• Coupled systems mechanics
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• v.5 no.3
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• pp.269-283
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• 2016

A two new high-order shear deformation theory for bending analysis is presented for a simply supported, functionally graded plate with porosities resting on an elastic foundation. This porosities may possibly occur inside the functionally graded materials (FGMs) during their fabrication, while material properties varying to a simple power-law distribution along the thickness direction. Unlike other theories, there are only four unknown functions involved, as compared to five in other shear deformation theories. The theories presented are variationally consistent and strongly similar to the classical plate theory in many aspects. It does not require the shear correction factor, and gives rise to the transverse shear stress variation so that the transverse shear stresses vary parabolically across the thickness to satisfy free surface conditions for the shear stress. It is established that the volume fraction of porosity significantly affect the mechanical behavior of thick function ally graded plates. The validity of the two new theories is shown by comparing the present results with other higher-order theories. The influence of material parameter, the volume fraction of porosity and the thickness ratio on the behavior mechanical P-FGM plate are represented by numerical examples.

• Journal of the Korea Fashion and Costume Design Association
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• v.4 no.1
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• pp.143-153
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• 2002

Fashion has been analyzed and explained in diverse ways. Fashion, like every phase of culture, is a reflection of the Zeitgeist. In order to understand the changing fashion we must understand the changing society. For fashion of a period are expressions of the interrelation of the various elements of the culture, including the social and political values, the economic and industrial progress, art, the development of technology, etc... Particularly fashion is closely connected with a style of art. In a style of art, futurism focused on the "dynamism" resulting from super-speed and high-technology. This study aimed to review literatures, fashion magazines, web-site in order to know how the dynamism of futurism is expressed in modern fashion. The results of this study were as follows; 1. Dynamism was expressed by means of lines, colors, patterns through the eyesights visually. Asymmetrical oblique lines, zig-zag lines or bold cutting expressed the mechanical and offensive dynamism. In contrast, such lines as curves and spirals expressed the soft and natural dynamism. Primary colors or complementary contrast expressed energetic and rhythmical dynamism. The geometrical patterns and automobile wheels patterns expressed dynamism resulting from mechanical aesthetics. 2. Dynamism was expressed through repeat of lines, colors, patterns, and textiles. Particularly Vinyl material, fluorescent material, metallic material, beads, and spangle expressed a strong dynamism. On the other hand, natural materials, paper and other similar ones are used to signify the orientation towards a futuristic high-technology society.y society.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.4
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• pp.303-308
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• 2004

We isolated a novel lactic acid bacterium from a Korean traditional fermented food, soybean paste. The newly isolated strain, dubbed RKY2, grew well on glucose, sucrose, galactose, and fructose, but it could not utilize xylose, starch, or glycerol. When the partially amplified 16S rDNA sequence (772 bp) of the strain RKY2 was compared with 10 reference strains, it was found to be most similar to Lactobacillus pentosus JCM $1588^T$, with 99.74% similarity. There-fore, the strain RKY2 was renamed Lactobacillus sp. RKY2, which has been deposited in the Korean Collection for Type Cultures as KCTC 10353BP. Lactobacillus sp. RKY2 was found to be a homofermentative lactic acid bacterium, because its end-product from glucose metabolism was found to be mainly lactic acid. It could produce more than 90 g/L of lactic acid from MRS medium supplemented with 100 g/L of glucose, with 5.2 g $L^-1$ $h^-1$ of productivity and 0.95 g/g of lactic acid yield.

• Fire Science and Engineering
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• v.16 no.1
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• pp.51-59
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• 2002

Manifold physical properties of PASCON cable trough were evaluated, and its suitability of domestic test for flammability of plastic materials was examined. Particularly, suitability of PASCON material was investigated through study on the legal propriety of PASCON cable trough used for highspeed rail line and on a fire safety. As results, domestic test for flammability of PASCON cable trough material(KS M3015) was similar to UL 94 flammability testing and from the test outstanding capability of PASCON cable trough material was proved. Besides, possibility of fire enlargement would be very low in case of fire in PASCON cable trough installed around train express. Also, fire safety of PASCON cable trough was shown to be credible.

• Journal of Welding and Joining
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• v.30 no.2
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• pp.76-80
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• 2012

In this study, the effect of the welding current on the hardness characteristics and microstructure in the resistance spot welding of 1GPa grade cold-rolled DP steel was investigated, Also, correlation between the hardness and microstructure was discussed. In spite of the change in the welding current, the hardness distributions near weld was similar. the hardness in the HAZ and the fusion zone was higher than that of the base metal and the hardness in the fusion zone was variated with the location. Especially, the hardness of HAZ adjacent to the base metal showed maximum value, and softening zone in the base metal adjacent to HAZ was found. With the increasing of welding current, there were no difference in maximum hardness and average hardness in the fusion zone were, but the hardness of the softening zone reduced. The difference in the hardness in each location of weld due to grain size of prior austenite. The softening of the base metal occurred by tempering of the martensite.

• Korean Journal of Materials Research
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• v.26 no.5
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• pp.266-270
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• 2016

Glass-ceramics were developed many years ago and have been applied in many fields such as electronics, chemistry, optics, etc. Much is already known about glass-ceramic technology, but many challenges in glass-ceramic research are still unresolved. Recently, large amounts of slag have steadily increased in the steel industry as by-products. To promote recycling of industrial waste, including steel industry slags, many studies have been performed on the fabrication of basalt-based high-strength glass-ceramics. In this study, we have fabricated such ceramics using various slags to replace high performance cast-basalt, which is currently imported. Glass-ceramic material was prepared in similar chemical compositions with commercial cast-basalt through a pyro process using slags and power plant by-product (Fe-Ni slag, converter slag, dephosphorization slag, Fly ash). The properties of the glass-ceramic material were characterized using DTA, XRD, and FE-SEM; measurements of compressive strength, Vicker's hardness, and abrasion were carefully performed. It is found that the prepared glass-ceramic material showed better performance than that of commercial cast-basalt.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1231-1238
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• 2010

Recently, the utilization of recycled aggregates for backfilling a power transmission pipeline trench has been increasing due to the issues of eco-friendly construction and shortage of natural aggregate resource. It is important to investigate the physical and thermal properties of the recycled aggregates that can be used as a backfill material. This study presents the thermal properties of two types of recycled aggregates with various particle size distributions. The thermal properties of the recycled aggregate were measured using the transient hot wire method and the probe method after performing the standard compaction test using an automatic compactor. Similar to silica sand, the thermal resistivity of the recycled aggregates decreased when the water content increased. This study shows that the recycled aggregate can be a promising backfill material substituting for natural aggregate when backfilling the power transmission pipeline trench.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.3
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• pp.241-246
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• 2012

A layered planer SOFC module was designed from planar-type SOFC. It was prepared by multi-layered ceramic technology. To form the cathode and the anode in the layered structure, reliable channels should be made on the both side of electrolyte perpendicularly. However, monolithic SOFC using multi-layered ceramic technology hasn't been studied another group, and the warpage of electrolyte in the channel, also, hasn't been studied, when electrode is printed on the electrolyte. In this study, the channels are prepared with electrode printing, and their warpage are evaluated. In the case of YSZ without electrode, the warpages are nothing in the limit of measurement using optical microscope. The warpage of 'YSZ-NiO printed' increases than that of 'NiO printed', and also, the case of 'double electrode printed' is similar to 'YSZ-NiO printed'. It is thought that, in the printed electrolyte, the warpage is related to the difference of the sintering behavior of each material.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.5
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• pp.353-360
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• 2012

As semiconductor device technology continuously shrinks, low-open area etch process prevails in front-end etch process, such as contact etch as well as one cylindrical storage (OCS) etch. To eliminate over loaded wafer processing test, it is commonly performed to emply diced small coupons at stage of initiative process development. In nominal etch condition, etch responses of whole wafer test and coupon test may be regarded to provide similar results; however, optical emission spectroscopy (OES) which is frequently utilize to monitor etch chemistry inside the chamber cannot be regarded as the same, especially etch mask is not the same material with wafer chuck. In this experiment, we compared OES data acquired from two cases of etch experiments; one with coupon etch tests mounted on photoresist coated wafer and the other with coupons only on the chuck. We observed different behaviors of OES data from the two sets of experiment, and the analytical results showed that careful investigation should be taken place in OES study, especially in coupon size etch.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.3
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• pp.39-44
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• 2018

The automotive headrest is intended to provide comfort, safety, convenience and durability to a vehicle's passengers and driver. In this study, impact and fatigue analyses were carried out for three headrest shape models-A, B and C. These models have the same material properties and the same force was applied to them. Impact and fatigue analyses demonstrated that all of the models obtained almost the exact same result values. This study found that all models had similar equivalent stress, deformation, fatigue life and main damage parts due to the fact that the shared same material properties. Better safety and fatigue life can be anticipated by changing the material of the headrest in order to secure more stable safety. An automotive headrest optimized for safety and durability is thought to have been developed through the impact and fatigue analyses of this study.