• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.131-136
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• 2002

In recent year, it has been investigated on the reduction of mass of structures for the purpose of the larger space and the economy with the industry developing very fast and qualitatively. So the purpose of this study is to investigate the manufacture of light weight concrete panel using the artificial light-weight aggregate as a part of the substitution of foamed styrene and polyurethane because of narrow allocable temperature zone in use. The compressive strength, flexural strength, unit weight, absorption test and thermal conductivity were practised at 3, 7 and 28 days after manufacturing the light-weight concrete lot the panel core: the filling ratio of continuous void was defied as 40%, 50%, and 60% and water-cement rate was 35, 40 and 45%. As a result of this, it was revealed that the mixture derived from filling ration of void of 50% and water-cement ratio 40% were developing the best properties of the others.

• The Korean Journal of Ecology
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• v.21 no.4
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• pp.329-335
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• 1998

The growth of Phytolacca L. grown under three light regimes at three nutrient concentrations was analyzed. The effect of shading treatment on plnat growth was greater than that of nutrient treatment. Plant dry mass increased more than 5-fold during 21 days under 33% and 100% irradiances, whereas that was strongly reduced under 8% irradiance. Net assimilation rate decreased with plant growth irrespective of light and nutrient treatments, though the highest net assimilation rate was shown under 100% irradiance. Under 33% irradiance leaf area in plants supplied with nutrient solution increased to such extent as to compensate reduction in net assimilation rate, whic maintains almost identical growth rate with that under 100% irradiance. The relatonship between total plant nitrogen and leaf nitrogen content was dependent on the growth irradiance. Moreover, leaf nitrogen and specific leaf weight were also changed depending on the light and nutrient conditions. Based on these findings, it is suggested that the adaptive characteristics of Pokeberry plant to light and nutrient conditions may contribute to rapid extension of Pokeberry habital in Korea rocently.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.1
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• pp.182-189
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• 2005

In this paper, A web-based server system was developed based on PDA(Personal Digital Assistants) for controlling and managing light facilities on-line with wireless communication efficiently. The control box of current light facilities may be implemented based on simple operational function. The operational quality of the light facilities will be efficiently improved with some practical advantages such as reduction of required facility, manpower and time in managing the lights and control boxes by using the popular PDA.

• Transactions of the Society of Information Storage Systems
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• v.6 no.1
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• pp.1-5
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• 2010

Holographic data storage system(HDSS) has many noise sources - crosstalk, scattering and inter pixel interference, etc. Generally the intensity of a light generated from the laser source has Gaussian distribution and this ununiformity of light also can make the data page to have a low SNR. A beam apodizer is used to make the laser as a flat-top beam but the intensity distribution is not strictly uniform. The intensity of light can be controlled using image mask. In this paper the intensity distribution of light used for HDSS is controlled by a digital image mask. The digital image mask is changed arbitrarily in real-time with suggested algorithm for the HDSS.

• Transactions on Electrical and Electronic Materials
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• v.9 no.3
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• pp.116-119
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• 2008

The purpose of this study is to develop the Photodynamic Therapy Equipment for medical treatment. We developed the equipment which was helpful in palpating wound healing by using 525 nm LEDs. The equipment was assembled with a micro-controller and green color LEDs, and designed to enable us to control light irradiation time, intensity and so on. In this study, the designed device was used to find out how 525 nm LEDs light affected the skin wound of SD-Rat(Sprague-Dawley Rat). We divided the participants into two groups; irradiation group which was irradiated one hour a day for 9 consecutive days, and none irradiation group. The results showed that the study group had lower incidence of inflammation and faster recovery, compared with the control group.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.1
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• pp.46-50
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• 2012

This paper amis at improving the heat radiation performance of thermoelectric module (TEM) for a commercialization of high-powered LED light with using a multichip LED module. In addition, a 10W multichip LED light was prepared for the heat performance on radiating of which LED light was made for a use of testing by the driving of the thermoelectric module. So, it was found that about 30% in the effect of temperature reduction was confirmed if compared with the radiation heat by heat sink only.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.4
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• pp.70-77
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• 2023

Fine dust is a cause of serious ecological problems, and fugitive dust generated from construction sites is a major source of fine dust in Korea. However, at construction sites, including concrete manufacturing industry sites, measurements are rarely made at the fugitive dust generation stage, and passive removal methods are the majority. Therefore, in this study, a fugitive dust measurement method suitable for managing fugitive dust generated during aggregate unloading in the concrete manufacturing industry sites was selected. In addition, the purpose was to analyze the amount of fugitive dust reduction according to the operation of the reduction system by applying the automatic fugitive dust reduction system to the aggregate unloading site. As a result, the reliability of the light scattering method was secured through the comparative measurement of the beta-ray absorption method and the light scattering method, and the light scattering method correction coefficient was calculated and applied to the measured value of the fugitive dust particle mass concentration at the concrete manufacturing industry sites. In addition, the fugitive dust reduction rate according to the operation of the automatic fugitive dust reduction system was derived.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.05a
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• pp.23-26
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• 2006

The study about the concrete to use recently a light weight aggregate, processed actively. And concrete pumping with a high pressure pump has been popularized, the mechanical development, such as high pressure pumps or pipes, is progressing rapidly. Concrete placing by pumping has the advantage of the reduction of the construction period with workability, easiness of work and the increase of placing, but the quality variation of concrete is caused by pumping is seldom considered, including the increase of the pipe length by high-rising and large-sizing, there by the loss of the unit quantity of water, with pumpability or workability deteriorated. In this research, we will compare and analyze before pumping and after pumping samples of ready-mixed light weight concrete. The result of study as follow. The case of a light weight concrete which the low slump is more decrement compared with high slump light weight concrete in after pumping samples. After pumping the water by pressure of a pump was absorbed to the aggregate inside, and it showed an increase of compression strength about $5{\sim}20%$.

• Current Optics and Photonics
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• v.5 no.3
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• pp.220-228
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• 2021

To improve the measurement accuracy of a solar-radiation observer instrument, aiming at the problem of multiorder-stray-light interference caused by the diffraction of the flat-field concave grating in the spectroscopic system, straylight suppression methods for different forms of optical traps are studied. According to the grating surface-scattering distribution-function model, the bidirectional scattering distribution function (BSDF) of a dust-polluted surface and the flat-field concave grating's transition area of the spectroscopic system is calculated, and a Lyot stop with blade baffle is designed to suppress this kind of stray light. For diffraction multiorder stray light, based on the theory of light-energy transmission, a design for precise positioning of the trench optical trap is proposed. The superiority of the method is verified through simulation and actual measurement. The simulation results show that in a spectroscopic system approximately 160 mm × 140 mm × 80 mm in size, the energy of the stray light is reduced by one order of magnitude by means of the trench optical trap and Lyot stop, and the number of beams is reduced from 5664 to 1040. The actual measurements show that the stray-light-suppression efficiency is about 69.4%, which is effective reduction of the amount of stray light.

• Fashion & Textile Research Journal
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• v.21 no.2
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• pp.231-236
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• 2019

This study investigated the proper dyeing conditions, color fastness and functionality of wool fabrics dyed with Zizania latifolia Turcz. We also tried to improve light fastness through treatment with benzophenone ultraviolet absorber. The dyeing of wool fabrics using Zizania latifolia Turcz was good even without pretreatment or mordanting treatment. Optimal wool fabric dyeing conditions were colorant concentration of 200% (o.w.f.), dyeing temperature of $100^{\circ}C$, dyeing time of 80 minutes and a dye bath pH of 3. Color fastness of dyed wool fabrics to washing, rubbing, perspiration and light was 4-5, 5, 4-4-5 (acidic), 4-5 (alkaline) and 2 respectively. The results after treatment with ultraviolet absorber for improving the fastness of daylight were improved to 3-4 grade. The UV protection rate were increased after dyeing and the deodorization of ammonia gas improved to 98%. Bacterial reduction rate (Staphylococcus aureus) of wool fabrics was excellent at 99.9%. All dye fastness (except for light fastness) was excellent; in addition, the functionality of wool fabrics dyed with Zizania latifolia Turcz also improved. The results are expected to be applied to various fields because they indicate excellent results after treatment with ultraviolet absorber for improving the fastness of daylight.