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ORBi

Geodasie und Hydrologie - gemeinsam zum erfolgreichen Resourcenmanagement Weigelt, Matthias Presentation (2011, November) Detailed reference viewed: 24 (4 UL)Reading between the lines: A transnational history of the Franco-British 'entente cordiale' in postwar television Fickers, Andreas ; in Journal of European Television History and Culture (2011), 1(2), Detailed reference viewed: 71 (1 UL)Hydrologische Effekte in der terrestrischen Gravimetrie Weigelt, Matthias Presentation (2011, November) Detailed reference viewed: 41 (1 UL)Semidefinite Relaxations of Robust Binary Least Squares under Ellipsoidal Uncertainty Sets ; ; Ottersten, Björn in IEEE Transactions on Signal Processing (2011), 59(11), 5169-5180 The problem of finding the least squares solution s to a system of equations Hs = y is considered, when s is a vector of binary variables and the coefficient matrix H is unknown but of bounded uncertainty ... [more ▼] The problem of finding the least squares solution s to a system of equations Hs = y is considered, when s is a vector of binary variables and the coefficient matrix H is unknown but of bounded uncertainty. Similar to previous approaches to robust binary least squares, we explore the potential of a min-max design with the aim to provide solutions that are less sensitive to the uncertainty in H. We concentrate on the important case of ellipsoidal uncertainty, i.e., the matrix H is assumed to be a deterministic unknown quantity which lies in a given uncertainty ellipsoid. The resulting problem is NP-hard, yet amenable to convex approximation techniques: Starting from a convenient reformulation of the original problem, we propose an approximation algorithm based on semidefinite relaxation that explicitly accounts for the ellipsoidal uncertainty in the coefficient matrix. Next, we show that it is possible to construct a tighter relaxation by suitably changing the description of the feasible region of the problem, and formulate an approximation algorithm that performs better in practice. Interestingly, both relaxations are derived as Lagrange bidual problems corresponding to the two equivalent problem reformulations. The strength of the proposed tightened relaxation is demonstrated by pertinent simulations. [less ▲] Detailed reference viewed: 168 (2 UL)Inhomogeneities of epitaxial chalcopyrites studied by photoluminescence Larsen, Jes K. Doctoral thesis (2011) Detailed reference viewed: 272 (57 UL)A Multi-Objective GRASP for Energy-aware Scheduling Pecero, Johnatan ; Pinel, Frédéric ; Bouvry, Pascal et al in International Congress on Computer Science Research (2011, October 28) Detailed reference viewed: 89 (2 UL)Mémoire et oubli dans l’espace public en Serbie et en Croatie Blondel, Cyril ; Scientific Conference (2011, October 28) Detailed reference viewed: 53 (0 UL)Identifying Attribute Importance in Early Product Development. Exemplified by Interactive Technologies and Age Pohlmeyer, Anna Elisabeth Doctoral thesis (2011) Detailed reference viewed: 89 (0 UL)Lipid and Immune Functions of the Liver X Receptors in Human Macrophages Diwo, Janine Doctoral thesis (2011) Detailed reference viewed: 68 (2 UL)Buchpräsentation: »Enzensbergers Kursbuch. Eine Zeitschrift um 68«. Henning Marmulla im Gespräch mit Jörg Magenau Marmulla, Henning Speeches/Talks (2011) Detailed reference viewed: 67 (0 UL)About hypersonic instabilities on different time scales in PNIPAM hydrogels Philipp, Martine ; Müller, Ulrich ; Astasheva, Olga et al Presentation (2011, October 25) Detailed reference viewed: 85 (0 UL)Rolle(n) im Welttheater des Andreas Gryphius. Unter besonderer Berücksichtigung des Trauerspiels "Leo Armenius Oder Fürstenmord" Peters, Jeanny Doctoral thesis (2011) Detailed reference viewed: 128 (3 UL)Dynamische Mathematik mit GeoGebra Kreis, Yves Speeches/Talks (2011) Die Bildungsstandards Mathematik für die Klassen begünstigen einen entdeckenden, problemorientierten Unterricht. Dynamische Geometriesysteme (DGS) wie GeoGebra erlauben den Schüler/-innen sich mit ... [more ▼] Die Bildungsstandards Mathematik für die Klassen begünstigen einen entdeckenden, problemorientierten Unterricht. Dynamische Geometriesysteme (DGS) wie GeoGebra erlauben den Schüler/-innen sich mit Fragestellungen auseinanderzusetzen und Hypothesen aufzustellen. Anschließend müssen diese natürlich noch immer mathematisch bewiesen werden; diese Beweise lehnen sich aber oft an den durchlaufenen Prozess der Schüler/-innen an und sind somit leichter verständlich. [less ▲] Detailed reference viewed: 36 (0 UL)Parallel hybrid optimization methods for permutation based problems Mehdi, Malika Doctoral thesis (2011) Solving efficiently large benchmarks of NP-hard permutation-based problems requires the development of hybrid methods combining different classes of optimization algorithms. The key challenge here is how ... [more ▼] Solving efficiently large benchmarks of NP-hard permutation-based problems requires the development of hybrid methods combining different classes of optimization algorithms. The key challenge here is how to find connections between the divergent search strategies used in each class of methods in order to build efficient hybridization strategies. Genetic algorithms (GAs) are very popular population-based metaheuristics based on stochastic evolutionary operators. The hybridization of GAs with tree-based exact methods such as Branch-and-Bound is a promising research trend. B&B algorithms are based on an implicit enumeration of the solution space represented as a tree. Our hybridization approach consists in providing a common solution and search space coding and associated search operators enabling an efficient cooperation between the two methods. The tree-based representation of the solution space is traditionally used in B&B algorithms to enumerate the solutions of the problem at hand. In this thesis, this special representation is adapted to metaheuristics. The encoding of permutations as natural numbers, which refer to their lexicographic enumeration in the tree, is proposed as a new way to represent the solution space of permutation problems in metaheuristics. Mapping functions between the two representations and special search operators are defined for general permutation problems. This common representation allows the design of efficient cooperation strategies between GAs and B&B algorithms. The proposed hybrid schemes have been parallelized and validated on standard benchmarks of the 3D quadratic assignment problem (Q3AP) using the computational grid Grid5000. [less ▲] Detailed reference viewed: 73 (11 UL)Le cerveu à l`école Schiltz, Christine Conference given outside the academic context (2011) Detailed reference viewed: 62 (2 UL)Axiomatizations of Lovász extensions of pseudo-Boolean functions Couceiro, Miguel ; Marichal, Jean-Luc in Fuzzy Sets and Systems (2011), 181(1), 28-38 Three important properties in aggregation theory are investigated, namely horizontal min-additivity, horizontal max-additivity, and comonotonic additivity, which are defined by certain relaxations of the ... [more ▼] Three important properties in aggregation theory are investigated, namely horizontal min-additivity, horizontal max-additivity, and comonotonic additivity, which are defined by certain relaxations of the Cauchy functional equation in several variables. We show that these properties are equivalent and we completely describe the functions characterized by them. By adding some regularity conditions, these functions coincide with the Lovász extensions vanishing at the origin, which subsume the discrete Choquet integrals. We also propose a simultaneous generalization of horizontal min-additivity and horizontal max-additivity, called horizontal median-additivity, and we describe the corresponding function class. Additional conditions then reduce this class to that of symmetric Lovász extensions, which includes the discrete symmetric Choquet integrals. [less ▲] Detailed reference viewed: 134 (8 UL)Fluctuation theorems for capacitively coupled electronic currents ; Esposito, Massimiliano ; in Physical Review. B (2011), 84(16), The counting statistics of electron transport is studied theoretically in a system with two capacitively coupled parallel transport channels. Each channel is composed of a quantum dot connected by ... [more ▼] The counting statistics of electron transport is studied theoretically in a system with two capacitively coupled parallel transport channels. Each channel is composed of a quantum dot connected by tunneling to two reservoirs. The nonequilibrium steady state of the system is controlled by two affinities or thermodynamic forces, each one determined by the two reservoirs of each channel. The status of a single-current fluctuation theorem is investigated starting from the fundamental two-current fluctuation theorem, which is a consequence of microreversibility.We show that the single-current fluctuation theorem holds in the limit of a large Coulomb repulsion between the two parallel quantum dots, as well as in the limit of a large current ratio between the parallel channels. In this latter limit, the symmetry relation of the single-current fluctuation theorem is satisfied with respect to an effective affinity that is much lower than the affinity determined by the reservoirs. This backaction effect is characterized quantitatively. [less ▲] Detailed reference viewed: 93 (1 UL)The adaptation of the Baltic parliaments to the EU multilevel governance: The case of Lithuania Pigeonnier, Anne-Sylvie Presentation (2011, October 14) While there is no lack of academic literature on national parliaments and European integration, empirical studies on the impact of the European Union on domestic legislatures are rare. This article is a ... [more ▼] While there is no lack of academic literature on national parliaments and European integration, empirical studies on the impact of the European Union on domestic legislatures are rare. This article is a case study about the adaptation of the Baltic parliaments to the EU multilevel governance. In the 1990s, the Baltic States wishing to join the EU, their parliaments had to face the simultaneous challenges of democratisation, Europeanisation and modernisation. During the pre-Accession period they were involved in the EU matters through the transposition of the EU law and the monitoring of the Accession negotiations. Inter-parliamentary contacts with their European counterparts were developed. This facilitated the learning of “good practices” and rules established in the EU Member States parliaments. Just after the EU Accession, the legal frameworks of the Baltic Parliaments were reinforced according to the Scandinavian model of parliamentary scrutiny system on EU affairs. Legally speaking today the Baltic parliaments are more powerful actors, but some limits to their real effectiveness still exist. [less ▲] Detailed reference viewed: 71 (1 UL)The Global Environment and Rural Sustainable Development: Case Study 2: Saarland Nienaber, Birte ; Scientific Conference (2011, October 12) Detailed reference viewed: 79 (2 UL) |
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