Editorial: E-Learning-Strategien für die Hochschullehre

27.04.2015 | Sabine Seufert (St. Gallen), Martin Ebner, Michael Kopp (Graz) & Bettina Schlass (Amsterdam

Aktuelle theoretische Ansätze und empirische Befunde im Bereich der Lehr-Lern-Forschung:Schwerpunkt Erwachsenenbildung

Das Gutachten dient dem im Jahr 2004 vom DIE ins Leben gerufenen „Expertenkreis Lehre in der Weiterbildung“ als Arbeitsgrundlage. Es stellt die aktuellen Ansätze und Befunde im Bereich des Lehrens und Lernens mit Schwerpunkt auf der Erwachsenenbildung dar. Neuere Ansätze zum Lehren und Lernen aus der Empirischen Pädagogik und Pädagogischen Psychologie werden vorgestellt und auf spezifische Aspekte der Weiterbildung wie Communities, berufliche Weiterbildung und Blended Learning eingegangen. Die verschiedenen Ebenen, Aufgabenfelder und Phasen des Bildungsmanagements werden beleuchtet und das Bildungscontrolling näher erläutert. Danach folgen Ausführungen zu einem mitarbeiterorientierten Implementationsmodell innovativer Lehr-Lern-Ansätze in Organisationen. Anhand der vorgestellten Ansätze und Befunde des Lehrens und Lernens werden Folgerungen für die Forschung und für die Ausund Weiterbildung der Lehrenden im Bereich der Erwachsenenbildung gezogen

Real-Time Operating System/360

RTOS has a cost savings advantage for real-time applications, such as those with random inputs requiring a flexible data routing facility, display systems simplified by a device independent interface language, and complex applications needing added storage protection and data queuing

Entanglement crossover close to a quantum critical point

We discuss the thermal entanglement close to a quantum phase transition by analyzing the concurrence for one dimensional models in the quantum Ising universality class. We demonstrate that the entanglement sensitivity to thermal and to quantum fluctuations obeys universal $T\neq 0$--scaling behaviour. We show that the entanglement, together with its criticality, exhibits a peculiar universal crossover behaviour.Comment: 12 pages; 5 figures (eps). References added; to be published in Europhysics Letter

Separate Universes Do Not Constrain Primordial Black Hole Formation

Carr and Hawking showed that the proper size of a spherical overdense region surrounded by a flat FRW universe cannot be arbitrarily large as otherwise the region would close up on itself and become a separate universe. From this result they derived a condition connecting size and density of the overdense region ensuring that it is part of our universe. Carr used this condition to obtain an upper bound for the density fluctuation amplitude with the property that for smaller amplitudes the formation of a primordial black hole is possible, while larger ones indicate a separate universe. In contrast, we find that the appearance of a maximum is not a consequence of avoiding separate universes but arises naturally from the geometry of the chosen slicing. Using instead of density a volume fluctuation variable reveals that a fluctuation is a separate universe iff this variable diverges on superhorizon scales. Hence Carr's and Hawking's condition does not pose a physical constraint on density fluctuations. The dynamics of primordial black hole formation with an initial curvature fluctuation amplitude larger than the one corresponding to the maximum density fluctuation amplitude was previously not considered in detail and so we compare it to the well-known case where the amplitude is smaller by presenting embedding and conformal diagrams of both types in dust spacetimes.Comment: Updated version corresponds to the published version 10.1103/PhysRevD.83.124025, 22 pages, 22 figure

Beam-Based Alignment of the NuMI Target Station Components at FNAL

The Neutrinos at the Main Injector (NuMI) facility is a conventional horn-focused neutrino beam which produces muon neutrinos from a beam of mesons directed into a long evacuated decay volume. The relative alignment of the primary proton beam, target, and focusing horns affects the neutrino energy spectrum delivered to experiments. This paper describes a check of the alignment of these components using the proton beam.Comment: higher resolution figures available on Fermilab Preprint Server (see SPIRES entry), accepted for publication in Nucl. Instr. and Meth.

A diagrammatic treatment of neutrino oscillations

We present a covariant wave-packet approach to neutrino flavor transitions in vacuum. The approach is based on the technique of macroscopic Feynman diagrams describing the lepton number violating processes of production and absorption of virtual massive neutrinos at the macroscopically separated space-time regions ("source" and "detector"). Accordingly, the flavor transitions are a result of interference of the diagrams with neutrinos of different masses in the intermediate states. The statistically averaged probability of the process is representable as a multidimensional integral of the product of the factors which describe the differential flux density of massless neutrinos from the source, differential cross section of the neutrino interaction with the detector and a dimensionless factor responsible for the flavor transition. The conditions are analyzed under which the last factor can be treated as the flavor transition probability in the usual quantum-mechanical sense.Comment: 27 pages,7 figures, iopart class. Includes minor corrections made in proofs. References update

Magnetic excitations in two-leg spin 1/2 ladders: experiment and theory

Magnetic excitations in two-leg S=1/2 ladders are studied both experimentally and theoretically. Experimentally, we report on the reflectivity, the transmission and the optical conductivity sigma(omega) of undoped La_x Ca_14-x Cu_24 O_41 for x=4, 5, and 5.2. Using two different theoretical approaches (Jordan-Wigner fermions and perturbation theory), we calculate the dispersion of the elementary triplets, the optical conductivity and the momentum-resolved spectral density of two-triplet excitations for 0.2 <= J_parallel/J_perpendicular <= 1.2. We discuss phonon-assisted two-triplet absorption, the existence of two-triplet bound states, the two-triplet continuum, and the size of the exchange parameters.Comment: 6 pages, 7 eps figures, submitted to SNS 200

Three-point correlations for quantum star graphs

We compute the three point correlation function for the eigenvalues of the Laplacian on quantum star graphs in the limit where the number of edges tends to infinity. This extends a work by Berkolaiko and Keating, where they get the 2-point correlation function and show that it follows neither Poisson, nor random matrix statistics. It makes use of the trace formula and combinatorial analysis.Comment: 10 pages, 2 figure