Lexicographic choice functions without archimedeanicity

We investigate the connection between choice functions and lexicographic probabilities, by means of the convexity axiom considered by Seidenfeld, Schervisch and Kadane (2010) but without imposing any Archimedean condition. We show that lexicographic probabilities are related to a particular type of sets of desirable gambles, and investigate the properties of the coherent choice function this induces via maximality. Finally, we show that the convexity axiom is necessary but not sufficient for a coherent choice function to be the infimum of a class of lexicographic ones

Martensite Nucleation at Grain Boundaries Containing Intrinsic Grain Boundary Dislocations

It is shown that grain boundaries containing intrinsic grain boundary dislocations act as preferential nucleation site for the martensitic transformation. The microstructure and crystallography of BCC alpha'-martensite formed in a sensitized AISI 304 stainless steel was studied in detail by means of convergent beam Kikuchi pattern analysis. The orientation relationship between martensite and austenite was determined to be Kurdjumov-Sachs type. The presence of intrinsic grain boundary dislocations was observed at a grain boundary 10.83 degrees from the exact Sigma 11 CSL boundary orientation, where a martensite nucleus formed by the faulting and extension of intrinsic grain boundary dislocations. The selection of the crystallographic variant for the martensite nucleus was not related to a reduction in interfacial energy at nucleation, nor was it related to the accommodation of transformation strain by easy slip in the austenite.X1155Ysciescopu

Limit behaviour of upper and lower expected time averages in discrete-time imprecise Markov chains

We study the limit behaviour of upper and lower bounds on expected time averages in imprecise Markov chains; a generalised type of Markov chain where the local dynamics, traditionally characterised by transition probabilities, are now represented by sets of ‘plausible’ transition probabilities. Our main result is a necessary and sufficient condition under which these upper and lower bounds, called upper and lower expected time averages, will converge as time progresses towards infinity to limit values that do not depend on the process’ initial state. Remarkably, our condition is considerably weaker than those needed to establish similar results for so-called limit—or steady state—upper and lower expectations, which are often used to provide approximate information about the limit behaviour of time averages as well. We show that such an approximation is sub-optimal and that it can be significantly improved by directly using upper and lower expected time averages

Continuity of the shafer-Vovk-Ville operator

Kolmogorov’s axiomatic framework is the best-known approach to describing probabilities and, due to its use of the Lebesgue integral, leads to remarkably strong continuity properties. However, it relies on the specification of a probability measure on all measurable events. The game-theoretic framework proposed by Shafer and Vovk does without this restriction. They define global upper expectation operators using local betting options. We study the continuity properties of these more general operators. We prove that they are continuous with respect to upward convergence and show that this is not the case for downward convergence. We also prove a version of Fatou’s Lemma in this more general context. Finally, we prove their continuity with respect to point-wise limits of two-sided cuts

A desirability-based axiomatisation for coherent choice functions

Choice functions constitute a simple, direct and very general mathematical framework for modelling choice under uncertainty. In particular, they are able to represent the set-valued choices that typically arise from applying decision rules to imprecise-probabilistic uncertainty models. We provide them with a clear interpretation in terms of attitudes towards gambling, borrowing ideas from the theory of sets of desirable gambles, and we use this interpretation to derive a set of basic axioms. We show that these axioms lead to a full-fledged theory of coherent choice functions, which includes a representation in terms of sets of desirable gambles, and a conservative inference method

A Desirability-Based Axiomatisation for Coherent Choice Functions

Choice functions constitute a simple, direct and very general mathematical framework for modelling choice under uncertainty. In particular, they are able to represent the set-valued choices that typically arise from applying decision rules to imprecise-probabilistic uncertainty models. We provide them with a clear interpretation in terms of attitudes towards gambling, borrowing ideas from the theory of sets of desirable gambles, and we use this interpretation to derive a set of basic axioms. We show that these axioms lead to a full-fledged theory of coherent choice functions, which includes a representation in terms of sets of desirable gambles, and a conservative inference method

Waterbodem- en palingpolluentenmeetnet: een tandem voor de waterbodemsanering

Within the sediment monitoring network from the Flemish Environmental Agency (VMM) the sediment quality of 600 locations in Flanders in both navigable as well as in unnavigable waters, is monitored by means of the TRIADE method. This TRIADE sediment quality assessment is based on a combination of chemical, biological and ecotoxicological parameters. The Research Institute for Nature and Forest (INBO) uses the Flemish eel pollutant monitoring network to monitor 350 locations in Flanders. These locations are situated on canals, rivers and on closed water bodies. The concentrations of PCBs, heavy metals and organochlorine pesticides are quantified in eel. At the same time these concentrations in eel give us valuable information on the bioavailability of these substances. Closer cooperation between both monitoring networks will provide an efficient policy tool, specifically for the sanitation/decontamination of the sediment and for the water policy in general. We will go into detail on the practical implications of such a kind of cooperation keeping in account the history, singularity and complementarity of both monitoring networks

Radiation chemistry of solid-state carbohydrates using EMR

We review our research of the past decade towards identification of radiation-induced radicals in solid state sugars and sugar phosphates. Detailed models of the radical structures are obtained by combining EPR and ENDOR experiments with DFT calculations of g and proton HF tensors, with agreement in their anisotropy serving as most important criterion. Symmetry-related and Schonland ambiguities, which may hamper such identification, are reviewed. Thermally induced transformations of initial radiation damage into more stable radicals can also be monitored in the EPR (and ENDOR) experiments and in principle provide information on stable radical formation mechanisms. Thermal annealing experi-ments reveal, however, that radical recombination and/or diamagnetic radiation damage is also quite important. Analysis strategies are illustrated with research on sucrose. Results on dipotassium glucose-1-phosphate and trehalose dihydrate, fructose and sorbose are also briefly discussed. Our study demonstrates that radiation damage is strongly regio-selective and that certain general principles govern the stable radical formation