• 제목/요약/키워드: Chi-bar-square

검색결과 12건 처리시간 0.024초

Testing for Failure Rate Ordering between Survival Distributions

  • Park, Chul-Gyu
    • Journal of the Korean Statistical Society
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    • 제23권2호
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    • pp.349-365
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    • 1994
  • We develop in this paper the likelihood ratio test (LRT) for testing $H_1 : F_1 \preceq F_2$ against $H_2 - H_1$ where $H_2$ imposes no restriction on $F_1$ and $F_2$ and '$\preceq$' means failure rate ordering. Both one and two-sample problems will be considered. In the one-sample case, one of the two distributions is known, while we assume in the other case both are unknown. We derive the asymptotic null distribution of the LRT statistic which will be of chi-bar-square type. The main issue here is to determine the least favorable distribution which is stochastically largest within the class of null distributions.

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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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    • 제25권3호
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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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An Attempt to Model Distributions of Machined Component Dimensions in Production

  • Cogun, Can;Kilinc, Biinyamin
    • Journal of Mechanical Science and Technology
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    • 제16권1호
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    • pp.60-74
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    • 2002
  • In this study, normal, log-normal, triangular, uniform. Weibull, Erlang and unit beta probability density functions are tried to represent the behaviour of frequency distributions of workpiece dimensions collected from various manufacturing firms. Among the distribution functions, the unit beta distribution function is found to be the best fit using the chi-square test of fit. An attempt is made for the adoption of the unit beta model to x-bar charts of quality control in manufacturing. In this direction, upper and lower control limits (UCL and LCL) of x-bar control charts of dimension measurements are estimated for the beta model, and the observed differences between the beta and normal model control limits are discussed for the measurement sets.

Statistical Inference Concerning Local Dependence between Two Multinomial Populations

  • Oh, Myong-Sik
    • Journal of the Korean Data and Information Science Society
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    • 제14권2호
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    • pp.413-428
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    • 2003
  • If a restriction is imposed only to a (proper) subset of parameters of interest, we call it a local restriction. Statistical inference under a local restriction in multinomial setting is studied. The maximum likelihood estimation under a local restriction and likelihood ratio tests for and against a local restriction are discussed. A real data is analyzed for illustrative purpose.

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Test of Local Restriction on a Multinomial Parameter

  • Oh, Myongsik
    • Communications for Statistical Applications and Methods
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    • 제10권2호
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    • pp.525-534
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    • 2003
  • If a restriction is imposed only to a (proper) subset of parameters of interest, we call it a local restriction. Statistical inference under a local restriction in multinomial setting is studied. The maximum likelihood estimation under a local restriction and likelihood ratio tests for and against a local restriction are discussed. A real data is analyzed for illustrative purpose.

Comparing More than Two Agreement Measures Using Marginal Association

  • Oh, Myong-Sik
    • Communications for Statistical Applications and Methods
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    • 제16권6호
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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 Inference Concerning Peakedness Ordering between Two Symmetric Distributions

  • Oh, Myong-Sik
    • Journal of the Korean Data and Information Science Society
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    • 제15권1호
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    • pp.201-210
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    • 2004
  • The peakedness ordering is closely related to dispersive ordering. In this paper we consider the statistical inference concerning peakedness ordering between two arbitrary symmetric distributions. Nonparametric maximum likelihood estimates of two distribution functions under symmetry and peakedness ordering are given. The likelihood ratio test for equality of two symmetric discrete distributions in the sense of peakedness ordering is studied.

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Tests For and Against a Positive Dependence Restriction in Two-Way Ordered Contingency Tables

  • Oh, Myongsik
    • Journal of the Korean Statistical Society
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    • 제27권2호
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    • pp.205-220
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    • 1998
  • Dependence concepts for ordered two-way contingency tables have been of considerable interest. We consider a dependence concept which is less restrictive than likelihood ratio dependence and more restrictive than regression dependence. Maximum likelihood estimation of cell probability under this dependence restriction is studied. The likelihood ratio statistics for and against this dependence are proposed and their large sample distributions are derived. A real data is analyzed to illustrate the estimation and testing procedures.

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18-24개월 시기에 경험하는 우식치와 탈회치에 영향을 미치는 요인 (Factors Affecting Experience of Decayed and Decalcified Teeth of Infants Aged 18-24 Months)

  • 임순연;우희선
    • 치위생과학회지
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    • 제11권3호
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    • pp.205-211
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    • 2011
  • 본 연구는 경기도 C치과의원에서 2010년 1월부터 12월까지 1년 동안 18-24개월에 해당되는 293명의 영유아 구강검진 결과표와 부모가 작성한 문진표를 토대로 구강건강상태와 구강건강행태 및 우식성 식품섭취가 우식치와 탈회치에 미치는 영향을 조사하였으며, 결과는 다음과 같다. 1. 18-20개월 영유아는 탈회치의 비율이 36.4%로 높고, 23-24개월 영유아는 우식치의 비율이 37.0%로 높게 나타났다. 2. 우유병을 뗀 여부는 탈회치와 우식치의 발생에 관련이 있다(p<.001). 3. 구강상태에서 썩은치아와 뿌연치아에 대해 부모가 인지하는 것으로 나타났다. 4. 식품군 중에서 2군(탄산음료/청량음료/가당 과일 쥬스)이 탈회치와 우식치와 관련이 있다(p<.001), 4군(케이크/과자/도우넛/말린과일/바나나), 5군(캐러멜/사탕류/초코렛바)은 탈회치와 관련이 있다(p<.001). 5. 구강검진 결과, 치아치료는 21-22개월(89.3%)에서, 예방치료와 치면세균막 제거는 18-20개월(94.5%)에서 가장 높게 필요한 것으로 나타났다. 이상의 결과를 통해 보면, 생후 18-24개월은 구강건강관리에 주의를 요하는 시기이므로 영유아 검진시에 부모의 체계화된 구강보건교육이 필요할 것으로 사료된다.

무용요법이 노인의 신체적.심리적 특성에 미치는 효과 (The Effect of Dance Therapy on Physical and Psychological Characteristics in The Elderly)

  • 이영란
    • 대한간호학회지
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    • 제29권2호
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    • pp.429-444
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    • 1999
  • This study was performed to explore the effects of a dance therapy on physical and psychological characteristics in the elderly. The design of this study was a non-equivalent pre-post test experiment. The subjects consisted of elderly persons living in a facility located in Suweon and Bucheon. Fifty eight subjects, aged between 65 and 93 years who had normal cognition, sensory function, balance, and resting blood pressure. They underwent tests of balance, flexibility, muscle strength, depression, and anxiety as baseline data before dance therapy, and at 6th week and at the end of the 12nd week after following dance therapy. Twenty seven elderly persons were assigned to the experimental group and participated with the dance therapy between April and July, 1998. The dance therapy was developed by the author with the help of a dance therapist and a physiatrist. This therapy was based on the Marian Chace's dance therapy and Korean traditional dance with music. The dance therapy consists of 50 minutes session, 3 times a week for 12 weeks. One session was consisted of warming-up, expression, catharsis, sharing, and closing stage. The intensity of the dance therapy was at the 40 % of age-adjusted maximum heart rates. Data were analysed with mead standard deviation, Chi-square test, unpaired t-test, repeated measures ANOVA, and Bonferroni multiple regression using SAS program. 1. The results related to the physical characteristics were as follows : 1) The balance (standing on one leg, walking on the balancing bar), flexibility and muscle strength (knee extensor, knee flexor, ankle plantarflexor and dorsiflexor) of the experimental subjects significantly increased over time mere than that of the control subjects. 2) The experimental group had significantly higher score for balance, flexibility, muscle strength of knee extensor, and knee flexor than the control group at the 12nd week after dance therapy. 3) The experimental group had significantly higher score for muscle strength of ankle dorsiflexor and plantarflexor than the control group at the 6th week and the 12nd week after dance therapy. 2. The results related to psychological characteristics were as follows : 1) Scores of Geriatric Depression Scale, Hamilton Depression Rating Scale, and Zung's Self-rating Anxiety Scale of the experimental group were significantly decreased over time more than that of the control group. 2) The experimental group had significantly lower score for depression than the control group at the 12nd week after dance therapy. 3) The experimental group had significantly lower score for anxiety than the control group at the 6th week and the 12nd week after dance therapy. The findings showed that the dance therapy could be effective in improving the balances, flexibility, and muscle strength of lower limb, and effective in decreasing the depression and anxiety of the elderly. Additional merits of the dance therapy would be inexpensiveness, easy accessibility, and increasing interpersonal relationship. It can be suggested that the dance therapy is effective in the health promotion of the elderly.

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