• Journal of the Korean Society for Precision Engineering
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• v.14 no.2
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• pp.33-40
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• 1997

Recently, there are an increasing needs for high speed rotating spindle which is an important mechanical ele- ment for a high efficiency machine tool in order to shorten machining time and cut production costs. The heat gen- eration is the most important problem in the motor integrated spindle. In this study, the effects of temperature distribution and thermal behavior according to the oil-air lubrication and cooling conditions are investigate theo- retically and experimentally on the motor-integrated spindle under unloading condition. The experimental spin- dle system is composed with the angular contact steel ball bearings, oil-air lubrication, air or oil jacket cooling system. To analyze the thermal behavior and cooling characteristics for the motor integrated spindle, the analysis using the finite element method is carried out. The analytical results are compared with the experimental results.

• Journal of Integrative Natural Science
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• v.2 no.4
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• pp.265-269
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• 2009

The photoluminescence was measured in GaAs-AlGaAs double-quantum-well structure at high magnetic field. Although the phototransition characteristics displayed a free-particle transition at low magnetic field, the change of free-particle transition into bound-exciton transition was observed at high magnetic field (above 10 T). A charged exciton formation due to charge-unbalanced electron-hole was identified by using a spin-polarized photoluminescence method. An increase of exciton formation due to the localization of free-particle at magnetic field was observed according to the increase of magnetic field.

• Proceedings of the Korean Magnestics Society Conference
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• 2003.12a
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• pp.72-72
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• 2003

• Proceedings of the Korean Magnestics Society Conference
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• 2004.12a
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• pp.26-27
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• 2004

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.50.2-50.2
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• 2007

• Journal of the Korean Magnetic Resonance Society
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• v.21 no.1
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• pp.1-6
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• 2017

Enhancements in NMR sensitivity have been the main driving force to extend the boundaries of NMR applications. Recently, techniques to shift the thermally populated nuclear spin states are employed to gain high NMR signals. Here, we introduce a technique called photochemically induced dynamic nuclear polarization (photo-CIDNP) and discuss its progresses in enhancing the solution-state NMR sensitivity.

• Journal of Photoscience
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• v.5 no.4
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• pp.175-179
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• 1998

In this paper, a brief overview of nanocrystallites of metal and semi-conductor materials will be presented, and then the novel synthetic method of high quality CdSe nanocrystallites developed by Bawendi group at MIT will be introduced . It will be shown that results of optical properties of surface modified nanocrystallites give the evidence that the luminescence of CdSe nanocrystallites is not originated from surface related trap states, but from intrinsic spin forbidden core states. Some of the interesting applications of CdSe nano-crystallites will also be discussed at the end.

• Proceedings of the Korean Society of Crop Science Conference
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• 2003.10a
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• pp.216-217
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• 2003

• Journal of Korea Technology Innovation Society
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• v.1 no.3
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• pp.351-363
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• 1998

This case study aims at investigating the factors which make venture firms successful. It analysedthree high-performance venture firms originated from the government-financed rese arch institute, the company and the university on the viewpoint of 'dynamic capability' theory. In this case study, technology integration capability and administrative innovation capability were identified as success factors of the three venture firms. The study also presented the role of the incubating organizations. Although incubating organizations supported technological and managerial resource-building of the entrepreneurs, there was not active interactive-learning between venture firms and incubating organizations after spin-off.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.12a
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• pp.132-133
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• 2007