86 research outputs found
Variational regularization for systems of inverse problems: Tikhonov regularization with multiple forward operators
No full textTikhonov regularization is a cornerstone technique in solving inverse problems with applications in countless scientific fields. Richard Huber discusses a multi-parameter Tikhonov approach for systems of inverse problems in order to take advantage of their specific structure. Such an approach allows to choose the regularization weights of each subproblem individually with respect to the corresponding noise levels and degrees of ill-posedness. Contents General Tikhonov Regularization Specific Discrepancies Regularization Functionals Application to STEM Tomography Reconstruction Target Groups Researchers and students in the field of mathematics Experts in the areas of mathematics, imaging, computer vision and nanotechnology The Author Richard Huber wrote his master’s thesis under the supervision of Prof. Dr. Kristian Bredies at the Institute for Mathematics and Scientific Computing at Graz University, Austria
On the Determinants of Cross Border Co-operation of Austrian Firms with Central and Eastern European Partners
Full text linkI analyse cross-border co-operation of Austrian firms with CEEC partners. Firm size, previous experience with co-operation and depth of integration with the most important partner are more important determinants of co-operation than distance to the closest potential partner. Firms with experience of co-operation are more likely to enter business relationships and less likely not to co-operate. Small firms are unlikely to co-operate in incentive contracts, while firms which are part of production networks typically co-operate in business and ownership relationships. Distance to the closest potential partner increases the probability of not co-operating and reduces the probability of ownership relationships.
A CLUE for CLUster ensembles
Full text linkCluster ensembles are collections of individual solutions to a given clustering problem which are useful or necessary to consider in a wide range of applications. The R package clue provides an extensible computational environment for creating and analyzing cluster ensembles, with basic data structures for representing partitions and hierarchies, and facilities for computing on these, including methods for measuring proximity and obtaining consensus and "secondary" clusterings. (author's abstract)Series: Research Report Series / Department of Statistics and Mathematic
An integral tool for the diagnostic evaluation of non-territorial offices
No full textMany organizations now have innovative workplaces, with desk-sharingand desk-rotation. The main objectives are 1) to improve organizationalperformance by better communication, and 2) cost reduction by the moreefficient use of accommodation and other facilities. Although some research has been done into the use and experience of new offices, there is a need for sound data about the overall effects on organizational performance and user needs. Commissioned by the government, the Center for People and Buildings in Delft has developed an instrument for an ex ante or ex post evaluation of non-territorial offices. The tool has been based on an extensive literature review and is being tested in a number of case studies. The tool can be used to indicate problems in the present situation, to evaluate the effects of design interventions, and in support of decisions to change the physical working environment.Design & Construction ManagementReal Estate Managemen
A CLUE for CLUster Ensembles
Full text linkCluster ensembles are collections of individual solutions to a given clustering problem which are useful or necessary to consider in a wide range of applications. The R package clue provides an extensible computational environment for creating and analyzing cluster ensembles, with basic data structures for representing partitions and hierarchies, and facilities for computing on these, including methods for measuring proximity and obtaining consensus and "secondary" clusterings.
Gatekeeping in Health Care
Full text linkWe study the competitive effects of restricting direct access to secondary care by gatekeeping, focusing on the informational role of general practitioners (GPs). In the secondary care market there are two hospitals choosing quality and specialisation. Patients, who are ex ante uninformed, can consult a GP to receive an (imperfect) diagnosis and obtain information about the secondary care market. We show that hospital competition is amplified by higher GP attendance but dampened by improved diagnosing accuracy. Therefore, compulsory gatekeeping may result in excessive quality competition and too much specialisation, unless the mismatch costs and the diagnosing accuracy are sufficiently high. Second-best price regulation makes direct regulation of GP consultation redundant, but will generally not implement first-best.gatekeeping, imperfect information, quality competition, product differentiation, price regulation
Takotsubo syndrome before and during the COVID‐19 pandemic in Austria: a retrospective cohort study (TOSCA‐19)
No full textAbstract Aims This study aims to investigate the prevalence of Takotsubo syndrome (TTS) as a percentage of the total number of acute coronary syndrome (ACS), including non‐STE‐elevation myocardial infarction and ST‐elevation myocardial infarction, as well as the short‐term outcome of TTS patients before and during the COVID‐19 pandemic. Methods and results We compared patients from two different periods: (i) Period 1 (before the COVID‐19 pandemic): 1 March to 30 December 2019, and (ii) Period 2 (during the COVID‐19 pandemic): 1 March to 30 December 2020. The retrospective database was created from the archives of the participating hospitals or electronic hospital systems by trained medical personnel. The subjects' medical history, cardiovascular risk factors, laboratory values, echocardiography findings, and an in‐hospital outcome were variables of interest. Furthermore, propensity score matching analysis was performed to evaluate the short‐term prognosis in TTS and ACS patients. Altogether six Austrian centres—(i) 3rd Medical Department of Cardiology and Intensive Care Medicine, Clinic Ottakring, Vienna, Austria; (ii) 5th Medical Department of Cardiology, Clinic Favoriten, Vienna, Austria; (iii) 2nd Medical Department, Hanusch Hospital, Vienna, Austria; (iv) University Clinic of Internal Medicine III, Cardiology and Angiology, Medical University of Innsbruck, Austria; (v) Department of Cardiology, University Hospital Graz, Graz, Austria; (vi) Department of Cardiology and Intensive Medicine, Kepler University Clinic, Linz, Austria—participated in the study. During period 1, 87 (3.5%) patients out of 2482 ACS patients had TTS in all participating centres. During period 2, 71 (2.7%) patients out of 2572 ACS patients had TTS in all participating centres. Accordingly, the prevalence of TTS remained stable irrespective of potential psychologic stress during the COVID pandemic. Furthermore, the baseline characteristics of TTS patients did not change during the COVID‐19 pandemic. The prevalence of in‐hospital complications [cardiogenic shock (4.6% vs. 4.3%, P = 0.925), ventricle thrombus (1.1% vs. 1.4%, P = 0.885) and in‐hospital bleeding (3.4% vs. 1.4%, P = 0.417)] remained stable. The all‐cause in‐hospital mortality of TTS patients did not change during the COVID‐19 pandemic [χ2(2) = 0.058, P = 0.810]. Moreover, a propensity score matching analysis of all‐cause in‐hospital mortality between matched TTS and ACS patients showed higher in‐hospital mortality in ACS patients during COVID‐19 pandemic (P = 0.043). Conclusions Despite the well‐known increased psychologic stress during the COVID‐19 pandemic, the prevalence of TTS during the COVID‐19 pandemic and the short‐term clinical outcome in Austria remained unimpacted
Differential expression analysis for sequence count data
Full text link*Motivation:* High-throughput nucleotide sequencing provides quantitative readouts in assays for RNA expression (RNA-Seq), protein-DNA binding (ChIP-Seq) or cell counting (barcode sequencing). Statistical inference of differential signal in such data requires estimation of their variability throughout the dynamic range. When the number of replicates is small, error modelling is needed to achieve statistical power.

*Results:* We propose an error model that uses the negative binomial distribution, with variance and mean linked by local regression, to model the null distribution of the count data. The method controls type-I error and provides good detection power. 

*Availability:* A free open-source R software package, _DESeq_, is available from the Bioconductor project and from "http://www-huber.embl.de/users/anders/DESeq":http://www-huber.embl.de/users/anders/DESeq
Die Donauraumstrategie zwischen EU-Mitgliedern und Nicht-EU-Mitgliedern : ein Vergleich zwischen Österreich und Serbien
No full textWith the implementation of the EU Danube Strategy the second macro regional strategy of the EU started. The Danube region comprises about 115 Million inhabitants in 14 countries. Most of them are already EU member states, but there are also prospect members and nonmember states part of the strategy. Therefore the region is one of the most diversified and faces as well challenges as opportunities. The aim of this thesis is to show the differences and similarities of an EU-member State and a nonmember State with regards to expectations and involvement in the strategy as well as the possibilities to finance actions and projects. After a thorough investigation of the theoretical basics, the author uses expert interviews to research the objectives of this thesis. The main findings show, that the countries differ from one another especially regarding their financing possibilities. Austria as an EU member state, for example, has much more possibilities of obtaining EU funds, shows a higher GDP and has more possibilities of national financing than Serbia. Furthermore, this thesis shows that the countries have different interests how they want to enforce using the EU Danube strategy. Regarding the involvement in the strategy, for instance, the analysis did not show any differences between the countries. Serbia is as engaged in the implementation as Austria and highly interested in the active participation.Marie-Sophie HuberMasterarbeit Fachhochschule des BFI Wien 2015 Fachbereich: Politikwissenschafte
Die Donauraumstrategie zwischen EU-Mitgliedern und Nicht-EU-Mitgliedern : ein Vergleich zwischen Österreich und Serbien
No full textWith the implementation of the EU Danube Strategy the second macro regional strategy of the EU started. The Danube region comprises about 115 Million inhabitants in 14 countries. Most of them are already EU member states, but there are also prospect members and nonmember states part of the strategy. Therefore the region is one of the most diversified and faces as well challenges as opportunities. The aim of this thesis is to show the differences and similarities of an EU-member State and a nonmember State with regards to expectations and involvement in the strategy as well as the possibilities to finance actions and projects. After a thorough investigation of the theoretical basics, the author uses expert interviews to research the objectives of this thesis. The main findings show, that the countries differ from one another especially regarding their financing possibilities. Austria as an EU member state, for example, has much more possibilities of obtaining EU funds, shows a higher GDP and has more possibilities of national financing than Serbia. Furthermore, this thesis shows that the countries have different interests how they want to enforce using the EU Danube strategy. Regarding the involvement in the strategy, for instance, the analysis did not show any differences between the countries. Serbia is as engaged in the implementation as Austria and highly interested in the active participation.Marie-Sophie HuberMasterarbeit Fachhochschule des BFI Wien 2015 Fachbereich: Politikwissenschafte
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