• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.17 no.2
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• pp.32-39
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• 2008

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.17 no.2
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• pp.18-24
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• 2008

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.17 no.2
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• pp.11-17
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• 2008

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.6
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• pp.5-10
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• 2010

• Journal of Distribution Science
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• v.15 no.4
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• pp.25-32
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• 2017

Purpose - The introduction and expansion of the railway network since the 19th century brought revolutionary changes in economic activities, performance, and structure. The purpose of this study is estimating the impact of railroads on the local agricultural and manufacturing structures in the 19th century USA. Research design, data, and methodology - To identify the impact of railroads on local economic structure, county-level panel data from the U.S. census were analyzed using a panel fixed-effect differences-in-differences regression. The empirical investigation focuses on whether railroads changed the overall volume and sectoral composition of the local agricultural sector, and whether they contributed to the growth of the local manufacturing industry and its productivity. Results - The railroad introduction led to the relative decline of the agricultural sector, while encouraging the growth of market-oriented gardening. As such, manufacturing productivity increased by the introduction of railroads, although manufacturing inputs and home manufactures were unaffected. Conclusions - The findings imply that railroads contributed to the growth of market-oriented farming in rural areas, and the rise of productivity in the local manufacturing sector. Meanwhile, evidence of railroad-driven growth for the entire agricultural sector or a massive reallocation of resources from agriculture to manufacturing were not found.

• The Journal of Information Systems
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• v.18 no.1
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• pp.145-157
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• 2009

If industrial disasters happen at workplace, work's desires of workers and business activities may be dispirited. Especially, industrial disasters frequently happen in the field of heavy and chemical industry companies. According to report of the korea occupational safety and health agency(KOSHA), damage due to industrial disasters is more 5 times than losses due to industrial strifes. Thus, in these manufacturing companies, a safety management field for preventing industrial disasters is emerging as an important factor of business activities. This paper proposes an industrial disaster prediction model for safety management and also implements industrial safety management system(after this, is called as u-Safety system) based on the proposed model using ubiquitous computing technologies like USN(ubiquitous sensor networks) which are given much attention among recent information technologies. The implemented system is successfully operating in the shipbuilding division of 'H' companies.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.2 no.2
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• pp.45-51
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• 2003

The multi-piloting type progressive die for U-bending sheet metal production part is a very specific division. This study reveals the sheet metal forming process with multi-forming die by center carrier type feeding system. Through the FEM simulation by DEFORM, it was accepted to u-bending process as the first performance to design of strip process layout. The next process of die development was studied according to sequence of die development, i.e die structure, machining condition for die making, die materials, heat treatment of partially die components, know-how and so on. The feature of this study is the die development of scrapless progressive die of multi-stage through the modeling on the I-DEAS program, components drawing on the Auto-LISP, CAD/CAM application, ordinary machine tool operating and revision by tryout.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.1
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• pp.117-125
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• 2013

Variations of springback in stamped parts are induced by the uncontrollable noises including the variation of incoming material properties, lubrication and other forming process parameters. Reduction of springback variation is very important during springback compensation processes on stamping dies and assembly processes. To reduce the variation of springback, a robust optimization methodology which uses complex method combined with orthogonal array is proposed. The proposed method is applied to the robust design of U-channel die for the reduction of side wall curl. It is shown that the drawbead and die radius of U-channel draw die can be effectively optimized by the proposed method.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.12
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• pp.52-58
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• 2019

This study numerically analyzed the icing process in a U-shaped pipe exposed to the outside by considering the mushy zone of freezing water. Numerical results showed that the flow was pulled outward due to the U-shaped bend in the freezing section exposed to the outside, which resulted in the ice wave formation on the wall of the bended pipe behind. At the same time, the formation of a corrugated ice layer became apparent due to the venturi effect caused by the ice. The factors affecting the freezing were investigated, including the change of the pipe wall temperature, the water inflow velocity, and the pipe bend spacing. It was found that, as a whole, the thickness of the freezing layer increased as the pipe wall temperature decreased. It was also found that the freezing layer became relatively thin when the inflow rate of water was increased, and that the spacing of the pipe bends did not significantly impact the change in the freezing layer.

• CDE review
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• v.20 no.2
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• pp.39-48
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• 2014