Deep-learning continuous gravitational waves : Multiple detectors and realistic noise

The sensitivity of wide-parameter-space searches for continuous gravitational waves is limited by computational cost. Recently it was shown that deep neural networks (DNNs) can perform all-sky searches directly on (single-detector) strain data [C. Dreissigacker, Phys. Rev. D 100, 044009 (2019)PRVDAQ2470-001010.1103/PhysRevD.100.044009], potentially providing a low-computing-cost search method that could lead to a better overall sensitivity. Here we expand on this study in two respects: (i) using (simulated) strain data from two detectors simultaneously, and (ii) training for directed (i.e., single sky-position) searches in addition to all-sky searches. For a data time span of T=105 s, the all-sky two-detector DNN is about 7% less sensitive (in amplitude h0) at low frequency (f=20 Hz), and about 51% less sensitive at high frequency (f=1000 Hz) compared to fully-coherent matched-filtering (using weave). In the directed case the sensitivity gap compared to matched-filtering ranges from about 7%-14% at f=20 Hz to about 37%-49% at f=1500 Hz. Furthermore we assess the DNN's ability to generalize in signal frequency, spin down and sky-position, and we test its robustness to realistic data conditions, namely gaps in the data and using real LIGO detector noise. We find that the DNN performance is not adversely affected by gaps in the test data or by using a relatively undisturbed band of LIGO detector data instead of Gaussian noise. However, when using a more disturbed LIGO band for the tests, the DNN's detection performance is substantially degraded due to the increase in false alarms, as expected. © 2020 authors

Autonomous weapon systems. TAB-Fokus

Robotic weapons systems that can select and engage targets without any human intervention are standing on the edge of being tangibly implemented. Proponents of this development expect decisive military and possibly even humanitarian benefits from such autonomous weapons systems. Critics, however, raise concerns over whether it would be ethically justifiable, politically responsible and legally allowed in compliance with (international) law to delegate the decision on the life and death of human beings to machines. Moreover, the development and possible use of AWS might entail some risks with regard to security policy. Within the framework of the TA project a broad analytical approach has been followed and a wide range of aspects regarding the topic have been examined. TAB\u27s policy brief in English TAB-Fokus no. 26 summarizes the key results of the TA project and provides an overview of technological developments, security policy implications, ethical arguments and issues in humanitarian law

Adjuvante Therapie von arterieller Hypertonie durch hochfrequentes Blutdruckbiofeedback

Introduction: A lack of studies on the effects of continuous blood pressure biofeedback lead to the development of screening and feedback software enabling a “beat-to-beat” representation of arterial blood pressure. With this method patients discover that they are able to influence their own blood pressure. Patients and methods: For evaluation purposes a pilot study was conducted with 84 hypertensive patients of the Clinic Höhenried in Bavaria. Two experimental groups which received the normal treatment program of the clinic and an additional two (N = 20 Ss) or three to six (N = 22 Ss) biofeedback sessions respectively were compared with a control group treated additionally by pseudo biofeedback (N = 20 Ss) and another control group (N = 22 Ss) which only underwent the clinic program without biofeedback. Results: Both experimental groups achieved a significantly higher blood pressure lowering (MAP) than the controls (p = .001), but subjects treated by three to six feedback sessions did not perform significantly better than those treated by only two sessions (p = .517). Conclusions: Even two sessions of feedback treatment can have clinically relevant effects suggesting a great influence of cognitive processes such as self effectiveness and self-control.Hintergrund: Der Mangel an praxisnahen Studien zur Wirksamkeit von kontinuierlichem Blutdruckbiofeedback führte zur Entwicklung und Erprobung einer Aufzeichnungs- und Feedbacksoftware, die eine beat-to-beat Darstellung des arteriellen Blutdrucks auf einem Computermonitor ermöglicht. In Biofeedbacksitzungen mit diesem System machen Hochdruckpatienten die Erfahrung, dass sie über eigene Ressourcen für eine klinisch relevante Blutdrucksenkung verfügen. Patienten und Methoden: Zur Evaluation des Verfahrens wurde an der Klinik Höhenried am Starnberger See/Obb. eine Pilotstudie mit 84 stationären Hypertoniepatienten durchgeführt. Zwei Experimentalgruppen, die das normale Heilbehandlungsprogramm der Klinik und zusätzlich zwei (N = 20 Pbn) bzw. drei bis sechs (N = 22 Pbn) jeweils 30minütige Biofeedbackbehandlungen erhielten, wurden mit zwei Kontrollgruppen verglichen (N = 20 Pbn mit Pseudobiofeedback und N = 22 Pbn, die nur das Klinikprogramm durchliefen). Ergebnisse: Aus den mittels Armmanschette gemessenen RR-Werten wurden bei allen Gruppen die Durchschnittswerte des medizinischen Mitteldrucks (MAP) in der ersten und in der Entlassungswoche berechnet und ein Differenzwert gebildet. Beide Versuchsgruppen erzielten signifikant höhere Senkungen des MAP als die Kontrollgruppen (p = .001), allerdings schnitt die Versuchsgruppe mit drei bis sechs Feedbacksitzungen nicht signifikant besser ab als die Gruppe mit nur zwei Sitzungen (p = .517). Schlussfolgerungen: Schon eine zweimalige Behandlung mit hochfrequentem Biofeedback kann bereits klinisch relevante Effekte haben, was Hinweise auf einen erheblichen Einfluss von kognitiven Prozessen wie Selbstwirksamkeit und Selbstkontrolle liefert

Kinetic Investigation of Polyurethane Rubber Formation from CO2‐Containing Polyols

A novel CO2 utilization technology allows for the inclusion of CO2 as carbonate units and double bond moieties to give additional functionality in polyether polyols. This study examines the chain‐elongation kinetics of these diols with diisocyanates to polyurethane rubbers by means of thermal analysis. A reaction order of 1 indicates a strong influence of the chains' mobility on the reaction rate. Spectrometry and comparison with non‐double‐bond polyols reveal that the effect cannot be attributed to a substantial occurrence of side reactions but is rather due to the intertwining of lengthy chains.BMBF, 033R350A‐D, Production DreamsTU Berlin, Open-Access-Mittel - 202

Economic Feasibility of Semi-Underground Pumped Storage Hydropower Plants in Open-Pit Mines

This work aims at the economic evaluation of a semi-underground pumped hydro storage power plant erected in an abandoned open-pit mine. For the exploratory model-based analysis, we develop and apply both a simple deterministic and a stochastic net present value (NPV) approach, the latter of which uses a Monte Carlo simulation to account for revenue uncertainty from electricity price fluctuations. The analytical framework developed is applied to two promising sites in the Rheinland region in Germany, Hambach and Inden, making reasonable parameter value assumptions and considering and ignoring the lengthy duration of lower reservoir flooding. The investor’s value-at-risk is computed for alternative performance indicators (NPV, net cash recovery, profit-to-investment ratio, and specific production costs) to compare the different outcomes in terms of the project’s financial risk distribution. Calculations show that a semi-underground pumped hydro storage power plant in an abandoned open-pit mine can be constructed at reasonably low investment costs and operated at low specific production costs. However, because the investment has to be made long before the pit lake is (naturally) flooded—a process that for realistic flow rates may take up to 20 years—the project is highly uneconomical and would require substantial subsidies, as compared to a situation where flooding happens immediately

Discrete event simulation for the purpose of real-time performance evaluation of distributed hardware-in-the-loop simulators for autonomous driving vehicle validation

Hardware-in-the-loop test benches are distributed computer systems including software, hardware and networking devices, which require strict real-time guarantees. To guarantee strict real-time of the simulator the performance needs to be evaluated. To evaluate the timing performance a discrete event simulation model is built up. The input modeling is based on measurements from the real system in a prototype phase. The results of the simulation model are validated with measurements from a prototype of the real system. The workload is increased until the streaming source becomes unstable, by either exceeding a certain limit of bytes or exceeding the number of parallel software processes running on the cores of the central processing unit. To evaluate the performance beyond these limits, the discrete event simulation model needs to be enriched by a scheduler and a hardware model. To provide real-time guarantees an analytical model needs to be built up

Implementation of Quantum Key Distribution with Composable Security Against Coherent Attacks using Einstein-Podolsky-Rosen Entanglement

Secret communication over public channels is one of the central pillars of a modern information society. Using quantum key distribution (QKD) this is achieved without relying on the hardness of mathematical problems which might be compromised by improved algorithms or by future quantum computers. State-of-the-art QKD requires composable security against coherent attacks for a finite number of samples. Here, we present the first implementation of QKD satisfying this requirement and additionally achieving security which is independent of any possible flaws in the implementation of the receiver. By distributing strongly Einstein-Podolsky-Rosen entangled continuous variable (CV) light in a table-top arrangement, we generated secret keys using a highly efficient error reconciliation algorithm. Since CV encoding is compatible with conventional optical communication technology, we consider our work to be a major promotion for commercialized QKD providing composable security against the most general channel attacks.Comment: 7 pages, 3 figure