• 제목/요약/키워드: Structure Equation Model

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유체운동에 의한 불규칙 가진을 받는 비선형계의 확률제어 (A Stochastic Control for Nonlinear Systems under Random Disturbance Based on a Fluid Motion)

  • 오수영;김용관;조경래;최영섭;허훈
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 춘계학술대회논문집
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    • pp.892-896
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    • 2001
  • 백색잡음 불규칙 과정으로 모델링된 난류형태의 유체운동에 의하여 가진되는 비선형 시스템의 특성과 제어기법에 대해 연구하였다. 고려된 물리적인 모델은 주질량과 끝단 집중질량을 갖는 보형태의 구조물이다. 그 지배방정식은 확률론적 관점에서 F-P-K 접근법으로 유도되었고, 비선형 해석법으로 Gaussian Closure방법을 이용하였다. 비선형 시스템의 제어기법으로는 슬라이딩 모드 제어기를 최초로 확률영역에서 설계하고 그 효과를 확률영역 및 시간영역에서 고찰하였다.

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강원도 영동권 지역 대학생들의 외식동기에 의한 정보탐색방법 (The Information Search Method According to Eating-out Motivation of College Students in Eastern Area of Kangwon Province)

  • 윤태환
    • 한국식품조리과학회지
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    • 제22권2호
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    • pp.213-221
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    • 2006
  • Although motivation and information search have both been studied continuously and separately as important marketing strategies, the relation between cause and effect has received little research attention. Therefore the objective of this study was to research the causal relationships between motivation and information search method. Frequency analysis and reliability analysis, factor analysis, and SEM(Structure Equation Model) were adopted to analyze the data. Motivation was divided into 5 factors which significantly influenced information search method. Factor 1, 'Reception and congratulation', influenced information search positively through 'newspaper, magazine', and 'word of mouth' but negatively through 'TV-advertising' and 'Flyer, Press copy'. Factor 2, 'Change of dietary life', influenced positively 'TV-advertising'. Factor 3, 'Economic saving', influenced positively 'newspaper, magazine', and 'the e-mail's advertising' Factor 4, 'Preference motivation', influenced negatively 'word of mouth' Factor 5, 'Advertisement and companion's need', influenced positively 'newspaper, magazine', and 'the e-mail's advertising' but negatively 'TV-advertising' As a result, customers appeared to choose various information search methods according to their eating-out motivation. 'The e-mail's advertising', and 'word of mouth' are popular among customers' information search methods. Therefore, food-service corporations need to try eliminating negative images of various advertisements and activate positive word of mouth marketing, promotion through internet.

Nonlinear vibration analysis of piezoelectric plates reinforced with carbon nanotubes using DQM

  • Arani, Ali Ghorbanpour;Kolahchi, Reza;Esmailpour, Masoud
    • Smart Structures and Systems
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    • 제18권4호
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    • pp.787-800
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    • 2016
  • The aim of the paper is to analyze nonlinear transverse vibration of an embedded piezoelectric plate reinforced with single walled carbon nanotubes (SWCNTs). The system in rested in a Pasternak foundation. The micro-electro-mechanical model is employed to calculate mechanical and electrical properties of nanocomposite. Using nonlinear strain-displacement relations and considering charge equation for coupling between electrical and mechanical fields, the motion equations are derived based on energy method and Hamilton's principle. These equations can't be solved analytically due to their nonlinear terms. Hence, differential quadrature method (DQM) is employed to solve the governing differential equations for the case when all four ends are clamped supported and free electrical boundary condition. The influences of the elastic medium, volume fraction and orientation angle of the SWCNTs reinforcement and aspect ratio are shown on frequency of structure. The results indicate that with increasing volume fraction of SWCNTs, the frequency increases. This study might be useful for the design and smart control of nano/micro devices such as MEMS and NEMS.

Origins of Brand Image, Customer Satisfaction, and Loyalty toward Telecommunication Service: An Emerging Market Perspective

  • Hossain, Md. Alamgir;Kim, Min-Ho;Jahan, Nusrat;Min, Bo-Yeon
    • 아태비즈니스연구
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    • 제9권2호
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    • pp.39-57
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    • 2018
  • As competition grows in the telecommunication service industry, understanding the origins of brand image and consumer behavioral intentions challenges practitioners to design an effective marketing strategy and branding plan. In this paper, brand image and behavioral relationships are investigated in Bangladesh, an emerging market that has a particular socio-cultural and economic context of one of the most densely populated countries of South Asia. This study employs confirmatory factor analysis and structural equation modeling to analyze the database. Empirical testing and the proposed model suggest that brand image is the prime determinant of consumer satisfaction and loyalty. The results highlight the importance of perceived value, perceived trust and price structure to project brand image and satisfaction. Additionally, confirmation exhibits a stronger total effect of brand image on customer loyalty. Empirical findings extensively contribute to the theoretical and managerial understanding of subscribers' attitudes toward telecommunication service in an emerging market context.

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불규칙한 대기교란을 받는 유연한 구조물의 플러터 제어 (Flutter Control of Flexible Structure under Random Atmospheric Disturbance)

  • 오수영;김용관;조경래;허훈;조윤현
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 춘계학술대회논문집
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    • pp.1210-1215
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    • 2000
  • 일반적인 형태의 동적 시스템에 가해지는 외란이 유색잡음이며, 외란의 형태가 시간에 따라 불규칙하게 변할 때와 감쇠계수와 강성계수가 시간에 따라 불규칙하게 변할 때의 그 확률 시스템의 특성과 제어기법에 대하여 연구하였다. 고려된 물리적인 모델은 불규칙한 대기교란을 받는 항공익으로써 이는 "시변계"가 되며 그 지배방정식이 확률론적 관점에서 F-P-K 접근법으로 유도되었으며, "유색잡음용 허-확률제어기"의 효과를 확률 영역 및 시간영역에서 고찰하였다. 또한 확률론적 플러터경계에 대해서도 고찰하였다.

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기업지배구조별 주가변동체계 간 통계적 연관성 (Statistical Interrelationships Among Variations in Stock Price System by Corporate Governance)

  • 김태호;김민정;이승은
    • 응용통계연구
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    • 제27권5호
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    • pp.797-808
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    • 2014
  • 건전성과 신뢰성이 높은 기업에 선별 투자가 이루어지면 이는 기업의 가치 상승으로 이어지므로 상위 등급의 기업 가치 변동 간 상관성 및 동적 특성에 대한 연구의 필요성이 증대하게 되었다. 본 연구에서는 증권거래소 분류 기업지배구조 등급별 주식수익의 중장기 변동성향을 분석하기 위한 연립방정식 통계모형을 설정하였다. 외생적 충격에 의해 등급별 주식수익에 일어난 변화는 시간이 흐르면서 완만히 조정되어 가는 구조적 특징을 공통적으로 가지고 있으며, 변동 과정이나 성향도 등급 간에 별다른 차이가 없는 것으로 판명되었다.

유한요소 구조 인자의 2차 민감도에 의한 동적 구조 최적화 (Structural Dynamics Optimization by Second Order Sensitivity with respect to Finite Element Parameter)

  • 김용연
    • 한국공작기계학회논문집
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    • 제15권3호
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    • pp.8-16
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    • 2006
  • This paper discusses design sensitivity analysis and its application to a structural dynamics modification. Eigenvalue derivatives are determined with respect to the element parameters, which include intrinsic property parameters such as Young's modulus, density of the material, diameter of a beam element, thickness of a plate element, and shape parameters. Derivatives of stiffness and mass matrices are directly calculated by derivatives of element matrices. The first and the second order derivatives of the eigenvalues are then mathematically derived from a dynamic equation of motion of FEM model. The calculation of the second order eigenvalue derivative requires the sensitivity of its corresponding eigenvector, which are developed by Nelson's direct approach. The modified eigenvalue of the structure is then evaluated by the Taylor series expansion with the first and the second derivatives of eigenvalue. Numerical examples for simple beam and plate are presented. First, eigenvalues of the structural system are numerically calculated. Second, the sensitivities of eigenvalues are then evaluated with respect to the element intrinsic parameters. The most effective parameter is determined by comparing sensitivities. Finally, we predict the modified eigenvalue by Taylor series expansion with the derivatives of eigenvalue for single parameter or multi parameters. The examples illustrate the effectiveness of the eigenvalue sensitivity analysis for the optimization of the structures.

급수를 이용한 DGMOSFET에서 소자 파라미터에 대한 전도중심 의존성 (Dependence of Conduction Path for Device Parameter of DGMOSFET Using Series)

  • 한지형;정학기;정동수;이종인;권오신
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2012년도 추계학술대회
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    • pp.835-837
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    • 2012
  • 본 연구에서는 상단게이트와 하단게이트를 갖는 (Double gate ; DG) MOSFET 구조의 소자 파라미터에 따른 전도중심을 분석하였다. 분석학적 모델을 유도하기 위하여 포아송 방정식을 이용하였다. 본 연구에서 제시한 모델을 사용하여 DGMOSFET 설계시 중요한 채널길이, 채널두께, 그리고 게이트 산화막 두께 등의 요소 변화에 대한 전도중심의 변화를 관찰하였다. 또한 채널 도핑농도에 따른 전도중심의 변화를 고찰함으로써 DGMOSFET의 타당한 채널도핑농도를 결정하였다.

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리더-구성원 교환관계(LMX)가 임파워먼트, 조직몰입, 직무만족, 고객지향성에 미치는 영향에 관한 연구 - 제주항공 중심으로 - (The Relationship among Leader-Member Exchange(LMX), Empowerment, Job Satisfaction, Organizational Commitment, and Customer Orientation : Focused on the Jeju-Air)

  • 이정아;이기종
    • 품질경영학회지
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    • 제44권4호
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    • pp.983-997
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    • 2016
  • Purpose: The purpose of this paper is to examine the structural relationship among leader-member exchange(LMX), empowerment, job satisfaction, organizational commitment, and customer orientation in a low-cost carrier industry. Methods: The collected data through the survey were analyzed using structure equation model analysis The sample used for the empirical analysis is a total of 231 questionnaires. Results: The results of empirical analysis are summarized as follows. First, LMX in a low-cost airline has a significant effect on empowerment, job satisfaction, and customer orientation Second, empowerment has a significant impact on organizational commitment and job satisfaction. However, it is not significantly related to customer orientation. Third, Organization Commitment has significant effect on jon satisfaction. Finally, job satisfaction has a significant impact on customer orientation. Conclusion: This paper has a contribution in that it extends the range of the academic research concerning LMX. Also this paper provides implications on effective human resource management method suitable for a Jeju-Air.

신경망 기법을 이용한 스튜어트 플랫폼의 순기구학 추정 (The Estimation for the Forward Kinematic Solution of Stewart Platform Using the Neural Network)

  • 이형상;한명철;이민철
    • 한국정밀공학회지
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    • 제16권8호
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    • pp.186-192
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    • 1999
  • This paper introduces a study of a method for the forward kinematic analysis, which finds the 6 DOF motions and velocities from the given six cylinder lengths in the Stewart platform. From the viewpoints of kinematics, the solution for the inverse kinematic is easily found by using the vectors of the links which are composed of the joint coordinates in base and plate frames, to act contrary to the serial manipulator, but forward kinematic is difficult because of the nonlinearity and complexity of the Stewart platform dynamic equation with the multi-solutions. Hence we, first in this study, introduce the linear estimator using the Luenberger's observer, and the estimator using the nonlinear measured model for the forward kinematic solutions. But it is difficult to find the parameter of the design for the estimation gain or to select the estimation gain and the constant steady state error exists. So this study suggests the estimator with the estimation gain to be learned by the neural network with the structure of multi-perceptron and the learning method using back propagation and shows the estimation performance using the simulation.

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