TY - JOUR A1 - Teichmann, Erik A1 - Lewandowski, Heather J. A1 - Alemani, Micol T1 - Investigating students’ views of experimental physics in German laboratory classes JF - Physical Review Physics Education Research N2 - There is a large variety of goals instructors have for laboratory courses, with different courses focusing on different subsets of goals. An often implicit, but crucial, goal is to develop students’ attitudes, views, and expectations about experimental physics to align with practicing experimental physicists. The assessment of laboratory courses upon this one dimension of learning has been intensively studied in U.S. institutions using the Colorado Learning Attitudes about Science Survey for Experimental Physics (E-CLASS). However, there is no such an instrument available to use in Germany, and the influence of laboratory courses on students views about the nature of experimental physics is still unexplored at German-speaking institutions. Motivated by the lack of an assessment tool to investigate this goal in laboratory courses at German-speaking institutions, we present a translated version of the E-CLASS adapted to the context at German-speaking institutions. We call the German version of the E-CLASS, the GE-CLASS. We describe the translation process and the creation of an automated web-based system for instructors to assess their laboratory courses. We also present first results using GE-CLASS obtained at the University of Potsdam. A first comparison between E-CLASS and GE-CLASS results shows clear differences between University of Potsdam and U.S. students’ views and beliefs about experimental physics. Y1 - 2022 U6 - https://doi.org/10.1103/PhysRevPhysEducRes.18.010135 SN - 1554-9178 VL - 18 SP - 010135-1 EP - 010135-17 PB - APS CY - College Park, Maryland, United States ET - 1 ER - TY - GEN A1 - Teichmann, Erik A1 - Lewandowski, Heather J. A1 - Alemani, Micol T1 - Investigating students’ views of experimental physics in German laboratory classes T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - There is a large variety of goals instructors have for laboratory courses, with different courses focusing on different subsets of goals. An often implicit, but crucial, goal is to develop students’ attitudes, views, and expectations about experimental physics to align with practicing experimental physicists. The assessment of laboratory courses upon this one dimension of learning has been intensively studied in U.S. institutions using the Colorado Learning Attitudes about Science Survey for Experimental Physics (E-CLASS). However, there is no such an instrument available to use in Germany, and the influence of laboratory courses on students views about the nature of experimental physics is still unexplored at German-speaking institutions. Motivated by the lack of an assessment tool to investigate this goal in laboratory courses at German-speaking institutions, we present a translated version of the E-CLASS adapted to the context at German-speaking institutions. We call the German version of the E-CLASS, the GE-CLASS. We describe the translation process and the creation of an automated web-based system for instructors to assess their laboratory courses. We also present first results using GE-CLASS obtained at the University of Potsdam. A first comparison between E-CLASS and GE-CLASS results shows clear differences between University of Potsdam and U.S. students’ views and beliefs about experimental physics. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1263 Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-560429 SN - 1866-8372 SP - 010135-1 EP - 010135-17 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - THES A1 - Teichmann, Erik T1 - Partial synchronization in coupled systems with repulsive and attractive interaction T1 - Partielle Synchronisation in Gekoppelten System mit Abstoßender und Anziehender Wechselwirkung N2 - Partial synchronous states exist in systems of coupled oscillators between full synchrony and asynchrony. They are an important research topic because of their variety of different dynamical states. Frequently, they are studied using phase dynamics. This is a caveat, as phase dynamics are generally obtained in the weak coupling limit of a first-order approximation in the coupling strength. The generalization to higher orders in the coupling strength is an open problem. Of particular interest in the research of partial synchrony are systems containing both attractive and repulsive coupling between the units. Such a mix of coupling yields very specific dynamical states that may help understand the transition between full synchrony and asynchrony. This thesis investigates partial synchronous states in mixed-coupling systems. First, a method for higher-order phase reduction is introduced to observe interactions beyond the pairwise one in the first-order phase description, hoping that these may apply to mixed-coupling systems. This new method for coupled systems with known phase dynamics of the units gives correct results but, like most comparable methods, is computationally expensive. It is applied to three Stuart-Landau oscillators coupled in a line with a uniform coupling strength. A numerical method is derived to verify the analytical results. These results are interesting but give importance to simpler phase models that still exhibit exotic states. Such simple models that are rarely considered are Kuramoto oscillators with attractive and repulsive interactions. Depending on how the units are coupled and the frequency difference between the units, it is possible to achieve many different states. Rich synchronization dynamics, such as a Bellerophon state, are observed when considering a Kuramoto model with attractive interaction in two subpopulations (groups) and repulsive interactions between groups. In two groups, one attractive and one repulsive, of identical oscillators with a frequency difference, an interesting solitary state appears directly between full and partial synchrony. This system can be described very well analytically. N2 - Partiell synchronisierte Zustände existieren zwischen voller Synchronisation und Asynchronie, in Systemen von gekoppelten Oszillatoren. Das Verständnis von partieller Synchronisation ist ein wichtiger Forschungszweig, da sie viele dynamische Zustände enthalten. Sie werden oft mithilfe von Phasendynamiken untersucht. Das ist jedoch ein Nachteil, da Phasendynamiken für gewöhnlich nur im Grenzfall von schwacher Kopplung, also einer Näherung in erster Ordnung der Kopplungsstärke, betrachtet werden. Die Verallgemeinerung zu höheren Ordnungen ist weiterhin ein offenes Problem. Systeme mit anziehender und abstoßender Kopplung zwischen den einzelnen Oszillatoren sind von speziellem Interesse in der Erforschung von partieller Synchronisation. Solch eine Mischung aus Kopplungsstärken führt zu bestimmten dynamischen Zuständen, die den Übergang von Synchronisation zu Asynchronie erklären könnten. Diese Arbeit untersucht solche Zustände in Systemen mit gemischten Kopplungsstärken. Zuerst wird eine neue Methode zur Bestimmung von Phasendynamiken in höheren Ordnungen eingeführt. Sie betrachtet mehr Kopplungsterme, als die einfachen paarweisen Interaktionen die in der ersten Ordnung der Kopplungsstärke auftreten, in der Hoffnung, dass diese Methode auch auf Systeme mit gemischter Kopplung anwendbar ist. Die neue Methode für Oszillatoren mit einer bekannten Phasendynamik, führt zu den richtigen Ergebnissen, ist aber aufwendig zu berechnen. Die Methode wird auf drei, in einer Linie gekoppelten, Stuart-Landau Oszillatoren angewendet. Eine numerische Methode wird abgeleitet, um die analytischen Ergebnisse zu verifizieren. Diese Ergebnisse sind interessant, aber durch die benötigte hohe Rechenleistung ist es weiterhin vorteilhaft einfachere Phasenmodelle zu untersuchen, die exotischere Zustände erreichen. Solch ein einfaches Model, das eher selten Beachtung findet, ist das Kuramoto Model mit anziehender und abstoßender Kopplung. Abhängig davon, wie die Oszillatoren gekoppelt und wie die Frequenzunterschiede zwischen den einzelnen Oszillatoren sind, ist es möglich viele verschiedene Zustände zu erreichen. Interessante Synchronisierungsdynamiken werden erreicht, wie zum Beispiel der Bellerophon Zustand, wenn ein Kuramoto Model mit zwei Gruppen, mit anziehender Kopplung innerhalb der Gruppen und abstoßender Kopplung zwischen den Gruppen, untersucht wird. Bei zwei Gruppen, eine anziehend und eine abstoßend, von identischen Oszillatoren mit einem Frequenzunterschied zwischen den Gruppen, wird ein interessanter solitärer Zustand beobachtet. Er befindet sich direkt am Übergang zwischen Synchronisation und partieller Synchronisation. Solch ein System ist sehr gut analytisch beschreibbar. KW - Synchronization KW - Dynamical Systems KW - Coupled Systems KW - gekoppelte System KW - dynamische Systeme KW - Synchronisation Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-528943 ER - TY - JOUR A1 - Teichmann, Erik A1 - Rosenblum, Michael T1 - Solitary states and partial synchrony in oscillatory ensembles with attractive and repulsive interactions JF - Chaos : an interdisciplinary journal of nonlinear science N2 - We numerically and analytically analyze transitions between different synchronous states in a network of globally coupled phase oscillators with attractive and repulsive interactions. The elements within the attractive or repulsive group are identical, but natural frequencies of the groups differ. In addition to a synchronous two-cluster state, the system exhibits a solitary state, when a single oscillator leaves the cluster of repulsive elements, as well as partially synchronous quasiperiodic dynamics. We demonstrate how the transitions between these states occur when the repulsion starts to prevail over attraction. Y1 - 2019 U6 - https://doi.org/10.1063/1.5118843 SN - 1054-1500 SN - 1089-7682 VL - 29 IS - 9 PB - American Institute of Physics CY - Melville ER - TY - JOUR A1 - Teichmann, Erik T1 - Using phase dynamics to study partial synchrony BT - three examples JF - European physical journal special topics N2 - Partial synchronous states appear between full synchrony and asynchrony and exhibit many interesting properties. Most frequently, these states are studied within the framework of phase approximation. The latter is used ubiquitously to analyze coupled oscillatory systems. Typically, the phase dynamics description is obtained in the weak coupling limit, i.e., in the first-order in the coupling strength. The extension beyond the first-order represents an unsolved problem and is an active area of research. In this paper, three partially synchronous states are investigated and presented in order of increasing complexity. First, the usage of the phase response curve for the description of macroscopic oscillators is analyzed. To achieve this, the response of the mean-field oscillations in a model of all-to-all coupled limit-cycle oscillators to pulse stimulation is measured. The next part treats a two-group Kuramoto model, where the interaction of one attractive and one repulsive group results in an interesting solitary state, situated between full synchrony and self-consistent partial synchrony. In the last part, the phase dynamics of a relatively simple system of three Stuart-Landau oscillators are extended beyond the weak coupling limit. The resulting model contains triplet terms in the high-order phase approximation, though the structural connections are only pairwise. Finally, the scaling of the new terms with the coupling is analyzed. Y1 - 2021 U6 - https://doi.org/10.1140/epjs/s11734-021-00156-3 SN - 1951-6355 SN - 1951-6401 VL - 230 IS - 14-15 SP - 2833 EP - 2842 PB - Springer CY - Heidelberg ER -