• Journal of Environmental Science International
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• v.7 no.3
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• pp.269-274
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• 1998

In order to develop of support medla for bloom reactor, physicochemical properties and attachability of surface of activated carbon, clay mineral, non-clay mineral, and waste mold sand were enamined. Measured physicochemical properties of materials were surface roughness, mean particle size, surface area, hydrophobicity, and surface charge. At a tested materials, activated carbon was the best attachable material and microorganisms were attached $20.1{\times}10^7CFU/cm^2$ at surface, compared with diatomaceous earth which were attached of $9.2{\times}10^7CFU/cm^2$ in our research, surface area and hydrophobicity show- ed more Influence than any other factor on attachment of microorganisms.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.04c
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• pp.98-102
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• 2008

Methods and analysis of a simple wireless sensor concept for detecting and locating faults as well as for load monitoring are presented. The concept is based on distributed wireless sensors that are attached to the incoming and outgoing power lines of secondary substations. A sensor measures only phase current characteristics of the wire it is attached to, is not synchronized to other sensors and does not need configuration of triggering levels. The main novelty of the concept is in detecting and locating faults by combining power distribution network characteristics on system level with low power sampling methods for individual sensors. This concept enables the sensor design to be simple, energy efficient and thus applicable in new installations and for retrofit purposes in both overhead and underground electrical distribution systems.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.1005-1009
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• 2008

The high efficiency insulation panel for transformer construction is needed in residential area because the making noise from transformer substation in side of city is appeared a lost of problem by increasing to conserve the living environment. Therefor in this paper, first the vibration and noise characteristic of existing insulation panel is analyzed according to attached material, cork and sponge-type. Second the insulation of sound performance is compared between the existing insulation panel. And high efficiency insulation panel that is proposal in this paper.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.11
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• pp.1-8
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• 2010

This study analyzes whether a person's visual perception differs according to the kinds of light source. Evaluations of the effects of space, color-tone and texture perception revealed that different kinds of light sources change the perception of finishing material. The perception from directly attached lamps was compared to an environment with both directly attached lamps and supplemental lighting. We found the perception changed with changes in the types of supplemental light source We compared the mean value of each perception and found that perceptions change most when incandescent lights were followed by halogen. Thus, one should account for the changes in perception that occur as a result of these changes.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.207-208
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• 2007

Epoxy resin insulators show a lot of advantages for electrical power apparatus. Because epoxy resin provide electrical and mechanical characteristic which is excellent, it is desirable to apply epoxy resin as a spacer and post insulation in Gas Insulated Switchgear (GIS). In this study, we have investigated the influence of surface electric field attached particle contaminated spacer surfaces under SF6 gas. Also, we performed analysis of electric field. As a result, when the particle was attached on spacer, we found out a surface electric field of characteristics.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.8
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• pp.28-37
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• 1999

This investigation is the result of the structural analysis by finite element method and test for considering stress distribution and stress concentration to be generated according to the change of attached shape and method of the bracket to pipe in welding structure. Generally, members that consist structures are subjected to various forces and are jointed each other with a number of bracket. In this case, circular pipe was adapted in order to weld these members easily and to study the optimal design which is used a beam with shape section as main components of the structure, According to attached shape and method, distributed stress on circular pipe is appeared so differently. This may result deeply effects with respect to thickness, material properties. So a study on attaching shape and method of bracket to circular pipe is needed. In this paper, to obtain the maximum equivalent stress or stress concentration was used experimental and F.E.M. analysis. First five parameter was defined with respect to attached a shape and method to circular pipe i.e. the variation of the attached area, the variation of the attached shape, the variation of the attached length, the variation of both directin angles, the variation of the upper angle. Afterward the experimental analysis was practiced as the variation of the both direction angel and the finite element analysis was practiced as each parameters. We can discover stress distribution and stress concentration according to the change of form of bracket. And the result can be referenced for a design of similar structure.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.107-108
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• 2016

When the construction in a low temperature, the concrete performance is deteriorated by frost damage at early age. In this study, the form utilizing heating sheet and insulation is measured the performance to prevent frost damage at 10 below zero. It produced five types of the form and to measure the temperature history and compressive strength. At first, form attached heating sheet showed the highest temperature. But the form attached vacuum insulation showed the highest temperature ever since 12hours. In the case of compressive strength, the form attached heating sheet + isopink(polystyrene foam board) showed the highest compressive strength. It was followed by vacuum insulation. As a result, the form utilizing insulation and heating sheet helped to prevent frost damage.

• Journal of the Korea Fashion and Costume Design Association
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• v.12 no.3
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• pp.57-71
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• 2010

This study is to understand the actual condition of design and material of peanut-shaped diaper with looking at the types and characteristics of baby cloth diapers and domestic peanut-shaped diapers registered in the Patent Office. Furthermore, it is to suggest the basic data for designing more functional and comfortable cloth diapers. Here are the research result on the actual condition of design and material of baby cloth diapers. Firstly, 11 cloth diapers registered in the Patent Office can be divided into panty-shaped and straight line-shaped diapers. There are 7 kinds of panty-shaped cloth diapers which satisfy both the convenience of a disposable diaper and sanitation of a cloth diaper, and 4 kinds of straight line-shaped cloth diapers that minimize the weaknesses of existing cloth diapers. Secondly, domestic peanut-shaped cloth diapers can be divided into peanut-shaped, inserted, winged, velcro-attached diapers. Among 23 kinds of peanut-shaped cloth diapers from 16 companies, there are 12 kinds of peanut-shaped diapers which consist of layers of cloth to make peanut shape. There are 6 kinds of inserted diapers that insert extra diapers or handkerchiefs in between two sheets of cloth diapers and 3 kinds of winged diapers designed to shorten drying time with sawing only one side of several layered sheets. Also, there are 2 kinds of velcro-attached diapers that are removable according to the amount of excreta. Commonly used materials are cotton woven of diamond jacquard and knit of diamond Hole Stitch or Plain Stitch. And for handing the edge of diaper, the method of wrapping up the edge with cotton woven or knit bias is used.

• Journal of Korea Water Resources Association
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• v.36 no.6
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• pp.1013-1023
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• 2003

This study was performed to improve water quality of stream by applying hydraulic structures (weir and river bed material) made of porous concrete. The physical and chemical characteristics of porous concrete were measured to estimate application possibility of it in hydraulic structures and it was considered as a proper material for the hydraulic structures. In the results of comparison for the component of matters attached on the hydraulic structures made of porous and ordinary concrete, DW (dry weight) amount attached on porous concrete was 1.6 times higher than that on ordinary concrete under the condition of the same flow rate but influence by flow rate (difference of 10 times) was not shown. Therefore, we could understand that the material of media was more important in DW amount than flow rate. The rate of AFDM (ash free dry mass) to DW also was more at porous concrete than at ordinary concrete. Especially, the high rates of nitrogen and phosphorous in matters attached on porous concrete verify that they were removed by assimilation, adsorption and metabolism of periphyton. The removal percentage of SS, BOD, COD, T-N and T-P by hydraulic structures applying porous concrete compared with ordinary concrete was increased by 34.6%, 36.9%, 33.9%, 18.3% and 21.6%, respectively. Therefore, applying porous concrete to hydraulic structure is expected to contribute to improvement of stream water quality.

• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.595-603
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• 2018

This study was conducted to understand the growth of attached microbial community in small and medium streams of Gyeonggi-do and the removal efficiency of fluoride with changes in growth. The sites monitoring were carried out for 12 weeks at the P1 and P2(P1 is the point where the discharge water flows. P2 is the downstream point of about 2 km flow), and investigated the water quality and the biomass analysis of the attached microbial community. The growth of the attached microbial community increased up to the 7th investigation, and it was observed that detachment phenomenon occurred. Influencing factors about growth of the attached microbial community were flow rate, velocity, and organic material(T-N & T-P). Meanwhile, fluoride content of attached microbial community also tended to increase until the 7th investigation, and decrease from the 8th. It is assumed that fluoride content has also be reduced with the detachment phenomenon of the attached microbial community. It is expected that this will contribute to the evaluation and management of the use of attached microbial community as a means of stream management. The application of techniques using the attached microbial community should include basic investigation of factors that may affect the growth of the attached microbial community and replacement of the attachment plate according to the time of removal.