• Proceedings of the Korean Society of Marine Engineers Conference
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• 2001.05a
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• pp.173-179
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• 2001

The torsional or axial critical vibration of the order coinciding with the number of propeller blades is simultaneously excited by the harmonic tangential or radial forces acting on the crank shaft and by the harmonic of the same order from the propeller. The exciting torque of propeller is relatively small comparing with that of crank side, but the exciting force of propeller rather larger than that of crank shaft. With this situation, the exciting force of propeller cannot neglect if the axial vibration of propulsion shafting is calculated. With the propeller in its optimal angular position, i.e. its excitation effect opposed to that of the engine, the stresses at the critical revolution will largely cancel themselves out. In this paper, a method of optimizing the angular propeller position with regard to torsional and axial vibration is studied. The optimal relative angle is determined theoretically by calculation results of coupled torsional-axial vibration.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.6
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• pp.115-121
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• 2011

This study is about comparison of tangental entry type cyclone dust collector with axial vane type cyclone dust collector. Cut diameter and dust collection efficiency of both collector was compared by theory and experiment. Cut diameter was calculated by an quasi-empirical formula by Lapple and Shepherd. Measurement of cut diameter was conducted by particle counter through dust generator. As the result, cut diameter obtained by experiment was a little larger than that by theory. But the error is within $0.5{\mu}m$ in both type of collector, so it could be confirmed that theoretical value and experimental value were almost identical. And, as flow rate increased, dust collection efficiency was increased. Also axial vane type showed higher dust collection efficiency than tangental entry type. Therefore, it can be said that axial vane type cyclone dust collector has higher performance than the other.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.5 no.4
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• pp.121-128
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• 1996

In order to examine spindle deformation characteristics that affects the performance of dynmic cutting acuracy due to tool weight variation in a experimental spindle. thermal deformation value of operrative spindle by the axial displacement and the radial run out was measured according to the rise of spindle temperature through the laps of operation time and the change of rotational speed under the tool weight variation. A qualitative summary is as follows ; 1) The results show that the tool weight affcets the spindle temperature variation in a experimental spindle. 2) Radial run out and axial displacement was measured according to the rise of the spindle temperature and the performance of dynamic cutting accuracy was affected by the tool weight variation. 3) Axial displacement is 1.3 times larger than the radial run out in a experimental spindle conditions. 4) Axial displacement is continuously elongated when the tool weight is repeatly exchanged since the spindle themal deformaion, however, when the same tool weight is used. the displacement is still constant.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.460-469
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• 2006

It is widely known that the temperature variation introduces the axial force along a CWR(Continuous Welded Rail) in the railway bridges. Additional axial forces are generated due to many other reasons. These includes the interaction between the bridge girder and the CWR; acceleration or deceleration of the vehicles; support rotation (or deflection) of the girder. Among aforementioned reasons, this study investigates the influence of the support rotation on additional axial forces throughout the numerical study and the field test. Several strains gauges are installed along the CWR and the strains are measured under passing trains. It is expected that the elaborated estimation of the axial force on CWR will be beneficial for future railway maintenance.

• Proceedings of the KIEE Conference
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• summer
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• pp.827-829
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• 2004

A characteristic of the rotating machine that has been receiving relatively little attention is the axial force on the rotor versus its axial displacement from magnetic neutral position. A knowledge of this force is essential to the economic application of thrust bearings for rotating machine and their connected loads. In this paper this axial force is analyzed and calculated and test values are verified with two different machines.

• Journal of Mechanical Science and Technology
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• v.20 no.2
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• pp.191-196
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• 2006

This paper presents the application of techniques of differential transformation method (DTM) to analyze the transverse vibration of a uniform Euler-Bernoulli beam under varying axial force. The governing differential equation of the transverse vibration of a uniform Euler-Bernoulli beam under varying axial force is derived and verified. The varying axial force was extended to the more general case which was high polynomial consisted of many terms. The concepts of DTM were briefly introduced. Numerical calculations are carried out and compared with previous published results. The accuracy and the convergence in solving the problem by DTM are discussed.

• Proceedings of the KAIS Fall Conference
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• 2003.06a
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• pp.256-259
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• 2003

Artificial heart is divided pulsation style and nonpulsation style greatly according to flowing of blood. nonpulsation pump is advantage of miniaturization avaliable because it is simple and non-volumic-pump than pulsation pump. Non pulsation pump is derided axial flow style and centrifugal style accordig to rotating style. An axial flow blood pump can be made smaller than a centrifugal blood pump because of its higher specific speed. A hemolysis is an important factor for the development of an axial flow blood pump. It is difficult to identify the areas where hemolysis nun. Evaluation of hemolysis both in in vitro and in vivo require a long time and are costly. Computational fluid dynamics(CFD) analysis enables the engineer to predict hemolysis on a computer. The aims of this study is Computational fluid dynamics in the whole axial flow pump and to verify the accuracy of prediction results of CFD analysis compare with in vitro experimental results.

• Structural Engineering and Mechanics
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• v.40 no.2
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• pp.215-231
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• 2011

The axial compressive strength of unidirectional FRP is generally quite lower than its axial tensile strength. This fact decreases the advantages of FRP as main load bearing member in engineering structure. In order to restrain the lateral expansion and splitting of GFRP, and accordingly heighten its axial compressive bearing capacity, a project that to confine GFRP pole with surrounding CFRP sheet is suggested in the present study. The Experiment on the CFRP sheet confined GFRP poles showed that a combined structure of high bearing capacity was attained. Basing on the experiment research a theoretical iterative calculation approach is suggested to predict the ultimate axial compressive stress of the combined structure, and the predicted results agree well with the experimental results. Then the influences of geometrical parameters on the ultimate axial compressive stress of the combined structure are also analyzed basing on this approach.

• Bulletin of the Society of Naval Architects of Korea
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• v.7 no.2
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• pp.61-70
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• 1970

Since there has been no analytical method to calculate principal dimensions of the axial vibration damper of marine diesel engine shaftings in design state, it has often happened to install the axial vibration damper after the ship's trial trip. In this paper a method to calculate the coefficient of equivalent damping of the axial vibration damper is introduced and with this value one can calculate fairy accurate vibrating amplitudes of the crankshaft that is fitted with an axial vibration damper, by using author's matrix methods.[1][2][3][4] A comparison of the calculated amplitudes with measured ones is shown and its result is fairy good, except values of the case where the damper nozzle is almost closed.

• Korean Journal of Optics and Photonics
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• v.31 no.1
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• pp.20-25
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• 2020

To design a wide-field two-mirror system, the system must feature an off-axial field, to avoid ray obstruction and field screening by the secondary mirror. The off-axial aberrations of the system cannot be corrected sufficiently, though, because there are only a few design parameters. The present study designs an improved off-axial-field two-mirror system using a decentered aperture stop.