. have not been reported yet for a cosmetic formulation. Thus, the objective of this study was to evaluate photoprotection capacities of pu'er tea and C. longa L. extracts for a sunscreen compound. The pu'er tea extract improved sun protection factor value of 2-ethyl-hexyl methoxycinnamate (a synthetic sunscreen compound) by 46% and showed a high antioxidant capability that could help skin recover from photo-induced damage. C. longa L. extract also showed a potential to protect skin from blue light-induced damage because it not only had a maximum absorption peak at the blue light range, but also protected human fibroblasts from blue light-induced damage. The addition of both extracts shifted the critical wavelength of 2-ethyl-hexyl methoxycinnamate from 350 nm to 386 nm, giving it a broad-spectrum feature. Thus, pu'er tea and C. longa L. extracts may enhance the photoprotection ability of synthetic sunscreen products.

• Journal of Microbiology and Biotechnology
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• v.13 no.5
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• pp.789-793
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• 2003

This study focused on the optimization of the illumination method for efficient use of light energies in a photobioreactor. In order to investigate the effect of radiator position, a model simulation study was carried out using Synechococcus sp. PCC 6301 and an internally radiating photobioreactor as a model system. The efficiency of light transfer in a photobioreactor was analyzed by estimating the average light intensity in a photobioreactor. The simulation result, indicate that there exists an optimal position of internal radiators, and that the optimal position varies with radiator number and cell concentration. When light radiators are placed at the optimal position, the average light intensity is about 30% higher than that obtained by placing radiators at the circumstance or center of a photobioreactor. The method presented in this work may be useful for improving light transfer efficiency in a photobioreactor.

• Korean Institute of Interior Design Journal
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• v.20 no.5
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• pp.13-22
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• 2011

The purpose of this study is to analyze Alva Aalto's libraries for understanding his efficient induction of natural light. To fulfill this purpose, Alvar Aalto's thought about library and natural light are examined through his working years and building types. The comparison of his libraries on usage of natural light shows different ways of natural light induction based on different locations and programs of libraries. Similarities and differences of Alvar Aalto's library architecture have strong relationship to the usage of natural light in libraries because Alvar Aalto himself regard reading as the core function of library and the efficient use of natural light is the main key of reading. In his natural light planning, regional characteristics including environmental factors and programmatic differences act as a basic standard for natural light plan. Especially, altitude of sun and its path, seasonal features affect the induction way of natural light. While conical skylights used at Viipuri library shows the characteristics of universality in Modernism architecture, later libraries presents not only various kinds of pan-shape plan but different ways of inducing natural light in according to appropriate function. From conical skylight to monitor with curved reflection wall make it possible shed diffused light to reading space and this affects to form Alvar Aalto's organic architecture. As a result, using natural light in Alvar Aalto's library architecture act as the core of forming library concepts and their development.

• Journal of Bio-Environment Control
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• v.22 no.1
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• pp.49-54
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• 2013

In this study, I was focusing on LED (Light Emitting Diode) light effect in growth of chrysanthemum. For this reason, I formed six monochromatic lights (red 650 nm, 647 nm, 622 nm, blue 463 nm, 450 nm, white), six mixed lights sources red : blue (9 : 1, 8 : 2, 7 : 3, 6 : 4, 5 : 5) and 3 control beds in light sources ratio between rad : blue (8 : 2) including sun light. It was totally 15 control beds. Depending on light investigation time in growth, 6/6 (on/off) was highest in the length of plant, the number of leaves, the fresh dry and leaf area. But statistical significance wasn't accepted in general. In case of monochromatic lights, length of plant and leaf area is biggest in the Blue 450 mm and the length of root is highest in RED 650 mm. Except for this 3 measuring points (length of plant, the number of leaves and fresh weight), sun light and white was highest. Besides there are monochromatic light effect but various wavelength range in light sources are needed to crop growth. In terms of mixed light resources, except for sun light, It turned out the length of plant is highest in the highest red light rate red : blue (9 : 1), and Red : white (7 : 3) is highest in fresh weight and dry weight. The sun light is the highest one in the leaf area. The results from LED light effect in growth of chrysanthemum are obviously effect on growth and building up the shape. We need to choose suitable light sources in the monochromatic lights and mixed lights for growing high quality of chrysanthemum or Supplemental Lighting.