• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.27 no.3
• /
• pp.7-15
• /
• 2013

In lighting design, the calculation of maintenance factor is performed by calculation considering light source, characteristics of luminaire and environmental factors. The method to calculate the current maintenance factor applied to tunnel lighting design takes into consideration only pollution factors in tunnels. In addition, the calculation method should be change in response to changes of tunnel conditions and used light sources. In this study, the calculated factor of the maintenance factor in tunnel is determine by four calculation factors generally applied to the calculation of maintenance factor. This study examined the method of calculating the maintenance factor of tunnel lighting that can be applied according to the installation conditions in designing tunnel lighting by applying the actual installation data of luminaire.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• pp.875-880
• /
• 2004

Stray light is the light except the light of the analytic wavelength and the source of measurement error of absorbance. Some experimental results showed that diffractive grating is the major factor of stray light in spectrophotometer. Through the ray tracing with the software tool, classified the paths of the diffractive light from grating and found the range of wavelength which reach the exit slit. The quantity of the stray light(0.025％) is more than the minimum limit of stray light(0.01％) of the single monochromator. A novel optical layout design method, which prevent the reflected rays entering the diffractive grating is proposed.

• Journal of Industrial and Engineering Chemistry
• /
• v.67
• /
• pp.365-372
• /
• 2018

Wounds that heal with excessive scar formation result in poor functional and aesthetic outcomes. To address this, in our study, visible light cured glycol chitosan (GCH) hydrogels containing endothelial growth factor (EGF) and basic fibroblast growth factor (bFGF) were prepared (GCH-EGF, GCH-FGF and GCH-EGF/FGF) and evaluated their efficacies on the improvement of wound healing in vivo. In vitro release test showed that the growth factors were released in a sustained manner along with initial burst for 24 h. In vitro cell proliferation assay of L-929 mouse fibroblast cell line resulted in the superior ability of GCH-EGF/FGF on the rate. In vivo results demonstrated that the growth factor loaded GCHs further enhanced wound healing compared with GCH. In particular, GCH-EGF/EFG showed the most remarkable wound healing effect among the samples.

• Korean Institute of Interior Design Journal
• /
• no.5
• /
• pp.30-36
• /
• 1995

Light plays an important role in making a continuity of space and in determining the distinctive expression and char-acter of a space. Particularly, the introduction of natural light derives from our esthetic needs, as well as from the fundamental biologi-cal necessities of human beings. And also, adaptation to time and space is the vital factor of human survival and prosperity. Our visual recognition of light is usually formed not only by practical illumination but by analogy, expection and expe-rienced of lighting itself. As the forecase of natural light is (almost) impossible be-cause of variables such as changing weather, reflection rate of light and the patterns of shade, in designing the introduc-tion of daylight, there should be follow-ed careful considera-tion of the adaptation to such variety and the impet-us of light. The research was conducted to mane a contribution to cre-ate more rich and beautiful interior spaces by studying the characteristic of light which is one of the important factors of interior space design, and by inquiring the way to intro-duce light and its effect through the practical examples of Alvar Aalto, Le Corbusier and Louis I. Kahn.

• Journal of Applied Biological Chemistry
• /
• v.66
• /
• pp.106-113
• /
• 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 The Korean Association For Science Education
• /
• v.41 no.5
• /
• pp.371-390
• /
• 2021

The purpose of this study is to develop a neuropsychological model for the spatial ability factor and to divide the brain active area involved in the light & shadow problem solving process into the domain-general ability and the domain-specific ability based on the neuropsychological model. Twenty-four male college students participated in the study to measure the synchronized eye movement and electroencephalograms (EEG) while they performed the spatial ability test and the light & shadow tasks. Neuropsychological model for the spatial ability factor and light & shadow problem solving process was developed by integrating the measurements of the participants' eye movements, brain activity areas, and the interview findings regarding their thoughts and strategies. The results of this study are as follows; first, the spatial visualization and mental rotation factors mainly required activation of the parietal lobe, and the spatial orientation factor required activation of the frontal lobe. Second, in the light & shadow problem solving process, participants use both their spatial ability as a domain-general thought, and the application of scientific principles as a domain-specific thought. The brain activity patterns resulting from a participants' inferring the shadow by parallel light source and inferring the shadow when the direction of the light changed were similar to the neuropsychological model for the spatial visualization factor. The brain activity pattern from inferring an object from its shadow by light from multiple directions was similar to the neuropsychological model for the spatial orientation factor. The brain activity pattern from inferring a shadow with a point source of light was similar to the neuropsychological model for the spatial visualization factor. In addition, when solving the light & shadow tasks, the brain's middle temporal gyrus, precentral gyrus, inferior frontal gyrus, middle frontal gyrus were additionally activated, which are responsible for deductive reasoning, working memory, and planning for action.

• Korean Institute of Interior Design Journal
• /
• v.16 no.2 s.61
• /
• pp.339-346
• /
• 2007

This thesis has purpose of explaining that light is not only appreciated but also physically percepted in contemporary space design and examining effects of space experience through the physical perception. In keeping with such developments, light has been perceived as the object of another architectural tool in modern space design and has provided men with new experience by providing space image and function different from previous ones. With the expansion of the area of light, light has changed a space that is not a simple architectural factor into the essential concept that gives the architectural space image ! by combining it with architectural space, structure, form and materials throughout the whole process from the beginning to the completion. Through phenomenological approach, light is percepted and experienced by body movement, intervention of senses and memories, and passing of time. The percepted and experienced light brings increase of mutual understanding in space, activation and continuance of user's sensation, recreational experience by event occurrence and space experience effect thorough information from media.

• Analytical Science and Technology
• /
• v.30 no.4
• /
• pp.159-166
• /
• 2017

Exposure to UV light, i.e., UV-A (320-400 nm) or UV-B (290-320 nm) radiation, can cause skin cancer. Titanium dioxide ($TiO_2$) effectively disperses UV light. Therefore, it is used as a physical UV filter in many UV light blockers. Usually, the $TiO_2$ content in commercialized UV blockers is 25 % at most. To block UV-B, a chemical UV blocker, octyl-methoxy cinnamate (OMC) is used. OMC is commonly used in combination with $TiO_2$. In this study, $TiO_2$ and OMC were mixed in different proportions to produce UV blockers with different compositions. Also the changes in the sun protection factor (SPF) based on the composition and $TiO_2$ particle sizes were investigated. In order to analyze the $TiO_2$ particle size, dynamic light scattering (DLS) and asymmetrical flow field-flow fractionation (AsFlFFF) were used. The results showed that the SPF was influenced by the proportion of $TiO_2$ and OMC, where the proportion of $TiO_2$ induced a more significant influence. In addition, changes in the $TiO_2$ particle size based on the proportion of OMC were observed.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.4D
• /
• pp.403-411
• /
• 2010

Nowadays, Light railway system is attracted public attention as solution for metropolitan traffic congestion. But it is difficult to decide an appropriate light railway system. It is especially hard in the Seoul metropolitan to decide an appropriate system, because there are many factors that must considered. So we research application status of light railway system that is scheduled or promoted in the Korea and the foreign nations. And we selected systems by types of city. In this paper, we divided into 6 types of city through factor analysis and cluster. And we considered various factor such as technology, transportation, environment etc that used previous research and feasibility study. To determine the priority among the factors, AHP(Analytic Hierarchy Process) was applied as a method for multi-standard decision method.

• Korean Journal of Optics and Photonics
• /
• v.10 no.1
• /
• pp.32-39
• /
• 1999

In this paper, we made CGH patterns that had continuous amplitude distribution binary coded patterns with two different methods, and analyzed those patterns by using LCSLM (liquid crystal spatial light modulator). The error diffusion algorithm and direct quantization method were used as the binarization methods. The parameters of overall average brightness, mean square error, and diffraction efficiency were used in the comparison of reconstruction characteristics. The LCSLM which we used in this experiment was a binary reflective ferroelectric liquid crystal spatial light modulator addressed electrically with 256$\times$256 pixels, 87% fill factor and 15$\mu$m pixel pitch.