• 제목/요약/키워드: Non-parametric methods

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한의학 연구에 활용된 통계분석 방법에 대한 고찰 (A Review of Statistical Analysis Methods Applied on Traditional Korean Medicine Research)

  • 장선일;윤용갑;최경호
    • 대한한의학방제학회지
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    • 제17권1호
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    • pp.75-83
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    • 2009
  • Objective : The purpose of this study is to indicate of problems in statistical analysis method of "The Korean Journal of oriental Medical Prescription" and we will be proposed the useful application of the statistical analysis method. Methods : In this paper, we were analysed statistical analysis methodology from published journal articles "The Korean Journal of Oriental Medical Prescription" December, year 2000 to December, year 2008. We were investigated of problems in application of structured analysis methods those journal articles that including statistical analysis techniques and analysis methods. Results : 1. A random allocation of the experimental group and control groups are important factors in the planning process of statistical analysis. However, there are less explanation those journal articles. 2. There are no consideration in specimen size that there will be considerate by the level of significance and statistical test. 3. Many article authors were confused between parametric methods and non-parametric methods that they were applied parametric statistical analysis methods although inapplicable sample size. 4. There were applied the parametric methods consists of t-test instead non-parametric methods in the comparison of average intergroup relations. 5. There were less understanding posterior analysis and were confused with t-test. Conclusion : Our goal was to outline the key methods with a brief discussion of problems(statistical analysis methods), avenues for solutions. we recommend authors to use an appropriate statistical analysis methods for obtaining a more cautions results.

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모수, 비모수, 베이지안 출산율 모형을 활용한 합계출산율 예측과 비교 (A comparison and prediction of total fertility rate using parametric, non-parametric, and Bayesian model)

  • 오진호
    • 응용통계연구
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    • 제31권6호
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    • pp.677-692
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    • 2018
  • 최근 2017년 우리나라 합계출산율은 1.05명로 2005년 1.08명 수준으로 회귀하는 현상을 보이고 있다. 1.05명은 인구대체선(2.1명), 안전선(1.5명)과도 거리가 먼 초저출산 수준이고 마치 초저출산 덫에 빠질 우려가 있다. 이에 합계출산율의 합리적인 예측과 이를 통한 출산정책에 유용한 자료를 제공하는 것은 그 어느 때 보다도 중요하다. 그 동안 다양한 통계적 방법으로 합계출산율 추이를 예측하였는데, 데이터 완비성이 높고 품질이 좋은 경우 모형 접근인 모수적 방법, 데이터 추이가 단절되거나 변동이 심한 경우 평활과 가중치를 적용한 비모수적 방법, 데이터 부족과 품질 등으로 선진국의 출산율 3단계 전이현상을 참고하여 이들의 사전분포를 활용하는 베이지안 방법 등이 적용되어 왔다. 본 연구는 최근 변동이 심한 우리나라 출산율에 모수, 비모수, 그리고 베이지안 방법을 적용하여 추정과 예측을 실시하고 도출된 결과 비교를 통해 적합성과 타당성 측면에서 어떤 방법이 합리적인지 모색하고자 한다. 분석결과 합계출산율 예측값 순위는 통계청 합계출산율이 가장 높고, 베이지안, 모수, 비모수 순으로 나타났다. 2017년 TFR 1.05명 수준을 감안할 때 모수, 비모수모형으로 도출된 합계출산율 예측값이 합리적이다. 또한 출산율 자료완비성이 높고 품질이 우수할 경우 계산 효율성과 적합도 관점에서 모수적 추정과 예측 접근 방법이 타 방법보다 우수한 것으로 도출되었다.

Note on response dimension reduction for multivariate regression

  • Yoo, Jae Keun
    • Communications for Statistical Applications and Methods
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    • 제26권5호
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    • pp.519-526
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    • 2019
  • Response dimension reduction in a sufficient dimension reduction (SDR) context has been widely ignored until Yoo and Cook (Computational Statistics and Data Analysis, 53, 334-343, 2008) founded theories for it and developed an estimation approach. Recent research in SDR shows that a semi-parametric approach can outperform conventional non-parametric SDR methods. Yoo (Statistics: A Journal of Theoretical and Applied Statistics, 52, 409-425, 2018) developed a semi-parametric approach for response reduction in Yoo and Cook (2008) context, and Yoo (Journal of the Korean Statistical Society, 2019) completes the semi-parametric approach by proposing an unstructured method. This paper theoretically discusses and provides insightful remarks on three versions of semi-parametric approaches that can be useful for statistical practitioners. It is also possible to avoid numerical instability by presenting the results for an orthogonal transformation of the response variables.

독립인 두 모집단 설계에서의 표본수 비교 (Sample size comparison for two independent populations)

  • 고해원;김동재
    • Journal of the Korean Data and Information Science Society
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    • 제21권6호
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    • pp.1243-1251
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    • 2010
  • 임상시험을 시행하는 경우 위약을 신약과 비교하는 경우가 대다수이다. 기존에 독립인 두 모 집단의 표본수를 계산하는 방법으로 모수적 방법에서는 t검정을 이용하였고, 비모수적 방법에서는 Wilcoxon 순위합검정 (Wilcoxon, 1945)을 이용하였다. 본 논문에서는 Orban과 Wolfe (1982)가 제안한 선형위치통계량의 검정법과, Kim (1994)이 선형위치통계량에 기초하여 계산한 검정력의 결과를 이용하여 표본수 구하는 방법을 제안한다. 또한 앞서 제안한 방법의 표본수를 기존의 Wilcoxon 순위합검정을 이용하여 Wang 등 (2003)이 제안한 공식을 이용한 표본수, 그리고 모수적 방법을 이용한 t검정의 표본수와 비교하였다.

꼬리가 두꺼운 분포의 고분위수에 대한 준모수적 붓스트랩 신뢰구간 (Semi-parametric Bootstrap Confidence Intervals for High-Quantiles of Heavy-Tailed Distributions)

  • 김지현
    • Communications for Statistical Applications and Methods
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    • 제18권6호
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    • pp.717-732
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    • 2011
  • 꼬리가 두꺼운 분포의 고분위수에 대한 신뢰구간을 구할 때 적절한 붓스트랩 방법은 무엇인가에 대해 알아보았다. 비모수적 방법과 모수적 방법, 그리고 준모수적 방법의 성능을 모의실험을 통해 비교하였다.

불규칙 매개변수 가진을 받는 비선형계의 확률론적 진동평가 (Vibration of Non-linear System under Random Parametric Excitations by Probabilistic Method)

  • 이신영
    • 한국정밀공학회지
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    • 제23권12호
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    • pp.72-79
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    • 2006
  • Vibration of a non-linear system under random parametric excitations was evaluated by probabilistic methods. The non-linear characteristic terms of a system structure were quasi-linearized and excitation terms were remained as they were An analytical method where the square mean of error was minimized was used An alternative method was an energy method where the damping energy and restoring energy of the linearized system were equalized to those of the original non-linear system. The numerical results were compared with those obtained by Monte Carlo simulation. The comparison showed the results obtained by Monte Carlo simulation located between those by the analytical method and those by the energy method.

비-파라미터 기반의 움직임 분류를 통한 비디오 검색 기법 (Video retrieval method using non-parametric based motion classification)

  • 김낙우;최종수
    • 대한전자공학회논문지SP
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    • 제43권2호
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    • pp.1-11
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    • 2006
  • 본 논문에서는 샷(shot) 기반 비디오 색인 구조에서 비-파라미터(non-parametric) 기반의 움직임 분류를 통한 비디오 영상 검색 기법을 제안한다. 본 논문에서 제안하는 비디오 검색 시스템은 장면 전환 기법을 통해 얻은 샷 단위의 짧은 비디오로부터 대표 프레임과 움직임 정보를 취득한 후, 이를 통해 시각적 특징과 움직임 특징을 추출하여 유사도를 비교함으로써 시-공간적 특징을 이용한 실시간 검색이 가능하도록 구현되었다. 비-파라미터 기반의 움직임 특징의 추출은 MPEG 압축 스트림으로부터 정규화된 움직임 벡터계(界)를 추출한 후, 각각의 정규화된 움직임 벡터를 여러 개의 각도 빈(bin)으로 양자화하고 이의 평균과 분산, 방향 등을 고려함으로써 효과적으로 이루어진다. 대표 프레임에서의 시각 특징 검출을 위해서는 에지 기반의 공간 기술자를 이용하였다. 실험 결과는 영상 색인 및 검색에 있어서 제안된 시스템이 매우 효과적임을 잘 나타내고 있다. 데이터베이스 내 영상의 색인을 위해서는 R*-tree 구조를 이용한다.

Practical statistics in pain research

  • Kim, Tae Kyun
    • The Korean Journal of Pain
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    • 제30권4호
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    • pp.243-249
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    • 2017
  • Pain is subjective, while statistics related to pain research are objective. This review was written to help researchers involved in pain research make statistical decisions. The main issues are related with the level of scales that are often used in pain research, the choice of statistical methods between parametric or nonparametric statistics, and problems which arise from repeated measurements. In the field of pain research, parametric statistics used to be applied in an erroneous way. This is closely related with the scales of data and repeated measurements. The level of scales includes nominal, ordinal, interval, and ratio scales. The level of scales affects the choice of statistics between parametric or non-parametric methods. In the field of pain research, the most frequently used pain assessment scale is the ordinal scale, which would include the visual analogue scale (VAS). There used to be another view, however, which considered the VAS to be an interval or ratio scale, so that the usage of parametric statistics would be accepted practically in some cases. Repeated measurements of the same subjects always complicates statistics. It means that measurements inevitably have correlations between each other, and would preclude the application of one-way ANOVA in which independence between the measurements is necessary. Repeated measures of ANOVA (RMANOVA), however, would permit the comparison between the correlated measurements as long as the condition of sphericity assumption is satisfied. Conclusively, parametric statistical methods should be used only when the assumptions of parametric statistics, such as normality and sphericity, are established.

Uncertainty quantification and propagation with probability boxes

  • Duran-Vinuesa, L.;Cuervo, D.
    • Nuclear Engineering and Technology
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    • 제53권8호
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    • pp.2523-2533
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    • 2021
  • In the last decade, the best estimate plus uncertainty methodologies in nuclear technology and nuclear power plant design have become a trending topic in the nuclear field. Since BEPU was allowed for licensing purposes by the most important regulator bodies, different uncertainty assessment methods have become popular, overall non-parametric methods. While non-parametric tolerance regions can be well stated and used in uncertainty quantification for licensing purposes, the propagation of the uncertainty through different codes (multi-scale, multiphysics) in cascade needs a better depiction of uncertainty than the one provided by the tolerance regions or a probability distribution. An alternative method based on the parametric or distributional probability boxes is used to perform uncertainty quantification and propagation regarding statistic uncertainty from one code to another. This method is sample-size independent and allows well-defined tolerance intervals for uncertainty quantification, manageable for uncertainty propagation. This work characterizes the distributional p-boxes behavior on uncertainty quantification and uncertainty propagation through nested random sampling.

An elaboration on sample size determination for correlations based on effect sizes and confidence interval width: a guide for researchers

  • Mohamad Adam Bujang
    • Restorative Dentistry and Endodontics
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    • 제49권2호
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    • pp.21.1-21.8
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    • 2024
  • Objectives: This paper aims to serve as a useful guide for sample size determination for various correlation analyses that are based on effect sizes and confidence interval width. Materials and Methods: Sample size determinations are calculated for Pearson's correlation, Spearman's rank correlation, and Kendall's Tau-b correlation. Examples of sample size statements and their justification are also included. Results: Using the same effect sizes, there are differences between the sample size determination of the 3 statistical tests. Based on an empirical calculation, a minimum sample size of 149 is usually adequate for performing both parametric and non-parametric correlation analysis to determine at least a moderate to an excellent degree of correlation with acceptable confidence interval width. Conclusions: Determining data assumption(s) is one of the challenges to offering a valid technique to estimate the required sample size for correlation analyses. Sample size tables are provided and these will help researchers to estimate a minimum sample size requirement based on correlation analyses.