Subtle and Ineffable Tree Properties

In the style of the tree property, we give combinatorial principles that capture the concepts of the so-called subtle and ineffable cardinals in such a way that they are also applicable to small cardinals. Building upon these principles we then develop a further one that even achieves this for supercompactness. We show the consistency of these principles starting from the corresponding large cardinals. Furthermore we show the equiconsistency for subtle and ineffable. For supercompactness, utilizing the failure of square we prove that the best currently known lower bounds for consistency strength in general can be applied. The main result of the thesis is the theorem that the Proper Forcing Axiom implies the principle corresponding to supercompactness.In Anlehnung an die Baumeigenschaft geben wir kombinatorische Prinzipien an, die die Konzepte der sogenannten subtle und ineffable Kardinalzahlen so einfangen, dass diese auch für kleine Kardinalzahlen anwendbar sind. Auf diesen Prinzipien aufbauend entwickeln wir dann ein weiteres, das dies sogar für superkompakte Kardinalzahlen leistet. Wir zeigen die Konsistenz dieser Prinzipien ausgehend von den jeweils entsprechenden großen Kardinalzahlen. Zudem zeigen wir die Äquikonsistenz für subtle und ineffable. Für Superkompaktheit beweisen wir durch das Fehlschlagen des Quadratprinzips, dass die besten derzeit bekannten unteren Schranken für Konsistenzstärke anwendbar sind. Das Hauptresultat der Arbeit ist das Ergebnis, dass das Proper Forcing Axiom das der Superkompaktheit entsprechende Prinzip impliziert

Was bringt eine geänderte Ertragskompetenz bei der Einkommensteuer? Eine Replik

In der Aprilausgabe 2014 veröffentlichte der Wirtschaftsdienst einen Aufsatz mit dem Titel Neuordnung der Besteuerungskompetenzen bei der Einkommensteuer. Die Autoren des vorliegenden Beitrags setzen sich kritisch damit auseinander, im Anschluss erläutern Gisela Färber, Carsten Kühl und Denis Alt ihren Standpunkt in einer Erwiderung.The Reply: The reform proposal would complicate the rules for sharing income tax revenues. The measures proposed are not compatible with the rules set out in the German Federal Constitution and the relevant decisions of the Constitutional Court. The states would lose tax revenues, whereas the federal government would gain them. As to individual states, the financially strong ones would be the losers, despite the fact that economic strength and fi nancial strength should be signifi cantly related. The Response: Future fi scal equalisation in Germany requires not only a new equalisation formula but also a fairer, more equal, broader and more transparent tax base for states and local governments. If necessary, changes to the Federal Constitution should be undertaken to achieve a more equal vertical assignment of tax powers. The actual reform discussion should not be a confrontation between rich and poor states but should lead to a fi nancial constitution by 2020 which can be unanimously approved by all of the German states

Modeling and System Identification of a Variable Excited Linear Direct Drive

Linear actuators are deployed in a wide range of applications. This paper presents the modeling and system identification of a variable excited linear direct drive (LDD). The LDD is designed based on linear hybrid stepper technology exhibiting the characteristic tooth structure of mover and stator. A three-phase topology provides the thrust force caused by alternating strengthening and weakening of the flux of the legs. To achieve best possible synchronous operation, the phases are commutated sinusoidal. Despite the fact that these LDDs provide high dynamics and drive forces, noise emission limits their operation in calm workspaces. To overcome this drawback an additional excitation of the magnetic circuit is introduced to LDD using additional enabling coils instead of permanent magnets. The new degree of freedom can be used to reduce force variations and related noise by varying the excitation flux that is usually generated by permanent magnets. Hence, an identified simulation model is necessary to analyze the effects of this modification. Especially the force variations must be modeled well in order to reduce them sufficiently. The model can be divided into three parts: the current dynamics, the mechanics and the force functions. These subsystems are described with differential equations or nonlinear analytic functions, respectively. Ordinary nonlinear differential equations are derived and transformed into state space representation. Experiments have been carried out on a test rig to identify the system parameters of the complete model. Static and dynamic simulation based optimizations are utilized for identification. The results are verified in time and frequency domain. Finally, the identified model provides a basis for later design of control strategies to reduce existing force variations

A guideline on how to recruit respondents for online surveys using Facebook and Instagram: Using hard-to-reach health workers as an example (Version 1.0)

Social Networking Sites (SNS) offer survey scientists a relatively new tool to recruit participants, especially among otherwise hard-to-reach populations. Facebook and Instagram, in particular, allow the distribution of advertisements to specific subsets of their users at low cost. Researchers can use such targeted advertisements to guide participants to their online questionnaires. In recent years, an increasing number of studies have shown that this approach can be successfully applied to a range of different target groups. However, a certain familiarity with the tools and mechanisms provided by Meta is necessary to employ this sampling method. Therefore, in this guideline, we will first give a general introduction to sampling via advertisements on Facebook and Instagram before providing detailed instructions on the implementation of such a recruitment campaign. This will be followed by a brief summary of a recent study conducted by GESIS using Meta's platforms to recruit professionals in the German health care sector. Finally, we provide recommendations with respect to the reporting of methodological parameters when using this approach, propose a flowchart to visualize sample sizes at different points during the recruitment process and offer a glossary containing definitions of essential terms researchers are confronted with when using Meta's advertisement interface.Soziale Netzwerkseiten (SNS) stellen eine vergleichsweise neue Möglichkeit dar, Teilnehmende für wissenschaftliche Befragungsprojekte zu rekrutieren. Besonderes Potential hat der Ansatz mit Blick auf die Rekrutierung anderweitig schwer erreichbarer Zielgruppen. So ermöglichen Facebook und Instagram die Schaltung kostengünstiger Werbung für genau definierte Teilgruppen der Nutzenden dieser Netzwerke. Entsprechende Werbunganzeigen können von Forschenden genutzt werden, um ausgewählte Personen zu ihren Onlinefragebögen zu leiten. In den letzten Jahren hat eine wachsende Zahl von Studien gezeigt, dass dieser Ansatz erfolgreich auf eine Reihe unterschiedlicher Zielgruppen angewendet werden kann. Allerdings ist eine gewisse Vertrautheit mit den von Meta bereitgestellten Instrumenten und Mechanismen erforderlich, um dieses Verfahren anzuwenden. Daher bieten wir in dieser Guideline zunächst eine allgemeine Einführung in das Sampling über Werbeanzeigen auf Facebook und Instagram, bevor wir eine detaillierte Anleitung für die Durchführung einer solchen Rekrutierungskampagne geben. Danach folgt eine kurze Zusammenfassung einer kürzlich von GESIS durchgeführten Studie, bei der die Meta-Plattformen zur Rekrutierung von Fachkräften aus dem deutschen Gesundheitswesen genutzt wurden. Abschließend geben wir Empfehlungen dazu, welche Parameter in Publikationen berichtet werden sollten, um die Vergleichbarkeit der Ergebnisse zu gewährleisten. Mit diesem Ziel stellen wir auch ein Flussdiagramm zur Visualisierung der Stichprobengrößen zu verschiedenen Zeitpunkten des Rekrutierungsprozesses zur Verfügung. Schließlich fassen wir in einem Glossar Definitionen wesentlicher Parameter zusammen, mit denen Forscher bei der Verwendung von Metas Werbeschnittstelle konfrontiert werden

Load prediction of hingeless helicopter rotors including drivetrain dynamics

Structural couplings between the flexible main rotor and the flexible drivetrain of the Bo105 helicopter are investigated by numerical simulation. For this purpose, the rotor hub constraint Omega = const. is dropped and a drivetrain model, consisting of discrete inertia elements and intermediate flexible elements, is connected to the hub. By use of the multibody-software SIMPACK, the coupled rotor-drivetrain system is linearized and the eigenmodes are compared to those obtained with a constrained rotor hub. The drivetrain has a significant influence on the shapes and eigenfrequencies of the collective lead-lag modes. While the first collective lead-lag eigenfrequency is raised by the finite drivetrain inertia, the second is lowered due to drivetrain flexibility. To assess the influence of modeling inaccuracies on the observed couplings, the study is complemented by a sensitivity analysis. Rotor blade mass axis offset, blade pitch (causing elastic coupling) and blade precone angle have only weak influence on the coupled modes. In contrast, variations of drivetrain inertia and stiffness strongly affect the eigenfrequencies of the coupled rotor-drivetrain modes

Scheduling a Proportionate Flow Shop of Batching Machines

In this paper we study a proportionate flow shop of batching machines with release dates and a fixed number $m \geq 2$ of machines. The scheduling problem has so far barely received any attention in the literature, but recently its importance has increased significantly, due to applications in the industrial scaling of modern bio-medicine production processes. We show that for any fixed number of machines, the makespan and the sum of completion times can be minimized in polynomial time. Furthermore, we show that the obtained algorithm can also be used to minimize the weighted total completion time, maximum lateness, total tardiness and (weighted) number of late jobs in polynomial time if all release dates are $0$. Previously, polynomial time algorithms have only been known for two machines.Comment: Version 2: replace initial preprint with authors' accepted manuscrip

How German health workers’ views on vaccine safety can be swayed by the AstraZeneca controversy

Several COVID-19 vaccines are now licensed, and the success of a rollout often depends on people’s willingness to accept any of them. Health workers are in a unique position to influence the public. Jan Priebe (German Institute for Global and Area Studies), Henning Silber, Christoph Beuthner, Steffen Pötzschke, Bernd Weiß, and Jessica Daikeler (GESIS – Leibniz Institute for the Social Sciences) show how their recommendations change when they are given different types of information about vaccines