• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.3
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• pp.210-216
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• 2003

A nonlinear dynamic modeling method for cantilever beams undergoing axially oscillating motion is presented in this paper. Hybrid deformation variables are employed for the modeling method with which frequency response characteristics of axially oscillating cantilever beams are investigated. It is shown that the geometric nonlinear effects of stretching and curvature play important roles to accurately predict the frequency response characteristics. The effects of the amplitude and the damping constant on the frequency characteristics are also exhibited.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.11
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• pp.868-874
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• 2003

A nonlinear modeling method for an axially oscillating cantilever beam with a concentrated mass is presented in this paper. Hybrid deformation variables are employed for the modeling method with which frequency response characteristics of axially oscillating cantilever beams are investigated. The geometric nonlinear effects of stretching and curvature are considered to accurately predict the frequency response characteristics of the oscillating cantilever beam. The effects of the size and the location of the concentrated mass on the frequency characteristics are investigated. It is found that the dynamic instability is significantly influenced by the two parameters.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.262-267
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• 2002

A nonlinear dynamic modeling method for cantilever beams undergoing axially oscillating motion is presented in this paper. Hybrid deformation variables are employed for the modeling method with which frequency response characteristics of a axially oscillating cantilever beams are investigated. It is shown that the geometric nonlinear effects of stretching and curvature play important roles to accurately predict the frequency response characteristics. The effects of the amplitude and the damping constant on the frequency characteristics are also exhibited.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.4
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• pp.332-338
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• 2014

Experimental study is conducted for investigating the characteristics of friction-induced noise with respect to the variation of system geometry. In this study, a vertically fixed rod is in contact with the reciprocating plate which is controlled by the step motor. Friction noise is generated during the reciprocating motion due to the frictional contact between the plastic pin and the aluminum plate. The frequencies of the friction noise are changed when the height of the rod varies. However, it is found that the vibration modes involved in the friction noise are not changed. It implies that the unstable modes remain unstable regardless of the change of the system geometry, and thus, there are the certain mode shapes which are likely to produce friction noise.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.333-336
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• 2002

This paper describes a detailed experimental Investigation of heat transfer In a reciprocating rectangular channel fitted with rib structures with particular reference to the design of a piston for marine propulsive diesel engine. The parametric test matrix involves Reynolds number, reciprocating frequency, and reciprocating radius, respectively, in the ranges, $1,000\;{\~}\;6,000,\;1.7\;{\~}\;2.5\;Hz,\;and\;7\;{\~}\;15cm$ with four different rib arrangements. The rib arrangements have considerable influences on the heat transfer in the reciprocating channel due to the modified vortex flow structure. The experimental data confirm that the increases in the heat transfer can be seen in order of Case (a), Case (d), Case (c), and Case (b)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.331.2-331
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• 2002

A modeling method for cantilever beams undergoing axially oscillating motion is presented in this paper. Hybrid deformation variables are employed for the modeling method. Frequency response characteristics are investigated with the modeling method. It is shown that the geometric nonlinear effects of stretching and curvature play important roles to accurately predict the dynamic response. (omitted)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.477-482
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• 2003

A nonlinear modeling method for an axially oscillating cantilever beam with a concentrated mass is presented in this paper. Hybrid deformation variables are employed fur the modeling method with which frequency response characteristics of axially oscillating cantilever beams are investigated. The geometric nonlinear effects of stretching and curvature are considered to accurately predict the frequency response characteristics of the oscillating cantilever beam. The effects of the magnitude and the location on the concentrated mass on the frequency characteristics are investigated. It is found that the dynamic instability is significantly influenced by the two parameters.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.2
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• pp.161-167
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• 2005

The improvements of the propulsive engine efficiencies could reduce the fuel consumption. Therefore. for a marine main diesel engine the substantial increase of stroke bore ratio. so that the engine speed can be significantly reduced in order to increase the Propulsive efficiency. As a typical example. a Sulzer RTA 60C engine has acylinder diameter of 600 mm and each cylinder is capable of delivering 2.369 kW in the speed range 91-114 rpm. In order to Provide basic data for thermal system of marine engine. this work performs an experimental study of heat transfer in a square channel with one rib-roughened wall under sin91e mode of reciprocating oscillation. A selection of heat transfer measurements illustrates the manner by which the reciprocating channel with two opposite heating walls has the higher heat transfer Performance than with four heating wall.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.7
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• pp.640-644
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• 2013

The present study provides the characteristics of friction noise under reciprocating sliding. The friction contact is generated between the aluminum plate and plastic, which results in friction noise. The experimental results reveal that the friction noise under reciprocating sliding can be produced as the friction coefficient increases. It is also shown that the vibration modes of the pin with dominant deflection in the sliding direction is participated on the friction noise.

• Journal of the Korean Applied Science and Technology
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• v.37 no.6
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• pp.1669-1677
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• 2020

The purpose of this study was to evaluate the effects of a 14-week proprioceptive resistance exercise on muscle endurance strength, dynamic balance and gait ability of elderly women in a social welfare facility. Thirty community dwelling elderly subjects (mean age 70.84±3.33) divided into experimental (n=15) and control (n=15) groups. The participants performed the muscle endurance strength(30sec hair stand), dynamic balance (3m up and go) and low extremity performance (10m walking, 400m walking) pre and after the training program. The exercise groups were submitted to 14 weeks proprioceptive training with a Swiss ball three times a week. As a results were as follow. Significantly improvements were observed in low extremity strength and dynamic balance. And there have significantly improvements in 10m walking, 400m walking. Conclusionly, the improvement of dynamic balance and gait ability by proprioceptive resistance training will reduce the possibility in female elderly people.