228 research outputs found
Density-matrix functionals from Green's functions
No full textThe exact reduced density-matrix functional is derived from the Luttinger-Ward functional of the single-particle Green's function. Thereby, a formal link is provided between diagrammatic many-body approaches using Green's functions on the one hand and theories based on many-body wave functions on the other. This link can be used to explicitly construct approximations for the density-matrix functional that are equivalent to standard diagrammatic resummation techniques and to nonperturbative dynamical mean field theory in particular. Contrary to functionals of the Green's function, the exact density-matrix functional is convex and thus provides a true minimum principle which facilitates the calculation of the grand potential and derived equilibrium properties. The benefits of the proposed Green's-function-based density-matrix functional theory for geometrical structure optimization of strongly correlated materials are discussed.Deutsche Forschungsgemeinschaft [FOR 1346
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Unternehmensverfassung in der privaten und öffentlichen Wirtschaft ::Festschrift für Prof. Dr. Erich Potthoff zur Vollendung des 75. Lebensjahres / Peter Eichhorn (Hrsg.)
No full textSupplementary table -Supplemental material for Long-term changes in liver elasticity in hepatitis C virus-infected patients with sustained virologic response after treatment with direct-acting antivirals
No full textSupplemental material, Supplementary table for Long-term changes in liver elasticity in hepatitis C virus-infected patients with sustained virologic response after treatment with direct-acting antivirals by Veronika Pietsch, Katja Deterding, Dina Attia, Kristina Imeen Ringe, Benjamin Heidrich, Markus Cornberg, Michael Gebel, Michael Peter Manns, Heiner Wedemeyer and Andrej Potthoff in United European Gastroenterology Journal</p
Group-analytic Practice Today: Intersubjective Perspectives and the Relational Paradigm
No full textOver the past 50 years psychoanalysis and group analysis have quite moved apart from each other with very little exchange and cooperation left, while the pioneers of group analysis (Foulkes, Bion) emphasized the link with psychoanalysis. With the ‘intersubjective turn’ in psychoanalysis during the 1980s substantial common ground for group analysis and psychoanalysis has emerged, but not been completely recognized and appreciated in both disciplines. The author demonstrates areas of possible overlap and cross-fertilization mainly drawing on concepts from relational psychoanalysis. The idea of the inevitable embeddedness of analyst and analysand in the psychoanalytic process has already been present in Foulkes’ writings concerning the role of the conductor, but not very much elaborated. Other relational concepts like dissociation, enactment, mutuality and self-disclosure might be fruitfully integrated into contemporary group-analytic theorizing, too. Conversely, group-analytic perspectives could increase awareness of the importance of context (social, cultural, institutional) also for the dynamics of individual analysis. The understanding of group processes could help to grasp and negotiate more successfully the notorious difficulties in psychoanalytic institutions. To illustrate theory the author presents detailed material from a group session.</jats:p
New Frontiers 2013-2014
No full textNew Frontiers 2013-2014 Features: Teaching Democracy - Dennis Potthoff Sweet Reading - Susan Honeyman Role of a Lifetime - Heather Schulz Plains Pathfinder - Peter Longo Piano Sculptor - Nathan Buckner Adolescent Advocate - David Hof Unlocking Lakes - Julie Shaffer Processing Process - Kathryn Zuckweilerhttps://openspaces.unk.edu/new-frontiers/1005/thumbnail.jp
Ermittlung der Zellkapazität alternder Lithium-Ionen-Zellen aus unter Betriebsbedingungen erfassten Messdaten
No full textLithium-Ionen-Akkumulatoren sind, im Rahmen der Elektromobilität und Energiespeichersysteme, derzeit eines der wichtigsten Forschungsthemen zur Verbesserung der Ökobilanz und Unterstützung des Umstiegs auf erneuerbare Energiequellen. Neben einer Vielzahl an Arbeiten zur Verbesserung der Zellen rückt die Überwachung des Lade- und Alterungszustandes der Zellen mit in den Schwerpunkt, da die Zellen lange und zuverlässig nutzbar sein sollen. Zur kapazitiven Alterung soll diese Arbeit einen Ansatz präsentieren, mit dem die Kapazität unter minimaler Vorarbeit und geringem Vorwissen aus Belastungsdaten geschätzt werden kann. Dazu soll lediglich der Spannungsverlauf des kapazitiven Verhaltens, in Form der Leerlaufspannungskennlinie, bekannt sein. Zusammen mit einem möglichst allgemein gültigen elektrischen Schaltungsmodell wird die verbliebene Kapazität geschätzt. Aufgrund des allgemeinen Ansatzes wäre dieser für eine Vielzahl unterschiedliche gestalteter Zellen nutzbar.Lithium ion accumulators are currently one of the most important research topics in the field of e-mobility and energy storage systems to improve the environmental performance and support the change to renewable energy sources. In addition to a great deal of work to improve the cells, the monitoring of the state of charge and aging of the cells is becoming more important, as the cells should be usable for a long and reliable time. For capacitive aging, this work will present an approach that can estimate the capacity from the load data with minimal preliminary work and little prior knowledge. For this purpose, only the voltage curve of the capacitive behavior, in form of the open-circuit voltage characteristic, should be known. Together with an electrical circuit model that is as universal as possible, the remaining capacity is estimated. This wouldbe usable for a variety of different cell designs, due to the general approach made
Entwicklung eines digitalen 4-Quadranten Electronic Speed Controllers (ESC) für eine permanenterregte Gleichstrommaschine
No full textIm Rahmen dieser Arbeit wird ein digitaler Drehzahlregler für eine permanenterregte Gleichstrommaschine entwickelt und aufgebaut. Dabei wird auf ein hohes Maß an Flexibilität geachtet, so dass Steuer- und Leistungselektronik getrennt aufgebaut werden. Kernstück der Leistungselektronik ist eine H-Brücke, durch die der Betrieb der Maschine in allen vier Quadranten ermöglicht wird: Beschleunigen und Bremsen in beiden Drehrichtungen. Nach Erarbeitung der physikalischen und regelungstechnischen Grundlagen zum Erstellen
einer mathematischen Beschreibung der Gleichstrommaschine wird der Drehzahlregler entworfen. Dazu werden verschiedene Regelverfahren vorgestellt, untersucht, und mittels Simulation miteinander verglichen.
Die Regelung der Drehzahl wird schließlich auf einem Microcontroller implementiert. So ist eine einfache Anpassung des Reglers möglich.
Des weiteren wird ausführlich auf den Software-Entwurf und die Implementierung der einzelnen Software-Module eingegangen, und die korrekte Funktion des entwickelten Reglers messtechnisch verifiziert.Within the scope of this thesis, a digital speed controller for a permanent-magnet DC motor is developed and built, while ensuring a high grade of flexibility, so that control- and power electronics are built separately. The core element of the power electronics is an H-bridge, which allows the machine to be operated in all four quadrants: acceleration and braking in both directions of rotation.
After elaboration of the physical and regulatory principles for creating a mathematical description of the DC machine, the speed controller is designed. For this purpose, various control methods are presented, examined, and compared by means of simulation. The control of the rotational speed is finally implemented on a microcontroller, which allows a simple adjustment of the controller.
Furthermore, the software design and the implementation of the individual software modules
are discussed in detail, and the correct function of the developed controller is verified by
measurements
Adiabatic Dynamics and Topological Effects in Systems of Classical Spins Coupled to Itinerant Electrons
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