• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.3
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• pp.139-144
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• 2005

[ $SF_6$ ] gas circuit breakers are widely used short circuit current interruption in EHV or UHV power system. For a $SF_6$ gas circuit breaker development, the $SF_6$ gas velocity measurement is necessary during $SF_6$ circuit breaker's trip operation. Small-gap flashover characteristics are used for this measurement. So, small-gap measuring system which will be used to develope GCB should be developed. This study shows the characteristic analysis and experimental results of small-gap measuring system.

• ETRI Journal
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• v.18 no.3
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• pp.181-193
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• 1996

A blue light emitting device has been successfully fabricated using a polymer with regulated conjugation length containing trimethylsilyl substituted phenylenevinylene units. Electroluminescence from the device has an emission maximum at 470 nm. The device shows typical diode characteristics with operating voltage of 20 V and the light becomes visible at a current density of less than $0.5;mA/cm^2$. The electroluminescence spectrum is virtually identical with the photoluminescence spectrum, indicating that the radiation mechanisms are the same for both. A light emitting device using the blend of a large band gap polymer and a small band gap polymer was also fabricated. Light emission from the small band gap polymer shows much improved quantum efficiency, but there is no light emission from the large band gap polymer. Quantum efficiency of the blend increases up to about two orders of magnitude greater than that of the small band gap polymer with increasing proportion of the large band gap polymer. The improvement in quantum efficiency is interpreted in terms of exciton transfer and the hole blocking behaviour of the large band gap polymer. Finally, we have fabricated a patterned flexible light emitting device using the high quantum efficiency polymer blend system.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.3
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• pp.155-158
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• 2006

$SF_6$ gas circuit breakers we widely used for short circuit current interruption in EHV or UHV power system. For a $SF_6$ gas circuit breaker development, the hot gas velocity measurement is necessary during $SF_6$ gas circuit breaker's trip operation. Small-gap flashover characteristics are used for this hot gas velocity measurement. This study sho was the hot gas velocity measurement results during $SF_6$ gas circuit breaker' trip operation.

• Journal of Labour Economics
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• v.42 no.1
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• pp.43-72
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• 2019

As a result of decomposing the wage gap between large enterprises and SMEs using Oaxaca's wage gap decomposition method, the total wage gap of supply side factors was 44.2%, and the service years and educational background were the biggest influences. and As a result of decomposing the wage gap by firm size based on demand side factors such as business performance, total wage gap was 44.9%, and the influence on wage gap was in the order of labor productivity, union and outsourcing ratio. The results of this analysis suggest that it is necessary to consider the demand side factors such as business performance and capital structure of supply side companies such as differences in human capital in order to solve wage gap by firm size.

• Parasites, Hosts and Diseases
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• v.50 no.1
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• pp.89-93
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• 2012

$Neodiplostomum$ $seoulense$ (Digenea: Neodiplostomidae) is an intestinal trematode that can cause severe mucosal pathology in the small intestines of mice and even mortality of the infected mice within 28 days after infection. We observed neuronal growth associated protein-43 (GAP-43) expression in the myenteric plexus of the small intestinal wall of $N.$ $seoulense$-infected mice until day 35 post-infection (PI). BALB/c mice were infected with 200 or 500 $N.$ $seoulense$ metacercariae isolated from naturally infected snakes and were killed every 7 days for immunohistochemical demonstration of GAP-43 in the small intestines. $N.$ $seoulense$-infected mice showed remarkable dilatation of intestinal loops compared with control mice through days 7-28 PI. Conversely, GAP-43 expression in the mucosal myenteric plexus was markedly ($P$<0.05) reduced in the small intestines of $N.$ $seoulense$-infected mice during days 7-28 PI and was slightly normalized at day 35 PI. From this study, it is evident that neuronal damage occurs in the intestinal mucosa of $N.$ $seoulense$-infected mice. However, the correlation between intestinal pathology, including the loop dilatation, and depressed GAP-43 expression remains to be elucidated.

• Journal of the Ergonomics Society of Korea
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• v.31 no.2
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• pp.363-370
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• 2012

Objective: The objective of this study is to analyze standards of ISO 9001, ISO 14001, KOSHA 18001, GAP and ISO 22000 to make an integrated system and check whether an integrated system can be used at small size companies. Background: There are many certification criteria for quality, safety and health such as ISO 9001, ISO 14001, KOSHA 18001, GAP and ISO 22000. However, these criteria are difficult and complicated to be used at a small size company. Thus. it is not easy for small size companies to obtain certifications using these criteria. But customers and workers of small size companies want the key points of these systems to be implemented. Method: ISO 9001, ISO 14001, KOSHA 18001, GAP and ISO 22000 were analyzed to find the commonality and duplications as well as the importance of the items in these standards. And a survey was conducted to check whether certain aspects of the anticipated integrated system can be implemented at small size companies. Results: Items were classified into categories based upon the importance to food safety, quality, safety, environment, and health. Items which are common among standards were also identified and thus give ideas to make the new standards simpler than the currently available standards. Items which were important but may not be easily implemented at the small size companies were also identified. Conclusion: By considering the fact that the currently used accreditation standards have many similar aspects, these systems can be integrated into one new system which small size companies can use relatively easily.

• Bulletin of the Korean Mathematical Society
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• v.37 no.2
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• pp.353-360
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• 2000

The fundamental gap between the lowest two Dirich-let eigenvalues for a Schr dinger operator HR={{{{ { { d}^{2 } } over { { dx}^{2 } } }}}}+V(x) on L({{{{ LEFT | -R,R RIGHT | }}}}) is compared with the gap for a same operator Hs with a different domain {{{{ LEFT [ -S,S RIGHT ] }}}} and the difference is exponentially small when the potential has a large barrier.

• Journal of Welding and Joining
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• v.34 no.1
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• pp.68-74
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• 2016

Adoption of narrow gap welding shall be increased for the butt joint of thick plate, because the deformation and welding cost is reduced by decrease of cross-sectional area. However, sometimes narrow gap causes defects such as lack of fusion since it has small groove angle and narrow groove width. Therefore, GMAW, GTAW and SAW process shall be adopted to narrow gap welding with small bead hight and low deposition rate. In this study, Super-TIG welding using C-type strip was applied to semi-narrow gap butt joint in order to increase the welding productivity. High deposition rate 10kg/hr was obtained by high current 600A without undercut, humping bead and other welding defects. Measuring the mean and standard deviation of the melting depth to evaluate the developed processes, the fusion line type was determined by measuring the difference between maximum and minium melting depth. Furthermore, a model on arch fusion line and linear fusion line was suggested in order to prevent LF on groove wall in narrow gap butt welding.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.10
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• pp.914-922
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• 2003

The FFS (fringe-field switching) mode was known to exhibit both a wide viewing angle and high transmittance, especially when using a liquid crystal with negative dielectric anisotropy. We have studied cell gap-dependent electrode-optic characteristics of the FFS mode using the LC with negative dielectric anisotropy. In case of a small cell gap of 2 ${\mu}$m, the transmittance at the center of pixel and common electrodes is relatively low because effect of surface anchoring that holds the LC to the initial state is larger than that in a large cell gap of 4 .urn such that the LCs in those regions cannot rotate enough. However, in case of a large cell gap of 4 .urn, the effect of surface anchoring becomes relatively small so that the LCs at the center of pixel and common electrode can be twisted enough by applied voltage, giving rise to high transmittance. Therefore, we can conclude that the light efficiency is dependent on the cell gap.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1031-1032
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• 2007

Gap servo NF (Near Field) system is one of technologies to reduce beam spot size by increasing NA (Numerical Aperture) of lens. To achieve higher NA, SIL (Solid Immersion Lens) is used. In the case of using a blue LD (405 nm) as the light source the gap distance should be controlled under 100 nm with much tighter margin. Because of very small gap distance between SIL bottom and the surface of media, relative tilt tolerance is limited. In this paper, we presented 2-axis tilt mechanism for skew adjustment within small tilt margin.