• Explosives and Blasting
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• v.26 no.2
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• pp.92-98
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• 2008

Measuring methods of the blasting vibration were generally divided the. manual method and the automatical method. When using the automatical method, field data of the vibration meter can be transferred to a operation computer by using remote equipments. In this study new automatical system using solar power supply is to be introduced. New automatical system is well suited for the field which is difficult to access and is needed frequent measurements of the blasting vibration. And it can make easy to accumulate the data and control the blasting vibration for safe blasting.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.6
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• pp.598-609
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• 2005

Conventional phase shift full bridge (PSFB) converter has serious voltage oscillation problem across the secondary rectifier diodes, which would require the dissipate snubber circuit, thus degrades the overall efficiency. To overcome this problem a new simple voltage oscillation reduction technique (VORT) which effectively reduce the voltage oscillation of the secondary rectifier diodes for phase shift full bridge converter is proposed. Therefore, no dissipate snubber for rectifier diodes is needed. In addition, since it has wide zero voltage switching (ZVS) range, high efficiency can be achieved. Operational principle, analysis of voltage oscillation, and design consideration are presented compare with that of the conventional PSFB converter. To confirm the validity of the proposed VORT, experimental results from a 420W prototype are presented.

• Journal of Energy Engineering
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• v.13 no.4
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• pp.275-280
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• 2004

Augmentation of heat transfer by ultrasonic vibration in pipes are investigated. Measurements of convective heat transfer coefficients on circular pipe walls are made with and without ultrasonic vibration applied to water. These data are compared with each other to quantify the effects of ultrasonic vibration on heat transfer enhancement. Numerical analysis has been also performed in order to extend the ranges of examined temperature and flow rate. FLUENT Ver.6.1 is used to simulate velocity and temperature fields and evaluate heat transfer coefficient with and without ultrasonic vibration. The results show that the ultra- sonic vibration enhances the Nusselt number of forced convection flow and the increase rate strongly depends on flow rate.

• Cement Symposium
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• s.37
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• pp.90-95
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• 2010

• Corrugated packaging logistics
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• v.7 no.32
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• pp.127-129
• /
• 2000

• Magazine of the Korea Concrete Institute
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• v.22 no.3
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• pp.95-98
• /
• 2010

• Geotechnical Engineering
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• v.21 no.7
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• pp.16-25
• /
• 2005

• The Science & Technology
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• v.10 no.12 s.103
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• pp.44-44
• /
• 1977

• The Science & Technology
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• v.7 no.3 s.58
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• pp.37-39
• /
• 1974

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.5
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• pp.603-610
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• 2012