Hable, Robert (2009): DataBased Decisions under Complex Uncertainty. Dissertation, LMU München: Fakultät für Mathematik, Informatik und Statistik 

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Abstract
Decision theory is, in particular in economics, medical expert systems and statistics, an important tool for determining optimal decisions under uncertainty. In view of applications in statistics, the present book is concerned with decision problems which are explicitly databased. Since the arising uncertainties are often too complex to be described by classical precise probability assessments, concepts of imprecise probabilities (coherent lower previsions, Fprobabilities) are applied. Due to the present state of research, some basic groundwork has to be done: Firstly, topological properties of different concepts of imprecise probabilities are investigated. In particular, the concept of coherent lower previsions appears to have advantageous properties for applications in decision theory. Secondly, several decision theoretic tools are developed for imprecise probabilities. These tools are mainly based on concepts developed by L. Le Cam and enable, for example, a definition of sufficiency in case of imprecise probabilities for the first time. Building on that, the article [A. Buja, Zeitschrift für Wahrscheinlichkeitstheorie und Verwandte Gebiete 65 (1984) 367384] is reinvestigated in the only recently available framework of imprecise probabilities. This leads to a generalization of results within the HuberStrassen theory concerning least favorable pairs or models. Results obtained by these investigations can also be applied afterwards in order to justify the use of the method of natural extension, which is fundamental within the theory of imprecise probabilities, in databased decision problems. It is shown by means of the theory of vector lattices that applying the method of natural extension in decision problems does not affect the optimality of decisions. However, it is also shown that, in general, the method of natural extension suffers from a severe instability. The book closes with an application in statistics in which a minimum distance estimator is developed for imprecise probabilities. After an investigation concerning its asymptotic properties, an algorithm for calculating the estimator is given which is based on linear programming. This algorithm has led to an implementation of the estimator in the programming language R which is publicly available as R package "imprProbEst". The applicability of the estimator (even for large sample sizes) is demonstrated in a simulation study.
Dokumententyp:  Dissertation (Dissertation, LMU München) 

Themengebiete:  500 Naturwissenschaften und Mathematik > 510 Mathematik
500 Naturwissenschaften und Mathematik 
Fakultäten:  Fakultät für Mathematik, Informatik und Statistik 
Sprache der Dissertation:  Englisch 
Datum der mündlichen Prüfung:  5. Februar 2009 
1. Berichterstatter/in:  Augustin, Thomas 
URN des Dokumentes:  urn:nbn:de:bvb:1998740 
MD5 Prüfsumme der PDFDatei:  5c5091b91db33734128401579eeaf34d 
Signatur der gedruckten Ausgabe:  0001/UMC 17731 
ID Code:  9874 
Eingestellt am:  20. Apr. 2009 08:59 
Letzte Änderungen:  19. Jul. 2016 16:26 