Flood damage, vulnerability and risk perception - challenges for flood damage research

The current state-of-the-art in flood damage analysis mainly focuses on the economic evaluation of tangible flood effects. It is contended in this discussion paper that important economic, social and ecological aspects of flood-related vulnerabilities are neglected. It is a challenge for flood research to develop a wider perspective for flood damage evaluation. --Flood damage analysis,flood vulnerability,risk perception,cost-benefit analysis,integrated assessment

National flood damage evaluation methods: A review of applied methods in England, the Netherlands, the Czech Republik and Germany

The focus of this guidance document is decision making under uncertainty in river basin management. Our purpose is to give hints for the analysis of decision situations in the HarmoniRiB case studies. The background of HarmoniRiB and thus of the case studies is the implementation of the EU-Water Framework Directive. The directive states the goal that all waters3 in the EU should reach a good status4 by 20155. In order to achieve this goal the member states need to set up river basin districts, each one having a management plan that includes a programme of measures which will achieve good status in the most costeffective manner. We conceptualize this management problem as a decision problem: Which measures should be selected for the programme of measures? The HarmoniRiB case studies are not able to cover all problems of the implementation of the EU-Water Framework Directive in all their complexity. They only investigate certain aspects of this problem. Therefore, we concentrate in this guidance document on a certain type of decision, the selection of management measures to reach a certain goal (this would usually be good status) for the case study river basins. Thereby we put a special focus on uncertainties. --

Noncommutative Geometry and Gravity

We study a deformation of infinitesimal diffeomorphisms of a smooth manifold. The deformation is based on a general twist. This leads to a differential geometry on a noncommutative algebra of functions whose product is a star-product. The class of noncommutative spaces studied is very rich. Non-anticommutative superspaces are also briefly considered. The differential geometry developed is covariant under deformed diffeomorphisms and it is coordinate independent. The main target of this work is the construction of Einstein's equations for gravity on noncommutative manifolds.Comment: 40pages; v2: references adde

Importance of interorbital charge transfers for the metal-to-insulator transition of BaVS3_3

The underlying mechanism of the metal-to-insulator transition (MIT) in BaVS$_3$ is investigated, using dynamical mean-field theory in combination with density functional theory. It is shown that correlation effects are responsible for a strong charge redistribution, which lowers the occupancy of the broader \a1g band in favor of the narrower $E_g$ bands. This resolves several discrepancies between band theory and the experimental findings, such as the observed value of the charge-density wave ordering vector associated with the MIT, and the presence of local moments in the metallic phase.Comment: improved discussion, new figure, added reference

Gauge-Field Theories and Gravity on Noncommutative Spaces

In this thesis gauge-field theories and gravity on noncommutative spaces are studied. We start with an introduction to the concepts underlying the construction of field theories on noncommutative spaces. By a noncommutative space we mean a noncommutative algebra, which replaces the algebra of functions on ordinary space. We construct derivatives and deformed symmetries ("Quantum Group" symmetries) acting on noncommutative spaces. Consistency requires us to change the action on a product of representations ("deformed coproducts"); this gives rise in particular to deformed Leibniz rules. We also show how a noncommutative space and the generators of deformed symmetries acting on it can be represented on the ordinary algebra of functions; the commutative, point-wise product is substituted by a noncommutative one ("star-product"). One possible way to define gauge-field theories on noncommutative spaces is to construct "Seiberg--Witten maps". In this approach it is possible to express all noncommutative quantities in terms of their commutative counterparts. We illustrate this by two examples, the two-dimensional q -deformed Euclidean plane and the \kappa -deformed Minkowski space-time. In addition gauge-field theory on "fuzzy" S^{2}\times S^{2} is discussed as a multi-matrix model. We show that this model reduces in an appropriate limit to gauge-field theory on noncommutative \mathbb{R}^{4} . We also present a new approach to deformed gauge theories, which is based on "twisted" gauge transformations. In this setting new fields occur in addition to the usual gauge fields. Consistent equations of motion and conserved currents are obtained. This is the first time that conservation laws have been derived from a generalized, Quantum Group symmetry. We discuss in detail how to construct deformed infinitesimal diffeomorphisms by deformations via generic "twists". Then we construct gravity as a theory, which is covariant with respect to these diffeomorphisms. This leads to a deformation of Einstein's equations. For canonically deformed spaces, a deformed Einstein--Hilbert action can be even defined. It reduces to the usual Einstein--Hilbert action in the commutative limit. All relevant quantities are expanded in terms of the usual, commutative fields up to second order in the deformation parameter

Recommender systems in industrial contexts

This thesis consists of four parts: - An analysis of the core functions and the prerequisites for recommender systems in an industrial context: we identify four core functions for recommendation systems: Help do Decide, Help to Compare, Help to Explore, Help to Discover. The implementation of these functions has implications for the choices at the heart of algorithmic recommender systems. - A state of the art, which deals with the main techniques used in automated recommendation system: the two most commonly used algorithmic methods, the K-Nearest-Neighbor methods (KNN) and the fast factorization methods are detailed. The state of the art presents also purely content-based methods, hybridization techniques, and the classical performance metrics used to evaluate the recommender systems. This state of the art then gives an overview of several systems, both from academia and industry (Amazon, Google ...). - An analysis of the performances and implications of a recommendation system developed during this thesis: this system, Reperio, is a hybrid recommender engine using KNN methods. We study the performance of the KNN methods, including the impact of similarity functions used. Then we study the performance of the KNN method in critical uses cases in cold start situation. - A methodology for analyzing the performance of recommender systems in industrial context: this methodology assesses the added value of algorithmic strategies and recommendation systems according to its core functions.Comment: version 3.30, May 201