• 응용통계연구
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• 제10권1호
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• pp.85-104
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• 1997

Cox(1972)가 제안한 비례위험모형은 두 표본의 처리를 비교하거나 공변량의 효과와 생존시간의 관계를 회귀적으로 해석하는 등 다양한 상황에 쓰일 수 있어 널리 이용되고 있다. 따라서 비례위험모형에 대하여 많은 통계 학자들이 연구를 하였는데, 그중에서도 적합도 검정법에 대하여 여러 편의 논문이 발표되었다. 본 논문에서는 지금까지 제안된 비례위험모형에 대한 적합도 검정법에 관하여 설명하고, 다양한 형태의 자료에 대한 모의실험을 통하여 비례위험모형을 이용하여 생존분석을 실시하려는 통계분석가들에게 도움이 되도록 각각의 특성에 관하여 논의하였다.

• 한국군사과학기술학회지
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• 제17권2호
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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.

• 아동학회지
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• 제6권1호
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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.

• 응용통계연구
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• 제13권2호
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• pp.407-414
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• 2000

Carroll과 Ruppert(1988)는 준가능도(quasi-likelihood)를 이용하여 에스트라제 측정자료를 회귀분석하였다. Jung과 Lee(1997)는 준가능도을 이용한 회귀분석모형의 적합도정통계량을 제안하였으며 검정 별과 기각되지 않아 본 분석모형이 타당하다고 주장하였다. 그러나 Lee와 Nelder(1998)의 잔차그림을 검토한 결과, 상기 모형으로는 평균증가에 따른 분산증가를 충분히 반영할 수 없었다. 본 논문에서는 Lee와 Nelder(1998)의 평균과 분산의 동시모형으로 에스트라제 자료를 재분석하고 잔차그림을 이용하여 모형의 타당성을 재평가하였다. 또한 분산에서 산포모형에 대한 적합도검정에는 Lee와 Nelder(1998)의 제한가능도(restricted likelihood)에 근거한 검정법이 보다 적절함을 제시하였다.

• 소성∙가공
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• 제29권5호
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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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• 제26권5호
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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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• 제19권6호
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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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• 제20권1호
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• pp.1-10
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• 2014

목적 본 연구의 목적은 초등학교 고학년 아동의 문제행동에 영향을 미치는 변수를 중심으로 탐색하여 영향요인들을 설명하는 모형을 구축하는 데 있다. 방법 본 연구를 위해 일개 도시의 3개 초등학교 고학년 아동과 그의 어머니를 대상으로 설문조사를 하였으며, 총 368명의 자료를 수집하였다. 수집된 자료는 SPSS 17.0 통계 프로그램을 이용하여 서술적 통계, t-test, ${\chi}^2$-test, ANOVA를 시행하였고, 가설적 모형 검정은 AMOS 17.0 통계 프로그램을 이용하였다. 결과 가설적 모형의 적합도는 GFI: .956, AGFI: .927, CFI: .953, RMSEA: .056, SRMR: .023으로 지지되었다. 모형에서 설정된 10개의 경로 중 6개의 경로가 지지되었다. 즉, 부모 양육태도에서 자아존중감으로, 부모양육태도에서 스트레스로, 부모 양육태도에서 스트레스 대처로, 부모양육태도에서 문제행동으로, 자아존중감에서 스트레스로, 자아존중감에서 문제행동으로 가는 경로가 지지되었다. 문제행동에 통계적으로 유의한 효과를 나타낸 것은 양육태도와 자아존중감이며 양육태도는 총 효과를, 자아존중감은 직접효과와 총 효과를 나타내었다. 결론 부모 양육태도와 자아존중감이 문제행동에 영향을 미치는 중요한 변수인 것으로 확인되었다. 그러므로 문제행동의 발생을 줄이기 위해서는 긍정적인 양육태도를 고취시키고 아동의 자아존중감을 높이는 간호중재가 이루어져야 하겠다.

• Communications for Statistical Applications and Methods
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• 제9권3호
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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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• 제6권3호
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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.