• Journal of Welding and Joining
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• 제31권4호
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• pp.1-6
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• 2013

Nowadays, the weight lightening of automotive is required as conserving the environment has become a major worldwide issue. To solve this issue, various researches for the use of light materials(Alalloy, Mgalloy)and ultra high strength steel as substitutes of the current structural material have been carried out. Application of laser stitch welding to the assembly of automotive produces improvement in strength, lightening of body, higher fuel efficiency, lower production cost as well as reduction in assemble line due to its fast welding speed, superior accessible and weld quality. This process overcomes the shortcomings of the current resistance spot welding such as high electricity consumption, electrode replacement, and economical, technical limitation in design and production method of automotives.

• Spatial Information Research
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• 제21권6호
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• pp.1-9
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• 2013

Recently, Construction information is being changed from CAD to BIM, and GIS is extending from outdoor to indoor information. In these circumstances, the needs of continuous use of construction information linked with GIS are growing constantly in stages of maintenance, operation and service as well as planning, design and construction. To this end, it is essential element to represent 3-dimensional large object efficiently in establishing BIM-GIS interoperability platform by combination of construction and spatial information. In this study, we design spatial data LOD for making spatial object and texture by level, and develop weight lightening algorithm of large spatial object.

• Journal of the Society of Cosmetic Scientists of Korea
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• 제23권3호
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• pp.86-91
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• 1997

Some natural polyhydroxy aromatic compounds have inhibitory activity against tyrosinase, key enzyme for formation of melanin pigment. We examined the structure-activity relationship of the natural polyhydrowy aromatic compounds and synthesized a number of new derivetives through various methods. Skin lightening effects of these compounds were examined through inhibition of mushroom tyrosinase and inhibitory of melanogenesis on B-16 melanoma cells. These new compounds showed strong inhibitory activity against tyrosinase. Good lightening effects sue to inhibition of melanogenesis were observed from several resorcinol and pyrogallol derivatives. In toxicological tests such as skin primary irritation and sensitization, the above compounds were sufficiently safe for cosmetic use.

• Proceedings of the Korean Institute of Building Construction Conference
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• 한국건축시공학회 2015년도 추계 학술논문 발표대회
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• pp.141-142
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• 2015

This literature study is focused on the improvement of lightweight concrete in perspective of foaming agent. Lightweight concrete is the cured concrete as putting required amount of foaming agent to slurry which is a mixture of a certain amount of cement, sand, and water. It has lower density than general concrete, because foaming agent disintegrates numerous bubbles evenly and independently. Thus, it is capable of lightening the weight and great for sound absorption and insulation, In foreign countries, studies for structural lightweight concrete mainly of tunnel grouting and weight lightening of heavy structures are going along actively. Domestically, exterior panel and ALC blocks are alternatively used for flooring. Therefore, this research consider improvement of lightweight concrete in perspective of foaming agent with foundation study.

• Journal of the Korean Society of Manufacturing Process Engineers
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• 제12권4호
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• pp.55-60
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• 2013

In this study, mechanical properties of versatile light weight plywood(manufacturing using piercing) are studied. A credibility evaluation was carried out for different perforation patterns including octagonal shape, rectangular shape and circular shape. A static structural analysis is conducted to find the stresses produced. Circular perforations are found to have better strength to weight ratio. Results of each type of perforation are discusses and compared.

• Journal of the Korean Professional Engineers Association
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• 제29권3호
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• pp.87-93
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• 1996

Lightening is a phenomenon in which electric charges accumulated in the air due to a strong ascending air current are instantly discharged. As the air current rises, the steam in the air turns into hail and grows to a certain size. Thunderclouds brought together by the ascending air current when the earth's surface is heated by strong summer sunlight produce what are called heat thunderstorms. Compared to transistors and IC's that operate at several volts, lightening induces voltages of from several 100 to several 10,000 volts and sometimes causes great damage, such as destroying equipment or delaying communication. The following describes the cause of lighting damage and basic idea behind countermeasures against such damage.

• Proceedings of the KIEE Conference
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• 대한전기학회 1998년도 하계학술대회 논문집 D
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• pp.1459-1461
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• 1998

This paper provides the results of analysis of lightening arrester failed in the field. XRD was used for qualitative analysis and SEM for microstructure analysis of zinc oxide (ZnO) block. The failure of lightening arrester might occur due to the following reasons: the uneven size of zinc oxide grains and cement layers. the re-crystallization of zinc oxide grains resulting from electrical stress around impurities, and the presence of too large pores($\simeq$ 50 ${\mu}m$).

• Asian-Australasian Journal of Animal Sciences
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• 제19권6호
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• pp.905-908
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• 2006

The purpose of this research was to study the effects of kefir whey (kefir whey, peptides, lactic acid) on skin care properties including skin lightening effect and acne treatment. The final aim was to develop a new cosmetic product and enhance the value of dairy products. The results of skin lightening tests showed that all three kefir whey components (kefir whey, peptides and lactic acid) had inhibitory ability against melanin synthesis. Furthermore, copper chelating analysis demonstrated that both kefir whey and kefir whey peptides could chelate the copper in tyrosinase, which might explain the mechanism of inhibition. The ability for acne treatment indicated that lactic acid level higher than 60 mg/ml could inhibit the growth of Propionibacterium acne, whereas no inhibition was found with other components.

• Corrosion Science and Technology
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• 제6권5호
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• pp.245-250
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• 2007

Recently, to avoid global warming, reduction of $CO_2$ generation has been demanded. Each car manufacture takes positive actions for improvement in fuel consumption by various kinds of countermeasures, e.g. improving engine efficiency, using alternative fuels, lightening the car body. Regarding lightening of the car body, aluminum alloys and high tensile strength steels has been gradually adopted as lightweight materials. However, such materials are normally not easy to be treated with zinc phosphate system. Focusing the pre-treatment processes, low temperature phosphate system could be demanded for energy saving. This time, new surface conditioning process for lightweight materials and low temperature phosphate system shall be discussed.

• The Transactions of The Korean Institute of Electrical Engineers
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• 제67권6호
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• pp.702-707
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• 2018

In case of Lighting occurs in Domestic combined distribution line, normally the voltage for the neutral line increase dramatically. General connection for underground cable is bundled common earth type so the lightning over voltage increase at the concentric-neutral line is not big enough to give impact on cable sheath. But in case of Non bundled common earth type it is necessary to analyze the phenomena on cable sheath caused by lightening overvoltage. Especially pole and cable joint are the core factor to consider. In this paper concrete pole and cable joint were evaluated in case of Non bundled common earth type combined distribution Line. EMTP simulation model has been designed and several case study were made. Also several experimental test were made to verify the simulation result.