Interaction effects in a microscopic quantum wire model with strong spin-orbit interaction

We investigate the effect of strong interactions on the spectral properties of quantum wires with strong Rashba spin-orbit interaction in a magnetic field, using a combination of Matrix Product State and bosonization techniques. Quantum wires with strong Rashba spin-orbit interaction and magnetic field exhibit a partial gap in one-half of the conducting modes. Such systems have attracted wide-spread experimental and theoretical attention due to their unusual physical properties, among which are spin-dependent transport, or a topological superconducting phase when under the proximity effect of an s-wave superconductor. As a microscopic model for the quantum wire we study an extended Hubbard model with spin-orbit interaction and Zeeman field. We obtain spin resolved spectral densities from the real-time evolution of excitations, and calculate the phase diagram. We find that interactions increase the pseudo gap at $k = 0$ and thus also enhance the Majorana-supporting phase and stabilize the helical spin order. Furthermore, we calculate the optical conductivity and compare it with the low energy spiral Luttinger Liquid result, obtained from field theoretical calculations. With interactions, the optical conductivity is dominated by an excotic excitation of a bound soliton-antisoliton pair known as a breather state. We visualize the oscillating motion of the breather state, which could provide the route to their experimental detection in e.g. cold atom experiments

Controlling a Vacuum Suction Cup Cluster using Simulation-Trained Reinforcement Learning Agents

Using compressed air in industrial processes is often accompanied by a poor cost-benefit ratio and a negative impact on the environmental footprint due to usual distribution inefficiencies. Compressed air-based systems are expensive regarding installation and lead to high running costs due to pricey maintenance requirements and low energy efficiency due to leakage. However, compressed air-based systems are indispensable for various industrial processes, like handling parts with Class A surface requirements such as outer skin sheets in automobile production. Most of those outer skin parts are solely handled by vacuum-based grippers to minimize any visible effect on the finished car. Fulfilling customer expectations and simultaneously reducing the running costs of decisive systems requires finding innovative strategies focused on using the precious resource of compressed air as efficiently as possible. This work presents a sim2real reinforcement learning approach to efficiently hold a workpiece attached to a vacuum suction cup cluster. In addition to pure energy-saving, reinforcement learning enables those agents to be trained without collecting extensive data beforehand. Furthermore, the sim2real approach makes it easy and parallelizable to examine numerous agents by training them in a simulation of the testing rig rather than at the testing rig itself. The possibility to train various agents fast additionally facilitates focusing on the robustness and simplicity of the found agents instead of only searching for strategies that work, making training an intelligent system scalable and effective. The resulting agents reduce the amount of energy necessary to hold the workpiece attached by more than 15% compared to a reference strategy without machine learning and by more than 99% compared to a conventional strategy

Trendumkehr in der Fertilitätsentwicklung von ausgewählten südeuropäischen Staaten (Griechenland, Italien, Portugal und Spanien)?

Diese Diplomarbeit, mit dem Thema „Trendumkehr in der Fertilitätsentwicklung von ausgewählten südeuropäischen Staaten?“ geht zunächst auf grundlegende Aspekte, wie die in der Arbeit verwendeten Maßzahlen sowie verschiedene Einflussfaktoren, in Bezug auf Fertilität ein und stellt außerdem die vier südeuropäischen Untersuchungsländer Griechenland, Italien, Portugal und Spanien vor. Dabei wird auf die Bevölkerungsentwicklung und -struktur – hier zeigen sich allgemeine Zuwächse, vor allem durch Migration bedingt, sowie eine künftig zu erwartende Überalterung – eingegangen, es werden die Regionen innerhalb der Staaten veranschaulicht und auch gesellschaftlichen Rahmenbedingungen – zum Beispiel die Familienstrukturen sowie das Bildungsniveau – in Bezug auf Fertilität werden untersucht. Anschließend wird die Fertilitätsentwicklung Südeuropas in der jüngeren Vergangenheit unter die Lupe genommen und dabei auf Perioden- sowie Kohortenfertilität, absolute Anzahl an Geburten nach Rangfolge, Kinderlosigkeit und das mittlere Gebäralter eingegangen. Es werden erhebliche Differenzen, vor allem zwischen Portugal und den drei restlichen Untersuchungsländern, aber auch zu EU-Staaten aus anderen Regionen, verdeutlicht. Außerdem werden die ideale Kinderzahl für Südeuropäer sowie Prognosen für die zukünftige Fertilitätsentwicklung beleuchtet und die Ergebnisse lassen eine Steigerung der Geburtenzahlen vermuten. Als mögliche Gründe für die in der jüngeren Vergangenheit zu beobachtende Fertilitätsentwicklung Südeuropas, werden Verzerrungen der TFR aufgrund des „Tempo-Effekts“, die Bedeutung von internationaler Migration, wirtschaftliche Aspekte, staatliche Eingriffe sowie sonstige Gründe wie der Anstieg von Frauenerwerbstätigkeit und außerehelicher Geburten analysiert. Dabei zeigt sich, dass die Einflussfaktoren in den einzelnen Untersuchungsländern in unterschiedlich starkem Zusammenhang mit der jeweiligen Fertilitätsentwicklung stehen. Im abschließenden Resümee kommt man zu dem Schluss, dass in den südeuropäischen Staaten durchaus von einer „Trendumkehr“ in der Fertilitätsentwicklung gesprochen werden kann, wobei, hinsichtlich zeitlichem Eintreten dieser, zwischen Portugal und den drei übrigen Untersuchungsländern differenziert werden muss

Evaluating a patient's request for life-prolonging treatment: an ethical framework

Contrary to the widespread concern about over-treatment at the end of life, today, patient preferences for palliative care at the end of life are frequently respected. However, ethically challenging situations in the current healthcare climate are, instead, situations in which a competent patient requests active treatment with the goal of life-prolongation while the physician suggests best supportive care only. The argument of futility has often been used to justify unilateral decisions made by physicians to withhold or withdraw life-sustaining treatment. However, we argue that neither the concept of futility nor that of patient autonomy alone is apt for resolving situations in which physicians are confronted with patients' requests for active treatment. Instead, we integrate the relevant arguments that have been put forward in the academic discussion about 'futile' treatment into an ethical algorithm with five guiding questions: (1) Is there a chance that medical intervention will be effective in achieving the patient's treatment goal? (2) How does the physician evaluate the expected benefit and the potential harm of the treatment? (3) Does the patient understand his or her medical situation? (4) Does the patient prefer receiving treatment after evaluating the benefit-harm ratio and the costs? (5) Does the treatment require many resources? This algorithm shall facilitate approaching patients' requests for treatments deemed futile by the physician in a systematic way, and responding to these requests in an ethically appropriate manner. It thereby adds substantive considerations to the current procedural approaches of conflict resolution in order to improve decision making among physicians, patients and families

Soft gamma-ray galactic ridge emission as unveiled by SPI aboard INTEGRAL

The origin of the soft gamma-ray (200 keV - 1 MeV) galactic ridge emission is one of the long-standing mysteries in the field of high-energy astrophysics. Population studies at lower energies have shown that emission from accreting compact objects gradually recedes in this domain, leaving place to another source of gamma-ray emission that is characterised by a hard power-law spectrum extending from 100 keV up to 100 MeV The nature of this hard component has remained so far elusive, partly due to the lack of sufficiently sensitive imaging telescopes that would be able to unveil the spatial distribution of the emission. The SPI telescope aboard INTEGRAL allows now for the first time the simultaneous imaging of diffuse and point-like emission in the soft gamma-ray regime. We present here all-sky images of the soft gamma-ray continuum emission that clearly reveal the morphology of the different emission components. We discuss the implications of our results on the nature of underlying emission processes and we put our results in perspective of GLAST studies of diffuse galactic continuum emission

Combined automotive safety and security pattern engineering approach

Automotive systems will exhibit increased levels of automation as well as ever tighter integration with other vehicles, traffic infrastructure, and cloud services. From safety perspective, this can be perceived as boon or bane - it greatly increases complexity and uncertainty, but at the same time opens up new opportunities for realizing innovative safety functions. Moreover, cybersecurity becomes important as additional concern because attacks are now much more likely and severe. However, there is a lack of experience with security concerns in context of safety engineering in general and in automotive safety departments in particular. To address this problem, we propose a systematic pattern-based approach that interlinks safety and security patterns and provides guidance with respect to selection and combination of both types of patterns in context of system engineering. A combined safety and security pattern engineering workflow is proposed to provide systematic guidance to support non-expert engineers based on best practices. The application of the approach is shown and demonstrated by an automotive case study and different use case scenarios.EC/H2020/692474/EU/Architecture-driven, Multi-concern and Seamless Assurance and Certification of Cyber-Physical Systems/AMASSEC/H2020/737422/EU/Secure COnnected Trustable Things/SCOTTEC/H2020/732242/EU/Dependability Engineering Innovation for CPS - DEIS/DEISBMBF, 01IS16043, Collaborative Embedded Systems (CrESt