• Title/Summary/Keyword: chi-square test

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Inference for Order Restrictions on Odds in 2 * k Contingency Tables

  • Oh, Myong-Sik
    • Journal of the Korean Statistical Society
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    • v.25 no.3
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    • pp.381-391
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    • 1996
  • In the analysis of contingency table with ordered categories, the relationship between odds for adjacent categories has received con-siderable interest. We consider likelihood ratio tests of independence against an order restriction on odds in 2 $\times$ k contingency tables.

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A Monte Carlo Comparison of the Small Sample Behavior of Disparity Measures (소표본에서 차이측도 통계량의 비교연구)

  • 홍종선;정동빈;박용석
    • The Korean Journal of Applied Statistics
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    • v.16 no.2
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    • pp.455-467
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    • 2003
  • There has been a long debate on the applicability of the chi-square approximation to statistics based on small sample size. Extending comparison results among Pearson chi-square Χ$^2$, generalized likelihood .ratio G$^2$, and the power divergence Ι(2/3) statistics suggested by Rudas(1986), recently developed disparity statistics (BWHD(1/9), BWCS(1/3), NED(4/3)) we compared and analyzed in this paper. By Monte Carlo studies about the independence model of two dimension contingency tables, the conditional model and one variable independence model of three dimensional tables, simulated 90 and 95 percentage points and approximate 95% confidence intervals for the true percentage points are obtained. It is found that the Χ$^2$, Ι(2/3), BWHD(1/9) test statistics have very similar behavior and there seem to be applcable for small sample sizes than others.

Detection of Random Effects in a Random Effects Model of a One-way Layout Contingency Table

  • Kim, Byung-Soo
    • Journal of the Korean Statistical Society
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    • v.13 no.1
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    • pp.1-19
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    • 1984
  • A random effects model of a one-way layout contingency table is developed using a Dirichlet-multinomial distribution. A test statistic, say $T_k$, is suggested for detecting Dirichlet-multinomial departure from a multinomial distribution. It is shown that the $T_k$ test is asymptotically superior to the classical chi-square test based on the asymptotic relative efficiency. This superiority is further evidenced by a Monte Carlo simulation.

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Comparing More than Two Agreement Measures Using Marginal Association

  • Oh, Myong-Sik
    • Communications for Statistical Applications and Methods
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    • v.16 no.6
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    • pp.1023-1029
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    • 2009
  • Oh (2009) has proposed a likelihood ratio test for comparing two agreements for dependent observations based on the concept of marginal homogeneity and marginal stochastic ordering. In this paper we consider the comparison of more than two agreement measures. Simple ordering and simple tree ordering among agreement measures are investigated. Some test procedures, including likelihood ratio test, are discussed.

Statistical Errors of Articles Published in the Journal of Oriental Rehabilitation Medicine(I) (한방재활의학과학회지의 통계적 오류에 관한 고찰(I))

  • Park, Tae-Yong;Heo, Tae-Young;Shin, Byung-Cheul
    • Journal of Korean Medicine Rehabilitation
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    • v.20 no.4
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    • pp.105-130
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    • 2010
  • Objectives : The purpose of this study was to assess the statistical methods errors used in the journal of Oriental Rehabilitation Medicine(JORM) and to identify the types of errors in statistical analysis. Methods : We reviewed quantitative articles that were published in the JORM from January 2005 through October 2009. Those were not used by statistical analysis such as literature studies, case study, review articles were not included in this analysis. A total of 296 articles was reviewed. We evaluated the adequacy and the validity of the statistical techniques with our checklist established be modified Lee's checklist, and three statistical evaluators assessed together to minimize bias. Results : Of the 222 articles, 213 were used in inferential and descriptive statistics. Of those 80% of articles adopting descriptive and inferential statistics were detected having statistical errors. One articles used 1.7 statistical method unit generally. Most frequently employed statistics were student t-test, one way ANOVA. pearson correlation analysis, Mann-whitney U test, paired t-test, and chi-square test in their order. However, most frequent statistics having errors were similar in order. The most common statistic errors were as follow: 1. absence of normality test, 2. misuse between paired test and unpaired test, 3. wrong choice of repeated measures analysis without consideration of time variables, 4, increase of Type I error by using inappropriate multiple test, 5. inappropriate application of discrete or categorical data instead of continuous data in correlation analysis, 6. poor consideration of basic consumption in chi-square test, 7. confusion between frequency comparison and average comparison, 8. mentioning the statistical technique without using it. Conclusions : We found various mistake or misuses in the applications of statistical methodologies in the articles published in the JORM. Careful consideration of statistical use and review from the specialist of statistics are warranted for improving the quality of JORM.

Characteristics of Work-related Musculoskeletal Disorders Compensated by the Industrial Accident Compensation Insurance in Shipbuilding Industry (조선업에서 산업재해로 인정된 근골격계질환의 특성)

  • Kim, Sang Woo;Shin, Yong Chul;Kang, Dongmug
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.15 no.2
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    • pp.114-123
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    • 2005
  • We analyzed the demographic and job features of 197 shipyard workers with work-related musculoskeletal disorders(WMSDs) compensated by the Industrial Accident Compensation Insurance Act, and the features of the disorders, the causes of operation and the induced behaviors. The three shipbuilding companies surveyed were located in Busan Metropolitan city and Gyungsangnam-do. The results were as follows. 1. The ages of WMSDs patients in shipyard were $43.6{\pm}8.6$ and the job tenure was $14.3{\pm}5.6$. The 40's of them was 40.1%, and the 30's was 29.4%. Patients less than 5 year-work duration were 85.3%, and ones more than 16 year-work duration 6.6%. In occupations, welders were 32.5%, pre-welders 17.3%, and setting engineers 6.6%. 2. The causes of WMSDs in shipyard were works(95.4%) and outer crash or accident shock (3.6%). Based on the standard of the NIOSH induced behaviors, the causes were awkward posture (62.9%), excessive movement(19.3%) and repetitive movement(13.7%). 3. The compensated WMSDs by body part was the highest, 36%, in the spines, 32.0% in both the upper limbs and the spines, and 14% in the upper limbs. The number of cases of WMSDs in body were 96 in the cervical, 79 in the lumbar and 72 in the shoulders. 4. As a result of chi-square test(${\chi}^2$) between diagnosis and operation in body, welding and spot welding had the most diagnoses in all parts of the body among other occupations. Chi-square test(${\chi}^2$) between diagnosis and induced behavior in body showed that awkward postures recorded the highest rate and repetitive movements was the second. 5. The most hazardous occupation was the welding(incidence rate=9.7) and the most hazardous behavior was the awkward posture.

Association of Knowledge, Attitude and Demographic Variables with Cervical Pap Smear Practice in Nepal

  • Ranabhat, Sabin;Tiwari, Mamta;Dhungana, Govinda;Shrestha, Reshmi
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.20
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    • pp.8905-8910
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    • 2014
  • Background: Coverage of cervical pap smear test in Nepal is below general global values. One of the reasons may be that cervical cancer prevention policy of Nepal has 'Visual Inspection of Cervix with Acetic Acid' as the only screening tool. The focus of present study was to find out association of demographic factors, knowledge and attitude regarding cervical Pap smear test with its practice by women in Nepal. Materials and Methods: This cross sectional analytical observational study was conducted between February 1, 2013 and April 30, 2013. Participants were interviewed with the help of a structured questionnaire. Chi square and multivariate logistic regression tests were used to detect associations of variables with pap smear practice. Results: Chi square test showed that practice was significantly associated with knowledge about pap smear test and cervical cancer, having favourable attitude towards the test, urban residency and 36-50 years age-group. Pap smear utilization was not associated with age-at-marriage, parity and age-at-first-child-birth. Multivariate logistic regression showed favorable attitude towards pap smear test as the only variable which significantly influenced pap smear practice (p= 0.006, OR: 2.4). Conclusions: Pap smear coverage has been found to be 15.7% which is lower than global average and that for developing countries. Health education programs which are effective not only in increasing knowledge about cervical cancer and pap smear test but also effective in positively changing attitude towards the test should be organized to increase pap smear coverage.

Test-Retest Method on Short Form Sasang Classification Questionnaire for American (SF_SSCQ-A) : Pilot Study (미국인 체질진단지 : 검사-재검사법)

  • Yoo, Jung-Hee;Lee, Eui-Ju;Park, Jin-Son;Hahn, Suk-Kyun;Lee, Jun-Hee;Kho, Byung-Hee
    • Journal of Sasang Constitutional Medicine
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    • v.21 no.1
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    • pp.79-84
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    • 2009
  • 1. Objectives This study was proposed to use the test-retest method to verify the independence and agreement between the questions (Short Form Sasang Classification Questionnaire for American ; SF_SSCQ-A). 2. Methods The questionnaire was administered to 50 American and they were asked to complete the questionnaire again two weeks after the first administration. The final subjects are 42 except of 5 dropouts and 3 insufficient respondents. A reliability analysis for each individual question was conducted using the test-retest method to verify the independence and agreement between the questions. To verify independence, a Chi-square test with crosstabs analysis and p-values was used. The agreement verification was conducted by using the Cohen kappa coefficient. In addition, the constitutional variable was defined as the constitutional attribute of each question, and Pearson's correlation coefficient was confirmed after testing the scale. 3. Results and Conclusions The test-retest method showed that Pearson's correlation coefficients for the results of the two tests ranged from 0.66 to 0.87. The Chi-square test results indicated that there are 7 independent item. Among the other 114 questions, the agreement test revealed that 88 questions (70.5%) showed above common agreement.

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The relationship between primary headache and constipation in children and adolescents

  • Park, Mi-Na;Choi, Min-Gyu;You, Su Jeong
    • Clinical and Experimental Pediatrics
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    • v.58 no.2
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    • pp.60-63
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    • 2015
  • Purpose: Many patients presenting with headache also complain of constipation; the relationship between these two symptoms has not been explored in detail. The aim of this study was to investigate the association between primary headache and constipation. Methods: This retrospective study included all children who attended the Inje University Sanggye Paik Hospital complaining of headache, and who had been followed up for at least 100 days. Patients were divided into 2 groups: group A, in whom the headache improved after treatment for constipation, and group B, in whom headache was not associated with constipation. Results: Of the 96 patients with primary headache, 24 (25.0%) also had constipation (group A). All 24 received treatment for constipation. Follow-up revealed an improvement in both headache and constipation in all patients. Group B contained the remaining 72 children. Comparison of groups A and B indicated a significant difference in sex ratio (P=0.009, chi-square test). Patients with probable tension-type headache were more likely to be in Group A (P=0.006, chi-square test). Conclusion: Resolution of constipation improves headache in many patients diagnosed with primary headache, especially those with probable tension-type headache. We suggest that either constipation plays a key role in triggering headache, or that both constipation and headache share a common pathophysiology.

INFLUNCE OF ELECTRO-MYOSCOPE(ACUSCOPE) ON INJURED QUADRICEPS FEMORIS WITH USING ELECTRO_MYOGRAPHIC ANALYSIS BUILT INTO THE ELCETROMYOSCOPE

  • Song, Byung-Ho
    • Journal of Korean Physical Therapy Science
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    • v.7 no.2
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    • pp.697-709
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    • 2000
  • The purpose of this study was to evaluate the effectiveness of ElectroMyoscope(Electro_Acuscope and Myopulse) in tissue repairing on fatigue quadriceps femoris(rectus femoris, vastus lateralis, vastus intermedius, and vastus medialis). Subjects were female adult volunteers with (n=13) and without (n=5) chronic fatigue muscle pain. We needed to fatigue the rectus femoris by overusing of a Cybex machine exercise. We turned the Electro-Myoscope to treatment mode and treated with treatment probe on the fatigue muscle, then turned instrument back to EMG and took the reading. The results indicated that the reading after the treatment was lower than before the treatment. A two-tailed t-test and Chi square indicated significant results(P<.03). It appears that the Electro-Myoscope is effective in treatment on the fatigue muscle.

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