• Korean Journal of Human Ecology
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• v.9 no.1
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• pp.33-45
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• 2000

The handle were observed by objective and subjective method as the washing was repeated for 4 kinds(sample A, B, C, D) of materials which have different water vapor transmission, and the change of water vapor transmission each others. The results of factor analyses for 18 polar adjective words on subjective handle test yielded 4 factors, that were 'elastic property', 'surface property', 'thickness and weight property' and 'thermal and rigid property'. The surface properties were deteriorated remarkably as washing was repeated and significant difference were observed. Compared with the primary hand value for each materials, the statistical difference of samples was shown at Koshi and Fukurami measured by the KES-FB system. Koshi decreased for all the materials after repeated washing, and Fukurami had a tendency to increase for all the materials in proportion to repeated washing. Significant difference of total hand value wasn't shown in repeated washing number, but in fabric types.

• Journal of Electrical Engineering and Technology
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• v.8 no.5
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• pp.1169-1174
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• 2013

The objective of this work was to increase the efficiency of ultraviolet-light emitting diodes at 375 nm for sterilization. Since $TiO_2$ had antibacterial properties, which were attributed to the appearance of hydroxyl radicals and superoxide radical anions on the surface species under ultra violet radiation at about 387 nm, photo-reactive layers such as Ag-doped $TiO_2$ were coated on aluminum substrates by electrostatic spraying. Crystallinity and surface morphology of the coating layer were examined by X-ray diffraction ${\theta}-2{\theta}$ scan and field emission-scanning electron microscope, respectively. In an antibacterial test, we observed above 99% reduction of Escherichia coli populations on 3 or 5 mol% Ag-doped $TiO_2$ layers after irradiation for 2 hrs at 375 nm, while very low inactivation on bare aluminum substrates occurred after irradiation as the same condition.

• Journal of Sensor Science and Technology
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• v.28 no.6
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• pp.371-376
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• 2019

We have developed an acoustic resonance inspection system to inspect the welding defects in the mechanical parts fabricated using friction stir welding method. The inspection system was consisted of a DAQ board, a microphone sensor, an impact hammer, and controlled by a PC software. The system was developed to collect and analyze the sound signal generated by hitting the sample with an impact hammer to determine whether it is defective. In this study, 100% welded good samples were compared with 95%, 90%, and 85% welded samples, respectively. The variation of the completeness in welding did not affect the visual appearance in the samples. As a result of analyzing the natural frequencies of the good samples, the five natural frequency peaks were identified. In the case of the defective samples, the frequency change was observed. The welding failure detection time was fast enough to be only 0.7 seconds. Employing our welding defect inspection system to the actual industrial field will maximize the efficiency of quality inspection and thus improve the productivity.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.5
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• pp.922-932
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• 1997

Blue jeans are finished with stonewashing process to give it optimal softness and color contrast of blue and white. So, Yellowing may well be generated during storage or use and thereby, their appearance may be damaged much. So, this study was aimed at finding the solutions to reduce the yellowing problem caused by residual metals after stonewshing. To this end, sample blue jeans were made to be finished with various methods of wet-treatment and then, be subject to daylight to check their photoyellowing. The results of this test can be summarized as follows; Since the stonewashing process was found to affect the yellowing, the residual metals of stone- washed blue jeans was analyzed. And it was found that it contained such residual metal as Al, Ca, Cu, Ti, Si, K and Zn. In particular, it was conceived that Al was a prime cause affecting the yellowing. Meanwhile, when the blue jeans were treated by the metal ionchelating agent of EDTA-2Na, the residual levels of Al and Ti were reduced by about 50%, while the photoyellolving was lowered by 75%, which is suggesed that EDTA is very effective in preventing the yellowing. On the other hand, when the blue jeans were bleached by the hypochlorite, chlorine remained in blue jean accelerated the yellowing. However, when this blue jean was treated again by the sodium thiosulfate for its dechloridization, the residual of chlorine was reduced, and the yellowing was lowered by about 43%.

• Journal of Powder Materials
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• v.10 no.6
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• pp.415-421
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• 2003

The study for producing the flake powders by milling of aluminum foil and gas atomized powders was carried out. The effects of lifter bars on the ball motions and milling of aluminum foils were also investigated. The aluminum foils were laminated each other, elongated, fragmented into small foils and finally formed into the flake powders during the dry ball-milling. The spherical atomized-powders were milled to coarse flake powders with high aspect ratio and then changed to fine flake powders with lower aspect ratio. Even though long times were required for making flake powders by milling of foils, the water covering areas of them were higher than those of powders milled using gas-atomized powders, suggesting aluminum foils were more plastically deformed by micro-forging. On the other hand, as the number of lifter bars increased, the necessary rotation speeds of milling jar for cascading mode and cataracting mode decreased drastically. It was possible to achieve same quality of milled flake powder by using the lifter bars under the lower milling speeds. The painting test showed that the appearance of painted surface was good and optimum content range of aluminum paste in car paint to maximize the degree of gloss was 3-5%.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.91-91
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• 2011

The quality of the surface layer in concrete structures plays an important role in the durability of the concrete. The concrete factory products are made as they improve the appearance of the surface and compressive strength in need. A common criterion to judge the quality of concrete products frequently seen in our daily life appears to be "beauty" in terms of consistent shaping. However, as for most concrete curb in such areas where a large amount of anti-freezing agents(NaCl) and ice and snow melting agents(CaCl2) are spread over roads to ensure road safety during the winter season, since deterioration advances from the surface, scaling is seen on the surface concrete due to deterioration which combined freezing damage and salt damage. Especially, In cold northern districts, the spreading amount of deicing salts increases by regulation of studded tire use, and the scaling of the concrete products, the various parts of concrete structures for roads is increasing in recent years. In this study, L-shape concrete curb were targeted, the permeable form method with the commercial permeable sheet was applied to it and the improvements of the quality were examined. By the permeable form method, surface layers got strengthened, which prevented permeation of the deterioration factor from the outside, and the scaling resistance of the upper surface where the permeable sheet was applied improved exceedingly. It will be expected by applying the permeable form method to various concrete products that frost resistance improves and scaling damage decreases.

• Journal of the Korean Society of Industry Convergence
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• v.19 no.1
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• pp.42-49
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• 2016

This study proposes a non-contact inspective technology based robot vision system for Faulty Inspection of welding States and Parts Shape. The maine focus is real time implementation of the machining parts' automatic inspection by the robotic moving. For this purpose, the automatic test instrument inspects the precision components designator the vision system. pattern Recognition Technologies and Precision Components for vision inspection technology and precision machining of precision parts including the status and appearance distinguish between good and bad. To perform a realization of a real-time automation integration system for the precision parts of manufacturing process, it is designed a robot vision system for the integrated system controller and verified the reliability through experiments. The main contents of this paper, the robot vision technology for noncontact inspection of precision components and machinery parts is useful technology for FA.

• Korean Journal of Human Ecology
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• v.22 no.6
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• pp.659-672
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• 2013

Nowadays, sports and outdoor market has been popular and expanding since the implementation of the five-day workweek and change of lifestyle. Outdoor clothing considered exclusive property of the middle-aged individuals in the past. Recently there is a drift towards having outdoor looking at the age of 10-20. The purpose of this study was to analyze the features of purchasing behaviors and demographics by each groups targeting middle school and high school students. The study was conducted with questionnaires towards people who live in the city of Busan and who have experiences of buying outdoor clothing. Data analysis was conducted via SPSS 18.0 with factor analysis, cluster analysis, ANOVA, cross tabulation, frequency analysis and Duncan's multiple range test. The results showed that there were five factors sought for outdoor wear benefits: Individuality/Fashion, Brand, Attractive appearance, Economic value, Comfort/Functional. Cluster analysis showed that there were four groups of outdoor wear benefits sought. Overall, the four groups were different in regard to purchasing behaviors and demographics. Based upon the results mentioned above, this study summarizes the key features of each group and can provide applicable suggestion for conducting strategic marketing activities.

• Korean Journal of Human Ecology
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• v.16 no.6
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• pp.1211-1221
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• 2007

To provide the basic information of the brassiere development for women with poor breast, we performed the survey on their wearing habits for brassieres by comparing the poor breast type women and the normal breast type women. Also, to suggest the advanced design methods for the mould brassiere for the poor breast women, we conducted the subjective wear test of commercial mould brassieres and measured the local thickness for mould cup under various loads. As the results, the good fitness of cup and wire, the natural wear silhouette, and the adaptation of soft and stretchy material for mould cup were very important to design the comfortable brassiere for the poor breast type. The good-fitness of upper cup was the key factor for the satisfactory wear appearance of brassiere and the cup should be designed not too thick at the upper and the bust point regions.

• Journal of Applied Reliability
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• v.16 no.2
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• pp.104-109
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• 2016

Purpose: The purpose of this study is to analyze fracture behavior and failure mechanism of porous titanium for dental implant fabricated by space holder process. Method: Three porous titanium specimens with a specific volume fraction of open pore were test by 3 point bending and compression stress condition, respectively. Fracture appearance was observed by scanning electron microscope and discussed in relation with oxygen content. Results: For compression-tested specimens, two specimen showed brittle failure, while the other one showed normal failure after deformation. High oxygen content was detected in the brittle-fractured specimen. Several micro-cracks initiated at the struts propagated down to the bottom of the specimen resulting in normal failure. Conclusion: Oxygen contamination during the fabrication process can leads brittle premature failure, and hence quality problem of the porous titanium for dental implant.