• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.3
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• pp.298-303
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• 2011

Recently, demand on machine tools has been increased because the machine and automobile industry is booming. Therefore, the machine tools need to have a high accuracy and productivity. To build a high precision machine tool and increase its productivity, structural analysis needs to be carried out for vibration and stiffness of the machine tool before its detail design. However, it is the fact that many manufacturers of machine tools depend on their know-how about design experience. Therefore, in this paper, the static and dynamic analysis is carried out for evaluating a horizontal CNC lathe and then, applied to its detail design. It is positive that the analysis can lead to reduction of design time and improvement of the quality of the lathe as its design proceeds.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.947-950
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• 2007

In this study, vibration analysis of a refrigerator was carried out to reduce vibration by considering grommet. When the refrigerator machine room is modeled by finite element method, spring elements are added to constructions of the FEmodel for each component and update. To design the grommet of refrigerator, FEmodel must have vibration characteristics of each components such as baseplate, pipe and compressor it self. The modal analyses are conducted to validate suggested approach when the components of machine room are assembled together. And, in this study, optimal design of grommet is conducted to avoid the resonance at the operating frequency of refrigerator. The experimental and FEM result of suggested design showed good agreement and are presented here.

• Journal of Advanced Marine Engineering and Technology
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• v.16 no.3
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• pp.51-57
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• 1992

Authors had analyzed the Press machine's vibrational characteristics by Substructure Synthesis Method. This paper discribes the structural Dynamic Optimization for the machine using Sensitive Analysis Method. The substructure synthesis method and sensitive analysis methods are used for the vibration analysis and structural modification. The results obtained are as follows ; 1. The tooling precision of the press machine is ruled by the bending vibration of the slide. 2. The structural Modification Method for minimizing impact responses is proposed, and modal analysis and sensitive analysis method are introduced to solve it. 3. The impact responses of running machine were reduced to 40% of the unmodified machine by using the proposed method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.232-237
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• 2006

Operation deflection shapes(ODS) is defined as a motion of structure at particular frequency. The ODS is eligible to show any types of structural motions while the modes supply solutions only to linear and stationary motion. The principal vibration source of an auto teller machine(ATM) case was occurred due to resonance which was found by modal analysis. To reduce the vibration of ATM case, the motion of the case was visualized using ODS analysis, which can suggest how to modify the structure. As a result the vibration of the ATM case was greatly reduced with a stiffening bar between the opposite plates.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.298-303
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• 2003

The eccentric rotor system has various problems by vibration of unbalance mass. Specially, it is difficult to analyze vibration problem for the drum washing machine due to correlation of transmission paths. We analyze the mechanical structure by multidimensional spectral density to identify the maximum vibration magnitude at the frequency domain. It estimates the coherence function of the signals to pass the transmission paths. In case of the drum washing machine, because the transmission paths are correlated partially it needs to determinate the priority ranking. And the correlated parts are eliminated using conditioned spectral density function. Finally the shielding effect method confirms the reasonability of the modeling.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.579-584
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• 2008

A nano-imprinting stage has been widely used in various fields of nanotechnology. In this study, an analysis method of a nano-imprinting stage machine using FEM and flexible multi-body vibration has been presented. The simulation using CAE for the imprinting machine is to analyze vibration characteristics of 3-axis nano-imprinting stage and 4-axis nano-imprinting stage. Structural components such as the upper plate have been modeled with finite elements to analyze flexibility effects during the precision stage motion. In this paper flexible multi-body dynamic simulation is executed to support robust design of the precision stage mechanism.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.932-937
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• 2003

When oil pressure of damper is lost or relative stiffness of spring drops in vibration system, it can be fatally dangerous situation. A fault diagnosis method for vibration system using Support Vector Machine(SVM)is suggested in the paper. SVM is used to classify input data or applied to function regression. System status can be classified by judging input data based on optimal separable hyperplane obtained using SVM which learns normal and abnormal status. It is learned from the relationship of system state variables in term of spring, mass and damper. Normal and abnormal status are learned using phase plane as in put space, then the learned SVM is used to construct algorithm to predict the system status quantitatively

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.304-307
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• 2004

To reduce the structure-born sound by floor impact source in an apartment building, it is necessary to identify the relationship between floor impact sound and vibration. Various impact sources which were made by a bang machine and an impact ball were used for measurement of impact sound and vibration. The experimental results show that the linear relationship between floor impact sound and vibration was in existence despite of various floor impact sources.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.9
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• pp.414-421
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• 2001

If a machine has some faults, we can detect them using vibration or noise signals. However some maintenance engineers who don\`t have export knowledge, need the help of vibration experts for diagnosing the machine. In this paper a case based reasoning (CBR) system is developed which is able to manipulate the past experiences of vibration diagnosis experts. In the CBR system, the maintenance engineers can retrieve the information form previous cases which are most similar to new problem s that they can solve new problem using solutions form the previous cases. In this paper, a new case retrieval method of CBR system using Petri net is proposed and also applied to diagnosis for electric motors as a practical problem.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.205-209
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• 2008

In this study, very accurate computational mechatronics method has been developed for typical N.C. machine model applying to manufacturing industry in these days. Computation analysis of high speed machine tools like N.C. machine needs consideration about mechatronical features because the machine shows close interaction between dynamic behavior of the mechanical structure, drives and numerical control. For this, nonlinear structural analysis tools based on FEM are linked numerical control program to control the dynamic behavior. In this study, we studied the dynamic feature of N.C. machine by using SAMCEF as nonlinear computational structural analysis tool and simulink as drivers.