• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.10a
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• pp.70-75
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• 1997

Power driving shaft systems with reduction gear are frequently equipped with elastic couplings to protect reduction gears and to relieve the torsional vibration problems. In this study, torsional vibration characteristics for the engine shafting system with elastic couplings are investigated and the calculating program is developed. It is confirmed that torsional vibration can be controled by careful selection of a elastic coupling with suitable characteristics and the suitability of a elastic coupling can only be determined as a result of a complete torsional vibration analysis including engine conditions such as misfring for shafting system.

• Journal of KSNVE
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• v.10 no.1
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• pp.107-116
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• 2000

The gear whine noise caused by tooth profile, elastic deformation, machining error, wear is directly correlated with the transmission error of mating gear. It is very important to build up the synthesized countermeasure by the modeling of the excitation forces and analyzing the vibratory characteristics. The mathematical models on the elements of vehicle transmission which is composed of helical gears, bearings, shafts and cases are developed. The elements are assembled by the substructure synthesis method. The cases of transmission are modeled by ANSYS. The system model of vehicle transmission is also verified by the experiments.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.760-763
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• 2005

Optimum design of the tooth surface for the reduction of transmission error is very difficult to determine analytically due to nonlinearity of transmission error under the several load condition. The design of tooth surface that can give a low noise under the various load condition is very important. Therefore, this study proposes the method to determine the optimal lead curve and robust design of the tooth surface by using the response surface method. To do so, the design variables are selected by a screening experiment. Then the fitted regression model Is built with the check of the usefulness of the model. The model with constraints is solved to obtain the optimum values for the lead curve and the robust design fur the tooth surface.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.619-624
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• 2004

In this research, the structural health monitoring method using wavelet packet analysis and artificial neural network (ANN) is developed. Wavelet packet Transform (WPT) is applied to the response acceleration of a 3 element-cantilever beam which is subjected to impulse load and Gaussian random load to decompose the response signal, then the energy of each component is calculated. The first ten largest components in magnitude among the decomposed components are selected as input to an ANN to identify the damage location and severity. This method successfully predicted the amount of damage in the structure when the structure is subjected to impulse load. However, when the beam is subjected to Gaussian random load which can be considered as ambient vibration it did not yield satisfactory results. This method is applicable to structures such as machinery gears that are subjected to repetitive loads.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.2
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• pp.127-137
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• 2009

Hypoid gears are widely used in rear drive and 4WD vehicle axles. Investigation of their sensitivity to deflections is one of the most important aspects of their design and optimization procedures. The deflection test is performed in the actual gear mounting using completely processed gear. This test should cover the full operating range of gear loads from no load to peak load. Under peak load the contact pattern should extend to the tooth boundaries without showing a concentration of the contact pattern at any point on the tooth surface. Transmission error is tested on an axle assembly triaxial real car load condition.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.12
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• pp.1243-1249
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• 2008

Gear system has been widely used in industrial applications and unexpected failures of gears are not only extremely damaging but also leading to economic losses. So, early detection of fault is important for diagnosis machine condition. And acoustic emission is an efficient non-destructive testing technique fur the diagnosis of machine health and is useful technique far early detection of fault because it can find low-amplitude and high-frequency signal on account of high sensibility. Therefore, in this paper, the AE signal was measured and preprocessed using envelope analysis for gearbox with misalignment between pinion and gear. And then the gear misalignment's vibration characteristic were analyzed.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.41.2-41
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• 2001

A torque transmission system, which is composed of several gears and couplings, is flexible. Therefore, the torsion vibration occurs when the motor speed abruptly changes. Consequently, for Accuracy characteristic response of motor, we must suppressed vibration. Therefore, vibration suppression is very important motor control. To vibration suppression, various control method have been proposed. Specially, one method of vibration suppression used disturbance observer filter. This method is torsion torque passing disturbance observer filter. By feedback of the estimated torsion torque, the vibration can be suppressed The coefficient diagram method is used to design the filter and proportional controller.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.4
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• pp.137-141
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• 2011

Driving mechanism, the central part of a robot, was designed in this study. Power for the motive drive was acquired by directly connecting the motor shaft in worm shape of the low-end DC motor, car window motor, to a decelerator. The decelerator consists of a worm gear to receive power from the motor shaft, a pinion gear to be connected in line with the worm gear, and an output shaft to be engaged to the pinion gear. Motion driving is achieved by the power from the motor shaft with the designed gears, transferred to the deceleration mechanism and to the output gear.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.4
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• pp.117-124
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• 2011

A gear pump is a type of pump that displaces a volume of fluid by physical or mechanical action, or positive displacement pump. Power is applied to one of the gears and transmitted to a second driven gear via meshing teeth. This paper describes the hydraulic gear pump for an elevator. In gear pump, since geometrically special forms of gear tooth, 'Pulsations' is always caused in the delivery pressure and quantity. In other words, it is found that the number of delivery pressure pulsation per each revolution is always equal to that of the gear-teeth of the gear, which is coincident with the pulsation of the ideal delivery quantity. Some experimental results are given to verify the effectiveness of the developed pump.

• Journal of Integrative Natural Science
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• v.5 no.3
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• pp.198-210
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• 2012

Circadian rhythms govern a remarkable variety of metabolic and physiological functions. Accumulating epidemiological and genetic evidence indicates that the disruption of circadian rhythms might be directly linked to cancer. Intriguingly, several molecular gears constituting the clock machinery have been found to establish functional interplays with regulators of the cell cycle, and alterations in clock function could lead to aberrant cellular proliferation. In addition, connections between the circadian clock and cellular metabolism have been identified that are regulated by chromatin remodelling. This suggests that abnormal metabolism in cancer could also be a consequence of a disrupted circadian clock. Therefore, a comprehensive understanding of the molecular links that connect the circadian clock to the cell cycle and metabolism could provide therapeutic benefit against certain human neoplasias.