• Korean Journal of Medicinal Crop Science
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• v.22 no.4
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• pp.295-300
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• 2014

This study was carried out to produce more Parasenecio firmus in forest farming. In order to achieve this purpose, it was surveyed the growth and photosynthetic characteristics of P. firmus. Relatively light intensity was controlled by 100%, 60%, 30% and 5% of full sunlight. Height was the highest under 5% of full sunlight. Shoot diameter was the highest in full sunlight. Fresh weight (leaf, stem, root and total) and dry weight (leaf, root and total) were the highest under 30% of full sunlight. S (leaf+stem)/R (root) ratio was the lowest under 30% of full sunlight and the highest under 5% of full sunlight. In leaf characteristics, leaf area, SLA and LAR were getting higher in the lower light level and the highest under 5% of full sunlight ($176.1cm^2$, $420.5cm^2{\cdot}g^{-1}$ and $123.5cm^2{\cdot}g^{-1}$). Especially, leaf area was surveyed higher under 30% of full sunlight in the next. Leaf thickness was getting lower in the lower light level and the lowest under 5% of full sunlight (overall 0.14~0.24 mm). As a result of surveying the whole experiment, P. firmus grows well under 30% and 5% of full sunlight in forest farming.

• Korean Journal of Medicinal Crop Science
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• v.22 no.2
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• pp.154-159
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• 2014

This study was carried out in order to investigate the early growth and root development characteristics of Atractylodes japonica container seedling. Experiment was performed by light intensity (100%, 60%, 25% and 10% of full sunlight). Height was surveyed well under 25% of full sunlight (overall 11.013.0%). Root collar diameter was the highest in the full sunlight (7.52 mm). It was the highest fresh weight (1.52 g, 0.92 g, 0.90 g and 3.34 g) under 25% of full sunlight, root dry weight was getting higher in the higher light level and the highest in the full sunlight (0.13 g). Total root length, root project area, root surface area and root volume were the highest under 25% of full sunlight (434.7 cm, $17.4cm^2$, $54.7cm^2$, $0.55cm^3$, respectively) and the lowest under 10% of full sunlight. As a result of surveying the whole experiment, A. japonica is judged nicely by maintaining 25% of full sunlight, excepting 10% of full sunlight. And light levels during the early growth are overly important to improve early growth.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.3
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• pp.59-68
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• 2023

Currently, yellow phosphor of Y3Al5O12:Ce3+ (YAG:Ce) fluorescent material is applied to a 450~480nm blue LED light source to implement a white LED device and it has a simple structure, can obtain sufficient luminance, and is economical. However, in this method, in terms of spectrum analysis, it is difficult to mass-produce white LEDs having the same color coordinates due to color separation cause by the wide wavelength gap between blue and yellow band. There is a disadvantage that it is difficult to control optical properties such as color stability and color rendering. In addition, this method does not emit purple light in the range of 380 to 420nm, so it is white without purple color that can not implement the spectrum of the entire visible light spectrum as like sunlight. Because of this, it is difficult to implement a color rendering index(CRI) of 90 or higher, and natural light characteristics such as sunlight can not be expected. For this, need for a method of implementing sunlight with one LED by using a method of combining phosphors with one light source, rather than a method of combining red, blue, and yellow LEDs. Using this method, the characteristics of an artificial sunlight LED device with a spectrum similar to that of sunlight were demonstrated by implementing LED devices of various color temperatures with high color rendering by injecting phosphors into a 405nm deep blue LED light source. In order to find the spectrum closest to sunlight, different combinations of phosphors were repeatedly fabricated and tested. In addition, reliability and mass productivity were verified through temperature and humidity tests and ink penetration tests.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1276-1278
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• 1998

In this paper, aging characteristics of silicone rubber used for outdoor insulation have been investigated with regards to sunlight effect. For this purpose, silicone rubbers were aged under the artificial sunlight by use of xenon arc lamp(1500W) and various tests were performed such as tracking, breakdown, contact angle, stress, strain. And then, in order to elucidate the changes of material, analysis have been followed as follows; FT-IR, SEM and EDS. Regarding the effect of the sunlight, it was obs that the surface of test samples are severely da with decreased hydrophobicity, tracking resistan breakdown strength.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1673-1674
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• 2006

The most ideal light source known to the mankind is sunlight. Therefore, whenever an artificial light source is needed in a dark place such as in a shadowed houses, the utmost goal is to find an artificial light characteristics of which approaches that of sunlight. On this ground, we have investigated a Neodymium lamp as a possible substitute for sunlight. Especially, the local and the color rendering, a life expectancy, and the overall efficiency are carefully studied.

• Proceedings of the KIEE Conference
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• 2007.11c
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• pp.93-96
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• 2007

In this paper, the testing equipment for evaluating aging characteristics of outdoor silicone rubber insulator resulting from the environmental aging effect with regards to sunlight(UV) was developed. Influence of sunlight effect aging is seriously increase due to destruction of ozone layer which is occurred by consumption of fossil fuel. For this purpose, silicone rubber was aged under the artificial sunlight by exposure of xenon lamp radiation in the accelerating aging chamber and various test and analysis were performed such as breakdown strength, contact angle. And FT-IR analysis has been followed.

• Korean Institute of Interior Design Journal
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• v.26 no.4
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• pp.30-41
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• 2017

Sunlight is perceived by human beings first through the epidermis to space, and is a non - material medium that provides physical awareness of space, diversified expression of spaces, and plenty experience. The purpose of this study is to investigate the characteristics of active building skin based on the inflow of natural light required by humans, looked through among the works of Jacques Herzog & Pierre de Meuron, which show the characteristics of active building skin, TEA(Tenerife Espacio de las Artes, 2008), Messe Basel New Hall (2013) and Elbphilharmonie (2016). First, the interaction between Sunlight and space is divided into spatial characteristics and sensitivities according to their concepts, properties, and characteristics. The characteristics of active skin by light are classified into a physical approach and a constructive approach. Second, (El Croquis 152/153) and analyzed the images, detail drawings, and elevations, and simulated them in 3D to express the relationship between light and active building skin. Third, the changes of light intensity, light color, and distribution of light according to the time of light entering and the skin are determined from 6:00 am to 6:00 pm. Fourth, the images taken from January 30th to February 7th, 2017 on the site were compared with the computer simulated images, and the relationship between active skin and light was compared. This study is to recognize the existence and necessity of light required for human being through the activated epidermis differentiated from the limited or closed epidermis focused on information transmission, I would like to emphasize that I would like to take a step closer to the necessity and possibility of new attempts and developments so that I can feel the various experiential spaces by.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1316-1317
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• 2011

This paper presents analysis of temperature and light intensity characteristics of PV modules with solar cell type. Taking the effect of sunlight irradiance on the cell temperature, the first experiment takes ambient temperature as reference input and uses the solar insolation as a unique varying parameter. Then taking the effect of the cell temperature on sunlight irradiance, the second experiment takes 1000W/$m^2$ as reference input and uses the cell temperature as a unique varying parameter. As a result, varying sunlight irradiance, the Cell-Type with the smallest change in output is HIT and the Cell-Type with the biggest change in output is a-Si. Varying the cell temperature, the Cell-Type with the smallest change in output is a-Si and the Cell-Type with the biggest change in output is Single-Si. And considering both temperature and light intensity characteristics, the Cell-Type with the smallest change in output is HIT.

• Journal of The Geomorphological Association of Korea
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• v.28 no.2
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• pp.59-70
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• 2021

This study aims to determine the sunlight exposure according to depositional environment to improve the accuracy of optically simulated luminescence (OSL) dating. Sufficient sunlight exposure during transportation of sediment is a basic assumption of the OSL dating, and if the process does not occur enough, the results may be overestimated compared to the actual depositional age. Therefore, the main purpose of this study is to establish a correction method by determining residual or unbleachable dose after sunlight exposure in the actual deposition process, not in the laboratory measurement. Four samples from two sites were collected according to the depositional environment from rivers and coasts, and various OSL signals, including the size of residual dose, degree of dispersion between grains, and OSL signal sensitivity, were measured. As a result, it was confirmed that sediments formed under temporarily high energy environments, such as floods and surges, had relatively high residual dose or large dispersion of residual dose between particles. In further studies, the OSL signal characteristics of river sediments by flow velocity will be identified and the relationship between energy and OSL signal characteristics will be identified in more detail. Moreover, a method of reconstructing the paleo-environment at the time of deposition for existing sediments will be devised. It is expected to provide important information for the frequency of disaster recurrence and prediction of future climate change.

• Journal of the Korean Society of Clothing and Textiles
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• v.28 no.7
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• pp.882-891
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• 2004

The purpose of this study was to improve dye effect and method in order to facilitate the use of persimmon juice dyeing. Silk fabrics were pad-dyed to 100% pick-up using padding machine after dipping in persimmon juice extracted from unripe persimmons indigenous to Jeju. The color of dyed silk fabrics by padding method was more even and repeatable than that by traditional hand method. Persimmon juice concentrations were 4 types 10, 25, 50 and 100%. The silk fabrics were pad-dyed to 100% pick-up and were repeatedly dyed two times and three times with 100% concentration. The higher the concentration, the more color deepened. UV Irradiation instead of sunlight was applied to color developing. Irradiation times were shortened to 1-8hrs. Color values which reguired 30-50 hrs. in sunlight irradiation. were obtained in 3-5 hrs. with UV irradiation. Tensile strengths of silk fabrics in UV irradiation decreased but not decreased in sunlight irradiation. Elongations of silk fabrics in sunlight irradiation increased but decreased in W irradiation. Drape stiffness increased up to three times.