• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.653-654
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• 2006

This paper proposes a new linear magnetic damper for absorbing shock from a crash accident involving high speed vehicles. The magnetic damper is composed of a conductive plate, a yoke and permanent magnets which are constructed to a Halbach array to improve the damping force. In order to calculate the damping force, finite element analysis(FEA) using J-Mag, a commercial FEA tool, is performed and the results are validated by the experiment. Also, the design optimization of the plate generating the eddy current causing the damping force performed to obtain the most efficient damping force. Finally, the specifications and the performance of the proposed magnetic damper are represented.

• Journal of the Semiconductor & Display Technology
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• v.2 no.3
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• pp.31-36
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• 2003

On this study, an E.E(End-Effector) for the 300 mm wafer transfer robot system is newly suggested. It is a mechanical type with $180^{\circ}$ rotating ranges and is composed of 3-point arms, two plate springs and single-axis DC motor controlled by microchip. To design, relationship between the gripping force and the wafer deformation is analyzed by FEM. By analytic results, the gripping force for 300 mm wafer is confirmed as 255~274 gf. From experimental results on gripping force, repeatable position accuracy and gripping cycle times in a wafer cleaning system, we confirmed that the suggested E.E was well designed to satisfiy on the required performance for 300 mm wafer transfer robot system.

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.1
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• pp.11-23
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• 2011

In this study, a finite element(FE) analysis on electro-mechanical impedance response of cable-anchor connection interface under various anchor force is presented. In order to achieve the objective, the following approaches are implemented. Firstly, an interface washer coupled with piezoelectric(PZT) material is designed for monitoring cable-force loss. The interface washer is a small aluminum plate on which a PZT patch is surface-bonded. Cable-force loss could be monitored by installing the interface washer between the anchor plate and the anchorage of cable-anchor connection and examining the changes of impedance of the interface washer. Secondly, a FE model for cable-anchor connection is established to examine the effect of cable-force on impedance response of interface washer. Also, the effects of geometrical and material properties of the interface washer on impedance responses under various cable-forces are investigated. Finally, validation of the FE analysis is experimentally evaluated by a lab-scale cable-anchor connection.

• Journal of the Korean Society of Safety
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• v.12 no.4
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• pp.108-113
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• 1997

Plate anchors are primarily used in the foundation construction of earth-supported and earth-retaining structures. In order to estimate uplift capacity as well as suction force of clay, model tests were peformed with respect to various embedment depths and two different moisture contents in the prepared saturated kaolinite. Further, suction effects on the ultimate uplift capacity, at the various embedment depths of anchor, were also taken into account. Test results show that ultimate uplift capacity including suction force increases from 4.2kg at H/D=1 upto 11.6kg at H/D=5 in K1 and from 2.3kg at H/D=1 upto 7.3kg at H/D=5 in K2 respectively. The ratio of $F_s/Q_n/$ decreases along with the increases in the embedment ratio. In general, mud suction force under the ultimate uplift capacity in kaolinite decreases or becomes constant along with the increase of the embedment ratio.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.356-363
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• 2003

The CWR of the plate girder bridges in non-ballast causes the additional axial force on the rail and the bearing due to the temperature axial force and the interaction between the CWR and bridges. This study shows the remarkable improvement of reducing the axial force of the CWR on the non-ballast bridge, compared to conventional methods. New method, which is differently designed in terms of longitudinal semi-rigid bearing, reduces the axial force on the bearing by making the girder act both directions. This method is applicable to most cases of bridges regardless of the restriction of length, and useful to reduce the abrasion and damage of the track material.

• Structural Engineering and Mechanics
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• v.34 no.1
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• pp.1-14
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• 2010

The innovative intelligent fuzzy weighted input estimation method which efficiently and robustly estimates the unknown time-varying input force in on-line is presented in this paper. The algorithm includes the Kalman Filter (KF) and the recursive least square estimator (RLSE), which is weighted by the fuzzy weighting factor proposed based on the fuzzy logic inference system. To directly synthesize the Kalman filter with the estimator, this work presents an efficient robust forgetting zone, which is capable of providing a reasonable compromise between the tracking capability and the flexibility against noises. The capability of this inverse method are demonstrated in the input force estimation cases of the plate structure system. The proposed algorithm is further compared by alternating between the constant and adaptive weighting factors. The results show that this method has the properties of faster convergence in the initial response, better target tracking capability, and more effective noise and measurement bias reduction.

• Journal of Korean Society of Steel Construction
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• v.15 no.3
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• pp.291-298
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• 2003

Recently, as the size of buildings structure becomes large increases, their mat area of building structure is supported or by an inhomogeneous foundation. This paper presents a vibration analysis on thick plates subjected to in-plane force is presented in this paper. The rectangular plate is isotropic, homogeneous, and composed of a linearly elastic material. A vibration analysis of the rectangular thick plate iwas done by useing ofarectangular finite element with 8 nodes and 9 nodes. In this study, the foundation was idealized as a Pasternak foundation model. A Pasternak foundation haves a shear layer on Winkler's model, which idealizes the foundation as a vertical spring. In order tTo analysze the vibration of a plate supported on by an inhomogeneous Pasternak foundation, the value of the Winkler foundation parameter of the central and border zones of the plate awere chosen as WFP1 and WFP2. (fFigure 4.). The Winkler foundation parameter of WFP1 and WFP2 is varied from 0 to 10, $10^2$, and $10^3$ and the shear foundation parameters is were 0, 5, and 10. The ratio of the in-plane force to the critical load iwas applied as 0.4 to 0.8

• Journal of Korean Association for Spatial Structures
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• v.10 no.4
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• pp.75-83
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• 2010

Laminated composite plates have shown their superiority over metals in applications requiring high specific strength, high specific modulus, and so on. Therefore, they have used in various industry. However, they have poor resistance to impact compared to typical metal materials. So, many researchers have investigated about impact behavior of laminated composite plate. To investigate impact behavior of laminated composite plate, we have to calculate contact force between impactor and laminated composite plate at the first. Impactor's equation of motion, plate's equation of motion and correlations for indentation were solved to know the contact force at the same time. In this study, low velocity impact behavior of composite plate was investigated using the finite element program which is involved the classical Hertzian law, Sun's law and Sun & Yang's experimental law and Sun & Tan's experimental law considering the stacking method.

• Asian Spine Journal
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• v.12 no.6
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• pp.967-972
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• 2018

Study Design: Biomechanical study. Purpose: To investigate the relative stiffness of a new posterior pelvic fixation for unstable vertical fractures of the sacrum. Overview of Literature: The reported operative fixation techniques for vertical sacral fractures include iliosacral screw, sacral bar fixations, transiliac plating, and local plate osteosynthesis. Clinical as well as biomechanical studies have demonstrated that these conventional techniques are insufficient to stabilize the vertically unstable sacral fractures. Methods: To simulate a vertically unstable fractured sacrum, 12 synthetic pelvic models were prepared. In each model, a 5-mm gap was created through the left transforaminal zone (Denis zone II). The pubic symphysis was completely separated and then stabilized using a 3.5-mm reconstruction plate. Four each of the unstable pelvic models were then fixed with two iliosacral screws, a tension band plate, or a transiliac fixation plus one iliosacral screw. The left hemipelvis of these specimens was docked to a rigid base plate and loaded on an S1 endplate by using the Zwick Roell z010 material testing machine. Then, the vertical displacement and coronal tilt of the right hemipelves and the applied force were measured. Results: The transiliac fixation plus one iliosacral screw constructions could withstand a force at 5 mm of vertical displacement greater than the two iliosacral screw constructions (p=0.012) and the tension band plate constructions (p=0.003). The tension band plate constructions could withstand a force at $5^{\circ}$ of coronal tilt less than the two iliosacral screw constructions (p=0.027) and the transiliac fixation plus one iliosacral screw constructions (p=0.049). Conclusions: This study proposes the use of transiliac fixation in addition to an iliosacral screw to stabilize vertically unstable sacral fractures. Our biomechanical data demonstrated the superiority of adding transiliac fixation to withstand vertical displacement forces.

• Steel and Composite Structures
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• v.42 no.2
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• pp.277-288
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• 2022

A novel flat steel plate-concrete-corrugated steel plate (FS-C-CS) sandwich panel was proposed for resisting impact load. The failure mode, impact force and displacement response of the FS-C-CS panel under impact loading were studied via drop-weight impact tests. The combined global flexure and local indentation deformation mode of the FS-C-CS panel was observed, and three stages of impact process were identified. Moreover, the effects of corrugated plate height and steel plate thickness on the impact responses of the FS-C-CS panels were quantitatively analysed, and the impact resistant performance of the FS-C-CS panel was found to be generally improved on increasing corrugated plate height and thickness in terms of smaller deformation as well as larger impact force and post-peak mean force. The Finite Element (FE) model of the FS-C-CS panel under impact loading was established to predict its dynamic response and further reveal its failure mode and impact energy dissipation mechanism. The numerical results indicated that the concrete core and corrugated steel plate dissipated the majority of impact energy. In addition, employing end plates and high strength bolts as shear connectors could prevent the slip between steel plates and concrete core and assure the full composite action of the FS-C-CS panel.