• Proceedings of the KSME Conference
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• 2000.11a
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• pp.111-116
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• 2000

A semi-infinite interfacial crack propagated with constant velocity in two bonded anisotropic strip under out-of-plane clamped displacements is analyzed. The asymptotic stress and displacement fields near the crack tip are obtained, where the results get more general expressions applicable not only to isotropic/orthotropic materials but also to the extent of the anisotropic material having one plane of elastic symmetry for the interfacial crack. The dynamic stress intensity factor is obtained as a closed form, which is decreased as the velocity of crack propagation increases. The critical velocity where the stress intensity factor comes to zero is obtained, which agrees with the lower value between the critical values of parallel crack merged in the material 1 and 2 adjacent to the interface. The dynamic energy release rate is also obtained as a form related to the stress intensity factor.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.970-976
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• 2003

In this paper, we analyse and present electro-mechanical dynamic characteristics of a micro-machined vibrating silicon ring gyroscope which can measure angular velocities about three orthogonal axes. The ring gyroscope has a ring connected to the gyroscope main body by support-ligaments which are arranged with cyclic symmetry. The natural modes of its vibration can be distinguished into the in-plane motion and the out-of-plane motion which are coupled by the gyro-effect due to the notation of the gyroscope main body. The motions of the ring are electro-statically derived, sensed and balanced by electrodes. The equations of motion are formulated. The scheme of angular velocities sensing by force-to-rebalance method is presented. The dynamic characteristics of a ring gyroscope are calculated and compared.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.12
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• pp.999-1006
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• 2014

Mindlin plate theory includes the shear deformation and rotatory inertia effects which cannot be negligible as exciting frequency increases. The statistical methods such as energy flow analysis(EFA) and statistical energy analysis(SEA) are very useful for estimation of structure-borne sound of various built-up structures. For the reliable vibrational analysis of built-up structures at high frequencies, the energy transfer relationship between out-of-plane waves and in-plane waves exist in Mindlin plates coupled at arbitrary angles must be derived. In this paper, the new wave transmission analysis is successfully performed for various energy analyses of Mindlin plates coupled at arbitrary angles.

• Journal of the Korean Society of Safety
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• v.14 no.1
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• pp.199-207
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• 1999

The differential quadrature method (DQM) is applied to computation of eigenvalues of the equations of motion governing the free in-plane and out-of-plane vibrations for circular curved beams. Fundamental frequencies are calculated for the members with various end conditions and opening angles. The results are compared with existing exact solutions and numerical solutions by other methods (Rayleigh-Ritz, Galerkin or FEM) for cases in which they are available. The differential quadrature method gives good accuracy even when only a limited number of grid points is used.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.1
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• pp.105-112
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• 2013

This paper presents the structural design and finite element analysis of precision stage based on a double triangular parallel mechanism for precision positioning and large force generation. Recently, with the acceleration of miniaturization in mobile appliances, the demand for precision aligning and bonding has been increasing. Such processes require both high precision and large force generation, which are difficult to obtain simultaneously. This study aimed at constructing a precision stage that has high precision, long stroke, and large force generation. Actuators were tactically placed and flexure hinges were carefully designed by optimization process to constitute a parallel mechanism with a double triangular configuration. The three actuators in the inner triangle function as an in-plane positioner, whereas the three actuators in the outer triangle as an out-of-plane positioner. Finite element analysis is performed to validate load carrying performances of the developed precision stage.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.12
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• pp.1001-1009
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• 2002

In this paper, we analyse and present mechanical dynamic characteristics of a micro-machined vibrating silicon ring gyroscope which can measure angular velocities about three orthogonal axes. The ring gyroscope has a ring connected to the gyroscope main body by support-ligaments which are arranged with cyclic symmetry. The natural modes of its vibration can be distinguished into the in-plane motion and the out-of-plane motion which are coupled by the gyro-effect due to the rotation of the gyroscope main body. The equations of motion, the response to angular velocities, and the relationships between the natural modes of vibration are derived and compared with the previous studies for the design of a micro three-axis ring gyroscope.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.129-133
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• 2004

This paper is the result of a experimental study about non-linear one to one modal coupling of a flexible circular cantilever beam which was transversely excited with harmonic excitation. It was proved that 2 order jumping in out of plane was caused by jump phenomenon in in-plane of flexible circular cantilever beam, because of non-linear coupling. In addition, cantilever beam showed hardening spring characteristics in in-plane and softening spring characteristics in out-of-plane.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.553-557
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• 2000

Nonlinear Vibrations of a flexible circular ring is studied in this paper. Based upon the von Karman strain theory, the nonlinear governing equations are derived, in which the in-plane bending and extension displacements as well as the out-of-plane bending displacement are fully coupled. After discretizing the governing equations by the Galerkin approximation method, we obtain the linearlized equation by using the pertubation method. The analysis results from the linearlized equations show that the in-plane displacement has effects on the natural frequencies of the out-of-plane displacement.

• The korean journal of orthodontics
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• v.21 no.2 s.34
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• pp.367-397
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• 1991

This study was aimed to investigate the occlusal plane inclination in relation to the skeletal and dental assessment measurements in order to provide a reference in orthodontic treatment planning as the occlusal plane should be reconstructed orthodontically or gnathologically. The sample consisted of 73 normal occlusions and 113 malocclusions of adults. The computerized statistical analysis of 38 occlusal plane's and 29 skeletal and dental measurements were carried out with SPSS. The conclusions were as follows; 1 In normal occlusion, COP-NaPog was average $83.63^{\circ}$ (2.44) and occlusal plane inclination had a strong negative correlation with SNB and FH-NaPog. 2. In normal occlusion, ArANS plane was nearly parallel to the occlusal plane. 3. In malocclusion, the larger the mandibular plane angle and the shorter the ramus height was, the more downward the occlusal plane had a tendency to tip anteriorly. 4. Occlusal plane was more horizontal in deep bite group, while it was steeper in openbite group. 5. The curve of Spee was severe in deep bite group but in openbite group mandibular occlusal plane showed average reverse curvature, where it was found that the configuration of the occlusal plane contributed to the excess or deficiency of anterior overbite.

• The korean journal of orthodontics
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• v.20 no.1
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• pp.169-179
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• 1990

Utilizing the repelling force of permanent magnet of find out weather it shows the findings of molar intrusion histologically and compares the result with the resin bite plane. As for the experimental animals, 10 cats of completion of permanent dentition with mean weight of 2.2kg which have flat occlusal plane of molar areas were used. I raised the cats under the condition of their being attached with manufactured appliance by direct bonding system and of their wearing vertical chin strap anesthetized for 12-14 hours per day through 5 days. Then, observing the root apex areas with lightmicroscope. The results were as follows; 1. In the group with resin bite plane, osteoblasts and osteoclasts could not find out but could find out periodontal ligment fiber obliquely angulated in the apical and lingual direction. 2. In the group with the permanent magnet, not only the obliquely angulated periodontal ligament fiber but also the osteoclasts at the apical areas were observed.