• Journal of Welding and Joining
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• v.26 no.2
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• pp.75-84
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• 2008

With the development of surface roughness textured steel for automotive body-in-white assemble, one of key issues is to understand the role of the surface roughness in textured steel sheets. To investigate effect of surface roughness on weldability in prepared steels, electrode force was varied. Steel sheets (T-H) with high surface roughness ($Ra\;=\;1.94\;{\mu}m$) reduced electrode life. It was attributed to the higher contact resistance at the electrode-sheet interface in the presence of the high surface roughness. The increased electrode diameter decreased current density, therefore reducing weld electrode life due to small weld button size. When an increased electrode force was used, a significant increase in the electrode life was observed in welding of high surface roughness steel sheet. This study suggested that contact resistance at the electrode-sheet interface was the dominant factor, as compared to the sheet-sheet interface for determining electrode life in welding of surface roughness textured steel.

• Journal of Fashion Business
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• v.16 no.4
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• pp.46-63
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• 2012

This research purposed to the conceptual model with integrates the expanded task technology fit theory(TTF) and technical acceptance model(TAM) for the effect of the motivational factor of the consumer characteristics in the used the fashion mobile commerce. To fulfill the study objectives, a total of 432 questionnaires were conducted to the customers with first-hand experience with merchandise in mobile commerce. The judgement sampling method was employed on sample population ages from 20s to 30s over two month period. Based on the results of the above-mentioned path analysis, The result showed that First, the utilization experience was adopted as the have the notes effect in the and information acquisition fit, support fit, quality fit, perceived ease of use. and the innovativeness was adopted as the have the notes effect in the information support fit, perceived trust, perceived ease of use. and the self-efficacy was adopted as the have the notes effect in the and information quality fit, perceived usefulness, perceived ease of use. Second, the information acquisition fit, support fit were adopted as the have the notes effect in the perceived trust, perceived usefulness, perceived ease of use. and the information quality fit was adopted as the have the notes effect in the perceived trust, perceived usefulness. Third, the appeared similar effect which considers from all relationships such as perceived trust, perceived usefulness, perceived ease of use, acceptance attitude and purchase intention.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.986-990
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• 2004

The immunomodulatory effect of Codonopsis lanceolata based on the production of cytokines and the activation of macrophage was studied. The mRNA expression of nitric oxide synthase (iNOS) was gradually induced after 24 hr treatment of Codonopsis lanceolata, and NO production was a maximum after 24 hr treatment with 1 mg/mL. RAW 264.7 cell on in vitro treatment with Codonopsis lanceolata induced mRNA of cytokines such as interleukin-1(IL-1)${\beta}$, interleukin-6(IL-6), tumor necrosis $factor(TNF)-{\alpha}\;and\;interferon(IFN)-{\gamma}$; $IL-1{\beta}$ and IL-6 mRNA were gradually induced up to 24 hr, $TNF-{\alpha}\;mRNA$ was regularly induced up to 24 hr, and $IFN-{\gamma}\;mRNA$ level was a maximum within 1 hr. These results suggest that Codonopsis lanceolata exerts as an effective immunomodulator and enhances antitumor activity of macrophages.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.4
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• pp.305-311
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• 2012

Geology, hydrogeology, and geochemistry are the main technical siting factors of a geological repository for spent nuclear fuels. This paper focused on how rock's different geological conditions, such as topography, soils, rock types, structural geology, and geological events, influence the functions of the geological repository. In the context, the site selection criteria of various countries were analyzed with respect to the geological conditions. Each country established the criteria based on its important geological backgrounds. For example, it was necessary for Sweden to take into account the effect of ice age on the land uplift and sea level change, whereas Japan defined seismic activity and volcanism as the main siting factors of the geological repository. Therefore, the results of the paper seems to be helpful in preparing the siting criteria of geological repository in Korea.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.5
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• pp.19-27
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• 2015

The results of Saemangeum seadike field inspection and material testing of armor stones in order to analyze causes of abrasion according to material characteristics of seaside armor stones in Saemangeum seadike are in the following: 1. The armor stones in Saemangeum seadike have been constructed by using internal stones (mainly, sinsi stones) and external stones, which had less strength (77.3 %) and more abrasion rate (133.3 %) compared with sinsi stones. 2. The compressive strength and abrasion rate were compared between ordinary wave section and high wave section for the purpose of analyzing the influence of waves. In compressive strength, sinsi stones were 4.0 % stronger and external stones were 0.6 % stronger in ordinary wave section than those of high wave section in average. In the case of abrasion rate, sinsi stones were 3.0 % higher and external stones were 8.2 % higher in the high wave section than those in the ordinary section. 3. The result of comparing compressive strength according to a zone is that the compressive strength in the Intertidal area was less strong in most of the zones. 4. Considering that deviated stones are moving around over the surface of armor stones in situ, it is important to compare material characteristics. So the comparison test about this factor showed that deviated sinsi stones were stronger than armor stones in situ in terms of compressive strength and resistance to abrasion. Based on these results, abraded armor stones may have resulted from their durability. Therefore it is assumed that armor stones are likely to be abraded when deviated stones which are more durable are moving around over armor stones which are less durable.

• Journal of Welding and Joining
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• v.26 no.6
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• pp.81-91
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• 2008

The weldability of resistance spot welding of TRIP1180 steels for automobile components investigated enhance in order to achieve understanding of weld fracture during tensile-shear strength (TSS) test. The main failure modes for spot welds of TRIP1180 steels were nugget pullout and interfacial fracture. The peak load to cause a weld interfacial failure was found to be related to fracture toughness of the weld and the weld diameter. Although interfacial fracture occurred in the spot welded samples, the load-carrying capacity of the weld was high and not significantly affected by the fracture mode. Substantial part of the weld exhibits the characteristic dimple (or elongated dimple) fractures on interfacial fractured surface also, dimple fracture areas were drawmatically increased with heat input which is propotional to the applied weld current. In spite of the high hardness values associated with the martensite microstructures due to high cooling rate. The high load-carrying ability of the weld is directly associated with the area of ductile fracture occurred in weld. Therefore, the judgment of the quality of resistance spot welds in TRIP1180 steels, the load-carrying capacity of the weld should be considered as an important factor than fracture mode.

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.2
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• pp.31-44
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• 2016

This study analyzed pore water pressure, earth pressure and settlement through field monitoring on the project site in which raising embankments are being built through backside extension, and compared the behaviors of seepage analysis, slope stability analysis and stress-strain during flood water levels and rapid drawdown under steady state and transient condition. The variation of pore water pressure showed an increase during the later period in both upstream and downstream slope, with downstream slope more largely increased than upstream slope overall. The variation of earth pressure increased according to the increase of embankment heights, while the change largely showed in the upstream slope, it was slowly increased in the downstream slope. The settlements largely increased until 23 m as embankment heights increased, and showed very little settlement overall. Under a steady state and transient conditions, the seepage quantity per day and leakage quantity per 100 m of embankment against total storage were shown to be stable for piping. The hydraulic gradient at the core before and after raising embankments was greater than the limit hydraulic gradient, showing instability for piping. The safety factor of upstream and downstream slopes were shown to be very large at a steady state, while the upstream slopes greatly decreased at a transit conditions, downstream slopes did not show any significant changes. The horizontal settlements, the maximum shear strain and stress are especially distributed at the connecting portion of the existing reservoir and the new extension of backside. Accordingly, the backside extension method should be designed and reinforced differently from the cases of other types reservoirs.

• Journal of the Society of Disaster Information
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• v.8 no.3
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• pp.242-257
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• 2012

Korea's population change trend is the aging and feminization as Reduction in mortality, average life extension. and is further increased Reduction of birth rate and aging population. if Our country concluded FTA(Free Trade Agreement) with the United States, Europe and China etc. labor-intensive industries will be the decline. Then, the construction workers' jobs are continually reduced. This is critical to the nation's economic, social and environmental influences due to Shortage of construction workforce and increasing labor costs. Eventually this is a major factor in reduced construction productivity. Therefore, this study is presented as a construction productivity development prospects on the value-added analysis per Labour productivity employee from Construction market trends, industry-specific productivity index, industry trends Employed, age tiered workforce trends, women's workforce trends, labor time trend, foreign workers, workforce trends, analysis of trends in construction contract, awarded by Company Size trends, construction management analysis index.

• Journal of Engineering Education Research
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• v.9 no.1
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• pp.43-60
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• 2006

This study was examining and analyzing the perception and significance for engineering teaching objectives and strategies designed for students. The optional sampled method with various levels was applied to all the junior students at college of engineering in Jeola North Province. The five applied universities were again divided into three divisions. The result of this study was as follows ; First, according to the analysis of students' conception about the significance degree of good education suitable for engineer and a number of a community, leaner's attitude and opinion learning were more important than any other instruction objectives. Second, according to the other analysis regarding to the significance degree of instruction objectives and methods, the teaching of technical operation was thought more important than any other instruction objectives. Overall, this study showed that the significance degree of instruction objectives and teaching strategies of engineering education had a little difference according to a various factor but they were arranged from three points (importance) and four points (very importance).

• The Journal of Engineering Geology
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• v.18 no.3
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• pp.287-295
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• 2008

Rock slope has a variety of irregular discontinuities and represents a discontinuous mass. Rock joint plays an important role of control hydraulic and mechanic movements in the rock mass. These characteristics between hydraulic and mechanic movements at the rock joints could be represent difference. Therefore they are quiet important factor for slope design. In this study the weathered rock slopes were carried out to analysis of slope stability and geophysical survey. The electrical resistivity survey with dipole-dipole array conducted five profiling sites, and SWEDGE and SLIDE for slope stability analysis were applied on 20 rock slopes far assessment of slope stability and understand to geological situations due to the weathering.