• 한국실내디자인학회논문집
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• 제15권5호
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• pp.112-119
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• 2006

This study intends to understand the visual experience of architectural space generated by users' movement based on the interpretation of visual properties. An analytic theory of Isovist is suggested for the objective and comparable measurement for such visual experience, and a computer program for the analysis has been proposed as well. By using the analytical theory and computer program, eight houses designed by Adolf Loos and Le Corbusler are analyzed for the purpose of understanding the visual characteristics of the Modern Architecture and the contemporaries. The result shows that, while the architectural space of Loos emphasizes personal privacy as for being livable spaces, the architectural space of Corbusier emphasizes users' movement as for including diverse visual arrays. These commensurable results exhibit that the analytical tool and research frame suggested in this study can be a competitive tool for such analysis.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.427-432
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• 2003

An analytical method to predict the flexural behavior of composite girder is presented in which the early-age properties of concrete are specified including maturing of elastic modulus, creep and shrinkage. The time dependent constitutive relation accounting for the early-age concrete properties is derived in an incremental format by expanding the total form of stress-strain relation by the first order Taylor series with respect to the reference time. The sectional analysis calculates the axial and curvature strains based on the force and moment equilibriums. The deflection curve of the box girder approximated by the quadratic polynomial function is calculated by applying to the proper boundary conditions in the consecutive segments. Numerical applications are made for the 3-span double composite steel box girders which is a composite bridge girder filled with concrete at the bottom of the steel box in the negative moment region. The one dimensional finite element analysis results are compared with those of the three dimensional finite element analysis and the analytical method based on the sectional analysis. Close agreement is observed among the three methods.

• 한국구조물진단유지관리공학회 논문집
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• 제7권1호
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• pp.131-138
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• 2003

This paper presents an analytical prediction of the prestress losses of prestressed concrete bridges. In this study a numerical procedure and computer program is developed to analyze the behavior of prestressed concrete bridges considering the time-dependent properties of material. It accounts for the aging, creep and shrinkage of concrete and the stress relaxation of prestressed steel. The structural model uses two dimensional plane frame elements with three nodal degree of freedom and is analyzed based on the finite element method. Member cross section can consist of concrete, reinforcement and prestressing steel. Two different set of equations for the prediction of time-dependent material properties of concrete are presented, which are ACI, CEB-FIP. The proposed numerical method for the prestress losses of prestressed concrete bridges is verified by comparison with reliable experimental results.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.420-423
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• 2003

This paper addresses the results of experimental and analytical study on the effects of dynamic interaction between vehicle and bridge on modal properties of bridge. Based on ambient vibration test and vehicle impact test on a bridge, it is found that the natural frequencies of bridge are varied by vehicle passing. Analytical studies for the effects of vehicle position, speed, damping, mass ratio and frequency ratio on bridge-vehicle interaction are carried out using complex eigenvalue analysis and numerical integration in time domain. The results show that vehicle properties except speed cause significant change of natural frequency as well as damping of bridge.

• Structural Engineering and Mechanics
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• 제59권2호
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• pp.227-241
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• 2016

A circular plate with constant thickness, finite radius and stiff edge lying on an elastic halfspace is considered. The half-space consists of a soft functionally graded (FGM) layer with arbitrary varying elastic properties and a homogeneous elastic substrate. The plate bends under the action of arbitrary axisymmetric distributed load and response from the elastic half-space. A semi-analytical solution for the problem effective in whole range of geometric (relative layer thickness) and mechanical (elastic properties of coating and substrate, stiffness of the plate) properties is constructed using the bilateral asymptotic method (Aizikovich et al. 2009). Approximated analytical expressions for the contact stresses and deflections of the plate are provided. Numerical results showing the qualitative dependence of the solution from the initial parameters of the problem are obtained with high precision.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.141-141
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• 2012

The electronic and optical properties of Indium Zinc Tin Oxide (IZTO) thin films using gas environment were investigated by X-ray photoelectron spectroscopy (XPS) and reflection electron energy loss spectroscopy (REELS). REELS spectra revealed that the band gaps of IZTO thin films are 3.26, 3.07, and 3.46 eV for water mixed with oxygen, argon mixed with oxygen, and air environments, respectively. The measured band gaps by REELS are consistent with the optical band gaps obtained by UV-Spectrometer. The optical properties represented by the dielectric function $\mathfrak{m}$, the refractive index n, the extinction coefficient k, and the transmission coefficient T of the IZTO thin films with different gas environments were determined from a quantitative analysis of REELS spectra. The calculated transmission from quantitative analysis of REELS spectra shows good agreement with transmission measured by UV-spectrometer. The transmission values of 89% and low electrical resistivity of $3.55{\times}10^{-3}{\Omega}{\cdot}cm$ have been achieved for argon mixed with oxygen which indicates that the gas enviroment plays an important role in improving the electronic and optical properties of films.

• Journal of Electrical Engineering and Technology
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• 제12권2호
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• pp.769-777
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• 2017

The research of air gap flux density has a significant effect on predicting and optimizing the structure parameters of electrical machines. In the paper, the air gap coefficient, leakage flux factor and saturation coefficient are first analytically expressed in terms of motor properties and structure parameters. Subsequently, the analytical model of average air gap flux density for surface-mounted permanent magnet synchronous machines is proposed with considering slotting effect and saturation. In order to verify the accuracy of the proposed analytical model, the experiment and finite element analysis (FEA) are used. It shows that the analytical results keep consistency well with the experimental result and FEA results, and the errors between FEA results and analytical results are less than 5% for SPM with high power. Finally, the analytical model is applied to optimizing the motor structure parameters. The optimal results indicate that the analytical calculation model provides a great potential to the machine design and optimization.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1993년도 가을 학술발표회논문집
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• pp.113-119
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• 1993

Atrium being on fire, the flame is spread vertically, the methods of fire protection and the standards of security are different respectively. Therefore, in the case of atrium, it has many problems on the fire protection and the application of statute according to the space properties. So it is important to analysis, atrium being on fire, fire properties to space properties. From these points of view, the purpose of this study is to analysis the fire properties of atrium .

• 분석과학
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• 제12권6호
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• pp.504-508
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• 1999

노블락형 페놀 수지로 부터 유도된 polyacene계 부극재에 대한 구조적 특성, 충방전 특성 및 임피던스 특성에 대하여 연구하였다. X-선 회절법에 의하여 구조변이를 확인한 결과, p-700, p-850, p-1000 화합물들은 반규칙성의 구조를 가짐을 확인할 수 있었다. 전기적 충전방전 특성을 알아본 결과 P-850의 경우는 나머지 두개의 경우보다 원활한 충전 방전 특성을 나타내었다. 또한 이들의 구조적인 특성 및 전기적인 충방전 특성과 관련하여 임피던스 특성을 알아본 결과 구조분석에서는 P-1000와 p-850의 경우는 원활한 전기적 특성이 나타남을 알 수 있었다.

• 호남수학학술지
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• 제14권1호
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• pp.1-6
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• 1992