• 제목/요약/키워드: Shapiro -Wilk statistic

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NORMALIZED SAMPLE LORENZ CURVE를 이용한 검정력이 높은 정규성 검정 (More Powerful Test for Normality Based on the Normalized Sample Lorenz Curve)

  • 강석복;조영석
    • 응용통계연구
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    • 제15권2호
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    • pp.415-421
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    • 2002
  • 통계적분석에서 가장 대표적인 가정이 정규성 가정이므로 데이터의 정규성 검정은 매우 중요하다. 이 논문에서는 정규성 검정을 위해 경제학에서 소득분배의 불균형에 관한 척도로 널리 이용되는 Lorenz curve를 변형한 새로운 플롯과 검정통계량을 제시한다. 그리고 제한한 검정을 W검정 (Shapiro and Wilk (1965)), Lorenz curve를 이용한 TL검정(Kang and Cho (1999))과 몬테칼로 방법을 이용하여 검정력을 비교한다. 제안된 검정이 특별한 대립분포의 경우를 제외하고는 대부분 검정력이 높았다.

임의중도절단자료에 대한 로그정규성 검정 (Testing Log Normality for Randomly Censored Data)

  • 김남현
    • 응용통계연구
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    • 제24권5호
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    • pp.883-891
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    • 2011
  • 수명시간에 대한 모형으로 로그정규분포가 자주 사용되며, 이는 자료의 변환에 의하여 정규성 검정과 동일한 문제로 생각할 수 있다. 따라서 자료의 로그정규성 검정을 위하여, 정규성 검정에 자주 이용되는 Shapiro-Wilk 형태의 검정통계량을 Kaplan-Meier의 product limit 경험분포함수를 이용하여 임의중도절단자료로 일반화한다. Cram er von Mises 통계량을 임의중도절단자료로 일반화한 Koziol과 Green (1976)의 통계량과 비교하였으며 이를 위하여 단순귀무가설을 가정하였다. 중도절단분포에 대한 모형으로는 Koziol과 Green (1976)에서 제시한 모형과 이와 유사한 다른 모형 두 가지를 고려하였다. 검정력 비교 결과 제시한 통계량이 로그정규성 또는 정규성 검정에 더 좋은 검정력을 보여주었으며 검정력은 중도절단분포 모형보다는 자료의 중도절단비율에 영향을 받는다는 것을 볼 수 있었다.

A note on Box-Cox transformation and application in microarray data

  • Rahman, Mezbahur;Lee, Nam-Yong
    • Journal of the Korean Data and Information Science Society
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    • 제22권5호
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    • pp.967-976
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    • 2011
  • The Box-Cox transformation is a well known family of power transformations that brings a set of data into agreement with the normality assumption of the residuals and hence the response variable of a postulated model in regression analysis. Normalization (studentization) of the regressors is a common practice in analyzing microarray data. Here, we implement Box-Cox transformation in normalizing regressors in microarray data. Pridictabilty of the model can be improved using data transformation compared to studentization.

A Modification of the W Test for Exponentiality

  • Kim, Nam-Hyun
    • Communications for Statistical Applications and Methods
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    • 제8권1호
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    • pp.159-171
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    • 2001
  • 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 statistic is inconsistent ; that is, the power of the test will not approach 1 as the sample size increases. Hence we give a test based on the ratio of two asymptotically efficient estimates of scale. We also have conducted a power study to compare the test procedures, using Monte Carlo samples from a wide range of alternatives. It is found that the suggested statistics have higher power for the alternatives with the coefficient of variation greater that or equal to 1.

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Development of Diameter Growth Models by Thinning Intensity of Planted Quercus glauca Thunb. Stands

  • Jung, Su Young;Lee, Kwang Soo;Kim, Hyun Soo
    • 인간식물환경학회지
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    • 제24권6호
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    • pp.629-638
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    • 2021
  • Background and objective: This study was conducted to develop diameter growth models for thinned Quercus glauca Thunb. (QGT) stands to inform production goals for treatment and provide the information necessary for the systematic management of this stands. Methods: This study was conducted on QGT stands, of which initial thinning was completed in 2013 to develop a treatment system. To analyze the tree growth and trait response for each thinning treatment, forestry surveys were conducted in 2014 and 2021, and a one-way analysis of variance (ANOVA) was executed. In addition, non-linear least squares regression of the PROC NLIN procedure was used to develop an optimal diameter growth model. Results: Based on growth and trait analyses, the height and height-to-diameter (H/D) ratio were not different according to treatment plot (p > .05). For the diameter of basal height (DBH), the heavy thinning (HT) treatment plot was significantly larger than the control plot (p < .05). As a result of the development of diameter growth models by treatment plot, the mean squared error (MSE) of the Gompertz polymorphic equation (control: 2.2381, light thinning: 0.8478, and heavy thinning: 0.8679) was the lowest in all treatment plots, and the Shapiro-Wilk statistic was found to follow a normal distribution (p > .95), so it was selected as an equation fit for the diameter growth model. Conclusion: The findings of this study provide basic data for the systematic management of Quercus glauca Thunb. stands. It is necessary to construct permanent sample plots (PSP) that consider stand status, location conditions, and climatic environments.

보건소의 환경, 조직구조와 조직유효성과의 관계 (A Study on Relationships Between Environment, Organizational Structure, and Organizational Effectiveness of Public Health Centers in Korea)

  • 윤순녕
    • 지역사회간호학회지
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    • 제6권1호
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    • pp.5-33
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    • 1995
  • The objective of the study are two-fold: one is to explore the relationship between environment, organizational structure, and organizational effectiveness of public health centers in Korea, and the other is to examine the validity of contingency theory for improving the organizational structure of public health care agencies, with special emphasis on public health nursing administration. Accordingly, the conceptual model of the study consisted of three different concepts: environment, organizational structure, and organizational effectiveness, which were built up from the contingency theory. Data were collected during the period from 1st of May through 30th of June, 1990. From the total of 249 health centers in the country, one hundred and five centers were sampled non proportionally, according to the geopolitical distribution. Out of 105, 73 health centers responded to mailed questionnaire. The health centers were the unit of the study, and a various statistical analysis techniques were used: Reliability analysis(Cronbach's Alpha) for 4 measurement tools; Shapiro-Wilk statistic for normality test of measured scores of 6 variables: ANOVA, Pearson Correlaion analysis, regressional analysis, and canonical correlation analysis for the test of the relationships and differences between the variables. The results were. as follows : 1. No significant differences between forma lization, decision-making authority and environmental complexity were found(F=1.383, P=.24 ; F=.801, P=.37). 2. Negative relationships between formalization and decision-making authority for both urban and rural health centers were found(r=-.470, P=.002 ; r=-.348, P=.46). 3. No significant relationship between formalization and job satisfaction for both urban and rural health centers were found (r=-.242, P=.132, r=-.060, P=.739). 4. Significant positive relationship between decision - making authority and job satisfaction were found in urban health centers (r=.504, P=.0009), but no such relationship was observed in rural health centers. Regression coefficient between them was statistically significant($\beta=1.535$, P=.0002), and accuracy of regression line was accepted (W=.975, P= .420). 5. No significant relationships among formalization and family planning services, maternal health services, and tuberculosis control services for both urban and rural health centers were found. 6. Among decision-making authority and family planning services, maternal health services, and tuberculosis control services, significant positive relationship was found between de cision-making authority and family planning services(r=.286, P=.73). 7. A significant difference was found in maternal health services by the type of health centers (F=5.13, P=.026) but no difference was found in tuberculosis control services by the type of health centers, formalization, and decision-making authority. 8. A significant positive relationships were found between family planning services and maternal health services and tuberculosis control services, and between maternal health services and tuberculosis control services (r=-.499, P=.001 ; r=.457, P=.004 ; r=.495, P=.002) in case of urban health centers. In case of rural health centers, relationships between family planning services and tuberculosis control services, and between maternal health services and tuberculosis control services were statistically significant (r=.534, P=.002 ; r=.389, P=.027). No significant relationship was found between family planning and maternal health services. 9. A significant positive canonical correlation was found between the group of independent variables consisted of formalization and de cision-making authority and the group of dependent variables consisted of family planning services, maternal health services and tuberculosis control services(Rc=.455, P=.02). In case of urban health centers, no significant canonical correlation was found between them, but significant canoncial correlation was found in rural health centers(Rc=.578, P=.069), 10. Relationships between job satisfaction and health care productivity was not found significant. Through these results, the assumed relationship between environment and organizational structure was not supported in health centers. Therefore, the relationship between the organizational effectiveness and the congruence between environment and organizational structure that contingency theory proposes to exist was not able to be tested. However decision-making authority was found as an important variable of organizational structure affecting family planning services and job satisfaction in urban health centers. Thus it was suggested that decentralized decision making among health professionals would be a valuable strategy for improvement of organizational effectiveness in public health centers. It is also recommended that further studies to test contingency theory would use variability and uncertainty to define environment of public health centers instead of complexity.

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