TY - JOUR A1 - Schmidt-Wellenburg, Christian T1 - Struggling over crisis T1 - Umkämpfte Krise BT - Discoursive Positionings and Academic Positions in the Field of German-Speaking Economists BT - Diskursive Positionierungen und akademische Positionen im Feld deutschsprachiger Volkswirt*innen JF - Historical Social Research N2 - If you put two economists in a room, you get two opinions, unless one of them is Lord Keynes, in which case you get three opinions.” Following the premise of this quotation attributed to Winston Churchill, varying perceptions of the European crisis by academic economists and their structural homology to economists’ positions in the field of economics are examined. The dataset analysed using specific multiple correspondence analysis (MCA) and hierarchical agglomerative clustering (HAC) comprises information on the careers of 480 German-speaking economists and on statements they made concerning crisis-related issues. It can be shown that the main structural differences in the composition and amount of scientific and academic capital held by economists as well as their age and degree of transnationalisation are linked to how they see the crisis: as a national sovereign debt crisis, as a European banking crisis, or as a crisis of European integration and institutions. KW - Economics KW - multiple correspondence analysis KW - Bourdieu KW - field KW - discourse KW - mixed methods KW - European Union KW - crisis Y1 - 2018 U6 - https://doi.org/10.12759/hsr.43.2018.3.147-188 SN - 0172-6404 VL - 43 IS - 3 SP - 147 EP - 188 PB - GESIS, Leibniz Institute for the Social Sciences CY - Cologne ER - TY - GEN A1 - Schmidt-Wellenburg, Christian A1 - Lebaron, Frederic T1 - There is no such thing as "the Economy" BT - Economic phenomena analysed from a field-theoretical perspective BT - Zur Analyse ökonomischer Phänomene aus feldtheoretischer Perspektive T2 - Historical Social Research N2 - This introductory essay to the HSR Special Issue “Economists, Politics, and Society” argues for a strong field-theoretical programme inspired by Pierre Bourdieu to research economic life as an integral part of different social forms. Its main aim is threefold. First, we spell out the very distinct Durkheimian legacy in Bourdieu’s thinking and the way he applies it in researching economic phenomena. Without this background, much of what is actually part of how Bourdieu analysed economic aspects of social life would be overlooked or reduced to mere economic sociology. Second, we sketch the main theoretical concepts and heuristics used to analyse economic life from a field perspective. Third, we focus on practical methodological issues of field-analytical research into economic phenomena. We conclude with a short summary of the basic characteristics of this approach and discuss the main insights provided by the contributions to this special issue. T2 - 'Die Ökonomie‘ gibt es nicht! KW - Economic sociology KW - field KW - Bourdieu KW - methodology KW - discourse KW - domination KW - state KW - economy Y1 - 2018 U6 - https://doi.org/10.12759/hsr.43.2018.3.7-38 SN - 0172-6404 VL - 43 IS - 3 SP - 7 EP - 38 PB - GESIS, Leibniz Institute for the Social Sciences CY - Cologne ER - TY - GEN A1 - Jackisch, Conrad A1 - Angermann, Lisa A1 - Allroggen, Niklas A1 - Sprenger, Matthias A1 - Blume, Theresa A1 - Tronicke, Jens A1 - Zehe, Erwin T1 - Form and function in hillslope hydrology BT - in situ imaging and characterization of flow-relevant structures T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The study deals with the identification and characterization of rapid subsurface flow structures through pedo- and geo-physical measurements and irrigation experiments at the point, plot and hillslope scale. Our investigation of flow-relevant structures and hydrological responses refers to the general interplay of form and function, respectively. To obtain a holistic picture of the subsurface, a large set of different laboratory, exploratory and experimental methods was used at the different scales. For exploration these methods included drilled soil core profiles, in situ measurements of infiltration capacity and saturated hydraulic conductivity, and laboratory analyses of soil water retention and saturated hydraulic conductivity. The irrigation experiments at the plot scale were monitored through a combination of dye tracer, salt tracer, soil moisture dynamics, and 3-D time-lapse ground penetrating radar (GPR) methods. At the hillslope scale the subsurface was explored by a 3-D GPR survey. A natural storm event and an irrigation experiment were monitored by a dense network of soil moisture observations and a cascade of 2-D time-lapse GPR "trenches". We show that the shift between activated and non-activated state of the flow paths is needed to distinguish structures from overall heterogeneity. Pedo-physical analyses of point-scale samples are the basis for sub-scale structure inference. At the plot and hillslope scale 3-D and 2-D time-lapse GPR applications are successfully employed as non-invasive means to image subsurface response patterns and to identify flow-relevant paths. Tracer recovery and soil water responses from irrigation experiments deliver a consistent estimate of response velocities. The combined observation of form and function under active conditions provides the means to localize and characterize the structures (this study) and the hydrological processes (companion study Angermann et al., 2017, this issue). T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 665 KW - Ground Penetrating Radar KW - preferential flow KW - solute transport KW - Catchment Hydrology KW - multiple scales KW - soil moisture KW - water content KW - tracer KW - field KW - model Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-419188 SN - 1866-8372 IS - 665 ER - TY - GEN A1 - Schrön, Martin A1 - Köhli, Markus A1 - Scheiffele, Lena A1 - Iwema, Joost A1 - Bogena, Heye R. A1 - Lv, Ling A1 - Martini, Edoardo A1 - Baroni, Gabriele A1 - Rosolem, Rafael A1 - Weimar, Jannis A1 - Mai, Juliane A1 - Cuntz, Matthias A1 - Rebmann, Corinna A1 - Oswald, Sascha Eric A1 - Dietrich, Peter A1 - Schmidt, Ulrich A1 - Zacharias, Steffen T1 - Improving calibration and validation of cosmic-ray neutron sensors in the light of spatial sensitivity T2 - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe N2 - In the last few years the method of cosmic-ray neutron sensing (CRNS) has gained popularity among hydrologists, physicists, and land-surface modelers. The sensor provides continuous soil moisture data, averaged over several hectares and tens of decimeters in depth. However, the signal still may contain unidentified features of hydrological processes, and many calibration datasets are often required in order to find reliable relations between neutron intensity and water dynamics. Recent insights into environmental neutrons accurately described the spatial sensitivity of the sensor and thus allowed one to quantify the contribution of individual sample locations to the CRNS signal. Consequently, data points of calibration and validation datasets are suggested to be averaged using a more physically based weighting approach. In this work, a revised sensitivity function is used to calculate weighted averages of point data. The function is different from the simple exponential convention by the extraordinary sensitivity to the first few meters around the probe, and by dependencies on air pressure, air humidity, soil moisture, and vegetation. The approach is extensively tested at six distinct monitoring sites: two sites with multiple calibration datasets and four sites with continuous time series datasets. In all cases, the revised averaging method improved the performance of the CRNS products. The revised approach further helped to reveal hidden hydrological processes which otherwise remained unexplained in the data or were lost in the process of overcalibration. The presented weighting approach increases the overall accuracy of CRNS products and will have an impact on all their applications in agriculture, hydrology, and modeling. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 636 KW - forested headwater catchment KW - moisture observing system KW - soil-water content KW - parameterization methods KW - scale KW - field KW - dynamics KW - observatories KW - networks Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-419134 IS - 636 SP - 5009 EP - 5030 ER - TY - THES A1 - Topaj, Dmitri T1 - Synchronization transitions in complex systems N2 - Gegenstand dieser Arbeit ist die Untersuchung generischer Synchronisierungsphänomene in interagierenden komplexen Systemen. Diese Phänomene werden u.a. in gekoppelten deterministischen chaotischen Systemen beobachtet. Bei sehr schwachen Interaktionen zwischen individuellen Systemen kann ein Übergang zum schwach kohärenten Verhalten der Systeme stattfinden. In gekoppelten zeitkontinuierlichen chaotischen Systemen manifestiert sich dieser Übergang durch den Effekt der Phasensynchronisierung, in gekoppelten chaotischen zeitdiskreten Systemen durch den Effekt eines nichtverschwindenden makroskopischen Feldes. Der Übergang zur Kohärenz in einer Kette lokal gekoppelter Oszillatoren, beschrieben durch Phasengleichungen, wird im Bezug auf die Symmetrien des Systems untersucht. Es wird gezeigt, daß die durch die Symmetrien verursachte Reversibilität des Systems nichttriviale topologische Eigenschaften der Trajektorien bedingt, so daß das als dissipativ konstruierte System in einem ganzen Parameterbereich quasi-Hamiltonische Züge aufweist, d.h. das Phasenvolumen ist im Schnitt erhalten, und die Lyapunov-Exponenten sind paarweise symmetrisch. Der Übergang zur Kohärenz in einem Ensemble global gekoppelter chaotischer Abbildungen wird durch den Verlust der Stabilität des entkoppelten Zustandes beschrieben. Die entwickelte Methode besteht darin, die Selbstkonsistenz des makroskopischen Feldes aufzuheben, und das Ensemble in Analogie mit einem Verstärkerschaltkreis mit Rückkopplung durch eine komplexe lineare Übertragungssfunktion zu charakterisieren. Diese Theorie wird anschließend für einige theoretisch interessanten Fälle verallgemeinert. N2 - Subject of this work is the investigation of generic synchronization phenomena in interacting complex systems. These phenomena are observed, among all, in coupled deterministic chaotic systems. At very weak interactions between individual systems a transition to a weakly coherent behavior of the systems can take place. In coupled continuous time chaotic systems this transition manifests itself with the effect of phase synchronization, in coupled chaotic discrete time systems with the effect of non-vanishing macroscopic mean field. Transition to coherence in a chain of locally coupled oscillators described with phase equations is investigated with respect to the symmetries in the system. It is shown that the reversibility of the system caused by these symmetries results to non-trivial topological properties of trajectories so that the system constructed to be dissipative reveals in a whole parameter range quasi-Hamiltonian features, i.e. the phase volume is conserved on average and Lyapunov exponents come in symmetric pairs. Transition to coherence in an ensemble of globally coupled chaotic maps is described with the loss of stability of the disordered state. The method is to break the self-consistensy of the macroscopic field and to characterize the ensemble in analogy to an amplifier circuit with feedback with a complex linear transfer function. This theory is then generalized for several cases of theoretic interest. KW - Synchronisierung KW - komplex KW - System KW - komplexe Systeme KW - gekoppelt KW - chaotisch KW - Chaos KW - Interaktion KW - Übergang KW - P hasensynchronisierung KW - Phase KW - Feld KW - Effekt KW - synchronization KW - complex KW - system KW - complex systems KW - coupled KW - chaotic KW - chaos KW - interaction KW - transition KW - phase KW - phase synchronization KW - field KW - meanfield KW - o Y1 - 2001 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-0000367 ER -