• Management Science and Financial Engineering
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• v.16 no.2
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• pp.99-114
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• 2010

The influencing factors of large-scale IT investment decisions are rarely investigated in an empirical perspective. We find out different behaviors in IT investment decisions according to the size of organization. Large scale IT-investment decisions (e.g. system downsizing) can be the outcome of decision-makers' motivation to adopt and control new IT systems- However, this phenomenon is salient in the large-sized organization rather than small-sized ones. Based on our investigation, we predict general IT decision-making behaviors in organizations when making IT investment decisions.

• Journal of Power System Engineering
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• v.19 no.5
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• pp.80-85
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• 2015

The unsteady-state, incompressible and three-dimensional large eddy simulation(LES) was carried out to analyze the structure of turbulent flow fields according to the operating loads of three-dimensional small-size axial fan(SSAF). LES shows the best prediction performance in comparison with any other Reynolds averaged Navier-Stokes(RANS) method because static pressure coefficients analysed by LES show a little bit larger than measurements including all flow coefficients. Also, it can be known that the wake of SSAF is divided into from axial flow to radial flow before and behind stall region according to the increase of static pressure through LES analysis.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.362-365
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• 2000

Rapid Prototyping(RP) techniques have revolutionized traditional manufacturing methods. These techniques allow the user to fabricate a part directly from a conceptual model before investing in production tooling and help develop new models with significant short time. This paper suggests to new process to manufacture large size hollow shape parts for prototype-car using Rapid Prototyping technology and Vacuum Molding with the reduction of delivery time. In addition, This paper introduces the dividing and combining method to make large size RP master model in spite of the limit of the build chamber dimensions of commercialized RP system and post-processing method to achieve sufficient surface quality.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.5
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• pp.96-102
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• 2004

In this study, we have developed the simulation tool in order to investigate driving trajectory of AGV for container transport. AGV for container transport is different from the indoor AGV in that it is a large size structure at being loaded the weight of 40 ton. and AGV for container transport is applied to front wheel steering, rear wheel steering, all wheel steering, and crap steering. Therefore, we have developed the simulation tool considering dynamic problems and a center of turning in accordance with fourth ways of steering mode. As the result of this study, we have confirmed that this tool is useful and cost-effective in the dynamic analysis or large size vehicles. Also, it is useful to calculate the minimum radius of turning for large size vehicles.

• Journal of Power System Engineering
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• v.20 no.6
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• pp.64-70
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• 2016

The unsteady-state, incompressible and three-dimensional large-eddy simulation(LES) was carried out to evaluate the vorticity distribution of a small-size axial fan(SSAF). The X-component vorticity profiles developed around blade tips turn from axial to radial, and diminish the density of distribution according to the increase of static pressure. Otherwise, the Z-component vorticity profiles evenly develop at the region larger than the half radial distance of blade at the operating points of A and B, partly at the trailing-edge region of blade and radially over bellmouth according to the increase of static pressure.

• Journal of Power System Engineering
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• v.21 no.2
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• pp.57-63
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• 2017

The large-eddy simulation(LES) was carried out to evaluate the drag and static pressure acting on the blade surface of a small-size axial fan(SSAF) under the condition of unsteady-state, incompressible fluid and three-dimensional coordination. The axial component of drag coefficient increases with the increase of operating load, but the radial components have negligible sizes regardless of operating loads. Otherwise, the static pressures acting on the blade surfaces of SSAF show different distributions around the operating point of D equivalent to the stall. Also, with the increase of operating load, the static pressures acting on the pressure and suction surfaces of blade concentrate at the tips and leading-edges as a whole.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.248-250
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• 2003

Recently, electric power system's situation grows gradually so Fault Diagnosis is being complicated and is felt difficult. And ability that operator who is using electric power system must do correct judgment of power system state, and can cope at fault of power system state is required. Therefore, large size power system is divided into predefined minimum module, and define each module accident type. We use and compare defined accident type, we can know easily accident that happen forward. Therefore, large size power system using module that is defined to each section common accident type search in this paper. Therefore, large size power system using module that is defined to each section, we search for common accident type. And when accident in electric power system happens, I wish to explain about process that can do fault diagnosis in more easy and fast time, because using accident type that it is verified in front.

• Journal of the Korea Institute of Building Construction
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• v.9 no.3
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• pp.103-107
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• 2009

It is necessary to develop a new technology for effectively controlling thermal crack caused hydration heat according to the increasing construction of large size massive concrete structures such as mat foundation of high-rise building. Therefore, to develop a new technology for reducing hydration heat of large size massive concrete in this study, it was investigated hydration heat generation properties of binder using latent heat materials. As a test result, it was confirmed that latent heat materials were advanced on the reduction of hydration heat and control of thermal crack. It is expected to be applied as the excellent technology on the management of hydration heat and thermal crack in large size massive concrete structures.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.531-534
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• 2008

A new forming process of the large-size forging within the limit of forming loads is developed by introducing the drawing process, which usually used to apply to sheet forming. For the development of the forming process, corresponding numerical simulation are carried out. The approach is based on the Taguchi method, and utilize the DOE for design of FEM analyses. In this study, the important factors are chosen at first, and then the concept of signal-to-nose(S/N) rate is applied to evaluate the formability of large size forging-products, and each value of the design parameter is determined.

• Journal of Preventive Medicine and Public Health
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• v.22 no.3 s.27
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• pp.323-327
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• 1989

Carbon monoxide diffusing capacity(DLco) was evaluated before and after nifedipine administration in coal workers' pneumoconiosis by the size of radioopacity. Nifedipine was administered to 18 men and 17 men of small round opacity group and large opacity group respectively. Placebo was administered to 19 men and 15 men of small and large opacity group respectively. In large opacity group DLco was increased after nifedipine administration. But, it was not significant statistically(0.05