• Title/Summary/Keyword: Model fit

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Prediction of Retail Beef Yield Using Parameters Based on Korean Beef Carcass Grading Standards

  • Choy, Yun-Ho;Choi, Seong-Bok;Jeon, Gi-Jun;Kim, Hyeong-Cheol;Chung, Hak-Jae;Lee, Jong-Moon;Park, Beom-Young;Lee, Sun-Ho
    • Food Science of Animal Resources
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    • v.30 no.6
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    • pp.905-909
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    • 2010
  • Two sets of data on carcass traits and beef cut parameters were used to investigate the relationships between carcass and beef cut measurements, which can be used to make predictions of retail cut percentages. One set had a total of 1,141 measurements of Hanwoo cattle of three different sex origins, which were slaughtered in an abattoir located at the National Institute of Animal Science, RDA, Korea from 1996 to 2008. To develop prediction models for retail cut percentage with higher accuracies than the current model, another set consisting of a total of 13,389 records of carcass and beef cut traits were collected from 30 abattoirs and butcheries in Korea from 2008 to 2009. Bulls yielded heavier and leaner carcasses than steers. High correlation coefficients were estimated between amount of body fat and percent retail cut (-0.82) as well as between back fat thickness (BF) and percent retail cut (-0.62). The amount of retail cut, however, was highly correlated with body weight before slaughter (BW, 0.95) or with cold carcass weight (CWT, 0.94). Relationships between percent retail cut and measurable beef yield traits, BF, loin eye area (LEA) or CWT varied by sex class, which must be considered for development of a prediction model with high accuracy. Models of data for all breeds and sexes fit the effects of breed, sex, and interaction of abattoir by butchers, whereas models of data for each breed and sex fit the effect of interaction of abattoir by butcher only. Due to possible future changes in back fat control, we performed a log transformation of BF. Our new models fit better than the currently used model.

Simple Forecasting of Surface Ozone through a Statistical Approach

  • Ma, Chang-Jin;Kang, Gong-Unn
    • Journal of Environmental Health Sciences
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    • v.44 no.6
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    • pp.539-547
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    • 2018
  • Objectives: Ozone ($O_3$) advisories are issued by provincial/prefectural and city governments in Korea and Japan when oxidant concentrations exceed the criteria of the related country. Advisories issued only after exposure to high $O_3$ concentrations cannot be considered ideal measures. Forecasts of $O_3$ would be more beneficial to citizens' health and daily life than real-time advisories. The present study was undertaken to present a simplified forecasting model that can predict surface $O_3$ concentrations for the afternoon of the day of the forecast. Methods: For the construction of a simple and practical model, a multivariate regression model was applied. The monitored data on gases and climate variables from Japan's air quality networks that were recorded over nearly one year starting from April 2016 were applied as the subject for our model. Results: A well-known inverse correlation between $NO_2$ and $O_3$ was confirmed by the monitored data for Iksan, Korea and Fukuoka, Japan. Typical time fluctuations for $O_3$ and $NO_x$ were also found. Our model suggests that insolation is the most influential factor in determining the concentration of $O_3$. $CH_4$ also plays a major role in our model. It was possible to visually check for the fit of a theoretical distribution to the observed data by examining the probability-probability (P-P) scatter plot. The goodness of fit of the model in this study was also successfully validated through a comparison (r=0.8, p<0.05) of the measured and predicted $O_3$ concentrations. Conclusions: The advantage of our model is that it is capable of immediate forecasting of surface $O_3$ for the afternoon of the day from the routinely measured values of the precursor and meteorological parameters. Although a comparison to other approaches for $O_3$ forecasting was not carried out, the model suggested in this study would be very helpful for the citizens of Korea and Japan, especially during the $O_3$ season from May to June.

An Empirical Investigation of Contingent Valuation Method with Preference Uncertainty (선호 불확실성을 고려한 조건부가치측정법의 고찰)

  • Chang, Jeong-In;Yoo, Seung-Hoon;Kwak, Seung-Jun
    • Environmental and Resource Economics Review
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    • v.14 no.1
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    • pp.75-100
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    • 2005
  • This study attempts to empirically investigate the respondents' preference uncertainty involved in stating their willingness to pay (WTP). In the contingent valuation (CV) survey, we employed two approaches using two split samples. The respondents of one sample were given the opportunity to express intensity of preference through polychotomous choice (PC) WTP question. Those of the other sample were given a follow-up question of confidence measure (0~100%). By incorporating the two elicited degrees of preference uncertainty into examining the WTP responses, we take a comparison of the two approaches in terms of the goodness-of-fit of the examination and the efficiency of the mean WTP estimates. In comparing the DC model with the PC models, the DC model provides more efficient estimates. Moreover, the conventional DC model give some gains in terms of the goodness-of-fit and efficiency in comparing with the PC model most similar to this model. In this specific study, incorporating the preference uncertainty in DC model results greater estimates than conventional DC model without loss of goodness-of-fit and efficiency. This implies that the consideration of preference uncertainty on DC model could correct underestimating. We conclude that DC model provides a better estimate of WTP and preference uncertainty could be a critical information on the DC-CV estimation.

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The Effects of Brand Extension of Terrestrial Broadcasting Channels on Parent Brand Evaluation: Focusing on Brand Extended Channel Evaluation, Pre-Brand Extension Parent Brand Evaluation, Perceived Fit, Brand Portfolio Quality Variance, and Perceived Number of Brand Extensions (지상파채널의 브랜드 확장이 모 브랜드 평가에 미치는 영향: 확장된 채널 브랜드 평가, 확장 전 모 브랜드 평가, 적합성, 브랜드 포트폴리오 품질 변량, 브랜드 확장 수에 대한 지각을 중심으로)

  • Lee, Sun-Hee;Baek, Sang-Ki;Chang, Byeng-Hee;Yun, Hae-Jin;Moon, Sung-Chul
    • Korean journal of communication and information
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    • v.61
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    • pp.28-51
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    • 2013
  • The present study analyzed the effects of brand extension on the existing parent brand by applying the media brand extension model which previous studies had suggested based on consumer based brand equity model. Based on previous studies, the present study constructed a research model in which pre-brand extension parent brand evaluation, brand portfolio quality variance, perceived number of brand extensions, perceived fit between parent brand and brand extended channel, and brand extended channel evaluation are supposed to affect post-brand extension brand extension evaluation, and tested the media brand extension feedback effects model through structural equation modeling. The analysis results show that pre-brand extension parent brand evaluation, brand portfolio quality variance, perceived fit, and brand extended channel evaluation affect post-brand extension parent brand evaluation while the effect of perceived number of brand extensions is not significant.

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Fitting of Soft Contact Lenses (소프트 콘택트 렌즈의 피팅)

  • Lee, Eun-Hee;Kim, Dae-Soo
    • Journal of Korean Ophthalmic Optics Society
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    • v.5 no.1
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    • pp.173-180
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    • 2000
  • To determine the effect of base curve and diameter of soft contact lenses on the fitting under the various corneal curvature, the model eyes which was made of either stainless steel or ordinary wood, were used as the substitutes for human eyes. The evaluations of fit of the soft contact lenses on both wood model eyes and human eyes were found to be very similar to each other. All the contact lenses except very thin ones became flat after fit on the stainless steel model eyes because the model eye could not preserve enough moisture to hold the edge of contact lenses on the steel ball's surface. The relationships between the base curves of contact lenses and radii of cornea for the optimum (normal) fit were measured as follows : corneal curvature (C.C)<7.6 mm : base curve(B.C) 8.4 mm, C.C 7.6~7.8 mm : B.C 8.4~8.5 mm. C.C 7.8~8.1 mm : B.C 8.6 mm. It is concluded that larger base curve is required for the eyes which have abnormal bulge on its cornea. It is found that very thin soft contact lenses can be easily twisted or folded regardless of moisture content when they were fit on the relatively dry eyes(corneas).

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A Study on Security Policy Violations of Organization Members (조직 구성원들의 보안정책 위반에 관한 연구)

  • Kim, Jong-Ki;Oh, Da-Woon
    • Informatization Policy
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    • v.25 no.3
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    • pp.95-115
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    • 2018
  • This study aims to examine organization members' intention to violate security policies based on the Person-Environment Fit Model. This study investigated the effect of the relationship between organizational security environment and the individual security value on the intention of organizational security policy violation. The security environments are classified into the organizational information security culture and peers' behavior of security compliance, while the personal values are classified into reconstructing the conduct, distorting the consequence, and devaluing the organization as presented in the moral disengagement theory. Based on the concept of the moral disengagement theory, we measured the individual security values as a second order factor. This study found that the information security culture had a statistically significant impact on devaluing the organization, but did not have as much impact on reconstructing the conduct and distorting the consequence. Peers' behavior of security compliance had a significant impact on reconstructing the conduct, distorting the consequence and devaluing the organization, all of which also had relevant impact on the organizational members' intention of security policy violation.This study measured a persons' perception on security policy breach by presenting scenarios of password sharing that is common in many organizations. This study is expected to make practical contributions, as it deals with challenges that many organizations are actually faced with.

A Predictive Model of Behavioral Problems in Elementary School Children (초등학교 고학년 아동의 문제행동 예측 모형)

  • Song, Hee Seung;Shin, Hee Sun
    • Child Health Nursing Research
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    • v.20 no.1
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    • pp.1-10
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    • 2014
  • Purpose: The purposes of the study were to develop and test a model which explains the relationship among factors affecting behavioral problems in elementary school children. Methods: The participants for the study were 368 elementary school children and their mothers at 3 elementary schools in one city. Data analysis was done using the SPSS 17.0 program for t-test, -test, and ANOVA and the AMOS 17.0 program for theoretical model testing. Results: The theoretical model showed a significant goodness of fit to the empirical data (Goodness of Fit Index: .96, Adjusted Goodness of Fit Index: .93 Comparative Fit Index: .95, Root Mean Square Error of Approximation: .06, Standardized Root Mean Square Residual: .02). Six paths were found to be statistically significant including from child rearing attitude to self-esteem, stress, stress coping and behavioral problems, and from self-esteem to stress and behavioral problems. Child rearing attitude showed a significant effect to behavioral problems by total effect. Self-esteem affected behavioral problems by total and direct effects. Conclusion: Child rearing attitude and selfesteem of children are important factors affecting behavioral problems in elementary school children.

Item Goodness-of-fit and Difficulty of Childhood Autism Rating Scale(CARS) - Application of Rasch Model - (아동기 자폐증 평정척도(CARS)의 문항 적합도 및 난이도 -Rasch 모형의 적용-)

  • Kim, Tae Hyung;Seo, Eunchul
    • 재활복지
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    • v.20 no.4
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    • pp.135-156
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    • 2016
  • The purpose of this study was to investigate item goodness-of-fit of Childhood Autism Rating Scale(CARS), Rasch rating scale model was applied to 15 items of the CARS in a sample of pervasive development disorder(n=238). An assumption to test Rasch Model, which is satisfaction of unidimensionality, is regarded through PCAR analysis, and jMetrik 4.03 program is used to test the goodness-of-fit of items. The results of this study were: First, 5-point rating scale was appropriate for the CARS rather than 7-point original rating scale. Second, the result of examining the CARS questions goodness-of-fit, there was a overfitting or misfitting items according to the classified groups. Only in particular Q11 item in diagnosis subject of integration population of autism has become inappropriate. Therefore, it is necessary to provide education for the CARS more systematically. Thirdly, the result of comparing the personal attributes score and difficulty of a CARS question, Q2, Q3, Q10, Q11 items are necessary to distinguish conceptually defined in more detail. Fourth, the results of investigating the difficulty of CARS question, it was found to exhibit a verbal communication is most serious problem for the population of autism.

A Psychometric Item Goodness-of-Fit of the Test of Performance Strategies for Athletes with Physical Disabilities Applying Rasch Model (Rasch 모형을 적용한 지체장애 엘리트선수의 스포츠수행전략(TOPS) 척도 타당화)

  • Seo, Eunchul;Baek, Jae keun
    • 재활복지
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    • v.21 no.2
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    • pp.169-190
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    • 2017
  • The purpose of this study was to investigate item goodness-of-fit of Scale, Rasch rating scale model was applied to 5 dimensions 24 items of the Test of Performance Strategies (TOPS) in a sample of athletes with physical disabilities (n=215). An assumption to test Rasch Model, which is satisfaction of unidimensionality, is regarded through PCAR test, and WINSTEPS 3.65 program is used to test the goodness-of-fit of items. The results of this study were: First, 3-point rating category was appropriate for the TOPS instead of the existing 5-point rating category. Second, as a result of analyzing the goodness-of-fit of the items, 21 items of the TOPS were suitable, but 3 items were not. Third, the item reliability of person separation of the TOPS was acceptable, but the person reliability of item separation was not suitable and it was necessary to adjust the item order considering the difficulty level of the items. Fourth, as a result of comparing the individual attribute score and the difficulty level through the Item-Person Map, the distribution of the item difficulty distribution was shown to be biased in some factors compared to the personal attribute score distribution.

The Korean Repeatable Battery for the Assessment of Neuropsychological Status-Update : Psychiatric and Neurosurgery Patient Sample Validity

  • Park, Jong-Ok;Koo, Bon-Hoon;Kim, Ji-Yean;Bai, Dai-Seg;Chang, Mun-Seon;Kim, Oh-Lyong
    • Journal of Korean Neurosurgical Society
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    • v.64 no.1
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    • pp.125-135
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    • 2021
  • Objective : This study aimed to validate the Korean version of the Repeatable Battery for the Assessment of Neuropsychological Status Update (K-RBANS). Methods : We performed a retrospective analysis of 283 psychiatric and neurosurgery patients. To investigate the convergent validity of the K-RBANS, correlation analyses were performed for other intelligence and neuropsychological test results. Confirmatory factor analysis was used to test a series of alternative plausible models of the K-RBANS. To analyze the various capabilities of the K-RBANS, we compared the area under the receiver operating characteristic (ROC) curves (AUC). Results : Significant correlations were observed, confirming the convergent validity of the K-RBANS among the Total Scale Index (TSI) and indices of the K-RBANS and indices of intelligence (r=0.47-0.81; p<0.001) and other neuropsychological tests at moderate and above significance (r=0.41-0.63; p<0.001). Additionally, the results testing the construct validity of the K-RBANS showed that the second-order factor structure model (model 2, similar to an original factor structure of RBANS), which includes a first-order factor comprising five index scores (immediate memory, visuospatial capacity, language, attention, delayed memory) and one higher-order factor (TSI), was statistically acceptable. The comparative fit index (CFI) (CFI, 0.949) values and the goodness of fit index (GFI) (GFI, 0.942) values higher than 0.90 indicated an excellent fit. The root mean squared error of approximation (RMSEA) (RMSEA, 0.082) was considered an acceptable fit. Additionally, the factor structure of model 2 was found to be better and more valid than the other model in χ2 values (Δχ2=7.69, p<0.05). In the ROC analysis, the AUCs of the TSI and five indices were 0.716-0.837, and the AUC of TSI (AUC, 0.837; 95% confidence interval, 0.760-0.896) was higher than the AUCs of the other indices. The sensitivity and specificity of TSI were 77.66% and 78.12%, respectively. Conclusion : The overall results of this study suggest that the K-RBANS may be used as a valid tool for the brief screening of neuropsychological patients in Korea.