• Title/Summary/Keyword: Model fit

Search Result 2,879, Processing Time 0.037 seconds

A Study on the Electrochemical Impedance Spectroscopy and the Electrical Circuit Model for the Electrode/Electrolyte Interface (전극/전해질 계면의 전기화학적 임피던스 측정 및 전기회로 모델 연구)

  • Chang, Jong-Hyeon;Hong, Jang-Won;Pak, Jung-Ho
    • Proceedings of the KIEE Conference
    • /
    • 2007.07a
    • /
    • pp.274-275
    • /
    • 2007
  • The investigation of the equivalent circuit models for the electrode/electrolyte interface has been pursued for a long time by several researchers. Previous circuit models fit the experimental results in limited conditions such as frequency range, type of electrode, or electrolyte. This paper describes a new electrical circuit model and its capability of fitting the experimental results. Electrochemical impedance spectroscopy was used to characterize the interface for Au, Pt, and stainless steel electrode in 0.9% NaCl solution. Both the proposed model and the previous model were applied to fit the measured impedance results for comparison. The proposed model fits the experimental data more accurately than other models especially at the low frequency range, and it enables us to predict the impedance at very low frequency range, including DC, using the proposed model.

  • PDF

Comparison of Analytical Bond Models between Reinforcement and Concrete (보강근과 콘크리트 사이의 해석적 부착모델 비교)

  • You Young Jun;Park Ji Sun;Park Young Hwan;Kim Hyeong Yeol;You Young Chan;Kim Keung Hwan
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2005.11a
    • /
    • pp.33-36
    • /
    • 2005
  • This paper presents the comparison of the goodness-of-fit test of analytical bond models between concrete and steel or GFRP reinforcements. Bond test specimens were made by the CSA code and the rebars used in the test were steel and two kinds of GFRP rebar commercially utilized. The comparison of goodness-of-fit test for existing bond models and new proposed bond model was carried out by the least squares method. The result indicates that the new proposed bond model has better goodness-of-fit test than the existing ones.

  • PDF

Latent Variable Fit to Interlaboratory Studies

  • Jeon, Gyeongbae
    • Communications for Statistical Applications and Methods
    • /
    • v.7 no.3
    • /
    • pp.885-897
    • /
    • 2000
  • The use of an unweighted mean and of separate tests is part of the current practice for analyzing interlaboratory studies, and we hope to improve on this method. We fit, using maximum likelihood(ML), a rather intricate, multi-parameter measurement model with the material's true value as a latent variable in a situation where quite serviceable regression and ANOVA calculations have already been developed. The model fit leads to both a weighted estimate of he overall mean, and to tests for equality of means, slopes and variances. Maximum likelihood tests for difference among variances poses a challenge in that the likelihood can easily becoem unbounded. Thus the major objective become to provide a useful test of variance equality.

  • PDF

Determinants of Health Promoting Behavior of Middle Aged Women in Korea (한국 중년 여성의 건강증진 행위 예측 모형 구축)

  • 이숙자;박은숙;박영주
    • Journal of Korean Academy of Nursing
    • /
    • v.26 no.2
    • /
    • pp.320-336
    • /
    • 1996
  • Health promoting behaviors of an individual are affected by various variables. Recently, there has been a growing concern over important health problems of the middle aged women. Physiological changes in the middle aged women and their responsibility for family care can result in physical and psychological burden experienced by middle aged women. This study was designed to test Pender's model and thus purpose a model that explains health promoting behaviors among middle-aged women in Korea. The hypothetical model was developed based on the Pender's health promoting model and the findings from past studies on women's health. Data were collected by self-reported questionnaires from 863 women living in Seoul, between 20th, April and 15th, July 1995. Data were analyzed using descriptive statistics and correlation analysis. The Linear Structural Relationship(LISREL) modeling process was used to find the best fit model which assumes causal relationships among variables. The results are as follows : 1. The Overall fit of the hypothetical model to the data was good expect chi-square value(GFI=.96, AGFI=.91, RMR=.04). 2. Paths of the model were modified by considering both its theoretical implication and statistical significance of the parameter estimates. Compared to the hypothetical model, the revised model has become parsimonious and had a better fit to the data expect chi-square value(GFI=.95, AFGI= .92. RMR=.04). 3. Some of modifying factors, especially age, occupation, educational levels and body mass index (BMI) are revealed significant effects on health promoting behaviors. 4. Some of cognitive-perceptual factors, especially internal health locus of control, self-efficacy and perceptive health status are revealed significant effects on health promoting behaviors. 5. All predictive variables of health promoting behaviors, especially age, occupation, educational levels, body mass index(BMI), internal health locus of control, self-efficacy & perceptive health status are explained 20.0% of the total variance in the model.

  • PDF

The Impact of Late-Night Fits on Utilitarian·Hedonic Value and Shopping intent (심야 적합성이 심야쇼핑의 실용적·쾌락적 가치와 쇼핑의도에 미치는 영향에 관한 연구)

  • Jeong, Yun-Hee
    • Management & Information Systems Review
    • /
    • v.33 no.5
    • /
    • pp.117-130
    • /
    • 2014
  • The purposes of this study were to consider the influence of person-late night fit in the perceived value, intent of late-night shopping. The late-night shopping model which we present in this study incorporates three effects including the time fit and the physiological fit, the mood fit factors. Also, we expect that these fits effect utilitarian value and hedonic value, in turn, utilitarian value and hedonic value effect shopping intent. Survey research is employed to test hypotheses involving late-night fits, values, shopping intent. We collected data involving various late-night shopping, and used 221 respondents to analyze these data using LISREL structural modeling. The proposed model was a good fit with the data(GFI= .96 NNFI= .80 CFI= .92, AGFI= .88, RMR= .044), the hypothesized relationships were partly significant(p< .05). In the final section, we discussed several limitations of our study and suggested directions for future research. We concluded with a discussion of managerial implications, including the potential to advance understanding experiential consumption and implying an enhanced ability to attract late-night shopper.

  • PDF

The Effects of Internal Market Orientation on Service Providers' adaptive service behavior : Serial Multiple Mediation Effects of Person-Environment Fit and Work Engagement (내부시장 지향성이 서비스 제공자의 적응적 서비스 행동에 미치는 영향: 개인-환경 적합성과 직무열의의 연속다중매개효과)

  • Lee, Myoung-Soung;Kim, Gi-Dae
    • Journal of Service Research and Studies
    • /
    • v.13 no.4
    • /
    • pp.24-46
    • /
    • 2023
  • This study sought to examine how internal market orientation of service organizations affects the service providers' adaptive service behavior and to determine what psychological processes go through for this purpose. To achieve this purpose, based on previous research, a research model was set up to predict that internal market orientation of service organizations will increase service providers' adaptive service behavior by continuously mediating the psychological processes of person-environment fit and work engagement. To test the hypothesis, a survey was conducted and data were collected from nutritionists at consignment catering companies located in Busan and Gyeongnam. As a result of testing the hypotheses proposed in this study's research model, internal market orientation increased person-job fit and person-organization fit, which are key elements of person-environment fit. And, it was confirmed that person-job fit and person-organization fit have a positive effect on work engagement. Additionally, work engagement improved service providers' adaptive service behavior. Lastly, this study confirmed that the influence of internal market orientation on adaptive service behavior is continuously mediated by person-environment fit and job enthusiasm.

An Empirical Study on the Effect of the Use of Information Technology on Revisit Intention of Theatre Audiences (연극작품 연출에서의 정보기술 활용이 관객 재방문의도에 미치는 영향에 관한 실증연구)

  • Choi, Ji-Ae;Kwon, Ohbyung
    • The Journal of Information Systems
    • /
    • v.28 no.4
    • /
    • pp.223-250
    • /
    • 2019
  • Purpose As the 4th Industrial Revolution proceeded, attempts to direct and utilize information technology such as robots and drones in plays have been active. Information technology, such as AI or media art, which is applied in the production of theater productions, shapes the possibility of expressing the difficulty of actors, the effectiveness of dramatic effects, and the illusion. Despite the inconsistent effects of information technology on theatrical studies, little has been done despite the fact that the research on what factors affect the audience's satisfaction through the play. Hence, The purpose of this study is to demonstrate the characteristics of information technology and theater, especially audience's revisit intention. Design/methodology/approach The research model combining the theory of task-technology fit and the experience-economic model is presented. Findings The results of the empirical analysis suggest that the fit of information technology and theatrical task enriches the audience's experience and has a beneficial effect on the dissemination and export of contents management of art management in terms of revisit as a consumer and production of theatrical performing arts. This leads to the conclusion that task-technical fit and experiential economy could be applied to the field of performing arts in theater. It may also give useful implications to related producers such as producers, directors, and actors.

Comparison of Goodness-of-Fit Tests using Grouping Strategies for Multinomial Logit Regression Model (다항 로짓 회귀모형에서의 그룹화 전략을 이용한 적합도 검정 방법 비교)

  • Song, Mi Kyung;Jung, Inkyung
    • The Korean Journal of Applied Statistics
    • /
    • v.26 no.6
    • /
    • pp.889-902
    • /
    • 2013
  • Several goodness-of-fit test statistics have been proposed for a multinomial logit regression model; however, the properties of the proposed tests were not adequately studied. This paper evaluates three different goodness-of-fit tests using grouping strategies, proposed by Fagerland et al. (2008), Bull (1994), and Pigeon and Heyse (1999). In addition, Pearson (1900)'s method is also examined as a reference. Simulation studies were conducted to evaluate the four methods in terms of null distribution and power. A real data example is presented to illustrate the methods.

Comparative Simulation Studies on Generalized Binomial Models (일반화 이항모형의 적합도 평가)

  • Baik, E.J.;Kim, K.Y.
    • Communications for Statistical Applications and Methods
    • /
    • v.18 no.4
    • /
    • pp.507-516
    • /
    • 2011
  • Comparative studies on generalized binomial models (Moon, 2003; Ng, 1989; Paul, 1985; Kupper and Haseman, 1978; Griffiths, 1973) are restrictive in that the models compared are rather limited and MSE of the estimates is the only measure considered for the model adequacy. This paper is aimed to report simulation results which provide possible guidelines for selecting a proper model. We examine Pearson type of goodness-of-fit statistic to its degrees of freedom and AIC for the overall model quality. MSE and Bias of the individual estimates are also considered as the component fit measures. Performance of some models varies widely for a certain range of the parameter space while most of the models are quite competent. Our evaluation shows that the Extended Beta-Binomial model (Prentice, 1986) turns out to be particularly favorable in the point that it provides consistently excellent fit almost all over the values of the intra-class correlation coefficient and the probability of success.

An Empirical Study on Influencing Factors of Intention to Use Third-Party Mobile Payment Services : Applying the Task-Technology Fit Model (과업기술적합도 모형을 활용한 모바일 간편결제 서비스 이용의도의 영향요인에 대한 실증연구)

  • Kim, So-Dam;Lim, Jay-Ick;Yang, Sung-Byung
    • Journal of Information Technology Services
    • /
    • v.15 no.2
    • /
    • pp.185-201
    • /
    • 2016
  • Recently, due to the rapid development of IT (information technologies), a variety of attempts have been made to incorporate IT into other fields such as finance and manufacturing. Among them, a novel concept in the spotlight is FinTech, which is a combined word of finance and technology. FinTech is a line of business demonstrating an innovation development through IT in the financial service industry. One of the most popular types of FinTech is a third-party mobile payment service (MPS), the examples of which can be easily found in South Korea while the actual use of the service is relatively inactive. Therefore, the main purpose of this paper is to empirically investigate influencing factors of intention to use the third-party MPS. Based on individual characteristics and the task-technology fit model, the research model of the study is developed, with switching cost included as a moderating variable. The results of structural equation model testing with 316 potential users of Kakao Pay, one of the most popular business models of the third-party MPS, show that innate innovativeness, task characteristics, and technology characteristics are positively influencing task-technology fit, which in turn significantly affects intention to use the third-party MPS. The negative moderating role of switching cost is also found. These results could help managers develop better strategies to motivate potential users to participate in their services.