• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1414-1417
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• 2004

A thick-layered RP process, transfer-type variable lamination manufacturing using expandable polystyrene foam (VLMST) has been developed to have the advantageous characteristics such as high building speed, low cost for introduction and maintenance of VLM-ST apparatus, and little staircase surface irregularities of parts. However, VLM-ST has difficulty fabricating an axisymmetric shape and a large-sized freeform shape because of the limited sloping angles and small build size. The objective of this paper is to develop a multi-functional hotwire cutting system using EPS-foam (MHC). MHC employs a four-axis synchronized hotwire cutter with the structure of two XY movable heads and a turntable. In order to examine the applicability of the developed MHC apparatus, an axisymmetric shape, a polyhedral shape and a large-sized freeform shape were fabricated on the apparatus.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.4
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• pp.742-747
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• 2009

Many works on the temperature distribution of power apparatus have usually done by coupled magneto-thermal analysis. Such a method can not consider the internal gas or oil flow in the power apparatus such as gas insulated switchgear, GIS bus bar, and power transformer. Moreover it can not show the internal temperature distribution of the power apparatus exactly. This paper proposes a coupled magneto-thermal-flow analysis considering Navier-Stokes equations. The convection heat transfer coefficient is calculated analytically by applying Nusselt number for natural convection and is applied to the boundary condition of proposed method. Temperature distribution of the GIS bus bar model considering thermal flow is obtained by the proposed method and shows good agreement with the experimental data.

• Journal of the Korean Society of Safety
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• v.30 no.3
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• pp.20-25
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• 2015

It is predicted the mass retirement of the post-war generation and the lack of young people according to reduces the recruitment. Therefore, industry fields are concerned by the low level of occupational safety and health from issued problem in a variety of industries; the charge of expanding business range/multi-functional, black box of technology, difficulty of systematic training, relative decrease in the skill of workers, loss of know-how in the field of information followed restricted site information. In response to these problems, it is necessary to establish the long-termly and actively based on for the adoption of a safety and health management techniques utilizing IT, which is digital assistant(tablet PC, PDA, etc.), RFID/USN/ICT, database systems, and etc. In this study, we developed and evaluated a worker's safety sensing apparatus using smart phone. The apparatus may be useful to prevent accidents in the construction industry as well as confined space work.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.2 no.2
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• pp.11-18
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• 2001

The design method of high potential generator of diagnostic X-ray apparatus by using inverter is presented. For the high potential generator, a line filter, a rectifier, a Pulse width modulation control, bridge drive, a high potential transformer and a high potential rectifier circuit were adopted. The high potential generator with switching frequency to be 40 KHz is fabricated by using design method presented in this method. The experimental results are as followings; variable volts of 0∼620 V and variable currents 50∼500 mA.

• Journal of Power System Engineering
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• v.16 no.2
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• pp.60-65
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• 2012

Pneumatic actuators are clean, lightweight, and can be easily serviced, whereas low energy efficiency has been considered as a critical shortcoming compared with corresponding hydraulic and electrical actuators. This study describes a new design method of pneumatic cylinder driving apparatus by lowering a supply pressure. The simulation study demonstrates that the designed system with the proposed method can operate at the smaller energy consumption state compare to the designed system with the conventional method for the specified working conditions.

• Journal of radiological science and technology
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• v.15 no.1
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• pp.107-113
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• 1992

Inverter type X-ray apparatus has been introduced and used several hospitals. Principle of inverter type X-ray generators are such as to convert the frequency of commercial power supply to high frequency and to control the high voltages for X-ray tube. Inverter generators are now on the way for futher development to elliminate single phase generators and three phase generators. We compared inverter type X-ray apparatus with conventional single phase 2 peak and three phase 12 peak, apparatus in the following aspects X-ray out put to tube voltage, linearity of X-ray out put to mA, HVL according to mA contrast to kV.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.593-596
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• 1992

An evaluation method for the effective length of electromagnet - which bas U-shape in frontview and trapezoidal in side view - is presented. Using 2D FEM, 2 analysing models are introduced for calculating effective length of the magnet ; the front model is using the normalized equi-pole face area of the magnet and the side model using the normalized equi-magnetic circuit. The ratio of the effective length to the length of bottom plate (core) comes out 1.25 - 1.30. In addition, 3D FEM analysis has been done and a proto-type test model is manufactured to verify the analysing method. The ratio by the experiment appears 1.2, which is reasonably in good agreement with the suggested numerical results.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.3
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• pp.89-95
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• 2013

This study focused on the development on functional shoe apparatus so that the appropriate impact can be applied to the feet in order to improve the density of mineral bone at lower limbs. The model with structure proposed in this study had an effective stress about 20 to 100% higher by comparing that of the model without it among most of 15 bone extraction points. Though there is a limitation that the finite element analysis data from the human body model are not the value of mineral bone densities by measuring directly but the effective bone stresses against impact, the proposed structure is designed to influence the increase of bone mass and improve the density of mineral bone by effecting the improvement of the density of mineral bone actually.

• Journal of Pharmaceutical Investigation
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• v.1 no.1
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• pp.53-57
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• 1971

A Diffusion analysis method is described for the determination of alcohol content in tinctures and spirits and then, the comparison test of the official alcohol number test with the diffusion analysis method has hen carried out. Throughout this experiments, a transformed Widmark apparatus is used. It is found that the diffusion analysis method using the transformed Widmark apparatus is very simple and occapy a small space. One of the most convenient fact is many sample can be analyzed at a time with this apparatus. Experimental data indicate that 95% of alcohol content obtained by the official alcohol number test is found in the diffusion analysis.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.42 no.4
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• pp.259-266
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• 2006

In this study, the 2-way condensation system was designed applying air-to-air heat pump to dry a marine product such as squid in the winter. And to be made the drying apparatuses by this system, there are two kinds of type, A type, was set a compressor outside of the drying apparatus, B type, was set a compressor in the drying room. And then the variations of temperature in drying room were measured to compare the heating performance of the drying apparatuses between A type and B type at $-6.5^{\circ}C$, outdoor temperature. The temperature of the drying room for B type was increased to $36^{\circ}C$ but the temperature of the drying room for A type was not increased to $36^{\circ}C$, to be increased to $20^{\circ}C$.