• Product Safety
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• s.13
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• pp.39-43
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• 1993

• Product Safety
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• s.200
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• pp.44-49
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• 2010

• Fire Protection Technology
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• s.43
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• pp.6-13
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• 2007

• Fire Science and Engineering
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• v.28 no.3
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• pp.87-91
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• 2014

This paper is aimed to find electrical fire danger for analyzing the characteristics of temperature, current and voltage signals for motor on electric fan. In order to attain this purpose, detected were the temperature, current and voltage signals on electric wire with free (normal state) and locked (abnormal state) motor. For voltage and current signals, voltage signal is no big difference with normal and abnormal states and current signal is higher in abnormal state (highest 309 mA) than the normal state (highest 203 mA). In the case of Temperature signal, the temperature distribution of the motor as a whole is different. It is difference in the case of the normal state $4^{\circ}C$ and the abnormal state $18^{\circ}C$. In particular, most of the electric wiring to the motor of the fan is attached to the fixture of motor back. Considering at allowable temperature ($60^{\circ}C$) of the electric wire could be accelerated to insulation deterioration. The results of this study will be effectively used in analyzing for electric fire and developing the preventive devices of electric fan.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.591-596
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• 2022

Since 4-bar linkage widely used in various industrial fields has a fixed link length, it is inconvenient to add an independent link structure or control device to change the movement of output link. Therefore, this paper proposes a new concept of variable 4-bar linkage mechanism to selectively adjust the movement of the output link to fit desired situations, and applied to the commercial table fans, which is a representative product using a 4-bar linkage system. The optimal rotation angle steps for efficiency are determined experimentally and the appropriate lengths of linkage to fit each step are calculated analytically. Changes in the linkage length are implemented by the rotational motion using a grooved cylindrical cam and the feasibility of the proposed variable linkage mechanism is verified through fabrication and measurement. The presented variable link mechanism is expected to improve the efficiency of industrial robots and fuel valve systems.

• Tunnel and Underground Space
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• v.27 no.1
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• pp.12-25
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• 2017

In local underground mines heavily depending on the natural ventilation, ducted fan auxiliary ventilation system is strongly recommended instead of the total mine ventilation system requiring large capital and operating costs. Optimizing the installation of ducted fans in series in long large-opening mines is required to assure the economy and efficiency of the ventilation system. The two most critical design parameters for optimization are the wall separation distance and gap length between adjoining ducts. This study aims at deriving the optimal values for those two parameters concerning the economic and environmental aspects through the extensive CFD analysis, which minimizes pressure loss, leakage and entrainment of the contaminated air in the gap space. The ranges of the wall separation distance and gap length for study are selected by taking into consideration the existing recommendations and guidelines. The ultimate goal is to optimize the auxiliary ventilation system using ducted fans in series to provide a reliable and efficient solution to maintain clean and safe workplace environment in local long underground mines.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.32-35
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• 2019

One of the major problems with the livestock industry is that in the summer, livestock will die from heat waves or infectious diseases. Under these circumstances, what livestock need is a proper indoor temperature and a regular sterilization system. Therefore, in this study, we developed a system that automatically controls the power of the fan according to the temperature inside the shaft, and a function that provides feed and sterilization on a regular basis, so that we could manage the toast efficiently. It also proposed the ability to automatically control the power of the fan, to display the temperature inside the shaft to mobile applications, and to provide food and sterilization. First, the function of controlling the power of the fan automatically turns the fan on when the temperature inside the shaft rises above a certain level. Conversely, if the temperature inside the shaft falls below a certain level, turn off the fan. Second, the function of the mobile application is to check the temperature inside the shaft. The third feeding function is periodically fed using a servo motor, and the feeding provided is delivered to livestock through a conveyor belt. Finally, the sterilization function is a function to sterilize livestock periodically using DC motor pump. The intelligent congratulatory functions proposed in this study may contribute to the health of livestock.

• Product Safety
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• s.248
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• pp.12-13
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• 2014

• Journal of Korean Electronics
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• v.2 no.7
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• pp.21-28
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• 1982

• Product Safety
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• s.138
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• pp.44-46
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• 2005