• 제목/요약/키워드: Statistical Analyses

검색결과 2,233건 처리시간 0.03초

Sensitivity Analysis for Ordered Categorical Data

  • Cho, Il-Hyun;Park, Taesung
    • Communications for Statistical Applications and Methods
    • /
    • 제6권2호
    • /
    • pp.375-382
    • /
    • 1999
  • Linear-by-linear association models are commonly used to analyze ordered categorical data. To fit these models appropriate scores need to be chosen. In this paper we perform sensitivity analyses in two-way contingency tables to investigate the effect of scores on goodness-of-fits and on tests of significance. In addition we show that the best score which yields the best fit of data can be selected based on the sensitivity analysis results.

  • PDF

Comparison of Variability in SCA Maps Using the Procrustes Analysis

  • Yun, Woo-Jung;Choi, Yong-Seok
    • 한국통계학회:학술대회논문집
    • /
    • 한국통계학회 2003년도 춘계 학술발표회 논문집
    • /
    • pp.163-165
    • /
    • 2003
  • Some multivariate analyses provide configurations for variables or objects in low dimensional space because we can see easily their relation. In particular, in simple correspondence analysis(SCA), we can obtain the various configurations which are called SCA Maps based on the algebraic algorithms. Moreover, it often occur the variability among them. Therefore, in this study, we will give a comparison of variability of SCA maps using the procrustes analysis which is a technique of comparing configurations in multidimensional scaling.

  • PDF

Explanatory Analysis for South Korea's Political Website Linking - Statistical Aspects

  • Choi, Kyoung-Ho;Park, Han-Woo
    • Journal of the Korean Data and Information Science Society
    • /
    • 제16권4호
    • /
    • pp.899-911
    • /
    • 2005
  • This paper conducts an explanatory analysis of the web sphere produced by National Assemblymen in South Korea, using some statistical methods. First, some descriptive metrics were employed. Next, the traditional methods of multi-variate analyses, multidimensional scaling and corresponding analysis, were applied to the data. Finally, cross-sectional data were compared to examine a change over time.

  • PDF

Results of Discriminant Analysis with Respect to Cluster Analyses Under Dimensional Reduction

  • Chae, Seong-San
    • Communications for Statistical Applications and Methods
    • /
    • 제9권2호
    • /
    • pp.543-553
    • /
    • 2002
  • Principal component analysis is applied to reduce p-dimensions into q-dimensions ( $q {\leq} p$). Any partition of a collection of data points with p and q variables generated by the application of six hierarchical clustering methods is re-classified by discriminant analysis. From the application of discriminant analysis through each hierarchical clustering method, correct classification ratios are obtained. The results illustrate which method is more reasonable in exploratory data analysis.

A Comparative Study of Restricted Randomization Methods in Clinicla Trials

  • Huh, Myung-Hoe
    • Journal of the Korean Statistical Society
    • /
    • 제14권1호
    • /
    • pp.48-55
    • /
    • 1985
  • In clinical trials subjects are avalible sequentially and must be assigned to treatments immediately. Completely randomized procedure for the allocation of treatments to each subject may result in severe imbalance among the number of subjects in treatment groups, especially for small experiments or interim analyses of large experiments. In this study, restricted randomization methods such as biased coin designs (Efron, 1971), permuted block design, and truncated binomial design are compared to teh completely randomized design in the presence of selection and/or accidential bias by Monte Carlo simulations.

  • PDF

Alias Component Permutation Matrices (ACPM) for the $3^n$ Parallel Fractional Factorial Design

  • Um, Jung-Koog
    • Journal of the Korean Statistical Society
    • /
    • 제9권1호
    • /
    • pp.1-12
    • /
    • 1980
  • A parallel flats faraction for the $3^n$ factorial experiment is symbolically written as $At = C(r\timesf)$ where $A(r\timesn)$ is of rank r. The A-matrix partitions the nonnegligible effects into $(3^{n-r}-1)/2+1$ alias sets. The $U_i$ effects in the i-th alias set are related pairwise by elements from $S_3$, the symmetric group on three symbols. For each alias set the f flats produce an $f \times u_i$ alias componet permutation matrices (ACPM) with elements from $S_3$. All the information concerning the relationships among levels of the effects is contained in the ACPM.

  • PDF

GMS Brightness를 사용한 구름 두께와 가강수량의 통계적 추정 (Statistical Estimates of Cloud Thickness and Precipitable Water from GMS Brightness Data)

  • 최영진;신동인
    • 대한원격탐사학회지
    • /
    • 제6권2호
    • /
    • pp.153-164
    • /
    • 1990
  • A statistical correlation between cloud thickness and brightness is shown by regression analysis using the least-square method. Cloud thicknesses are obtained from radiosonde observation. Brightness values are obtained from GMS visible channel. Regression analyses are preformed on both thickness data used in conjunction with brightness data for summer season. The results are shown by the regression curve relating thickness and brightness accounting for 79% of variance. And the relationship between thickness and precipitable water in the cloud layers is analyzed. The thickness shows a positive correlation with precipitable water in cloudy layers.

수의학회지 논문에 적용된 통계기법의 타당성 평가 (An assessment of statistical errors in articles in the Korean journal of veterinary research)

  • 박선일
    • 대한수의학회지
    • /
    • 제39권6호
    • /
    • pp.1187-1196
    • /
    • 1999
  • The purpose of this study is to assess the suitability of the statistical techniques employed in papers published in the Korean Journal of Veterinary Research from March 1997 to March 1999 and it is hoped that the critical assessment may be of help to other researchers preparing their works for publication. Of the 246 original papers 94 were included in the analysis. Of 62 papers with the measure of central location and dispersion of data 34 (54.8%) used them correctly : 9 (39.1%) of 23 for t-test ; 1 (33.3%) of 3 for correlation analysis ; 7 (43.8%) of 16 for analysis of variance (ANOVA) ; 5 (62.5%) of 8 for chi-square test ; 44 (71%) of 62 for description of p-value. A number of papers employed ANOVA did not perform subsequent analysis of multiple comparison. Compared to the results of others, relatively higher proportion of papers in the present study was evaluated as appropriate analysis. The reason is that papers described insufficiently on the study design were not included, and evaluation items were restricted to the cases violated seriously inherent assumptions for each statistical technique. Statistical misuse or abuse appeared in the study is due to lack of knowledge on statistics and short of its importance for improvement the quality of paper. Because an inappropriate analysis can lead the readers to misunderstand on findings, observed statistical analyses must be valid, and correctly undertaken. It is suggested that more intensive statistical refereeing are needed, and the communication should be allowed for the controversial points.

  • PDF

철강 제조업 근로자의 직무 스트레스 분석 및 대책 방안 (Analysis and Countermeasure of Occupational Stress for Steel Manufacturing Worker)

  • 이선용;우흥식;원종일
    • 한국안전학회지
    • /
    • 제28권5호
    • /
    • pp.61-65
    • /
    • 2013
  • Occupational stresses of steel manufacturing workers have been investigated using an organized questionnaire composed of 40 items. Three hypothesizes were developed based on the literature review of related researches. Empirical data surveyed from ones working in steel manufacturing jobs were collected and the in-depth statistical analyses using Statistical Package for the Social Sciences(SPSS) software were performed. These statistical results indicate that the existence of occupational stress may cause to take place industrial accidents. Consequentially, the prevention of occupational stress helps to promote the will to work, following by increasing job satisfaction in working circumstance of steel manufacturing.

PISA와 TIMSS 결과에 나타난 우리나라 학생의 정의적 성취 실태 분석 - 수학 교과를 중심으로 - (Analysis of the current situation of Affective Characteristics of Korean Students Based on the Results of PISA and TIMSS)

  • 최승현;박상욱;황혜정
    • 한국학교수학회논문집
    • /
    • 제17권1호
    • /
    • pp.23-43
    • /
    • 2014
  • TIMSS와 PISA의 두 국제평가에서 우리나라 학생들의 경우, 수학 교과에 대한 인지적 영역의 성취도는 매우 우수한 반면 정의적 영역의 성취도는 참가국 중 최하위권의 순위를 기록하여 우리나라 교육의 문제점을 드러내고 있다. 이즈음에, 우리나라 학생들이 취약한 정의적 특성 요인의 함양 방안을 모색해 보는 것은 의미 있은 일일 것이다. 이러한 취지하에, 한국교육과정평가원에서는 PISA와 TIMSS 두 국제평가에 공통적으로 포함되어 있는 우리나라 학생들의 수학 학습에 대한 흥미와 자아효능감, 그리고 수학에 대한 가치 인식의 정의적 특성 요인을 대상으로, PISA와 TIMSS 결과에 나타난 우리나라 학생의 정의적 특성의 성취 실태 및 사례를 파악하여 이의 실천적 함양 방안을 모색해 보고자 하였다(최승현 외, 2013). 본고에서는 PISA와 TIMSS에 관한 선행 연구 재분석 및 통계 분석 결과를 중심으로 이에 초점을 두어 수학 교과에서의 우리나라 학생의 정의적 성취 실태를 탐색하고자 하였다.

  • PDF