• Title/Summary/Keyword: Model fit

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A Structural Equation Model on Quality of Life of Mothers of Children with Attention Deficit Hyperactivity Disorder (ADHD 아동 어머니의 삶의 질 구조모형)

  • Park, Chan Gyeong;Jeon, Mi Yang
    • Child Health Nursing Research
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    • v.23 no.3
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    • pp.279-291
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    • 2017
  • Purpose: The aim of this study was to explore how characteristics of ADHD children affect social support for mothers, parenting stress, parenting sense of competence, coping, and quality of life. The conceptual model was based on the Lazarus and Folkman's stress-evaluation-coping theory. Methods: Data were collected 208 mothers of children with ADHD. Data were analysed using SPSS 18.0 and AMOS 18.0 programs. Results: The proposed model was good fit for the data based on the model fit indices. Parenting stress, parenting sense of competence and coping directly affected quality of life but characteristics of the children and social support had only an indirect effect. The explanatory power of these variables was 52.1%. Conclusion: The results of this study indicate that nursing strategies to increase social support for mothers with ADHD children, lowers parenting stress, improves parenting sense of competence, and guides the parents to choose appropriate coping. In particular, as social support has the strongest influence on the quality of life, it is necessary to develop nursing intervention programs that utilize social support for parents with ADHD children.

Genetic Parameter Estimation with Normal and Poisson Error Mixed Models for Teat Number of Swine

  • Lee, C.;Wang, C.D.
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.7
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    • pp.910-914
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    • 2001
  • The teat number of a sow plays an important role for weaning pigs and has been utilized in selection of swine breeding stock. Various linear models have been employed for genetic analyses of teat number although the teat number can be considered as a count trait. Theoretically, Poisson error mixed models are more appropriate for count traits than Normal error mixed models. In this study, the two models were compared by analyzing data simulated with Poisson error. Considering the mean square errors and correlation coefficients between observed and fitted values, the Poisson generalized linear mixed model (PGLMM) fit the data better than the Normal error mixed model. Also these two models were applied to analyzing teat numbers in four breeds of swine (Landrace, Yorkshire, crossbred of Landrace and Yorkshire, crossbred of Landrace, Yorkshire, and Chinese indigenous Min pig) collected in China. However, when analyzed with the field data, the Normal error mixed model, on the contrary, fit better for all the breeds than the PGLMM. The results from both simulated and field data indicate that teat numbers of swine might not have variance equal to mean and thus not have a Poisson distribution.

Structural Equation Modeling on Personal Satisfaction with Life in Grandmothers Parenting Grandchildren (손자녀 양육 조모의 생활만족도 구조모형)

  • Kim, Moon-Jeong
    • Women's Health Nursing
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    • v.15 no.3
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    • pp.231-241
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    • 2009
  • Purpose: This study was designed to construct and test a structural equation model for life satisfaction in grandmothers who were parenting grandchildren Methods: Grandmothers assuming part-time parenting responsibilities for grandchildren were recruited in four cities in South Korea. They were asked to complete a questionnaire through face to face interviews or self reports, and 248 data units were analyzed with Structural Equation Modeling. Results: Model fit indices for the final model revealed a fit at an excellent level, and all of the 12 paths were statistically significant explaining 51% of the variance. Predictors of life satisfaction in the final model were parenting efficacy, perceived health status, parenting stress, amount of parenting, and demographic factors. The new findings of this study were as follows: First, the satisfaction with life of part-time parenting grandmothers was less than that of non-parenting grandmothers. Second, parenting stress and parenting efficacy revealed determinants to life satisfaction. Third, motivation of parenting and amount of parenting affect both parenting stress and parenting efficacy. Conclusion: The value of parenting and the grandmother-adult children relationship quality should also be considered in developing a grandmothers' educational program, because these are the factors which strengthen parenting efficacy and alleviate parenting stress.

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An Accurate Model of Multi-Type Overcurrent Protective Devices Using Eigensystem Realization Algorithm and Practice Applications

  • Cheng, Chao-Yuan;Wu, Feng-Jih
    • Journal of Electrical Engineering and Technology
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    • v.11 no.1
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    • pp.9-19
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    • 2016
  • Accurate models of the characteristics of typical inverse-time overcurrent (OC) protective devices play an important role in the protective coordination schemes. This paper presents a novel approach to determine the OC protective device parameters. The approach is based on the Eigensystem Realization Algorithm which generates a state space model to fit the characteristics of OC protective devices. Instead of the conventional characteristic curves, the dynamic state space model gives a more exact fit of the OC protective device characteristics. This paper demonstrates the feasibility of decomposing the characteristic curve into smooth components and oscillation components. 19 characteristic curves from 13 typical and 6 non-typical OC protective devices are chosen for curve-fitting. The numbers of fitting components required are determined by the maximum absolute values of errors for the fitted equation. All fitted equations are replaced by a versatile equation for the characteristics of OC protective devices which represents the characteristic model of a novel flexible OC relay, which in turn may be applied to improve the OC coordination problems in the sub-transmission and distribution systems.

A Study on a Model for Internet Addiction of Adolescents (청소년의 인터넷 중독에 관한 모형 개발)

  • 조영란;이화자
    • Journal of Korean Academy of Nursing
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    • v.34 no.3
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    • pp.541-551
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    • 2004
  • Purpose: This study was to identify the effects of the predictive factors of Internet addiction and to develop a predictive model that explains Internet addiction among adolescents in Korea. Method: Data was collected from 664 adolescents in Puasan and Ulsan. Data analysis was done using the SPSS 10.0 Win Program for descriptive and correlational statistics and the LISREL 8.53 Win Program for Covariance structural analysis. Result: The fit of the hypothetical model to the data was moderate, it was modified by deleting four paths. Compared to the hypothetical model, the revised one had a better fit to the data($\chi^2$/df=6.50, GFI=.99, AGFI=.90, RMR=.02, NNFI=.88, NFI=.98, CN=279). Gender, friend support, and loneliness had significant direct effects on Internet addiction. The direct and indirect effect of self-esteem on Internet addiction was significant. The indirect effect of family support on Internet addiction was significant but its direct effect was insignificant. The direct and indirect effects of stress and impulsiveness on Internet addiction were significant but their total effects were insignificant. Conclusion: Finally, to decrease loneliness, and to increase family support and self-esteem, an effective intervention program and education should be developed to prevent Internet addiction of adolescents.

Allometric Equation for Biomass Determination in Chuqala Natural Forest, Ethiopia: Implication for Climate Change Mitigation

  • Balcha, Mecheal Hordofa;Soromessa, Teshome;Kebede, Dejene
    • Journal of Forest and Environmental Science
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    • v.34 no.2
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    • pp.108-118
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    • 2018
  • Biomass determination of species-specific in forest ecosystem by semi-destructive measures requires the development of allometric equations; predict aboveground biomass observable independent variables such as, Diameter at Breast Height, Height, and Volume are crucial role. There has not been equation of this type in mountain Chuqala natural forest. In this study two species namely, Hypericum revolutum Vahl. & Maesa lanceoleta Forssk. with tree diameter classes (15-20, 20.5-25, and 25.5-35 cm), with the purpose of conducting allometric equations were characterized. Each species assumed considered individually. For the linear model fit the two observed variable DBH, H and V were preferred for the prediction of above ground biomass. The best fitted model choose among the two formed model were identified using Akaike Information Criterion (AIC), and $R^2$ and adjacent $R^2$. Based on this the best fit model for Hypericum revolutum Vahl. was AGB=-681.015+4,494.06 (DBH), and for Maesa lanceoleta Forrsk. was. AGB=-936.96+5,268.92 (DBH).

An Empirical Study of the Factors Influencing the Task Performances of SaaS Users

  • Park, Sung Bum;Lee, Sangwon;Chae, Seong Wook;Zo, Hangjung
    • Asia pacific journal of information systems
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    • v.25 no.2
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    • pp.265-288
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    • 2015
  • IT convergence services, as the main stream of the digital age, are currently on their way to include the concept of Software as a Service (SaaS), where IT products and services are integrated as one. In particular, the recently introduced web-service-based SaaS is expected to be a more developed SaaS model. This new model provides greater influence on clients' job performances than its previous models, such as application service providers and the web-native phase. However, the effects of technology maturity on task performance have been overlooked in adoption and performance studies. Accordingly, this study introduces SaaS technology maturity as the exogenous technological characteristic influencing job performance. This study also examines the relationships among various SaaS-related performances according to the different levels of SaaS maturity. Results suggest that applying innovative technologies (such as SaaS), particularly when the technology reaches a certain level of maturity, is more helpful for managers in improving task-technology fit and job performance. This study makes an academic contribution by establishing and validating a performance model empirically with SaaS technology maturity perspectives.

A Study on Advertising Expressive Factors of Fashion Products on Brand Equity -Focused on Mediate Role of Brand Personality- (패션제품 광고표현요소와 브랜드 자산에 관한 연구 -브랜드 개성의 매개효과를 중심으로-)

  • Lee, Seung-Hee;Chang, Yoon-Kyung;Park, Soo-Kyeong
    • Journal of the Korean Society of Clothing and Textiles
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    • v.32 no.11
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    • pp.1659-1668
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    • 2008
  • The purpose of this study was to examine the impact of advertising expressive factors on brand equity and to investigate the role of brand personality as a factor mediate variable. The subject used for this study were 352 female university students. The data was analyzed by descriptive analysis, correlation analysis and confirmatory factor analysis using SPSS program and Amos program. As the result, model fit index showed $X^2$=57.824, df=19, GFI=0.969, CFI=0.959, NFI=0.942, and RMSEA=0.076, providing good model fit. Out of the advertising expressive factors, sophistication and model preference factors gave impact on brand personality. Also, among advertising expressive factors, novelty, sophistication, model preference, information factors affected brand equity. Finally, brand personality influenced on brand equity. Brand equity was affected directly by advertising expressive factors. It was also affected by brand personality which is a mediate factor between advertising expressive factors and brand equity. The results of this study would provide advertising strategy for fashion brand.

A Structural Model Development on the Cardiovascular Disease Risk Factors among Male Manufacturing Workers (제조업 남자 근로자의 심혈관질환 위험요인에 대한 모형 구축)

  • Choi, Eun-Sook
    • Research in Community and Public Health Nursing
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    • v.17 no.2
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    • pp.153-165
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    • 2006
  • Purpose: The purpose of this study was to develop and test a structural model on cardiovascular disease risk factors among male manufacturing workers. Methods: Data were collected through questionnaires and health exams from 201 workers in a local electronic company during September 2004. Data analysis was done with SAS 9.1 for descriptive statistics and PC-LISREL 8.54 for covariance structural analysis Results: The overall fit of the hypothetical model to the data was moderate, it was modified by deleting five paths. The modified model had a better fit to the data($x^2=504.23$(p<001, df: 180), $x^2/df=2.80$, GFI=.95, RMR=.07, NFI=.90, PGFI=.64). Health behaviors and psychosocial distress were found to have significant direct effects on the cardiovascular disease risk factors. Self-concept had direct effect on psychosocial distress or health behaviors. Self-concept, work environment, and work condition had direct effect on social support. Work environment had indirect effect on psychosocial distress. Social support had indirect effect on health behaviors. But work environment and work condition were found to have little direct effect on health behaviors, psychosocial distress or cardiovascular disease risk factors. Conclusion: A cardiovascular health promotion program should therefore include psycho-social factors as well as health behavioral determinants in worksites.

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A Development of Optimal Design Model for Initial Blank Shape Using Artificial Neural Network in Rectangular Case Forming with Large Aspect Ratio (세장비가 큰 사각케이스 성형 공정에서의 인공신경망을 적용한 초기 블랭크 형상 최적설계 모델 개발)

  • Kwak, M.J.;Park, J.W.;Park, K.T.;Kang, B.S.
    • Transactions of Materials Processing
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    • v.29 no.5
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    • pp.272-281
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    • 2020
  • As the thickness of mobile communication devices is getting thinner, the size of the internal parts is also getting smaller. Among them, the battery case requires a high-level deep drawing technique because it has a rectangular shape with a large aspect ratio. In this study, the initial blank shape was optimized to minimize earing in a multi-stage deep drawing process using an artificial neural network(ANN). There has been no reported case of applying artificial neural network technology to the initial blank optimal design for a square case with large aspect ratio. The training data for ANN were obtained though simulation, and the model reliability was verified by performing comparative study with regression model using random sample test and goodness-of-fit test. Finally, the optimal design of the initial blank shape was performed through the verified ANN model.