• KOREAN POULTRY JOURNAL
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• v.44 no.11
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• pp.161-163
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• 2012

• KOREAN POULTRY JOURNAL
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• v.44 no.7
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• pp.145-147
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• 2012

• KOREAN POULTRY JOURNAL
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• v.44 no.5
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• pp.141-143
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• 2012

• KOREAN POULTRY JOURNAL
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• v.44 no.8
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• pp.141-143
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• 2012

• Environmental engineer
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• s.328
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• pp.69-69
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• 2013

• KOREAN POULTRY JOURNAL
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• v.44 no.10
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• pp.148-151
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• 2012

• Journal of the Korean Society for Railway
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• v.20 no.1
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• pp.111-119
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• 2017

In this study, deflection limits based on the vibration serviceability of guideway structures are proposed considering maglev train-guideway interaction. Equations of motion are derived for a simplified maglev railway. Feedback constants for the control of the electromagnetic force for levitation are optimized in order to minimize the airgap fluctuations. Deflection limits for a guideway are calculated for various operating speeds of a maglev train, span lengths of a guideway, and natural frequencies and damping ratios of the second suspension in order to satisfy the serviceability criteria for airgaps and for the vertical acceleration of a cabin. From the analysis results, proposed are requirements for the second suspension of maglev trains and deflection limits for guideway structures.

• Convergence Security Journal
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• v.16 no.5
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• pp.73-79
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• 2016

EPG (Electronic Program Guide), which shows the title, broadcasting time, genre, parental rating of a program, is recognized as one of the most successful data service by viewers and broadcasting stations, who want an improved TV watching experience and a more fruitful profit model, respectively. In the circumstance, the request for the development or renewal of EPG frequently occurs and so the developers are looking for ways to improve the efficiency of the EPG development. This paper addresses the need of the developers by devising an EPG feature model based on FODA (Feature-Oriented Domain Analysis) and the testcases of each feature of the model. By utilizing the EPG feature model and the testcases, the tasks of requirement analysing and testcase designing, which are major tasks of the EPG development process, can be improved.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.7
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• pp.709-716
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• 2013

A fan filter unit (FFU) is a device which supplies clean air from the ceiling in a clean room. With an increase in its size, velocity variation occurs within the exhaust plane and this damage the product quality or productivity. Hence, a guide vane is installed inside the device to enhance the velocity uniformity. Because the vane reduces the flow rate for a given pumping power, an optimum design is required to achieve velocity uniformity while minimizing the flow rate reduction at the same time. To find a geometry that satisfies these requirements, a series of numerical simulations has been conducted while changing the angle and length of the guide vanes. By changing the geometry of the side guide vane, the velocity uniformity increased by 3.7% and the flow rate decreased by 1.5%. For the center guide vane, the velocity uniformity increased by 2.9% and the flow rate decreased by 0.7%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.344-349
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• 2018

This paper proposes a method of designing the main parameters of the Teflon coating equipment of a guide wire used in medical treatment. The proposed device was designed to be guided by a reel-to-reel method in which the guide wire performs all processes continuously, such as Teflon coating and heat treatment. At this time, the conveyed guide wire vibrates between the rollers, which affects the quality of the coating. Therefore, this paper proposes a dynamic equation of the guide wire to be transported in the longitudinal direction, and design parameters setting method of the feed speed and the interval of the roller supporting the wire is proposed to minimize the vibration amplitude of the guide wire during transport. The Teflon coating of the medical guide wire was carried out based on the developed coating equipment. The target coating thickness of the guide wire was set to less than $10{\mu}m$ in the circumferential direction, and the results were examined by optical microscopy.