• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.287-290
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• 1999

This paper describes an optimal design method of VSI output filter for CVCF system. The cost function is used for design, and all parameters are described in p.u(per unit) so that can be adapted to the change of CVCF rating. The capacitor current feedback scheme is proposed to control the damping ratio of the filter plant to meet the system more stable. This means that the LC resonance can be suppressed well in transient condition and can use the same control gains under the change of system capacity. The validity of the proposed method is well verified with the theoretical analysis and simulation results.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 I
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• pp.512-516
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• 2001

It is recent trend that the manufactures of refrigerator use BLDC motor which RPM is changed by voltage of DC power, instead of induction motor in order to reduce energy consumption and noise radiation. It can be controlled two or more RPM suitable to environmental condition. For example it is operate much lower RPM than normal(usual) in the night. This paper introduce the method of noise control in the case of using BLDC Fan motor for refrigerator.

• 한국해양학회지
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• 제19권2호
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• pp.195-199
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• 1984

풍파발생초기 세계에서 바람에 의해 형성된 취송류가 초기 단계의 파의 특성을 결정하는데 미치는 영향을 이론적으로 다루었다. 본 연구의 관점은 Phillips(1957)의 풍파발생이론의 관점과 유사하다. 취송류를 고려하면 Phillips가 구한 결과를 상당히 변경시키는 것으로 판명되었다. 특히 공명 조건에 있어서 취송류가 큰 역할을 하고 있다.

• Journal of Korean Neurosurgical Society
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• 제37권2호
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• pp.157-159
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• 2005

The authors present two cases of intrasellar schwannoma, a condition rarely reported in the literature. The patients presented with symptoms of hypopituitarism. Sellar magnetic resonance imaging(MRI) revealed intrasellar masses extending into the suprasellar region, with the normal pituitary gland also identifiable in the imaging study. The tumors were removed via trans-sphenoidal route, and found to be very firm, unlike usual pituitary adenomas. Tissue diagnosis confirmed the tumors as schwannoma.

• 대한방사선협회지
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• 제28권1호
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• pp.153-160
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• 2002

The MRI to be established currently in march in pusan city medical treatment engine about the activate situation on hand current situation of the operation accrual condition we investigate from 2002 year February 8 days of march 9. 2002 the analysis exami

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.779-781
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• 2005

In this paper, Firstly, it is shown that the bending mode vibration source of vertical pump system is comparatively large because resonance. Secondly in order to reduce the bending mode vibration of vertical pump, The improvement of some boundary condition have been developed and its effectiveness is investigated as appling it at the vertical pump system pratically.

• Journal of Advanced Marine Engineering and Technology
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• 제9권3호
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• pp.214-224
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• 1985

In this paper, some theoretical equations are derived to calculate natural frequencies and their modes of a portal type derrick system and developed a computer program to carry out their calculations. The ship's structures, such as funnels, upper decks, engine structures, shaft systems suffer local vibrations of the ship. The exciting forces of vibrations are induced by the bearing force and the surface force of propeller or by the main engine. For solving the vibration problem of riggings like the derrick system the natural frequency of its system must be exactly estimated as far as possible and its resonance condition must be kept out of the normal engine operating speed range. When some severe resonances are encountered after the ship's launching, it may be required a tremendous cost to amend their condition. An experimental model of the portal type derrick is made, which is composed of two posts and a truss. This experimental model is excited by an electrical-magnet, and its vibration responses are found out. The calculating results of the model by the developed computer program are compared with those of measured values of model experiment, and they show fairly good agreements.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.702-707
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• 2007

A Color Discerning Device(CDD) is the equipment to use in a Rice Processing Complex(RPC). A CDD can sorting discolored grain according to light and shade. The existing a CDD's driving performance is not so good as overseas machine. Besides, transportation process causes a defect in the mechanism from impact or harmonic excitation or etc. This study is represented the problem of CDD through experiment and simulation on a CDD. To analysis the problem of driving condition, devide each part of CDD for performed modal analysis. The problem of driving of driving condition and transportation process solved by carry out modal analysis and static analysis.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.571-576
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• 2006

A Color Discerning Device(CDD) is the equipment to use in Rice Processing Complex(RPC). By use a high-speed charge-coupled device camera, CDD can sorting discolored grain according to light and shade. The existing CDD's driving performance is not so good as overseas machine. Besides, transportation process causes a defect in the mechanism from impact or harmonic excitation or etc. This study is represented the problem of CDD through modal analysis and static analysis by using ANSYS workbench. To analysis the problem of driving condition, devide each part of CDD for performed modal analysis. The problem of driving condition and transportation process solved by carry out modal analysis and static analysis.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.340-343
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• 2007

In this paper, we present our method to reduce vibration of the base plate of a refrigerator by avoiding resonance between base plate and compressor operation. To verify the modes of the base plate, FE models of the base plate with free-free condition and applied boundary condition were built and validated by results from experimental modal analysis. Operating Deflection Shape analysis was applied to find the sensitive area on the base plate during compressor operation. In optimization process, Finite Difference Method - based sensitivity analysis is used to detect the most sensitive area. Finally, based on this numerical result, we will make beads on the base plate to reduce vibration of refrigerator.