• Proceedings of the Computational Structural Engineering Institute Conference
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• 1997.04a
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• pp.11-18
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• 1997

Mechanical properties of a composite mixed by components with known material properties are numerically predicted at various volume fractions rather than investigated through experiments. The properties, elastic modulus and Poisson's ratio, are estimated by minimizing the error between the static displacements computed from a model for the composite and those computed from a model of homogeneous and isotropic material. A finite element model for a composite is proposed to distribute different types of material components easily into the model depending on the volume fraction. Mechanical properties of a composite filled with solid mircospheres are predicted numerically through a sample study and the estimated results are compared with experimental results and some theories.

• Applied Science and Convergence Technology
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• v.26 no.2
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• pp.30-33
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• 2017

ZnO thin films which were deposited by RF magnetron sputtering system were annealed by furnace and insitu heat treatment methods. We investigated the effect of heat treatment method on physical properties of ZnO thin films. The structural and optical properties of ZnO thin films were improved by heat treatment. Through the annealing treatment of ZnO film by furnace, the good crystallinity and ultraviolet emission were obtained. These results are attributed to the improved formation of Zn-O bond in ZnO thin film annealed at by furnace. We confirm that the formation of Zn-O bond plays an important role in obtaining the excellent structural and optical properties of ZnO thin films.

• Structural Engineering and Mechanics
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• v.30 no.4
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• pp.481-500
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• 2008

In this paper, a model updating technique in dynamics is used to identify elastic properties for pultruded GFRP-Glass Fiber Reinforced Plastic framed structural systems used in civil construction. Traditional identification techniques for composite materials may be expensive, while this alternative approach allows to identify several properties simultaneously, with very good precision. Furthermore, the procedure of a non-destructive type has a relatively simple implementation. Properties describing the mechanical behavior for beam and shell finite element modeling are identified. The used formulation is based on the minimization of eigensolution residuals. Important points concerning model updating procedures have been observed, such as the particular vibrational behavior of the test structure, the modeling strategies and the optimal placement of the sensors in the experimental procedure. Results obtained by experimental tests show the efficiency of the proposed procedure.

• Electrical & Electronic Materials
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• v.8 no.6
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• pp.787-794
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• 1995

To improvement the magnetic and frequency properties of YIG(Yttrium-Iron Garnet) in microwave region, it is investigated that the effect of $Al^{3+}$ ions on magnetic and frequency characteristics of YIG, using samples of basic YIG composition( $Y_{3}$F $e_{5}$ $O_{l2}$) added with A1$_{2}$ $O_{3}$ from 0 to 2.5 [mol%]. The measurment is conducted mainly for the structural properties and magnetical properties. The structural properties is measured using SEM(Scanning Electro Microscope), EDX(Energy-dispersive X-ray spectrometer) and XRD(X-ray diffraction equipment). The magnetical properties is measured with B-H curve tracer and impedance analyzer. As a result, it is confin-ned that the effect of eddy current loss is minimized while maintaining high saturation flux density of YIG, when YIG is added with 0.5 [mol%] of A1$_{2}$ $O_{3}$.>.>.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.145-146
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• 2005

Cadmium sulphide (CdS) films have been prepared on polycarbonate (PC), polyethylene terephthalate (PET), and Coming 7059 substrates by r.f. magnetron sputtering technique at room temperature. A comparison of the properties of the films deposited on polymer and glass substrates was performed. In addition, the effect of the sputter pressure on the structural and optical properties of these films was evaluated.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.1
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• pp.33-38
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• 2021

Using facing target magnetron sputtering (FTMS) with a graphite target source, carbon nitride thin films were deposited on silicon and glass substrates at different substrate temperatures to confirm the tribological, electrical, and structural properties of thin films. The substrate temperatures were room temperature, 150℃, and 300℃. The tribology and electrical properties of the carbon nitride thin films were measured as the substrate temperature increased, and a study on the relation between these results and structural properties was conducted. The results show that the increase in the substrate temperature during the fabrication of the carbon nitride thin films increased the hardness and elastic modulus values, the critical load value was increased, and the residual stress value was reduced. Moreover, the increase in the substrate temperature during thin-film deposition was attributed to the improvement in the electrical properties of carbon nitride thin film.

• Journal of the Semiconductor & Display Technology
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• v.22 no.2
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• pp.87-95
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• 2023

TiO₂ thin films were grown using the Atomic Layer Deposition (ALD) and their structural and electrical properties were investigated. The crystal structure, dielectric constant, and surface roughness of the TiO₂ thin films grown by the ALD deposition method were studied. The grown TiO₂ thin films showed an anatase crystal structure, and their properties varied with temperature. In particular, the properties of the TiO₂ thin films were confirmed by changing the process temperature. The electrical properties of Metal-Insulator-Silicon (MIS) capacitor structures were analyzed using a probe station. The performance improvement of capacitors using TiO₂ as a dielectric was confirmed by measuring capacitance through Capacitance-Voltage (C-V) curves.

• Structural Engineering and Mechanics
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• v.33 no.1
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• pp.109-112
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• 2009

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.169-169
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• 2012

The high-temperature superconductor YBa2Cu3O7-x (YBCO) have attached attentions because of a high superconducting transition temperature, low surface resistance, high superconducting critical current density (Jc), and superior superconducting capability under magnetic field. Moreover, the Jc of YBCO superconductors can be enhanced by adding impurities to the YBCO films for vortex-pinning. Understanding and controlling pinning centers are key factors to realize high Jc superconductors. We synthesized vertically-aligned ZnO nanorods on SrTiO3 (STO) substrates by catalyst-free metal-organic chemical vapor deposition (MOCVD), and subsequently, deposited YBCO films on the ZnO nanorods/STO templates using pulsed laser deposition (PLD). The various techniques were used to analyze the structural and interfacial properties of the YBCO/ZnO nanorods/STO hybrid structures. SEM, TEM, and XRD measurements demonstrated that YBCO films on ZnO nanorods/STO were well crystallized with the (001) orientation. EXAFS measurements from YBCO/ZnO nanorods/STO at Cu K edge demonstrated that the local structural properties around Cu atoms in YBCO were quite similar to those of YBCO/STO.

• Earthquakes and Structures
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• v.6 no.4
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• pp.335-350
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• 2014

Historical masonry mosques are the most important structures of Islamic societies. To estimate the static and dynamic behavior of these historical structures, an examination of their restoration studies is very important. In this study, Kara Mustafa Pasha Mosque, which was built as a domed mosque by Kara Mustafa Pasha between 1666-1667 in Amasya, Turkey, has been analyzed. This study investigates the structural behavior and architectural features of the mosque. In order to determine specific mechanical properties, compression and three-point bending tests were conducted on materials, which have similar age and show similar properties as the examined mosque. Additionally, a three-dimensional finite element model of the mosque was developed and the structural responses were investigated through static and dynamic analyses. The results of the analyses were focused on the stresses and displacements. The experimental test results indicate that the construction materials have greatly retained their mechanical properties over the centuries. The obtained maximum compression and tensile stresses from the analyses have been determined as smaller than the materials' strengths. However, the stresses calculated from dynamic analysis might cause structural problems in terms of tensile stresses.