• 한국의류학회지
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• 제42권3호
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• pp.474-485
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• 2018

Smart sensors and connected devices have changed the concept of garments along with IT technology convergent garments that transform the performance of basic functions. Various types of products have been researched and developed due to the increased interest in smart clothing; in addition, studies based on physical and mechanical properties have also been actively studied to improve accuracy and reliability. This study represents a basic study for the development of smart textiles based on motion recognition for the surfing practice of beginners interested in IT convergence type. A physical durability evaluation of conductive yarn according to sewing method was later carried out. This study is a conditional specimen sewn with cotton lower thread and 100mm pattern length based on the results of previous studies. The durability of the conductive yarn according to the sewing method was evaluated according to the sewing method. Durability was evaluated by two kinds of repeated strain and abrasion tests. The specimen with applied cotton in a lower thread zigzag pattern 2mm stitch size 100mm stitch length was shown to have the most suitable durability for smart textile.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.643-648
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• 2002

A research for recycling the demolished-concrete as concrete aggregate has been concerned in all over the world. There, however, are some problems that qualities of recycled aggregates are not only largely different, but also mechanical properties of recycled aggregate concrete decrease a little in comparison with that of natural aggregate concrete. In this study, the resistance of freezing and thawing of concrete using source-concrete recycled aggregate(SRN) and demolished-concrete recycled aggregate(DRA) was investigated. Futhermore a research for improvement of freeze and thaw durability of recycled aggregate concrete was performed. Relative dynamic modulus of elasticity of SRN and DRA recycled aggregate concrete was dropped 60% before 150 of freezing and thawing cycle, and was much lower than that of control concrete. Relative dynamic modulus of elasticity of recycled aggregate concrete was increased to decrease water-cement ratio, but the freeze and thaw durability of recycled aggregate concrete was not enough improved. Futhermore, when metakaolin and silica fume were repalced, the freeze and thaw durability of recycled aggregate concrete containg metakaolin was more improved than that of silica fume.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.173-176
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• 2006

Concrete has been considered as a semi-permanent structural material, because its excellent durability. But concrete durability is affected by carbon dioxide, chloride, water, etc. This study is about surface protection materials-one materials is silane type and the other silicate type for the promoting of concrete durability. As a results, Silane type could protect affection of chloride(Cl-), water(H2O), carbon dioxide(CO2). Also silicate type could improve the abrasion of concrete.

• 동력기계공학회지
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• 제5권4호
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• pp.61-66
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• 2001

Electro-Rheological(ER) fluids undergo a phase-change when subjected to an external electric field, and this phase-change typically manifests itself as a many-order-of magnitude change in the rheological behavior. This paper presents experimental results on material properties for an ER fluids of arabic gum components subjected to electrical fatigues. As a first step, ER fluids are made of arabic gum 25% of particle weight-concentration. Following the construction of test mechanism for estimated durability of ER fluid, the dynamic yield stress, shear stress and current density of the ER fluids are experimentally distilled as a function of DC electric field. The durability estimation of operated ER fluids are distilled and compared with those of unused ER fluids. In addition, the surface roughness of the employed electrode for copper and aluminum are evaluated as a function of the number of the electric-field cycles.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.189-194
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• 2000

The optimum mix proportioning of concrete is to produce a concrete which satisfies the strength, workability and durability required with minimum component of materials. However in practice the cement content of mix proportioning in construction field is normally higher then required. In this study, the existing mix proportioning of concrete currently used in Korea Highway Corporation has been reviewed by reducing 10kg of cement content by 3~5 strength in strength and workability during the first year of this project. The optimum mix design is established based on the results of the above review and durability were examined during the second year. The experimental results though 2 year show that 103~0% of the reduction of cement content still satisfies the specified strength of concrete and produces higher durability concrete.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2003년도 학술대회지
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• pp.185-190
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• 2003

Synchronizer ring performance is strictly required in order to extend manual transmission oil drain interval. Zn type additive, which is used as dispersant and anti-wear additive instead of SP additives in manual transmission oil, is applied to improve Synchronizing function and durability. But only Zn type additive is not suitable for high torque transmission because it has not good extreme pressure characteristics. We research on the synchronizer friction and extreme pressure properties in according to change additive types. As a result, it was found that the use of non-active extreme pressure and friction modifier additives has benefit in the improvement of synchronizer friction characteristics and durability.

• 한국염색가공학회지
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• 제16권2호
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• pp.41-46
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• 2004

We have studied on the experimental variables such as optimum adsorption condition, color changes, light fastness, antimicrobial properties, and wash durability of the cotton fabrics treated with gallnut extracts. Treatment of gallnut extracts on the cotton fabrics was optimally achieved at 6$0^{\circ}C$ for 60min. Gallnut extracts did not cause unintended color change after treatment on the cotton fabrics dyed with reactive dyes. The cotton fabrics treated with gallnut extracts showed good light fastness, though we took into the account the extract is a natural material. The cotton fabrics treated with 10.0% o.w.f. of gallnut extracts had strong antimicrobial activity and good wash durability.

• 한국자동차공학회논문집
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• 제12권5호
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• pp.73-78
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• 2004

The liquid phase LPG injection (LPLi) system (the third generation technology) has been considered as one of the next generation fuel supply systems for LPG vehicles, since it has a very strong potential to accomplish the higher power, higher efficiency, and lower emission characteristics than the mixer type(the second generation technology) fuel supply system. To investigate the durability property of core part of injector in liquid phase LPG injection system, leakage test, SEM test of injectors and analysis of unvaporized fuel components with various LPG fuel qualities were tested. The experimental results showed that no serious problem in durability test using favorable LPG fuel quality, while high leakage amount due to the large scratches in the needle and nozzle of the injector were found using LPG fuel with highly containing olefin components, especially butadiene species.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2007년도 추계 학술논문 발표대회
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• pp.91-94
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• 2007

It is essential every concrete structure should continue to perform its intended functions, that is maintain its required strength and durability, during the service life. However, deterioration occurs more progressively from the outside of concrete exposed to severe conditions. Deterioration in the concrete structure is due to carbonation and chloride ion attack. Therefore, concrete structure is needed to surface protection for increase durability using impregnant. Impregnant classify into two large groups in polymeric and silicate materials. Silicate impregnant is included silane and alkali silicate(sodium and lithium silicate). Thus, this study is concerned with carbonation and chloride ion resistance of self cleaning hydrophilic impregnant of concrete structure using lithium and potassium silicate. From the experimental test result, lithium and potassium silicate have a good properties as a carbonation and chloride ion resistance. Lithium and potassium silicate make good use of hydrophilic impregnant.

• 센서학회지
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• 제31권4호
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• pp.244-248
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• 2022

Recently, several studies on the development of superhydrophobic surfaces using various nano-sized carbon-based materials have been conducted. The superhydrophobic surfaces developed using carbon soot have advantages such as low processing cost and remarkable physical and chemical properties. However, their durability is low. To address this problem, in this study, a superhydrophobic surface with high durability and a multilayer structure was fabricated using ethanol vapor treatment. Candle soot was deposited on an aluminum substrate coated with paraffin wax, and a micro-nano multilayer structure with a size of several micrometers was fabricated via ethanol vapor treatment. The fabricated superhydrophobic surface was confirmed to have a contact angle of at least 156° and high durability. Finally, it was confirmed that ethanol vapor not only changed the nanostructure of carbon but also affected the durability of the structure.