• Structural Engineering and Mechanics
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• v.78 no.5
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• pp.557-572
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• 2021

The current study considers free vibration of the spherical panel with magnetorheological (MR) fluids core and magneto-electro-elastic face sheets. The panel is subjected to electro-magnetic loads and also is located on an orthotropic visco-Pasternak elastic foundation. To describe the displacement components of the structure, the first-order shear deformation theory (FSDT) is used and the motion equations are extracted by employing Hamilton's principle. To solve the motion differential equations, Navier's method is selected as an exact analytical solution for simply supported boundary conditions. Effect of the most important parameters such as magnetic field intensity, loss factor, multi-physical loads, types of an elastic medium, geometrical properties of the panel, and also different material types for the face sheets on the results is considered and discussed in details. The outcomes of the present work may be used to design more efficient smart structures such as sensors and actuators.

• Journal of the Korean Wood Science and Technology
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• v.20 no.3
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• pp.39-54
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• 1992

Hollow core wood flush doors for wardrobes, and other general openings and bathroom were designed and fabricated to investigate the factors causing the bowing of them and to find out the countermeasure for the phenomena. Balance in grain orientation, thickness, specific gravity and M.C.(%) of face panel and symmetrical construction were the essential factors to prevent the deflection of flush doors just after manufacturing. Under one-sided severe service condition, the unbalance of M.C. between opposite face panels is inevitable. So the material as thick plywood with high stiffness is considered as an alternative for the stile. UF resin mixing into PVAc emulsion is preferred for bathroom.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.9
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• pp.782-787
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• 2008

First, the effect of the geometry such as the curved shape of the struts composing the truss structure of WBK is elaborated. Then, analytic solutions for the material properties of WBK and the maximum loads of a WBK-cored sandwich panel under bending are derived. A design optimization with the face sheet thickness and the core height selected as the design variables is presented for given slenderness ratios of the WBK core. Unless the face sheet thickness is limited, the optimal design to give the maximum load per weight is always found at a confluence of three failure modes, namely, face sheet yielding, indentation plastic, and core shear modeB plastic.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.51-63
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• 2017

The touch panel was developed decades ago and has become a popular input device in daily life. Because human-computer interaction is becoming more important, the next generation of touch panels require stretchability and bio-compatibility to allow integration with the human body. However, because most touch panels were developed based on stiff, brittle electrodes, electronic touch panels face difficulties to achieve such requirements. In this paper, for the first time, we demonstrate an ionic touch panel based on polyacrylamide hydrogel containing LiCl ions. The panel is soft and stretchable and thus, can sustain a large deformation. The panel can freely transmit light information through it because the hydrogel is transparent, with 99 % transmittance for visible light. A 1-dimensional touch strip was investigated to reveal the basic mechanism of sensing, and a 2-dimensional touch panel was developed to demonstrate its functionalities. The ionic touch panel was operated under high deformation with more than 1000% areal strain without sacrificing its functionalities. Furthermore, an epidermal touch panel on the skin was developed to demonstrate the mechanical and optical invisibility of the ionic touch panel through writing words, playing the piano and playing games.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.617-620
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• 2007

The temporal dark image sticking phenomena for both the face-to-face and coplanar sustain electrode structures were compared. For both structures, the temporal dark image sticking phenomena were examined by measuring the difference in the IR emission, display luminance, perceived luminance, and temperature between the image sticking and the no image sticking cells. For the face-to-face structure, the 10-min sustain discharge causes a small increment of the panel temperature thanks to the ITO-less electrode structure, thereby resulting in mitigating the temporal dark image sticking phenomenon.

• Asian Journal for Public Opinion Research
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• v.4 no.2
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• pp.73-87
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• 2017

The Korean Academic Multimode Open Survey (KAMOS) is a national survey first conducted in 2016. Stratified cluster random sampling was used in an initial face-to-face survey during which panel members were recruited. The second survey allowed invited panel members to answer online or by phone. KAMOS includes both longitudinal items and omnibus items, i.e., researchers can propose questions to include on KAMOS. This paper seeks to establish that KAMOS is representative of the South Korean adult population. The demographic variables from the first survey were comparable to demographic variables from two well-respected surveys in South Korea: the KOSTAT Social Survey and the Gallup Korea Omnibus Survey. To ensure that there was no substantial difference between those who answered the first survey and those who answered the second survey, we compared the results of 22 items from the first survey. The 2,000 panel members who were invited to participate in the second survey had similar responses to the 1,008 of those who responded to the second survey. Based on our findings, KAMOS can be considered a representative sample.

• Aerospace Engineering and Technology
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• v.9 no.1
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• pp.9-16
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• 2010

In this study, structural analyses were carried out on the composite sandwich panel which was tested under compression loading. In the structural analyses, three types of finite element modelling were considered and linear buckling analysis and nonlinear analysis were performed for each FE-model. Through the analyses, it was found that shell elements for face parts and solid elements for core part were appropriate for the better prediction of the buckling load of the panel. If the material failure of the face is critical than overall buckling of the sandwich panel, the use of one shell element through the thickness direction was suitable in the FE-model for the better predictions of failure location and failure load.

• Journal of the Society of Naval Architects of Korea
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• v.44 no.5
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• pp.467-473
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• 2007

Cavitation phenomena appearing on ship propellers have long been interested and recent theoretical analysises give good results comparing with model tests. In accordance with a continuous rise in heavy powered and high speed ships, hull forms have been changed and loads acting on the propeller surface have also been increased, and they result in various and particular cavitations. In some cases, cavitation appears not only on the back but also on the face of the propeller and it causes additive pressure fluctuations and erosion of the propeller and reduces propulsion efficiency of the ship. In this study, we predict the face cavity inception using unsteady propeller analysis based on the panel method and compare the results with experimental observations.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.998-1002
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• 2004

As the public use part of the railway and the road, the railway crossing is important to work properly by two transportation means. Also, It is important to provide the good face of friction on the railway crossing in aspect of protecting the railway crossing accident. Lately, Many kinds of the material are used for railway crossing panel. As they have a various fault, it was studied to analyze the structural action of the new material, rubber panel. This paper analyzed stress and displacement by truck passing weight using the Finite Element Modeling.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.459-466
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• 2001

As the Public use part of the railway and the road, the railway crossing is important to work properly by two transportation means. Also, It is important to provide the good face of friction on the railway crossing in aspect of protecting the railway crossing accident. Lately, the material of railway crossing panel is the wood, the asphalt, and the steel. As they have a various fault, it was studied to analyze the structural action of the new material, rubber panel. This paper analyzed eigenvalue, stress and displacement by truck passing weight, thermal stress and train moving weight, using the FEM model.