• The Korean Journal of Applied Statistics
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• v.10 no.1
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• pp.85-104
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• 1997

Proportional hazards model has been widely used for analyzing survival data. This article reviews some well-known goodness-of-fit tests for proportional hazards model. Simulation studies also provide some insights into the properties of these test statistics across several types of survival distributions and degerees of censorship.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.2
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• pp.204-212
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• 2014

The purpose of this paper is to investigate the effects of calibration rounds on the statistical distribution of the muzzle velocity in acceptance test of propelling charge. It is shown that the normal distribution fits best among statistical distributions from goodness-of fit test. The 3p-Weibull distribution is also acceptable because the shape of the probability density function curve is similar to that of normal distribution and it also has near zero skewness value. Muzzle velocities of test rounds uncompensated by calibration rounds showed high variation and had comparatively higher skewness. Because the skewness of normal distribution is defined to be zero, calibration rounds make the normality of data higher.

• Korean Journal of Child Studies
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• v.6 no.1
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• pp.3-16
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• 1985

The purpose of this study was the application of sequential analysis to mother-infant interaction data, with particular reference to goodness of fit. The subjects of this study were 22 7- to 16-month-old infants(12 girls and 10 boys) and their mothers. Each mother-infant dyad was videotaped in a 5-min free-play session in the playroom. The videotaped data was transcribed on the behavioral checklist every 3 seconds. The recorded raw data were lagged by one time interval (3 sec.). Transitional probabilities from behavior at time t-1 to behavior at time t were gathered. The statistical analysis of frequency data and transitional probabilities consisted of Z test, t test, and sign test. It was found that regarding 1) direction of effect: the transitional probability of infant vocalization following maternal vocalization was significantly higher than the reverse; the transitional probability of a 'Coacting State' following a 'Mother Active State' was significantly higher than the reverse; the probability of a 'Mother Active State' following 'Quiescent State' was significantly higher than that of a 'Coacting State' following an 'Infant Active State'; 2) sex differences: male infants' transitional probability from an 'Infant Active State' to a 'Quiescent State' was significantly higher than that of female infants; 3) age differences: more than younger infants older infants had higher transitional probabilities from a 'Mother Active State' to a 'Coacting State', from a 'Parallel State' to a 'Coacting State', and from a 'Quiescent State' to a 'Parallel State'. These showed goodness of fit for sex and age differences, particularily for direction of effect.

• The Korean Journal of Applied Statistics
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• v.13 no.2
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• pp.407-414
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• 2000

Carroll and Ruppert(1988) analyzed the esterase assay data with regression model based on quasi-likelihood. Jung and Lee(1997) introduced a goodness-of-fit test for testing the adequacy of the quasi-likelihood and claimed that there is no gross inadequacy with the model because their test was not rejected. However, Lee and Xelder(199S)'s residual plots revealed that the model did not sufficiently reflect the increase of the variance with that of the mean. In this paper, we re-analyze the esterase assay data with the joint modelling of mean and dispersion in Lee and l\elder(1998) and evaluate the validity of the fitted model by applying the residual plots. And it is illustrated that Lee and Nelder(199S)'s restricted likelihood is more efficient in goodness-of-fit test for the dispersion model.

• 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.

• Communications for Statistical Applications and Methods
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• v.26 no.5
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• pp.431-443
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• 2019

Goodness-of-fit techniques are an important topic in statistical analysis. Censored data occur frequently in survival experiments; therefore, many studies are conducted when data are censored. In this paper we mainly consider test statistics based on the empirical distribution function (EDF) to test normal distributions with unknown location and scale parameters when data are randomly censored. The most famous EDF test statistic is the Kolmogorov-Smirnov; in addition, the quadratic statistics such as the $Cram{\acute{e}}r-von$ Mises and the Anderson-Darling statistic are well known. The $Cram{\acute{e}}r-von$ Mises statistic is generalized to randomly censored cases by Koziol and Green (Biometrika, 63, 465-474, 1976). In this paper, we generalize the Anderson-Darling statistic to randomly censored data using the Kaplan-Meier estimator as it was done by Koziol and Green. A simulation study is conducted under a particular censorship model proposed by Koziol and Green. Through a simulation study, the generalized Anderson-Darling statistic shows the best power against almost all alternatives considered among the three EDF statistics we take into account.

• Communications for Statistical Applications and Methods
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• v.19 no.6
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• pp.837-847
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• 2012

Inverse Gaussian distribution is widely used in applications to analyze and model right-skewed data. To assess the appropriateness of the distribution prior to data analysis, Mudholkar and Tian (2002) proposed an entropy-based test of fit. The test is based on the entropy power fraction(EPF) index suggested by Gokhale (1983). The simulation results report that the power of the entropy-based test is superior compared to other goodness-of-fit tests; however, this observation is based on the small-scale simulation results on the standard exponential, Weibull W(1; 2) and lognormal LN(0:5; 1) distributions. A large-scale simulation should be performed against various alternative distributions to evaluate the power of the entropy-based test; however, the use of a theoretical method is more effective to investigate the powers. In this paper, utilizing the information discrimination(ID) index defined by Ehsan et al. (1995) as a mathematical tool, we scrutinize the power of the entropy-based test. The selected alternative distributions are the gamma, Weibull and lognormal distributions, which are widely used in data analysis as an alternative to inverse Gaussian distribution. The study results are provided and an illustrative example is analyzed.

• 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.

• Communications for Statistical Applications and Methods
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• v.9 no.3
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• pp.629-637
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• 2002

Shapiro and Wilk(1972) developed a test for exponentiality with origin and scale unknown. The procedure consists of comparing the generalized least squares estimate of scale with the estimate of scale given by the sample variance. However the test based on the statistic is inconsistent Kim(2001a) proposed a modified Shapiro-Wilk's test statistic using the ratio of two asymptotically efficient estimators of scale. In this paper, we study the consistency of the proposed test.

• Communications for Statistical Applications and Methods
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• v.6 no.3
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• pp.687-694
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• 1999

The goodness of fit statistics of normality plots are obtained using the Receiver Operating Characteristic(ROC) method. This work is intended to compare with Shapiro-Wilk W statistic. Wel will use and discuss an accuracy of the test and the best cut-off value which minimizes the sum of the type I and II error probabilities.