• Title/Summary/Keyword: Goodness-of-Fit

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Evaluation of Information Representation Goodness-of-fit According to Protein Visualization Pattern (단백질 가시화 형태에 따른 정보표현적합도 평가)

  • Byeon, Jaehee;Choi, Yoo-Joo;Suh, Jung-Keun
    • Journal of Internet Computing and Services
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    • v.16 no.2
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    • pp.117-125
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    • 2015
  • The information about protein structure gives the clues for the function of protein. It is needed for the improvement for the efficacy and fast development of protein drugs. So, the studies visualizing the structure of protein effectively increase. Most studies of visualization focus on the structural prediction for protein or the improvement on the rendering speed. However, studies of information delivery depending on the form of protein visualization are very limited. The major objective of this study is to analyze the information representation goodness-of-fit for the patterns of the hybrid visualization with primary and secondary structures of protein. Those hybrid visualizations included the patterns which updated current representative visualization services, Chimera, PDB and Cn3D. Information factor to analyze information representation goodness-of-fit is assorted by protein primary structure, secondary protein structure, the location of amino acid and ratio information about protein secondary structure, based on the result of subject-analysis. Subject is the group of experts who are involved in protein drug development over 5 years. The result of this study shows the meaningful difference in the information representation goodness-of-fit by the patterns of hybrid visualization and proves the difference in the information by the pattern of visualization.

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.

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.

Derivation of Modified Anderson-Darling Test Statistics and Power Test for the Gumbel Distribution (Gumbel 분포형의 수정 Anderson-Darling 검정통계량 유도 및 기각력 검토)

  • Shin, Hong-Joon;Sung, Kyung-Min;Heo, Jun-Haeng
    • Journal of Korea Water Resources Association
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    • v.43 no.9
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    • pp.813-822
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    • 2010
  • An important problem in frequency analysis is the estimation of the quantile for a certain return period. In frequency analysis an assumed probability distribution is fitted to the observed sample data to estimate the quantile at the upper tail corresponding to return periods which are usually much larger than the record length. In most cases, the selection of an appropriate probability distribution is based on goodness of fit tests. The goodness of fit test method can be described as a method for examining how well sample data agrees with an assumed probability distribution as its population. However it gives generally equal weight to differences between empirical and theoretical distribution functions corresponding to all the observations. In this study, the modified Anderson-Darling (AD) test statistics are provided using simulation and the power study are performed to compare the efficiency of other goodness of fit tests. The power test results indicate that the modified AD test has better rejection performances than the traditional tests. In addition, the applications to real world data are discussed and shows that the modified AD test may be a powerful test for selecting an appropriate distribution for frequency analysis when extreme cases are considered.

Derivation of Probability Plot Correlation Coefficient Test Statistics and Regression Equation for the GEV Model based on L-moments (L-모멘트 법 기반의 GEV 모형을 위한 확률도시 상관계수 검정 통계량 유도 및 회귀식 산정)

  • Ahn, Hyunjun;Jeong, Changsam;Heo, Jun-Haeng
    • Journal of Korean Society of Disaster and Security
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    • v.13 no.1
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    • pp.1-11
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    • 2020
  • One of the important problem in statistical hydrology is to estimate the appropriated probability distribution for a given sample data. For the problem, a goodness-of-fit test is conducted based on the similarity between estimated probability distribution and assumed theoretical probability distribution. Probability plot correlation coefficient test (PPCC) is one of the goodness-of-fit test method. PPCC has high rejection power and its application is simple. In this study, test statistics of PPCC were derived for generalized extreme value distribution (GEV) models based on L-moments and these statistics were suggested by the multiple and nonlinear regression equations for its usability. To review the rejection power of the newly proposed method in this study, Monte Carlo simulation was performed with other goodness-of-fit tests including the existing PPCC test. The results showed that PPCC-A test which is proposed in this study demonstrated better rejection power than other methods, including the existing PPCC test. It is expected that the new method will be helpful to estimate the appropriate probability distribution model.

A Structural Model for Maternal Adaptation and Family Stress in Families with Mentally Retarded Children (정신 박약 아동 어머니의 스트레스와 적응에 관한 구조 모형)

  • 이경희
    • Journal of Korean Academy of Nursing
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    • v.22 no.4
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    • pp.476-490
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    • 1992
  • This study was designed to develop and test a structural model for maternal adaptation and family stress in families with mentally handicapped children. A hypothetical model was constructed on the basis of the family stress theory developed by McCubbin etc. The model included 6 theoretical concepts and 11 paths. For the purpose of the model testing, empirical data were collected from May to August, 1992. The subjects of the study constituted 190 mothers of children in five special schools and one private institute in Seoul and Choong Nam. An SPSS PC+ and PC-LISREL 7.13 computer programs were used for descriptive and covariance structure analysis. The results of the study were as follows. (1) The hypothetical model showed itself a good fit to the empirical data [Chi - square=18.35(df=7, P=0.005), Goodness of Fit Index=0.991, Adjusted Goodness of Fit Index=0.959, Root Mean Square Residual=0.042), Non Normed Fit Index=0.90, Normed Fit Index=0.96]. (2) The results of Hypothesis testing indicated : 1) Social support(${\gamma}$$_{11}$=.238, T=2.352), Family functioning(${\gamma}$$_{12}$=.729, T=5.957) and Family life event stress(${\gamma}$$_{13}$=.125) had direct effects on situational definition. 2) Life event stress(${\gamma}$$_{23}$=.319, T=3.872) had direct effects on the effect of the handicapped child on the family. Family functioning(${\gamma}$$_{22}$=-.245) and situational definition($\beta$$_{21}$=-.335, T=3.227) had direct effects on the effect of the handicapped child on the family. 3) Situational definition($\beta$$_{31}$=-.273, T=3.493), family life event stress (${\gamma}$$_{33}$=.124, T=2.169) and the effect of the handicapped child on the family($\beta$$_{32}$=.264, T=-3.227) showed the direct effect on the maternal adaptation. The model was supported by the empirical data. Thus it was suggested that the model could be applied to family nursing care with the families with the mentally handicapped. The construction and testing of the comprehensive model seem to be the first trial in Korea.a.a.a.

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Kullback-Leibler Information-Based Tests of Fit for Inverse Gaussian Distribution (역가우스분포에 대한 쿨백-라이블러 정보 기반 적합도 검정)

  • Choi, Byung-Jin
    • The Korean Journal of Applied Statistics
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    • v.24 no.6
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    • pp.1271-1284
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    • 2011
  • The entropy-based test of fit for the inverse Gaussian distribution presented by Mudholkar and Tian(2002) can only be applied to the composite hypothesis that a sample is drawn from an inverse Gaussian distribution with both the location and scale parameters unknown. In application, however, a researcher may want a test of fit either for an inverse Gaussian distribution with one parameter known or for an inverse Gaussian distribution with both the two partameters known. In this paper, we introduce tests of fit for the inverse Gaussian distribution based on the Kullback-Leibler information as an extension of the entropy-based test. A window size should be chosen to implement the proposed tests. By means of Monte Carlo simulations, window sizes are determined for a wide range of sample sizes and the corresponding critical values of the test statistics are estimated. The results of power analysis for various alternatives report that the Kullback-Leibler information-based goodness-of-fit tests have good power.

A Structural Model for Paternal Stress of Handicapped Children (장애 아동 아버지의 스트레스와 적응에 관한 구조 모형)

  • Lee, Kyung-Hee
    • The Korean Nurse
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    • v.31 no.5
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    • pp.72-87
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    • 1992
  • This study was designed to develop and lest a structural model for paternal adaplation and family stress in the families with the handicapped children. A hypothetical model was constructed on the basis of family stress theory developed by McCubbin etc. The model included 6 theoretical concepts and 11 paths. For the purpose of the model testing, empirical data were collected from May to August, 1992. The subject of the study constituted 190 mothers whose children admitted in the five special schools and one privale institutes in Seoul and Choong Nam. In data analysis, SPSS PC+ and PC-LISREL 7.13 computer program were utilized for descriptive and covariance structure analysis. The results of lhe study were as follows. (1) Hypothetical model showed a good fit to the empirical data [Chi-square = 21.19 (df = 7, P = o. 003), Goodness of Fit Index=O.986, Adjusted Goodness of Fit Indes=0.946, Root Mean Square lesidual=0.048), Non Normed Fit Index = 0.80, Normed Fit Index=0.91]. (2) The results of Hypothesis testing indicated: 1) Social support(${\gamma}_11=.238$, T=2.352), Family Functioning(${\gamma}_12=.729$, T=5.957) had direct effects on situational definition. 2) life event stress(${\gamma}_23=.284$, T=5.220) had direct effects on the effect of the handicapped chid on the family. 3) Family functioning(${\gamma}_32=-.239$, T= -3.370) had direct effects on paternal adapation. From the above results, the significance of this study can be delineated as follows : The construction and testing of the comprehensive model seem to be the first trial in Korea. The model was supported by empirical dala. Thus it was suggested that model could be adequately applied to framily nusing care with the handicapped.

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A Study of Probability Functions of Best Fit to Distribution of Annual Runoff -on the Nakdong River Basin- (년유출량의 적정확률 분포형에 관한 연구 -낙동강 유역을 중심으로-)

  • 조규상;이순탁
    • Water for future
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    • v.7 no.2
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    • pp.107-111
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    • 1974
  • Annual runoff in the Nakdong river basin has been analyzed to find the probability functions of best fit to distribution of historical annual runoff. The results obtained are as follows; (1) Log-normal 3-parameter disrtibution is believed as the probability function of best fit to historical distribution (2) Log-normal 3-parameter disrtibution is believed as the best fit probability function among Log-normal dist-ributions. (3) In the test of goodness of fit, $x^2-test$ shows that probability of $x^2-valus$ in Log-normal 3-parameter distribution is nearly more than 90%. But in the Simirnov-Kolmogorov test, hypotheses for the probability distributions cannot be rejected at significance level 5% & 1%. (4) Among 7 gauging stations, Dongchon & Koryung-Bridge's records show lower fitness to the theoretical probability functions than other 5 gauging station's

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Goodenss of Fit Test on Density Estimation

  • Kim, J.T.;Yoon, Y.H.;Moon, G.A.
    • Communications for Statistical Applications and Methods
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    • v.4 no.3
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    • pp.891-901
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    • 1997
  • The objective of this research is to investigate the problem of goodness of fit testing based on nonparametric density estimation with a data-driven smoothing parameter. The small and large smaple properties of the proposed test statistic $Z_{mn}$ are investigated with the minimizer $\widehat{m}$ of the estimated mean integrated squared error by the Diggle and Hall (1986) method.

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