• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.833-834
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• 2014

In recent years, a pattern recognition method has been widely used by researchers for fault diagnoses of mechanical systems. A pattern recognition method determines the soundness of a mechanical system by detecting variations in the system's vibration characteristics. Hidden Markov model has recently been used as pattern recognition methods in various fields. In this study, a HMM method for the fault diagnosis of a mechanical system is introduced, and a rotating machine with mass unbalance is selected for fault diagnosis. Moreover, a diagnosis procedure to identity the size of a defect is proposed in this study.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1321-1327
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• 2006

This paper presents the calculation of unbalanced magnetic pull (UMP) that causes rotor misalignment in induction motor. The excessive noise and vibration will be occurred by means of rotor misalignment. Angular misalignment of rotor will produce air-gap permeance wave which is function of axial and circumferential coordinate. In this paper, the UMP is calculated using permeance and magneto motive force (MMF) in the case of static and dynamic misalignment. Based on the percentage of misalignment, the result shows that the UMP and magnetic pressure are increased according to the increasing of misalignment. The UMP is occurred not only in It frequency component but also the others.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.8
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• pp.180-189
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• 1999

This paper describes the collapse characteristics of the rectangular tube under eccentric compressive load. Local buckling stress and maximum crippling load are investigated. A thin-walled tube under load is controlled by local buckling or yielding of material according to the ratio of thickness to width (t/b) of the cross section, and subsequent collapse of the section. The relationship can be divided into three regions : elastic , post-buckling and crippling . the load-displacement relationship is theoretically presented in each region by introducing the stress distribution of the cross section in the loading process. And the maximum load carrying capacity is derived in the closed form as a function of normal stress on the flange and web.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.9 no.1
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• pp.55-61
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• 1991

The accidential errors of horizontal angles are influenced by sighting, reading and eccentric errors etc. This paper deals with the influence of eccentric error by the formula of theory and evaluation, and actually testing measurement. The results show that the eccentric error is calculated through the sighting distance, observed angle, eccentric distance and angle. And then, three repeating method is of practical use, and also, eccentric error is able to evaluate through the sighting distance and observed angle in according to performance of each instrument.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.12-13
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• 2019

The bearing capacity of the wall against the eccentric load when the washbasin was attached on the ALC block wall was tested. Test methods are BS EN 14688 and BS 5234-2. Tests in accordance with BS EN 14688 showed that the holding capacity of steel was much stronger and more stable when HA-II (chemical anchor) was used than when the washbasin was fixed using HA-I (plastic anchor). As an experimental result according to the Annex K of BS 5234-2, the bearing capacity of ALC block wall corresponded to the "stage in which the force works(performance grade) 1,500N" for all of the cases where a washbasin is fixed using two types of the wall's dedicated anchors(HA-I and HA-II).

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.11
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• pp.1449-1458
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• 2004

The influence of eccentric(=staggeredness) ratio between stationary upstream circular cylinders on heat transfer characteristics of a heated downstream circular cylinder installed in a channel was investigated experimentally. In order to enhance the heat transfer rate of the heated downstream cylinder surface, we have changed the configuration of upstream cylinder. As a result, we were able to obtain local time-averaged convective heat transfer enhancement of the heated cylinder by the relative replacement of upstream cylinder. This is basically attributed to the mean flow structure change, such as flow separation, vortex shedding, and recirculation of the upstream cylinder including the reattachment and new thermal boundary developed at the downstream cylinder which are the results of the increase of the staggeredness ratio.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1863-1868
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• 2004

The present study concerns a computational study of fully developed laminar flow of a Newtonian fluid through an eccentric annulus with a combined bulk axial flow and inner cylinder rotation. This study considers the identical flow geometry as in the calculation of Escudier et $al.^{(3)}$ An unexpected feature of the calculations for eccentricity ${\varepsilon}$)0.7 is the appearance of a second peak in the axial velocity, located in the narrowing gap. The distribution of the axial component of the surface shear stress has a maximum in the narrowing gap and a minimum in the widening gap.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.792-797
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• 2004

Dynamic modeling of an eccentric MEMS gyroscope is presented and the dynamic characteristics of the gyroscope are investigated with the modeling method. It is found that the eccentricity of the MEMS gyroscope affects the dynamic characteristics significantly. Different from conventional MEMS gyroscopes, the zero-rate output is significantly reduced in this gyroscope. To obtain general guidelines of the gyroscope design, dimensionless parameters are first identified and the effects of the parameters on the gyroscope performance measures are investigated.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.6
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• pp.133-139
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• 2007

In this paper, optics polishing technology using adaptive tool and eccentric motion mechanism was suggested. Optics polishing can make high reflective and accurate surface. The optics polishing process based on the eccentric motion mechanism has been used to manufacture the ophthalmic lens mold. Also ophthalmic lens mold factory hold conventionally a lot of the curved polishing tools for the versatile mold curves of eye diopters and want to reduce tool numbers. Therefore, a polishing machine with adaptive airbag tool was developed and experimentally verified in view of surface roughness and form accuracy.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.306-309
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• 2010

강철도 플레이트거더교의 경우 일반적으로 레일의 폭보다 거더 사이의 폭이 넓기 때문에 거더에 편심이 작용하게 된다. 이러한 편심 영향으로 거더 내측 상부플랜지에 휨변형이 일어나게 되어, 상부플랜지와 수직보강재 용접이음부에 반복하중에 의한 피로균열이 발생되고 있는 것으로 보고되고 있다. 본 연구에서는 공용중인 강철도 플레이트거더교를 대상교량으로 하여 공용하중에 대한 구조해석을 실시하였다. 대상교량에 대한 현장계측을 기초로 구조모델링을 검증하였고, 검증된 구조모델링을 사용하여 열차하중 하에서의 상부플랜지와 수직보강재 용접연결부에서의 피로균열 보강방안에 대한 구조해석을 실시하였다. 또한 상부플랜지와 수직보강재 용접이음부 상세해석을 통하여 피로균열 발생위치를 확인하고 연결이음부의 적절한 보강방안을 제시하고자 한다.