• Structural Engineering and Mechanics
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• v.5 no.6
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• pp.715-728
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• 1997

The aim of this paper is to investigate the secondary buckling behaviour and mode-coupling of spherical caps under uniformly external pressure. The analysis makes use of a rotational finite shell element on the basis of strain-displacement relations according to Koiter's shell theory (Small Finite Deflections). The post-buckling behaviours after a bifurcation point are analyzed precisely by considering multi-mode coupling between several higher order harmonic wave numbers: and on the way of post-buckling path the positive definiteness of incremental stiffness matrix of uncoupled modes is examined step by step. The secondary buckling point that has zero eigen-value of incremental stiffness matrix and the corresponding secondary mode are obtained, moreover, the secondary post-buckling path is traced.

• Journal of Families and Better Life
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• v.6 no.1
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• pp.205-221
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• 1988

The purpose of this study is to classify several variable which were assumed to have relationship with the college students behavior of Hyo, to see their possible correlation with demographic characteristics, and to proved some useful data for their possible correlation with demographic characteristics. and to provide some useful data for their sound value system. The data for this study was obtained form the survey of the 477 students who reside in the city of Seoul by using questionnaire methods. The frequency of variables was statistically analyzed to see the general character of the samples and factor analysis was made for classification of the college student's behavior of Hyo. In order to study th characteristic of demographic variables, t-test and ANOVA were conducted The major findings of this study can be summarized as follows. 1) As the result of factor analysis about behavior of Hyo, six factors (Which Eigen value was above 1.0) out of 64 questions were extracted : 'respect' familiarity' 'family consciousness' 'serve' self-preservation, establishmence of them-selves in life' and 'self-reliance' were selected. 2)In general, it can be said that the college students' behavior of Hyo varies by demographic variables. 3) By surveying the level of actualizing Hyo of the college students' all of factors ranged from 'the middle' to 'the high level'. The result confirmed that students fulfilled the behavior of Hyo to their parents in all items.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.9
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• pp.2173-2180
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• 1995

This paper presents free vibration analysis method using the characteristics of the rotationally periodic structures and includes the analysis results of a tire as an example. The normal modes of the rotationally periodic structures are the kind of standing waves, so all sectors have the same deflection shapes, and only different phases. This property makes it possible to derive the analysis method called sector method. The sector method can give the accurate natural frequencies and the corresponding mode shapes of the rotationally periodic structure with information of only one sector. When the free vibration analysis is performed to find the dynamic characteristics of the rotationally periodic structure by using the sector method, the computer memory spaces and the CPU times can be saved. We obtained much economic benefits by using the sector method in the analysis of dynamic characteristics of a tire made of non-linear materials.

• Journal of Distribution Science
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• v.16 no.5
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• pp.17-29
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• 2018

Purpose - This study analyzed the success strategy of Korean small & medium cosmetics exporting companies to enter the Southeast Asian market. Research design, data, and methodology - The independent factors are classified into firm capacity, financial factor, institutional factor, and operational factor. The results of the selection of distributor partners of cosmetics related export companies as a were classified as financial performance and non - financial performance. In order to analyze this, 65 Korean small and medium export companies were recruited through structured online questionnaire for 44 days from September 18, 2017 to October 31, 2017. These data were analyzed by frequency analysis, correlation analysis, factor analysis and regression analysis using SPSS. Results - The Cronbach's alpha coefficient was found to be 0.846. Factor analysis between variables revealed that the eigen value exceeded 1 and was considered valid. As a result of the correlation analysis between the variables, the financial factor and the corporate's competence showed the highest correlation with 0.774. Conclusions - Among the factors influencing the financial performance of the exporting firms, the factors influencing the financial performance of the exporting companies are the factors that influence the non - financial performance rather than the financial performance.

• Journal of Korean Association for Spatial Structures
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• v.3 no.4 s.10
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• pp.53-58
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• 2003

In order to control seismic responses of building structures effectively and stably, it is very important to estimate the dynamic characteristics of target structure exactly based on input-output signal data. In this paper, it is shown that Subspace Identification Method is able to be applied effectively to system identification of building structures. To verify the efficiency of Subspace Identification Method, the vibration experiments were conducted on a specimen structure which is a 5-storied building structure model consisted of H-shaped steel beam, and the simulated seismic responses of the identified structure model were compared with the observed ones under the same excitation. It was observed that the experimental results coincided with the analyzed ones proposed in this paper.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2005.04a
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• pp.12-19
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• 2005

The single layer latticed dome is very sensitive on the slenderness ratio and half open angle of the elements, load condition and the connection type because it is organized by a lot of thin elements, so we have to use the geometrically nonlinear buckling load when the buckling behavior of the structures is analyzed But, it is very difficult to design the single layer latticed domes considered all conditions. Therefore the purpose of this paper is to propose the appropriate design method of the single layer latticed dome considered the geometrically nonlinear buckling load in base on the linear buckling load by the eigen-value analysis.

• Structural Engineering and Mechanics
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• v.55 no.3
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• pp.495-510
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• 2015

Free vibration of non-uniform embedded nanoplates based on classical (Kirchhoff's) plate theory in conjunction with nonlocal elasticity theory has been studied. The nanoplate is assumed to be rested on two-parameter Winkler-Pasternak elastic foundation. Non-uniform material properties of nanoplates have been considered by taking linear as well as quadratic variations of Young's modulus and density along the space coordinates. Detailed analysis has been reported for all possible casesof such variations. Trial functions denoting transverse deflection of the plate are expressed in simple algebraic polynomial forms. Application of the present method converts the problem into generalised eigen value problem. The study aims to investigate the effects of non-uniform parameter, elastic foundation, nonlocal parameter, boundary condition, aspect ratio and length of nanoplates on the frequency parameters. Three-dimensional mode shapes for some of the boundary conditions have also been illustrated. One may note that present method is easier to handle any sets of boundary conditions at the edges.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1271-1275
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• 1987

With the stochastic process which consists of the harmonic sinusoid and the white nosie, the power spectrum of background EEG is estimated by the Pisarenko Harmonic Decomposition. The estimating results are examined and compared with the results from the maximum entropy spectral estimation, and the optimal order of this model can be determined from the eigen value's fluctuation of autocorrelation of background EEG. From the comparing results, this paper ensures that this method is possible to analyze the power spectrum of background EEG.

• Journal of Korean Association for Spatial Structures
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• v.15 no.4
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• pp.99-105
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• 2015

The serviceability design of the high-rise building is affected by the wind response vibration such as the acceleration, at this time it is important to calculate the natural frequency correctly. Since the suggestion equation of the natural frequency being used in the design phase is not the regression equation obtained from the vibration measurement of the high-rise building, the verification to use for the serviceability design of the high-rise building is necessary. This thesis conducted an ambient vibration measuring on the high-rise building through the mobile-phone application to calculate the natural frequency and suggested a natural frequency approximate expression following the building's height, and compared with the domestic/foreign standard and the result of the eigen-value analysis.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.7-10
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• 1990

In this paper the instability analysis of Inverter fed Induction motor drive system is performed by calculate the eigen value of the linearised equation which describe the behavior of the Induction motor. Inverter fed Induction motor drive system may become unstable at low speeds(frequencies) even though balanced, sinusoidal voltage are applied. Effect for the change of machine parameter and Inverter delay time are simulated by digital computer.