Michaela Dvorzak

Dr. Michaela Dvorzak


Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 April 2015 in BMC Bioinformatics
Verified
Journal Article
Open access
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GLGunnar Libiseller
Gunnar Libiseller
MDMichaela Dvorzak
Michaela Dvorzak
UKUlrike Kleb
Ulrike Kleb
EGEdgar Gander
Edgar Gander
Tobias EisenbergTobias Eisenberg
Tobias Eisenberg
CMChristoph Magnes
Christoph Magnes
Untargeted metabolomics generates a huge amount of data. Software packages for automated data processing are crucial to successfully process these data. A variety of such software packages exist, but the outcome of data processing strongly depends on algorithm parameter settings. If they are not carefully chosen, suboptimal parameter settings can easily lead to biased results. Therefore, parameter settings also require optimization. Several parameter optimization approaches have already been proposed, but a software package for parameter optimization which is free of intricate experimental labeling steps, fast and widely applicable is still missing.

18 June 2015 in Statistical Modelling
Verified
Journal Article
Open access
MDMichaela Dvorzak
Michaela Dvorzak
HWHelga Wagner
Helga Wagner
We consider Bayesian inference for regression models of count data subject to underreporting. For the data generating process of counts as well as the fallible reporting process a joint model is specified, where the outcomes in both processes are related to a set of potential covariates. Identification of the joint model is achieved by additional information provided through validation data and incorporation of variable selection. For posterior inference we propose a convenient Markov chain Monte Carlo (MCMC) sampling scheme which relies on data augmentation and auxiliary mixture sampling techniques for this two-part model. Performance of the method is illustrated for simulated data and applied to analyse real data, collected to estimate risk of cervical cancer death.

6 October 2022 in Applied Sciences
Verified
Journal Article
Open access
PDF file
MDMichaela Dvorzak
Michaela Dvorzak
JMJulien Magnien
Julien Magnien
UKUlrike Kleb
Ulrike Kleb
Elke KrakerElke Kraker
Elke Kraker
MMManfred Mücke
Manfred Mücke
Remaining useful life (RUL) prediction is central to prognostics and reliability assessment of light-emitting diode (LED) systems. Their unknown long-term service life remaining when subject to specific operating conditions is affected by various sources of uncertainty stemming from production of individual system components, application of the whole system, measurement and operation. To enhance the reliability of model-based predictions, it is essential to account for all of these uncertainties in a systematic manner. This paper proposes a Bayesian hierarchical modelling framework for inverse uncertainty quantification (UQ) in LED operation under thermal loading. The main focus is on the LED systems’ operational thermal resistances, which are subject to system and application variability. Posterior inference is based on a Markov chain Monte Carlo (MCMC) sampling scheme using the Metropolis–Hastings (MH) algorithm. Performance of the method is investigated for simulated data, which allow to focus on different UQ aspects in applications. Findings from an application scenario in which the impact of disregarded uncertainty on RUL prediction is discussed highlight the need for a comprehensive UQ to allow for reliable predictions.