Search for dissertations about: "rank sum test"

Showing result 1 - 5 of 8 swedish dissertations containing the words rank sum test.

2. 1. Contributions to generalized Wilcoxon rank tests

   Author : Marie-Louise Öhman; Hans Nyquist; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Censored data rank sum tests; Gehan s test; Generalized Wilcoxon test; Jackknifing; Two sample problem; Simulation; Survival data; Variance estimation; Influence function; Gross error sensitivity; Sensitivity curve; Misclassification; Statistics; computer and systems science; Statistik; data- och systemvetenskap; Statistics; statistik;

   Abstract : In unbalanced small sample size problems with right censorings, the variance estmators of linear rank statistics, may be biased. This is the case with the commonly applied variance estimators for the generalized Wilcoxon rank test statistics of Gehan and Prentice. READ MORE

4. 2. On Rank-invariant Methods for Ordinal Data

   Author : Yishen Yang; Sune Karlsson; Elisabeth Svensson; Rolf Larsson; Örebro universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ordinal data; rank-invariance; systematic change; agreement; association; inter-rater reliability; ranking; Spearman; multi-item scale; Statistik; Statistics;

   Abstract : Data from rating scale assessments have rank-invariant properties only, which means that the data represent an ordering, but lack of standardized magnitude, inter-categorical distances, and linearity. Even though the judgments often are coded by natural numbers they are not really metric. READ MORE

5. 3. Aspects of analysis of small-sample right censored data using generalized Wilcoxon rank tests

   Author : Marie-Louise Öhman; Hans Nyquist; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Censored generalized Wilcoxon rank test statistics; Variance estimation; Jackknifing; Influence function; Gross error sensitivity; Break-Down point; Sensitivity curve; Location parameter estimation; Product-Limit estimator and Monte-Carlo Simulation; Statistics; computer and systems science; Statistik; data- och systemvetenskap; Statistics; statistik;

   Abstract : The estimated bias and variance of commonly applied and jackknife variance estimators and observed significance level and power of standardised generalized Wilcoxon linear rank sum test statistics and tests, respectively, of Gehan and Prentice are compared in a Monte Carlo simulation study. The variance estimators are the permutational-, the conditional permutational- and the jackknife variance estimators of the test statistic of Gehan, and the asymptotic- and the jackknife variance estimators of the test statistic of Prentice. READ MORE

6. 4. Multivariate non-invasive measurements of skin disorders

   Author : Josefina Nyström; Britta Lindholm-Sethson; Paul SLU Geladi; Lars Noergaard; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Multivariate Data Analysis; Non-invasive techniques; Clinical studies; Principal Component Analysis; Partial Least Squares Discriminant Analysis; Wilcoxon Signed Rank Sum Test; Near-InfraRed spectroscopy; Frequency Bio Impedance Analysis of whole body; Laser Doppler Imaging; Digital Colour Photography; Analytical chemistry; Analytisk kemi;

   Abstract : The present thesis proposes new methods for obtaining objective and accurate diagnoses in modern healthcare. Non-invasive techniques have been used to examine or diagnose three different medical conditions, namely neuropathy among diabetics, radiotherapy induced erythema (skin redness) among breast cancer patients and diagnoses of cutaneous malignant melanoma. READ MORE

7. 5. Bringing Silicon Microsystems to Space : Manufacture, Performance, and Reliability

   Author : Johan Köhler; Gert Andersson; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Space technology; Rymdteknik; Space engineering; Rymdteknik; teknisk fysik med inriktningen mikrosystemteknik; engineering science with specialization in microsystems technology;

   Abstract : The incorporation of extremely compact multifunctional microsystems is a highly profitable long-term approach in spacecraft design. These systems bring substantial launch-cost reductions, and enable exciting space exploration and science missions.Silicon microsystems technology is an adequate choice for the multifunctional microsystem development. READ MORE