• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.3
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• pp.30-38
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• 2015

As products using LEDs are developed actively, also there has been large request for LED products that can replace traditional lamps like fluorescent lamps and metal halide lamps. But so far there is no proper standard that manufacturer can use and test it. As a result manufacturer can't develop retrofit LED lamps and sell it even they have technology. In this study, by analyzing control gear for fluorescent lamp that is currently used in market which is magnetic or electronic ballast, I'd like to develop proper test method by investigating compatibility between all-type control gear and LED retrofit products.

• International Journal of Automotive Technology
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• v.7 no.5
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• pp.565-570
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• 2006

The development of a light-weight vehicle is in great demand for enhancement of fule efficiency and dynamic performance. The vehicle weight can be reduced effectively by using lightweight materials such as aluminum and magnesium. However, if such materials are used in vehicles, there are often instances when different materials such as aluminum and steel need to be joined to each other. The conventional joining method, namely resistance spot welding, cannot be used in joining different materials. Self-piercing rivet(SPR) and adhesive bonding, however, are good alternatives to resistance spot welding. This paper is concerned with the crushing test of double hat-shaped member made by resistance spot welding, SPR and adhesive bonding. Various parameters of crashworthiness are analyzed and evaluated. Based on these results, the applicability of SPR and adhesive bonding are proposed as an alternative to resistance spot welding.

• Toxicological Research
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• v.26 no.1
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• pp.61-66
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• 2010

Retinoids have many beneficial effects on dermatological applications. But, retinoids cause skin irritation. In this study, the safety of retinoids was clarified via both primary skin irritation test in rabbits and sensitization study using an integrated model for the differentiation of chemical-induced allergic and irritant skin reaction (IMDS), an alternative method to sensitization test. The effects of retinoids on the change of ultraviolet A (UVA)-induced matrix metalloproteinase-1 (MMP-1) in human skin fibroblasts and the modulation of type-1 pN collagen synthesis in hairless mice were examined to clarify the anti-wrinkle effects. Alltrans retinol (t-ROL) and its derivative, all-trans retinoic acid (t-RA), showed mild skin irritation but did not induce the sensitization. t-ROL and t-RA exerted anti-wrinkle effects by inhibiting the UVA-induced MMP-1 in human skin fibroblasts and increasing the type-1 pN collagen synthesis in hairless mice. These findings suggest that retinoids do not induce the allergy, and show anti-wrinkle effects by decreasing MMP-1 activation and increasing collagen synthesis.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.874-877
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• 2000

Pre-coated sheet materials are a cost-effective and environmentally attractive alternative to conventional sheet materials coated after forming. At present but the high scratch sensitivity of coating used for pre-coated metal sheet is a major limitation to use of these materials. Because of high scratch sensitivity, products made by pre-coated metal sheet are not formed by conventional design method. This study has been performed to investigate scratch characteristic of non-vinyl pre-coated metal (PCM) sheet. Using the simple U-bending test equipment, three non-vinyls PCM's were tested. This paper provides the results of bending tests showing the influence of sheet surface texture, tool material and process conditions. It was found that the influence of punch, die clearance and tool material had an effect upon the scratch characteristic.

• The Journal of Korean Academic Society of Nursing Education
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• v.21 no.1
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• pp.86-94
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• 2015

Purpose: The purpose of this study was to compare practice stress and practice satisfaction between clinical practice and simulation-based practice groups. Methods: A total of 159 nursing students (85 in the simulation group and 74 in the NICU group) participated in the study. Research tools measuring practice stress and practice satisfaction were used. Data was analyzed utilizing a t-test, Mann Whitney U-test, and descriptive statistics. Results: The simulation group showed a lower level of practice stress(practice instruction, practice evaluation, interpersonal relationship) a higher level of practice satisfaction compared with the NICU group. Conclusion: Simulation-based practice is an effective learning method for high-risk newborn nursing and can be used as an alternative to clinical practice.

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3145-3150
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• 2010

Ruthenium catalysts modified by selenium have been introduced as alternative materials to Pt in Direct methanol fuel cells (DMFCs). RuSe nano-particles were synthesized on the Vulcan XC72R carbon supports via polyol method. The prepared catalysts were electrochemically and physically characterized by cyclic voltammetry (CV,) linear sweep voltammetry, methanol tolerance test, X-ray diffraction (XRD), Transmission electron microscopy (TEM), Energydispersive Spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS). Increasing the Se concentration up to 20 at % increased the electro-catalytic activity for the oxygen reduction. By increasing Se amount, Ru metallic form on the surface was increased. The $Ru_{80}Se_{20}$/C catalysts showed the highest oxygen reduction reaction (ORR) activity and outstanding methanol tolerant property in half cell tests as well as single cell test.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.10
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• pp.1-6
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• 2015

As lamps using LEDs are developed actively, also there have been large request for LED lamps that can replace traditional lamps like fluorescent lamps and metal halide lamps. But so far there are no proper standards that manufacturer can use and test their lamps. As a result of this, manufacturers are not only unable to develop LED lamps but also sell it even though they have technology. In this study, It is proposed that proper test method by investigating compatibility between all-type control gear and LED lamps by analyzing control gear for fluorescent lamp such as magnetic or electronic ballast that is currently used in the market.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.4
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• pp.305-310
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• 2012

Through our entire life, oral care products such as toothpaste are used. Thus the safety of oral care products used every day to our mouth is very important. As the previous study in animal tests or clinical trials, surfactant in toothpaste may cause the oral irritation. However, EU cosmetics legislation prohibits animal testing of cosmetics and its ingredient for animal welfare. Therefore the development of alternative in vitro test has been actively performed to replace or reduce using the animal in many areas. However, the way to evaluate oral mucosal toxicity has been done using animal models or clinical trials from now on. Even more, the experiment with human oral 3D tissue or human oral cell line is used recently. The aim of this study is the development of oral mucosal irritation method without using animal for the safety of the oral care product. We developed in vitro test method for oral irritation by using human oral cell line (YD-38 cell) acceptable to toothpaste which contains insoluble material. By the results of this assay, we could discriminate toothpaste with or without irritating substance as same manner in animal studies reported previously. In addition, we confirmed that toothpaste for babies and children toothpaste irritated oral musoca lower than the general adult toothpaste. The present study suggest that this new in vitro method by using human oral cell line (YD-38 cell) could be used for evaluation of oral irritation without using animal.

• Journal of Broadcast Engineering
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• v.23 no.1
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• pp.63-73
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• 2018

These days, VR contents are created in three ways: CG based method, game engine based method, and live action shooting method. The most universal method is live action shooting. So far, most live actions are shot with action cams. Therefore, this method is different from professional image production method for movies and TV dramas. This study tries to point out the difference between professional image production method and action cam based shooting method, and proposes an alternative. The proposed method is log shooting based HDR filming and editing. As the result of test shooting and editing, the proposed method was able to obtain more color information than conventional action cam based shooting method and thereby to implement high-definition images which are hard in an action cam.

• Journal of the Korean GEO-environmental Society
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• v.18 no.10
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• pp.15-22
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• 2017

The soil improvement method so far has been developed with an emphasis on enhancing the strength of the ground. A soil improvement method using a excellent cementitious stabilizer in economical efficiency and handling property is mainly used. The soil improvement method using cementitious stabilizer is effective but environmental and human harmful substances are detected and environmental problems such as carbon dioxide emission and groundwater pollution are pointed out. Therefore, as part of an alternative method capable of solving such problems, researches on the soil improvement method incorporating biological technology are being actively carried out. This study was conducted to investigate the characteristics of strength change when mixed with environmentally friendly soil binder and microorganism in clay, and it was analyzed by uniaxial compression test, direct shear test, SEM, XRD. As a results of the test, we confirmed the cementation caused by microbially induced calcite precipitation and the strength increase enhancement by it.