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Dieser Beitrag geht der Frage nach Möglichkeiten einer systematischen Vernetzung von germanistischer Literaturwissenschaft und -didaktik in der Hochschullehre nach. Dazu sind im Rahmen eines Projekts insgesamt zwölf Seminarkooperationen durchgeführt worden, in denen jeweils ein fachwissenschaftliches mit einem fachdidaktischen Seminar kooperiert hat. Die Auswertung dieser Kooperationsseminare, die auf der Grundlage einer Auseinandersetzung mit in der Forschungsliteratur skizzierten bestehenden Problemlagen im Lehramts-Studium Deutsch und aktuellen vergleichbaren Projekten erfolgt, ist qualitativ-analytisch angelegt und erfolgt auf der Basis leitfadengestützter Interviews mit den betreffenden Dozentinnen und Dozenten. Diese ausführliche Reflexion der Kooperationsseminare zeigt zum einen Probleme der Kooperation zwischen Fachwissenschaft und -didaktik auf, zum anderen werden auf dieser Basis aber auch mögliche Gelingensbedingungen effektiver Kooperation(en) auf den Ebenen der Planung, Durchführung und Reflexion von Kooperationsseminaren eruiert. Die Befunde haben darüber hinaus auch Implikationen für die Studienordnung im Lehramt Deutsch und wurden bereits mit ersten Änderungen berücksichtigt.
Mapping Damage-Affected Areas after Natural Hazard Events Using Sentinel-1 Coherence Time Series
(2018)
The emergence of the Sentinel-1A and 1B satellites now offers freely available and widely accessible Synthetic Aperture Radar (SAR) data. Near-global coverage and rapid repeat time (6–12 days) gives Sentinel-1 data the potential to be widely used for monitoring the Earth’s surface. Subtle land-cover and land surface changes can affect the phase and amplitude of the C-band SAR signal, and thus the coherence between two images collected before and after such changes. Analysis of SAR coherence therefore serves as a rapidly deployable and powerful tool to track both seasonal changes and rapid surface disturbances following natural disasters. An advantage of using Sentinel-1 C-band radar data is the ability to easily construct time series of coherence for a region of interest at low cost. In this paper, we propose a new method for Potentially Affected Area (PAA) detection following a natural hazard event. Based on the coherence time series, the proposed method (1) determines the natural variability of coherence within each pixel in the region of interest, accounting for factors such as seasonality and the inherent noise of variable surfaces; and (2) compares pixel-by-pixel syn-event coherence to temporal coherence distributions to determine where statistically significant coherence loss has occurred. The user can determine to what degree the syn-event coherence value (e.g., 1st, 5th percentile of pre-event distribution) constitutes a PAA, and integrate pertinent regional data, such as population density, to rank and prioritise PAAs. We apply the method to two case studies, Sarpol-e, Iran following the 2017 Iran-Iraq earthquake, and a landslide-prone region of NW Argentina, to demonstrate how rapid identification and interpretation of potentially affected areas can be performed shortly following a natural hazard event.
We investigate the role of interatomic interactions when a Bose gas, in a double-well potential with a finite tunneling probability (a 'Bose–Josephson junction'), is exposed to external noise. We examine the rate of decoherence of a system initially in its ground state with equal probability amplitudes in both sites. The noise may induce two kinds of effects: firstly, random shifts in the relative phase or number difference between the two wells and secondly, loss of atoms from the trap. The effects of induced phase fluctuations are mitigated by atom–atom interactions and tunneling, such that the dephasing rate may be suppressed by half its single-atom value. Random fluctuations may also be induced in the population difference between the wells, in which case atom–atom interactions considerably enhance the decoherence rate. A similar scenario is predicted for the case of atom loss, even if the loss rates from the two sites are equal. We find that if the initial state is number-squeezed due to interactions, then the loss process induces population fluctuations that reduce the coherence across the junction. We examine the parameters relevant for these effects in a typical atom chip device, using a simple model of the trapping potential, experimental data, and the theory of magnetic field fluctuations near metallic conductors. These results provide a framework for mapping the dynamical range of barriers engineered for specific applications and set the stage for more complex atom circuits ('atomtronics').