Sökning: "right censoring"

Hittade 5 avhandlingar innehållade orden right censoring.

  1. 1. EM Estimation in Phase Type Models

    Författare :Marita Olsson; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; phase type distributions; coxian distribution; EM algorithm; I-divergence; density estimation; right censoring; interval censoring; standard error estimation; asymptotic theory; jackknife; relapse clinical trials; survival data; hidden Markov chain; I-divergence;

    Sammanfattning : This thesis consists of four articles whose theme in common is the class of phase type distributions. In the first article an EM algorithm is presented to estimate the parameters of a phase type distribution of fixed order. Also, it is shown that the algorithm can be used to approximate other continuous distributions by phase type distributions. LÄS MER

  3. 2. Regression Analysis of Censored Data with Applications in Perimetry

    Författare :Anna Lindgren; Matematisk statistik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; censored covariate; L_1 minimization; right-censoring; Quantile regression;

    Sammanfattning : This thesis treats regression analysis when either the dependent or the independent variable is censored. We deal with quantile regression when the dependent variable is censored. LÄS MER

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

    Författare :Marie-Louise Öhman; Hans Nyquist; Umeå universitet; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  5. 4. Machine learning methods for precision medicine

    Författare :Pablo Gonzalez Ginestet; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :;

    Sammanfattning : In precision medicine, predicting the risk of an event during a specific period may help, for example, to identify patients that need early preventive treatment. Modern machine learning (ML) techniques are therefore ideal for building these predictions. LÄS MER

  7. 5. Data Importance in Power System Asset Management

    Författare :Wadih Naim; Patrik Hilber; Miroslav Begovic; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Data availability; data quality; asset management; power systems; maintenance optimization; Datatillgänglighet; datakvalitet; tillgångsförvaltning; kraftsystem; underhållsoptimering; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : The current shift towards a higher degree of data-driven decision making in power system asset management highlights the importance of asset data. This thesis identifies, investigates, and proposes methods for data-related research gaps that are encountered by asset managers. These research gaps are in data availability and data quality. LÄS MER