• Proceedings of the KIEE Conference
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• 2007.04c
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• pp.62-64
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• 2007

This paper deals with design of high speed linear switched reluctance motor(LSRM). First, we derived design factor from pole arc ratio of stator and mover, and calculated time constant using inductance and resistance. Second, we decided design parameter from design factor using time constant. Finally, analyze characteristics for LSRM using finite element analysis.

• Journal of ILASS-Korea
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• v.13 no.4
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• pp.193-199
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• 2008

Spray coating is a versatile surface modification technology in which coating is built-up based on the successive deposition of micron-scaled particles. Depending on the coating materials, the coatings can meet the required mechanical properties, corrosion resistance, and other properties of base materials. Spraying processes are mainly classified into thermal and kinetic spraying according to their bonding mechanism and deposition characteristics. Specifically, thermal spraying process can be further classified into many categories based on the design and mechanism of the process, such as frame spraying, arc spraying, atmospheric plasma spraying (APS), and high velocity oxygen-fuel (HVOF) spraying, etc. Kinetic spraying or cold gas dynamic spraying is a newly emerging coating technique which is low-temperature and high-pressure coating process. In this paper, overall view of thermal and kinetic spray coating technologies is discussed in terms of fundamentals and industrial applications. The technological characteristics and bonding mechanism of each process are introduced. Deposition behavior and properties of technologically remarkable materials are reviewed. Furthermore, industrial applications of spray coating technology and its potentials are prospected.

• Transactions of Materials Processing
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• v.23 no.1
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• pp.5-9
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• 2014

Although much research has been conducted to reduce the thickness of PET bottles in order to save manufacturing costs, the challenge remains of guaranteeing mechanical strength for top-loaded thin PET bottles. The current study investigates the large deformation characteristics of a circle shaped PET bottle and a square shaped PET bottle when compressively loaded using FEA. The arc length method is used in the nonlinear FEA to understand the buckling phenomenon. For PET bottles with the same capacity, the circle shaped bottle shows more resistance to buckling and compression loading than the square shaped bottle.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.333-336
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• 2006

In general, polymer materials undergo degradation when exposed to ultraviolet radiation, which can cause dissociation of chemical bonds. FRP composites which are used in strengthening existing structure are usually adhered on the concrete surface, its mechanical properties as well as appearance such as color, surface conditions are affected by sunlight and expecially ultraviolet light. In this study, variations of tensile strength after exposure for certain period of time through accelerated exposure by Xe arc methods specified in KS F 2274 are measured in order to examine strength degradation characteristics of FRP composite. As a result of ultraviolet light test for FRP composite after accelerated exposure for 0, 500, 1000, 1500 hour, discoloration of FRP composite occurs according to the passage of time. But, few strength degradations of FRP composite are observed due to exposure of ultraviolet ray with an small variation of tensile strength.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.315-318
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• 2001

In this paper recommends the development of automated silo dry & storage system. Most of existing round shaped iron silo arc used for only storage after dry and have many problems in storing. So We have developed an automated dry system which used the previously equipped silo and enables it to be used for storage after dry. The system features high frequency-resistance water sensor in Hopper scale that is in general use within the country its silo that is manufactured by the nerve DSP(TMS320C32) system water compensator and visualization that is finally realized with a personal computer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.1109-1112
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• 2004

This study reports on the pressure relief design and braided composite of surge arrester. Surge arresters with porcelain housing must not have explosive breakage of the housing to minimize damage to other equipment when subjected to internal high short circuit current. As a solution, this study describes pressure relief design performance of arresters with braided composite module. In general, braided composite has Potential for improved impact and delamination resistance. Manufacturing processes of the braided composite could also be automated and could potentially lead to lower costs. Therefore, in consideration of characteristics of pressure relief for polymer arrester, the fabric pattern of braided composite was decided. And Polymer arrester module was manufactured with braid. The mechanisms of pressure occurrence and relief were investigated basically by analyzing arc energy and the correlation between thermal shock and indoor pressure in pressure relief test.

• Proceedings of the KIEE Conference
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• 2008.10c
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• pp.59-61
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• 2008

This paper deals with design of Linear Switched Reluctance Motor (LSRM) considering to normal force. First, we derived design factor from pole arc ratio of stator and mover, and calculated time constant using inductance and resistance. Second, we decided design parameter from design factor using time constant, and analyze characteristics for LSRM using finite element analysis. Finally, we analyzed force characteristic according to design factor.

• Journal of Advanced Marine Engineering and Technology
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• v.19 no.4
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• pp.42-50
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• 1995

To study the effect of welding methods on the Stress Corrosion Cracking (SCC) behavior of welded AISI type 316L and 304 austenitic stainless steel, the Slow Strain Rate Technique(SSRT) has been adopted in the boiling 45 wt% $MgCl_2$ solution. The results are as follows. 1) Welded sections are more susceptible than base metal in SCC, and the rank of SCC, and the rasistance in welding method is TIG, MIG, $CO_2$ and ARC. 2) The Ultimate tensile strength(UTS) and the strain of both base metal and welded joint are reduced as decreasing extension rate. 3) The SCC resistance of 316L base metal and welded sections are superior than that of 304. 4) The tendency of pitting and the SCC suseptibility are agreed well, and the SCC site is welded deposit section in 316L whereas HAZ in 304.

• KIEE International Transactions on Electrophysics and Applications
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• v.5C no.1
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• pp.1-7
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• 2005

This paper describes the lightning surge analysis model of extra high voltage GIS using EMTP. Various lightning current parameters were investigated in order to confirm the impact on the lightning surge analysis such as lightning current amplitude, waveform, size of GIS, tower footing resistance and surge arresters. The multi-story tower model and EMTP/TACS model were introduced for the simulation of dynamic arc characteristics. The margin between the maximum overvoltage and BIL of the GIS was about 10 percent and the margin between the maximum overvoltage and BIL of the transformer was 21 percent.

• Journal of Welding and Joining
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• v.31 no.1
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• pp.21-25
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• 2013

Aluminum alloy, Al5083-O, is one of candidate materials for the LNG storage tank, because of its excellent weldability, cryogenic characteristics, and corrosion resistance. The good weldability of Al5083-O is very important in LNG storage tank manufacturing. In this study, high current metal inert gas(MIG) welding process was used to get one pass welding of thick plate aluminum alloy. Bead on plate(BOP) welding was performed to evaluate the effect of welding conditions on the height of bead and depth of penetration. The optimum welding conditions were derived to get one pass welding of the thickness of 14.5mm. The mechanical properties of the welded joint were evaluated. The cross-sectional macro test, tensile test, and bending test satisfied the class rule.