• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.597-600
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• 2009

Sound transmission loss (TL) is experimently investigated on the multi-layered panel used for the floor of a tilting train. Measurement of the intensity transmission loss is performed according to ASTM E 2249-02. The floor structure consists of corrugated steel panel, glass wool, plywood and cover. On the corrugated steel panel, TL drop by local resonance is considered and the TL improvement effect by damping treatment is estimated. Total sound transmission loss of the entire floor structure is obtained and the contribution of each layer is examined.

• Structural Engineering and Mechanics
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• v.44 no.5
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• pp.571-584
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• 2012

Appropriate assessment of lateral capacity of pile foundation is known to be a complex problem involving soil-structure interaction. Having reviewed the available methods in brief, relative paucity of simple and rational technique to evaluate lateral capacity of pile in layered soil is identified. In this context, two efficient approaches for the assessment of lateral capacity of short pile embedded in bi-layer cohesive deposit is developed. It is presumed that the allowable lateral capacity of short pile is generally dictated by the permissible lateral displacement within which pile-soil system may be assumed to be elastic. The applicability of the scheme, depicted through illustration, is believed to be of ample help at least for practical purpose.

• Journal of information and communication convergence engineering
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• v.4 no.2
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• pp.88-91
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• 2006

In this paper, a novel physical structure for planar spiral inductors is proposed. The spiral inductors were designed and fabricated on multi-layered substrate Bragg-reflector/silicon (BR/Si) wafer. The impacts of multi-layered structure substrate and pattern on characteristics of inductor were studied. Experimental results show that the inductor embedded on Bragg reflector/silicon substrate can achieve the best improvement. At 0.4-1.6 GHz, the Bragg reflector seems to significantly increase the S11-parameter of the inductor.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.3
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• pp.242-247
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• 2009

The ability of time reversal techniques to focus ultrasonic beams on the source location is important in many aspects of ultrasonic nondestructive evaluation. In this paper, we investigate the time reversal beam focusing of ultrasonic array sensors on a defect in layered media. Numerical modeling is performed using the commercially available software which employs a time domain finite difference method. Two different time reversal approaches are considered - the through transmission and the pulse-echo. Linear array sensors composed of N elements of line sources are used for signal reception/excitation, time reversal, and reemission in time reversal processes associated with the scattering source of a side-drilled hole located in the second layer of two layer structure. The simulation results demonstrate the time reversal focusing even with multiple reflections from the interface of layered structure. We examine the focusing resolution that is related to the propagation distance, the size of array sensor and the wavelength.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.4
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• pp.391-397
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• 2001

The guided wave propagation in inhomogeneous multi-layered structures is experimentally explored based on theoretical dispersion curves. It turns out that proper selection of incident angel and frequency is critical for guided wave generation in multi-layered structures. Theoretical dispersion curves greatly depend on adhesive zone thickness, layer thickness and material properties. It was possible to determine the adhesive zone thickness of an inhomogeneous multi-layered structure by monitoring experimentally the change of dispersion curves.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.3
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• pp.468-477
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• 1994

Existing fuzzy control methods do not perform well when applied to systems containing nonlinearities arising from unkonwn deadzones. In particular, we show that a conventional fuzzy logic controller applied to a system with a deadzone suffers from poor transient performance and a large steady-syate error. In this paper, we propose a novel two-layered fuzzy logic controller for controlling systems with deadzones. The two-layered control structure consists of a fuzzy logic-based precompensator followed by a conventional fuzzy logic controller. Our proposed controller exhibits superior transient and steady-state performance compared to conventional fuzzy controllers. In addition, the controller is robust to variations in deadzone nonlinearities. We illustrate the effectiveness of our scheme using computer simulation examples.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.255-258
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• 2006

In this paper, a novel physical structure for planar spiral inductors is proposed. The spiral inductors were designed and fabricated on multi-layered substrate Bragg-reflector/silicon (BR/Si) wafer. The impacts of multi-layered structure substrate and pattern on characteristics of inductor were studied. Experimental results show that the inductor embedded on Bragg reflector/silicon substrate can achieve the best improvement. At 0.4-1.6 GHz, the Bragg reflector seems to significantly increase the $S_{11}-parameter$ of the inductor.

• Bulletin of the Korean Chemical Society
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• v.14 no.1
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• pp.132-137
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• 1993

The electronic structure of two dimensional layered compound, FeOCl, is studied with the band model and the cluster model approximation employing Extended-Huckel (EH) method. We examine the effects of intercalation (e.g., localization of transferred electron, conductivity increase). FeOCl has the electronic structure typical for layered compounds as expected. For FeOCl-$Li_{1/2}$ system, the charge transfer from Li to the FeOCl lattice occurs, and electrons are built up almost exclusively on Fe atoms. The partially filled band of FeOCl-$Li_{1/2}$ complex is responsible for the increase in conductivity.

• Nano
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• v.13 no.12
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• pp.1850138.1-1850138.6
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• 2018

Two-dimensional (2D) or layered materials have a great potential for applications in energy storage, catalysis, optoelectronics and gas separation. Fabricating novel 2D or quasi-2D layered materials composed of relatively abundant and inexpensive atomic species is an important issue for practical usage in industry. Here, we suggest the layer-structured AlOOH (Boehmite) as a promising candidate for such applications. Boehmite is a well-known layer-structured material and a single-layer can be exfoliated from the bulk boehmite by breaking the interlayer hydrogen bonding. We study atomic and electronic band structures of both bulk and single-layer boehmite, and also obtain the single-layer exfoliation energy using first-principles calculations.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.04b
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• pp.289-296
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• 2000

This paper presents a method of seismic analysis for a 2-D fluid-structure-soil interaction systems. With this method, the fluid can be modeled by spurious free 4-node displacement-based fluid elements which use rotational penalty and mass projection technique in conjunction with the one point reduced integration scheme to remove the spurious zero energy modes. The structure and the near-field soil are discretized by the standard 2-D finite elements, while the unbounded far-field soil is represented by the dynamic infinite elements in the frequency domain. Since this method directly models the fluid-structure-soil interaction systems, it can be applied to the dynamic analysis of a 2-D liquid storage structure with complex geometry. Finally, results of seismic analyses are presented for a spent fuel storage tank embedded in a layered half-space and a massive concrete dam on a layered half-space.