• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.857-858
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• 2006

Estrangement hierarchical by bipolarization is deepened and time space that social welfare by graying corresponds great so. Specially, is real condition that indifference by patient's increase which is solitary life string is come to involve by social problem. Together, Jaetaek bone fracture patient's ratio is zooming. Domestic BT technology, medical treatment solution technology offer more important role than role assistance enemy of modern technology and utilize by creative technology can . Specially, if apply supersonic waves in bone fracture treatment, there is treatise data that can reduce bone fracture treatment period of bone that bone does not stick well about 40%. Supersonic waves operation frequency used on both end because do 1m Hz, 1.3mHz, supersonic waves origination that have 1.5mHz's Piezo-ceramic crystal tranducer material each 4 premature senilitys in this research, and outside diameter according to impedance and Phase d used Gakgak4mm, 5.4mm, Dukke0.5mm, transformer deuce of length 70mm. Manufactured, and investigated supersonic waves distribution chart by capacity 50m W. Supersonic waves used by diagnosis mainly but is seen to become convenient medical treatment mounting in bone fracture patient's treatment if supplement clinically. If supplement system furthermore, is going to apply to osteoporosis patient, and this research tried to design poetic theme width directly and study rain standardization special quality and approach basic form because do modelling.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.357-361
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• 2010

When high-pressure gas is exhausted through nozzle exit to the atmosphere, expanded supersonic jet is formed with the Mach disk at a specific condition. In two-dimensional supersonic jets, the hysteresis phenomenon of the reflected shock waves is found to occur under quasi-steady flow conditions. Transitional pressure ratio between the regular reflection and Mach reflection in the jet is affected by this phenomenon. In the present study, experiments are carried out on internal flow in a supersonic nozzle to clarify the hysteresis phenomena for the shock waves and to discuss its interdependence on the rate of the change of pressure ratio with time. Flow visualization is carried out separately on the straight and divergent channels downstream of the nozzle throat section. The influence that the hysteresis phenomena have on the location of shock wave in a supersonic nozzle is also investigated experimentally.

• Journal of the Korean Society of Visualization
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• v.8 no.2
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• pp.31-39
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• 2010

Hysteresis is an effect by which the order of previous events influences the order of subsequent events. Hysteresis phenomenon of supersonic internal flows with shock waves has not yet been clarified satisfactorily. In the present study, experiments are carried out on internal flow in a supersonic nozzle to clarify the hysteresis phenomena for the shock waves. Flow visualization is carried out separately on the straight and divergent channels downstream of the nozzle throat section. Results obtained were compared with numerically simulated data. The results confirmed hysteresis phenomenon for shock wave in the Laval nozzle at a certain specific condition. The relationship between hysteresis phenomenon and the range of the rate of change of pressure ratio with time was shown experimentally. The existence of hysteretic behavior in the formation, both the location and strength, of shock wave in the straight part of the supersonic nozzle with a range of pressure ratio has also been confirmed numerically.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.2165-2166
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• 2006

Estrangement hierarchical by bipolarization is deepened and time space that social welfare by graying corresponds great so. Specially, is real condition that indifference by patient's increase which is solitary life string is come to involve by social problem.Together, Jaetaek bone fracture patient's ratio is zooming. Domestic BT technology, medical treatment solution technology offer more important role than role assistance enemy of modern technology and utilize by creative technology can. Specially, if apply supersonic waves in bone fracture treatment, there is treatise data that can reduce bone fracture treatment period of bone that bone does not stick well about 40%. Supersonic waves operation frequency used on both end because do 1m Hz, 1.3mHz, supersonic waves origination that have 1.5mHz's Piezo-ceramic crystal tranducer material each 4 premature senilitys in this research, and outside diameter according to impedance and Phase d used Gakgak4mm, 5.4mm, Dukke0.5mm, transformer deuce of length 70mm. Manufactured, and investigated supersonic waves distribution chart by capacity 50m W. Supersonic waves used by diagnosis mainly but is seen to become convenient medical treatment mounting in bone fracture patient's treatment if supplement clinically.If supplement system furthermore, is going to apply to osteoporosis patient, and this research tried to design poetic theme width directly and study rain standardization special quality and approach basic form because do modelling.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.05a
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• pp.341-344
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• 2003

There communicates using tire supersonic waves in tire underwater, that is different from tire ground that use tire propagation. Because using Law frequency to come under tire waves, bandwidth that is able to communicate is very smaller that tire mobile communication of tire ground. Also, The channel environment changes rapidly in tire shallow underwater than tire ground. Due to such a reason, data transmission technic that is able to tire maximum application to restricted bandwidth and tire signal processing technics that is able to conquer tire rapid changes of tire channel environment are being used. Algorithm is used at tire application of these technic has a lot of tire calculating quantity. So this research reveals small bulk and equal performance using one DSP chip and then implements QPSK transmitter, that uses SHARC DSP of Analog Device company, for tire underwater supersonic waves communication rapidly decrease tire calculating quantity.

• 한국연소학회:학술대회논문집
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• 1998.10a
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• pp.123-129
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• 1998

A numerical study has been conducted to investigate the effect of shock waves on the mixing and the recirculation zone of a hydrogen jet diffusion flame in a supersonic combustor. The general trends are compared with the experimental results obtained from the supersonic combustor at the University of Michigan. For the numerical simulation of supersonic diffusion flames, multi-species Navier-Stokes equations and detailed chemistry reaction equations of $H_2$-Air are considered. The $K-{\omega}/k-{\varepsilon}$ blended two equation turbulent model is used. Roe's FDS method and MUSCL method are used for convection fluxes in governing equations. Numerical results show that when slender wedges are mounted at the combustor wall the mixing and the combustion are enhanced and the size of recirculation zone is increased . The flame shape of supersonic flames is different in the flame-tip; it is not closed but open. The flame shape is shown to be greatly affected by shock waves.

• Advances in aircraft and spacecraft science
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• v.7 no.5
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• pp.387-404
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• 2020

The numerical simulation of shock waves in supersonic flows is challenging because of several instabilities which can affect the solution. Among them, the carbuncle phenomenon can introduce nonphysical perturbations in captured shock waves. In the present work, a hybrid numerical flux is proposed for the evaluation of the convective fluxes that avoids carbuncle and keeps high-accuracy on shocks and boundary layers. In particular, the proposed flux is a combination between an upwind approximate Riemann problem solver and the Local Lax-Friedrichs scheme. A simple strategy to mix the two fluxes is proposed and tested in the framework of a discontinuous Galerkin discretisation. The approach is investigated on the subsonic flow in a channel, on the supersonic flow around a cylinder, on the supersonic flow on a flat plate and on the flow in a overexpanded rocket nozzle.

• Journal of the Korea Computer Industry Society
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• v.7 no.5
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• pp.583-590
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• 2006

BT technology, medical treatment engineering technology is offering important role and grow by creative technology. Specially, bone fracture treatment can achieve very important role in research of bone, physiology and dynamics of bone is very useful patient's diagnostic and treatment in presence at a sickbed. <중략>Furthermore embedded base of in administration aspect as well as if supersonic waves curer is treatment innocuously and without invasion very efficient tell. If apply supersonic waves in bone fracture treatment, can reduce curer about 40%. Operation frequency through bone fracture treatment supersonic waves curer of embedded base designs and manufactured 1m Hz, 1.2mHz, 1.3mHz, 1.4mHz, supersonic waves origination that have 1.5mHz's tranducer, and embodied protocol in PDA base in this research, and did so that is interfaced to general PC. If is using but supplement research water that see clinically by diagnosis in city, is seen to become convenient medical treatment assistance mounting to bone fracture patient's treatment and courtesy call. Specially, tried to approach basic form after modeling processing if may be applied variously to physiotherapy, orthopaedics patient who gouge late, and study standardization special quality little more.

• Journal of the Korea Computer Industry Society
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• v.7 no.3
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• pp.245-252
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• 2006

Estrangement hierarchical by bipolarization is deepened and time space that social welfare by graying corresponds great so. Specially, is real condition that indifference by patient's increase which is solitary life string is come to involve by social Voblem. Together, Jaetaek bone fracture patient's ratio is zooming. <중략>Supersonic waves operation frequency used on both end because do 1mHz, 1.3mHz, supersonic waves origination that have 1.5mHz's Piezo-ceramic crystal tranducer material each 4 premature senilitys in this research, and outside diameter according to impedance and Phase d used Gakgak4mm, 5.4mm, Dukke0.5mm, transformer deuce of length 70mm. Manufactured, and investigated supersonic waves distribution chart by capacity 50m W. Supersonic waves used by diagnosis mainly but is seen to become convenient medical treatment mounting in bone fracture patient's treatment if supplement clinically. If supplement system furthermore, is going to apply to osteoporosis patient, and this research tried to design poetic theme width directly and study rain standardization special qualify and approach basic form because do modelling.

• Journal of Mechanical Science and Technology
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• v.20 no.4
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• pp.522-532
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• 2006

It is well known that screech tones of supersonic jet are generated by a feedback loop driven by the instability waves. Near the nozzle lip where the supersonic jet mixing layer is receptive to external excitation, acoustic disturbances impinging on this area excite the instability waves. This fact implies that the nozzle lip thickness can influence the screech tones of supersonic jet. The objective of the present study is to experimentally investigate the effect of nozzle-lip thickness on screech tones of supersonic jets issuing from a convergent-divergent nozzle. A baffle plate was installed at the nozzle exit to change the nozzle-lip thickness. Detailed acoustic measurement and flow visualization were made to specify the screech tones. The results obtained obviously show that nozzle-lip thickness significantly affects the screech tones of supersonic jet, strongly depending on whether the jet at the nozzle exit is over-expanded or under-expanded.