• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.157.1-157.1
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• 2016

In this work, we experimentally investigated the solar absorption performance of Cu-based scalable nanostructured surfaces and compared their performance with the conventional TiNOX. We fabricated Cu-based nanostructured surfaces with a controlled chemical oxidation process applicable to a large area or complex geometry. We optimized the process parameters including the chemical compounds, dipping time and process temperature. We conducted both lab-scale and outdoor experiments to characterize the conversion efficiency of each absorber surfaces with single and double glazing setup. Lab-scale experiment was conducted with $50mm{\times}50mm$ absorber sample with 1-sun condition (1kW/m2) using a solar simulator (PEC-L01) with measuring the temperature at the absorber plate, cover glass, air gap and ambient. From the lab-scale experiment, we obtained ${\sim}91^{\circ}C$ and $94^{\circ}C$ for CuO and TiNOX surfaces after 1 hr of solar illumination at single glazing, respectively. To measure the absorber performance at actual operating condition, outdoor experiment was also conducted using $110mm{\times}110mm$ absorber sample. We measured the solar flux with thermopile detector (919P-040-50). From outdoor experiment, we observed ${\sim}123^{\circ}C$ and $131^{\circ}C$ for CuO and TiNOX with 0.6 kW/m2 insolation at double glazing, respectively. We showed that the suggested nanostructured CuO solar absorber has near-equivalent collection efficiency compared with the state-of-the-art TiNOX surfaces even with much simpler manufacturing process that does not require an expensive equipment.

• Restorative Dentistry and Endodontics
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• v.29 no.5
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• pp.413-422
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• 2004

Established microleakage tests have their own disadvantages. In this study, 3D reconstruction method was tried to overcome these disadvantages. Four types of microleakage tests were used and relationships among them were estimated: penetrated dye volume: marginal adaptability: degree of dye penetration and relative penetrated length to cavity wall. Twenty-four Class V cavities were bulk filled with composite (Esthet X) following surface treatments: N group (no treatment): E group (etching only): T group (etching + Prime & Bond NT). 50% silver nitrate was used as a dye solution after thermocycling ($5^{\circ}C{\;}&{\;}55^{\circ}C$, 1.000 times). Teeth were serially ground with a thickness of 0.2 mm. Volume of dye penetration was estimated from a three-dimensionally reconstructed image with a software (3D-DOCTOR). Percentage of margin without gap was estimated from SEM and degree of dye penetration and the relative length of dye penetration to overall cavity wall were also estimated. ANOVA and Scheffe test for dye volume, Kruskal-Wallis and Mann-Whitney test for marginal quality, Spearman's rho test for checking of relationships among methods were used. The results were as follows: 1. Dye penetration could be seen from several directions, furthermore, its volumetric estimation was possible. 2. Reverse relationship was found between dye volume and marginal quality (r = -0.881/ p = 0.004). 3. Very low relationship was seen between dye volume and two-dimensional tests (degree of dye penetration and relative length). However, 2D evaluation methods showed high relationship (p = 0.002-0.054) each other. 4. Three times vertical section could be recommended as a 2D test.

• Journal of the Korean Society of Costume
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• v.51 no.3
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• pp.129-139
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• 2001

The purpose of this study is to suggest the standard size specification of the apparel item as finding out apparel products'sizing problem in the domestic and foreign interned shopping malls. Though that, to suggest basic data of web page offered sizing system given to consumer higher satisfaction and based on ISO (International Organization For Standardization), domestic industry standard and service related size. The summarized findings are as follow. 1. The result of size description research, the size description system between internet site were very different, in addition in the department shopping malls it was different by manufacturing industry. Also in domestic and foreign shopping malls, It was not correspond to ISO and domestic industry standard, used Numeric and Alphabetical size. In the foreign shopping mall it distinguish body type and age group. 2. The result of consumer's satisfaction, the superior fashion malls were Samsung, LG, Fashionpia in the domestic shopping mall, were Gap, JCPenny, Jcrew in the foreign shopping malls. In the total group, 1-5 grades were ranked in the foreign shopping malls. 3. Satisfaction of the foreign fashion mall was higher than that of the domestic fashion malls. Exactly, foreign fashion mall described size chart, size description, product size and body size measuring method but domestic fashion malls didn't describe that. Domestic fashion malls need sizing system development given to consumer higher satisfaction. In addition sizing system based on ISO and domestic industry standard and subdivided to body type and ale group must be studied. Aloe, fashion information, coordination information and product explanation must be reinforced.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.5 s.164
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• pp.753-764
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• 2007

Apparel goods can be customer-oriented in the extreme and the apparel industry is one of the most customer-centered industries that should maximize customers' satisfaction. Recently, mass customization, a customer-centered system is widely discussed in the apparel industry to provide consumers with new, differentiating, distinctive, yet personalized products. The purpose of this study is to provide useful insights for apparel brands' mass customization(hereafter, MC) implementation by comparing the apparel brands' current status with consumers' expectation. One hundred apparel brands' practitioners and 116 consumers were surveyed in this research. First, we found that, on the basis of the five stages of MC presented by Pine(1993), apparel brands' MC stages were identified. Then, customers' expectation levels were examined according to the five stages. When compared the gap between the customers' expectation level and the apparel brands' implementation, consumers' expectation of MC was significantly higher than the implementation level by apparel brands for the stage 2(customized products creation), the stage 5(modular production). Second, by conducting a factor analysis with the scales measuring the MC activities of the five stages, apparel brands' current MC strategies could be classified as 'mass customized strategy', 'quick response strategy', 'MOT(moment of truth) customized strategy', and 'individualized service strategy.' Apparel brands showed significant differences in mass customized strategy, quickresponse strategy, and MOT customized strategy according to their product characteristics. Finally, consumers' expectation level of MC strategies was significantly different by their characteristics such as shopping orientation.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.1
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• pp.87-95
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• 2012

In recent years, laser-arc hybrid welding has begun to be adopted for assembly welding of automotive bodies and parts, because the hybrid welding process can weld lapped steel sheets having a larger gap than is possible with laser welding. In this paper, to predict the twist deformation by the hybrid welding when brackets are welded in B pillar of a passenger car, the residual stress using CAE is analyzed and the deformation result of CAE is compared with the measured deformation. First of all, after modeling heat source as intended to be expressed with laser-arc hybrid welding method, heat source fitting is done with welding conditions and a section of welding part obtained through specimen test. In case of heat source functions, laser used conical source and arc used double ellipsoid source. Through the local model analysis, elements which are located in the center of the model are selected. The elements are called WME(Welding Macro Element). This WME is extruded in the welding lines and welding phenomenon of complex parts is accomplished. The deformation amount after hybrid welding is got through a simulation, the validity of simulation is verified by measuring the panel and comparing with the simulation result.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.3
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• pp.243-247
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• 2015

The characteristics of the fluid force reduction of a square prism having a small triangular prism at the upstream side was investigated by measuring of lift and drag on the square prism The experimental parameters were the width ratios (H/B=0.2~0.6) of triangular prisms to the prism width and the gap ratios (G/B=0~3) between the square prism and the triangular prism. The drag reduction rate of the square prism was increased and then decreased with G/B in case of the same H/B, and was increased with H/B in case of the same G/B. The maximum drag reduction rate was represented by 78.5% at H/B=0.6 and G/B=1.5. The lift reduction rate of the square prism was hardly not affected by the width and gaps ratios, the average value was about 52.4%.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.7
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• pp.900-908
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• 2014

The Characteristics of the flowfields of a square prism having a small vertical plate at the upstream side was investigated by measuring of fluid force on the square prism and by visualization of the flow fields using PIV. The experimental parameters were the width ratios(H/B=0.2~0.6) of vertical plates to the prism width and the gap ratios (G/B=0~3) between the prism and the vertical plate. The drag reduction rate of the square prism was increased with H/B in case of the same G/B, and was increased and then decreased with G/B in case of the same H/B. The lift reduction rate of the square prism was hardly not affected by the width and gaps ratios, the average value was about 48.1%. In case of a square prism having a small vertical plate, the stagnation regions were represented in the upstream and downstream sides of the square prism.

• The Journal of the Korea Contents Association
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• v.20 no.10
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• pp.496-509
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• 2020

This study analyzes 5-year efficiency of the game industry, from 2014 to 2018 which is aimed at 25 online and mobile game companies, that are emerging as a new growth engine of a national economy to come and as a core areas of late entertainment industry. The DEA is used for static efficiency analyze and the DEA-Window is used for dynamic efficiency analyze. This study uses assets, the number of employees and costs as input variables and it also uses operating profits and sales as output variables. The main results show that scale efficiency presents a resonable result over 0.85 on a total average except 2014. However, there has not been a year that is over 0.80 of the whole period in technical efficiency. Also, in terms of business scale, there is a huge efficiency gap between high rank companies and low rank companies and the average trend of efficiency has been increased from 2014 to 2016 but it has been decreased since 2017.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5758-5762
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• 2014

Electrostatically-actuated Micro device have been used widely in a variety of integrated sensors and actuators. Electrostatically-actuated micro devices with a gap of several micrometers or less between the electrodes have shown failure problems by electrostatic adhesion. To improve this adhesion phenomenon, micro devices of varying lengths and widths in electrodes were fabricated, and an alumina coating was then deposited using atomic layer deposition technology. The effects of improving adhesion phenomenon were compared by measuring the pull-in voltage before and after the coating process. The pull-in voltage increased with increasing length of the upper electrode after the coating. An increase in the electrode area results in an increase in the pull-in voltage after coating. The alumina coating method applied to improve the adhesion on an electrostatically-actuated micro device was observed as an effective method.

• Journal of Advanced Navigation Technology
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• v.12 no.2
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• pp.170-179
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• 2008

This study designed model that could scientifically and objectively evaluate a level of informatization of construction companies in consideration of informatization characteristics and limitations identified in researches related to the evaluation of informatization level of construction companies, so at to create the e-business environment for the construction companies including the enhancement of informatization consciousness and to improve capacity to carry out informatization. To do this, the study defined requirements to develop new model of construction informatization level and the characteristics of construction companies, and developed components of informatization level model and measuring methods that could meet the requirements based on theories and literature. The developed informatization level model were reviewed for validity and reliability through statistical method by carrying out the questionnaire survey on 200 companies along with an advisory group of experts. As the result of this study, we could suggest the directions for informatization to narrow the gap between the current level of informatization and the managerial goals in construction company.