• 제목/요약/키워드: cross-over model

검색결과 428건 처리시간 0.032초

A Longitudinal Study on Adolescent's Multicultural Acceptability and School Adjustment using Autoregressive cross-lagged model

  • Kim, Hyun-Joo;Park, Hwie-Seo
    • 한국컴퓨터정보학회논문지
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    • 제24권7호
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    • pp.153-160
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    • 2019
  • This study aims to analyze the mutual influences between adolescents' multicultural acceptability and school adjustment. Research problems for research are as follows. First, is multicultural acceptability and school adjustment stable over time? Second, what is the longitudinal impact of school adjustment on multicultural acceptability over time? Third, what is the longitudinal impact of multicultural acceptability on school adjustment over time? The results of analyzing the research problems by applying the autoregressive cross-lagged model are as follows. First, the autoregressive model of school adjustment has a significant effect on the future time point and is stable over time. Second, the autoregressive model of multicultural acceptability have a significant effect on the future time point and is stable over time. Third, cross-lagged effect from school adjustment to multicultural acceptability has a statistically significant effect on the multicultural acceptability at a later time, and is stable over time. Fourth, cross-lagged effect from multicultural acceptability to school adjustment was not statistically significant at the time of multicultural acceptability, and there was no change with time. This study is meaningful to provide the theoretical and practical implications by verifying the influence of the three - year term data over time.

$3\times3$ 교차실험을 범주형 자료 분석을 위한 주변확률모형 (The Marginal Model for Categorical Data Analysis of $3\times3$ Cross-Trials)

  • 안주선
    • 응용통계연구
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    • 제14권1호
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    • pp.25-37
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    • 2001
  • 세 처리, 세 기간을 갖는 3$\times$3 교차실험에서 c($\geq$3)개의 범주를 가진 자료의 분석에 사용될 수 있는 주변확률모형을 제안한다. 이 모형은 Kenward and Jones(1991)의 결합확률 모형의 대조물 (counterpart)로 사용될 수 있고 2항 변수를 갖는 3$\times$3 교차실험에서 처리 효과를 분석하기 위한 Balagtas et al(1995)의 일변량주변로지트모형의 일반화이다. 세 종류의 링크변화를 사용하여 주변확률모형방정식의 구성된다. 링크변환행렬과 모형행렬을 구성하는 방법이 주어지고, 모수의 추정이 논의된다. 제안된 모형을 Kenward and Jones 자료의 분석에 응용한다.

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비정렬 유한 체적법을 이용한 횡류홴 유동장 해석 (Prediction of Cross Flow Fan Flow Using an Unstructured Finite Volume Method)

  • 강동진;배상수
    • 한국유체기계학회 논문집
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    • 제8권3호
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    • pp.7-15
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    • 2005
  • A Navier-Stokes code has been developed to simulate the flow through a cross flow fan. It is based on an unstructured finite volume method and uses moving grid technique to model the rotation of the fan. A low Reynolds number turbulence model is used to calculate eddy viscosity. The basic algorithm is SIMPLE. Numerical simulations over a wide range of flow rate aye carried out to validate the code. Comparison of all numerical solutions with experimental data confirms the validity of the present code. Present numerical solutions show a noticeable improvement over a previous numerical method which is based on a model of body force to simulate the rotation of the impeller.

비정렬 유한 체적법을 이용한 횡류 홴 유동장 해석 (Prediction of Cross Flow Fan Flow Using an Unstructured Finite Volume Method)

  • 강동진;배상수
    • 한국유체기계학회 논문집
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    • 제9권4호
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    • pp.27-35
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    • 2006
  • A Navier-Stokes code has been developed to simulate the flow through a cross flow fan. It is based on an unstructured finite volume method and uses moving grid technique to model the rotation of the fan. A low Reynolds number turbulence model is used to calculate eddy viscosity. The basic algorithm is SIMPLE. Numerical simulations over a wide range of flow rate are carried out to validate the code. Comparison of all numerical solutions with experimental data confirms the validity of the present code. Present numerical solutions show a noticeable improvement over a previous numerical method which is based on a model of body force to simulate the rotation of the impeller.

The behaviour of structures under fire - numerical model with experimental verification

  • Toric, Neno;Harapin, Alen;Boko, Ivica
    • Steel and Composite Structures
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    • 제15권3호
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    • pp.247-266
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    • 2013
  • This paper presents a comparison of results obtained by a newly developed numerical model for predicting the behaviour of structures under fire with experimental study carried out on heated and simply supported steel beam elements. A newly developed numerical model consists of three submodels: 3D beam model designed for calculating the inner forces in the structure, 2D model designed for calculation of stress and strain distribution over the cross section, including the section stiffness, and 3D transient nonlinear heat transfer model that is capable of calculating the temperature distribution along the structure, and the distribution over the cross section as well. Predictions of the calculated temperatures and vertical deflections obtained by the numerical model are compared with the results of the inhouse experiment in which steel beam element under load was heated for 90 minutes.

삼축 시험을 이용한 미소 변형 모델의 비선형 직교 이방 계수에 대한 평가 방법 고찰 (Evaluation of Alternative Approaches for Nonlinear Cross-anisotropic Parameters on the Small Strain Model based on Triaxial Test Results)

  • 천성호;정충기
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2006년도 춘계 학술발표회 논문집
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    • pp.286-300
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    • 2006
  • Nonlinear cross-anisotropic properties of soil is critical for exact numerical simulation. Theoretically, initial cross-anisotropic properties can be evaluated from triaxial tests with bender element tests, and nonlinear cross-anisotropic properties over initial strain level cannot be evaluated from triaxial tests. In this study, a supposed condition among nonlinear cross-anisotropic properties is suggested to calculate nonlinear cross-anisotropic properties from triaxial tests. Maximum strain and incremental strain energy are applied to combine triaxial test results and theoretical normalized shear modulus curve, respectively Based on combined results, nonlinear cross-anisotropic properties are calculated. Numerical simulation for triaxial tests Is carried out to verify the applicability of the supposed condition with calculated cross-anisotropic properties and simplified nonlinear cross-anisotropic model.

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Analytical Study Considering Both Core Loss Resistance and Magnetic Cross Saturation of Interior Permanent Magnet Synchronous Motors

  • Kim, Young-Kyoun
    • Journal of Magnetics
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    • 제17권4호
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    • pp.280-284
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    • 2012
  • This paper presents a method for evaluating interior permanent magnet synchronous motor (IPMSM) performance over the entire operation region. Using a d-q axis equivalent circuit model consisting of motor parameters such as the permanent magnetic flux, copper resistance, core loss resistance, and d-q axis inductance, a conventional mathematical model of an IPMSM has been developed. It is well understood that in IPMSMs, magnetic operating conditions cause cross saturation and that the iron loss resistance - upon which core losses depend - changes according to the motor speed; for the sake of convenience, however, d-q axis machine models usually neglect the influence of magnetic cross saturation and assume that the iron loss resistance is constant. This paper proposes an analysis method based on considering a magnetic cross saturation and estimating a core loss resistance that changes with the operating conditions and speed. The proposed method is then verified by means of a comparison between the computed and the experimental results.

Stability evaluation for the excavation face of shield tunnel across the Yangtze River by multi-factor analysis

  • Xue, Yiguo;Li, Xin;Qiu, Daohong;Ma, Xinmin;Kong, Fanmeng;Qu, Chuanqi;Zhao, Ying
    • Geomechanics and Engineering
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    • 제19권3호
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    • pp.283-293
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    • 2019
  • Evaluating the stability of the excavation face of the cross-river shield tunnel with good accuracy is considered as a nonlinear and multivariable complex issue. Understanding the stability evaluation method of the shield tunnel excavation face is vital to operate and control the shield machine during shield tunneling. Considering the instability mechanism of the excavation face of the cross-river shield and the characteristics of this engineering, seven evaluation indexes of the stability of the excavation face were selected, i.e., the over-span ratio, buried depth of the tunnel, groundwater condition, soil permeability, internal friction angle, soil cohesion and advancing speed. The weight of each evaluation index was obtained by using the analytic hierarchy process and the entropy weight method. The evaluation model of the cross-river shield construction excavation face stability is established based on the idea point method. The feasibility of the evaluation model was verified by the engineering application in a cross-river shield tunnel project in China. Results obtained via the evaluation model are in good agreement with the actual construction situation. The proposed evaluation method is demonstrated as a promising and innovative method for the stability evaluation and safety construction of the cross-river shield tunnel engineerings.

해외직구에 대한 고객 만족도 : 최종사용자 만족 모형을 기반으로 (Consumers' Satisfaction for Cross Border Online Shopping : Based on the End-User Computing Satisfaction Model)

  • 김태환
    • 산업경영시스템학회지
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    • 제41권3호
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    • pp.170-175
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    • 2018
  • While the term online shopping refers to all online transactions, cross-border online shopping means shopping activities purchasing products or services over the internet for the customers abroad. As Internet use for the international shopping activity increasing, cross border online shopping has grown substantially for last decade. This study is about the problem regarding the cross border online shopping for two different countries and the variables that influence their shopping behavior. The cross border online shopping has been increased by the growth of Internet access. However, the growth of the Internet use does not guarantee a successful development of cross border e-commerce for every country. To find out the perception for cross-border online shopping for two different cultures, shoppers from two countries with different cultural background were chosen, and the perception for cross-border online shopping from each culture is contrasted. For statistical Analysis, ANOVA is used to find the relationship between a single non-metric independent variable, and multiple metric dependent variables. Hofstede's cultural dimensions model is adopted for this study as a tool to find out the patterns of cross border online shopping. This study showed what the variables would affect the perception in cross border online shopping. The results of this study indicated that cross border online shoppers with different culture were notably different on two variables identified-timeliness and ease of use.

Seismic and collapse analysis of a UHV transmission tower-line system under cross-fault ground motions

  • Tian, Li;Bi, Wenzhe;Liu, Juncai;Dong, Xu;Xin, Aiqiang
    • Earthquakes and Structures
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    • 제19권6호
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    • pp.445-457
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    • 2020
  • An ultra-high voltage (UHV) transmission system has the advantages of low circuitry loss, high bulk capacity and long-distance transmission capabilities over conventional transmission systems, but it is easier for this system to cross fault rupture zones and become damaged during earthquakes. This paper experimentally and numerically investigates the seismic responses and collapse failure of a UHV transmission tower-line system crossing a fault. A 1:25 reduced-scale model is constructed and tested by using shaking tables to evaluate the influence of the forward-directivity and fling-step effects on the responses of suspension-type towers. Furthermore, the collapse failure tests of the system under specific cross-fault scenarios are carried out. The corresponding finite element (FE) model is established in ABAQUS software and verified based on the Tian-Ma-Qu material model. The results reveal that the seismic responses of the transmission system under the cross-fault scenario are larger than those under the near-fault scenario, and the permanent ground displacements in the fling-step ground motions tend to magnify the seismic responses of the fault-crossing transmission system. The critical collapse peak ground acceleration (PGA), failure mode and weak position determined by the model experiment and numerical simulation are in relatively good agreement. The sequential failure of the members in Segments 4 and 5 leads to the collapse of the entire model, whereas other segments basically remain in the intact state.