• Current Optics and Photonics
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• v.4 no.6
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• pp.551-557
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• 2020

A mirror-in-slab waveguide is fabricated on a slab waveguide by using the refractive-index contrast between two materials, with the reflection performance depending on the slab waveguide's design. In this research, a slab waveguide design consisting of silicon (Si) as the core and SiO2 as the substrate was designed and developed to determine the coupling, waveguide, and mirror losses. Based on experimental results, coupling loss is dominant and is affected by the design of the slab waveguide. Furthermore, the mirror loss is affected by the design of the mirror, such as the curvature radius and the size of the mirror. TE and TM polarizations of light are used in the measurements. The experimental results show that mirror losses due to reflection by mirrors are 0.011 dB/mirror and 0.007 dB/mirror for TE and TM polarizations respectively. A simulation was performed to confirm whether the size of mirror is sufficient to reflect the input light, and to check the quality of the surfaces of fabricated mirrors.

• Journal of Photoscience
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• v.5 no.4
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• pp.149-152
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• 1998

Expression of light-harvesting chlorophyll a/b-binding protein gene(cab) is repressed in the dark and activited by light. However, the detail of its regulatory mechanism is not characterized so far. To identify the interactions of cis-acting elements and trans-acting factors involvedin this regulation, nuclear extracts from the light-grown and dark-adapted Arabidopsis thaliana leaves were anlayzed for mobility shift assay against 134bp fragments had two retarded bands and one retardation band, respectively, both in light-grown and dark-adapted bands in the dark-adapted tissues. A new retardation the cab 3 expression in the dark. Several light regulatory motifs are scattered in the 146 bp region of cab 3 promoter. One of the light-regulatory motifs could be the binding site for the negative regulatory factor.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.10
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• pp.1-13
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• 2011

The aim of this study is to analyze the emotion adjectives for light emitting diode(LED) light colors using a twofold adjective image scales from Kobayashi and I.R.I. A set of psychophysical experiments using category judgment was conducted in an LED light color simulation system, in order to evaluate each emotion scale coordinate for those test light colors in both adjective image scales. In total, 49 test light colors from a combination of 6 color series were assessed by 15 human observers. As a result, Kobayashi adjective image scale clearly expressed to emotion adjectives of 'Dynamic', 'Casual', 'Chic', 'Cool-casual', 'Modern', and 'Natural' for different hues. In contrast, I.R.I adjective image scale expressed only 2 adjectives of 'dynamic' and 'luxurious' for the all hues.

• Molecules and Cells
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• v.38 no.7
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• pp.651-656
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• 2015

Plant growth and development are coordinately orchestrated by environmental cues and phytohormones. Light acts as a key environmental factor for fundamental plant growth and physiology through photosensory phytochromes and underlying molecular mechanisms. Although phytochromes are known to possess serine/threonine protein kinase activities, whether they trigger a signal transduction pathway via an intracellular protein kinase network remains unknown. In analyses of mitogen-activated protein kinase kinase (MAPKK, also called MKK) mutants, the mkk3 mutant has shown both a hypersensitive response in plant hormone gibberellin (GA) and a less sensitive response in red light signaling. Surprisingly, light-induced MAPK activation in wild-type (WT) seedlings and constitutive MAPK phosphorylation in dark-grown mkk3 mutant seedlings have also been found, respectively. Therefore, this study suggests that MKK3 acts in negative regulation in darkness and in light-induced MAPK activation during dark-light transition.

• KIEAE Journal
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• v.13 no.2
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• pp.61-66
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• 2013

This study is to eliminate the need for conventional high density plant factory's artificial light source such as LED to reduce the initial investment of the light source installation as well as the operation cost. Use of solar light could enhance the quality of the vegetables similar to those grown in the natural environment. Provision of solar light into the multilayer vegetable cultivation facilities and collecting maximum and sustainable sunlight without too much loss by tracing solar path and properly distributing it through careful control during daytime are crucial for realizing the investigated rooftop light shelf system for multi-layered vegetable cultivation. In this study, we developed an innovative way of effectively allocating sunlight inside even to otherwise shaded zone of a multi-layer vegetable cultivation facility. To prove the effectiveness of the system's sunlight collection and distribution capability, both simulation and experiment in Daejeon are performed and the outcome is analyzed.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2005.10a
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• pp.151-154
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• 2005

These days we are more interested in the space of architecture that how the change is likely to affect and how to be realized human. Human beings are recognizable the space and the creation of the space is eventually effected through human beings being perceptible the space of architecture and the equivalence of the space. That is the light, one of phenomenological elements, has been the first visual experience at birth. This study will concentrate on the importance of the phenomenological light especially indoors and study how architectural elements influence human beings with the light as one of the basic design factors for human life. That is exactly purpose of this research paper and this paper can make our lives worth living significant with the actively various uses inside spaces through the phenomenological light as a natural light in our human beings.

• Korean Journal of Ecology and Environment
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• v.53 no.4
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• pp.336-343
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• 2020

Large-scale cultivation of Microcystis aeruginosa in different light conditions was conducted for verifying the cell growth in a greenhouse system. Environmental and chemical parameters of the large-scale culture medium were measured for analyzing the interaction between M. aeruginosa and its symbiotic bacteria. During cultivation, a difference in cell growth pattern was observed between control (natural light) and light-limited groups (reduction of blue, green, and blue/green light, respectively). Comparing the control group, the light reduced groups showed slow and delayed cell growth through the cultivation period. Also, there is differences in the consuming pattern of total nitrogen and total phosphorus which indicated that the possibility of interaction between M. aeruginosa and symbiotic bacteria.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.93-102
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• 2021

In this research, we present a natural lighting system with transmission distance of 30m and lighting efficiency of 35% (30m standard) for operating hours of 7h/day (based on clear sky). The system is composed of parabolic reflective mirror and modified light pipe that can secure more than 88% of light concentration efficiency. The light loss rate of newly designed light pipe transmission system is demonstrated to 0.8 %/m in the straight-line part and 2%/m in the curved part. Modified light pipe daylighting system shows better performance over fiber optic daylighting system in terms of transmission distance (1.5 times longer) and illuminance (3.05 times higher).

• 한국약용작물학회:학술대회논문집
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• 2012.05a
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• pp.43-44
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• 2012

• Current Research on Agriculture and Life Sciences
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• v.6
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• pp.19-24
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• 1988

The present experiment was undertaken to study the influence of light intensity on plug establishment of zoysia-82, chewings fescue and red fescue. The results obtained are summarized as follows : In chewings fescue and zoysia-82, plant height and leaf length were increased and leaf width was decreased by reducing light intensity. But in red fescue, plant height and leaf length measured at 90 and 120 days after plugging under 9% of incident light were shorter than those under 30% of incident light. Percent ground cover was decreased by reducing light intensity in chewings fescue, red fescue and zoysia-82. Each part of dry weight in three species was getting lighter by reducing light intensity. Decrease of light intensity in zoysia-82 causes increasing chlorophyll a, b, and total chlorophyll content. But red fescue and chewings fescue had the most plentiful chlorophyll under 30% of incident light. Chewings fescue and red fescue had the lowest concentration of chlorophyll a/b under natural light intensity. But zoysia-82 had the lowest concentration of chlorophyll a/b under 30% of incident light. Tillering number of chewings fescue and red fescue was decreased by reducing light intensity. Internode length of zoysia-82 was longer in the order of : 1) 30% of incident light, 2) natural light, 3) 9% of incident light. And internode diameter was decreased by reducing light intensity.