75 research outputs found

    Towards long term monitoring of electrodermal activity in daily life

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    Manic depression, also known as bipolar disorder, is a common and severe form of mental disorder. The European research project MONARCA aims at developing and validating mobile technologies for multi-parametric, long term monitoring of physiological and behavioral information relevant to bipolar disorder. One aspect of MONARCA is to investigate the long term monitoring of Electrodermal activity (EDA) to support the diagnosis and treatment of bipolar disorder patients. EDA is known as an indicator of the emotional state and the stress level of a person. To realize a long-term monitoring of the EDA, the integration of the sensor system in the shoe or sock is a promising approach. This paper presents a first step towards such a sensor system. In a feasibility study including 8 subjects, we investigate the correlation between EDA measurements at the fingers, which is the most established sensing site, with measurements of the EDA at the feet. The results indicate that 88% of the evoked skin conductance responses (SCRs) occur at both sensing sites. When using an action movie as psychophysiologically activating stimulus, we have found weaker reactivity in the foot than in the hand EDA. The results also suggest that the influence of moderate physical activity on EDA measurements is low and has a similar effect for both recording sites. This suggests that the foot recording location is suitable for recordings in daily life even in the presence of moderate movemen

    Unobtrusive physiological monitoring in an airplane seat

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    Air travel has become the preferred mode of long-distance transportation for most of the world's travelers. People of every age group and health status are traveling by airplane and thus the airplane has become part of our environment, in which people with health-related limitations need assistive support. Since the main interaction point between a passenger and the airplane is the seat, this work presents a smart airplane seat for measuring health-related signals of a passenger. We describe the design, implementation and testing of a multimodal sensor system integrated into the seat. The presented system is able to measure physiological signals, such as electrocardiogram, electrodermal activity, skin temperature, and respiration. We show how the design of the smart seat system is influenced by the trade-off between comfort and signal quality, i.e. incorporating unobtrusive sensors and dealing with erroneous signals. Artifact detection through sensor fusion is presented and the working principle is shown with a feasibility study, in which normal passenger activities were performed. Based on the presented method, we are able to identify signal regions in which the accuracies for detecting the heart- and respiration-rate are 88 and 82%, respectively, compared to 40 and 76% without any artifact remova

    Automatisierte Optimierung und Strukturierung von OCR-Ergebnissen mit nachnutzbaren Werkzeugen

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    Bibliotheken leisten einen wichtigen Beitrag zur Digitalisierung des kulturellen Erbes und ermöglichen Forschenden weltweit den Zugang zu diesen Werken. Textbasierte Dokumente werden häufig zusätzlich durch OCR (optical character recognition) erschlossen. Dies ermöglicht eine Suche nach Stichwörtern im gesamten Inhalt sowie weitere Analysemöglichkeiten. Vielen Bibliotheken fehlt es jedoch an Know-how und Werkzeugen, um optimale OCR-Ergebnisse zu erzielen oder weitere Strukturerkennungsschritte selbstständig auszuführen. Im Zuge des DFG-finanzierten Digitalisierungsprojekts "Aktienführer-Datenarchiv II" wurden mehrere softwaretechnische Werkzeuge entwickelt, um in einem einheitlichen Workflow sowohl den Umgang mit den OCR-Daten zu vereinfachen als auch die Ergebnisse zu optimieren. Unter anderem werden dabei die OCR-Ergebnisse durch die Kombination der Ausgaben mehrerer OCR-Engines verbessert und eine Strukturerfassung im Volltext, inklusive Tabellenextraktion, vorgenommen.In diesem Beitrag werden die entwickelten Lösungsansätze und Tools vorgestellt. Um sie für ähnliche Projekte nachnutzbar und anpassbar zu machen, sind alle Tools als Open-Source-Software verfügbar

    Nuclear excitation of the 229^{229}Th isomer via defect states in doped crystals

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    When Th nuclei are doped in CaF2_2 crystals, a set of electronic defect states appears in the crystal bandgap which would otherwise provide complete transparency to vacuum-ultraviolet radiation. The coupling of these defect states to the 8 eV 229m^{229m}Th nuclear isomer in the CaF2_2 crystal is investigated theoretically. We show that although previously viewed as a nuisance, the defect states provide a starting point for nuclear excitation via electronic bridge mechanisms involving stimulated emission or absorption using an optical laser. The rates of these processes are at least two orders of magnitude larger than direct photoexcitation of the isomeric state using available light sources. The nuclear isomer population can also undergo quenching when triggered by the reverse mechanism, leading to a fast and controlled decay via the electronic shell. These findings are relevant for a possible solid-state nuclear clock based on the 229m^{229m}Th isomeric transition

    Coordinated activation of VEGFR-1 and VEGFR-2 is a potent arteriogenic stimulus leading to enhancement of regional perfusion

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    Objective: The process of arteriogenesis is driven by various growth factors including vascular endothelial growth factor (VEGF)-A, which mediates its activity through VEGFR-2 (Flk-1/KDR) on endothelial cells and through VEGFR-1 (Flt-1) on endothelial cells and monocytes. The purpose of this study was to identify which of the VEGF receptors are involved in arteriogenesis in vivo. Methods: Collateral vessel growth was induced by femoral artery ligation in a mouse model of hindlimb ischemia. Following ligation, Balb/c mice were treated with different growth factors (VEGF-A, VEGF-E, PlGF-2, VEGF-E plus PlGF-2 or VEGF-A plus PlGF-2, activating either VEGFR-1, VEGFR-2, or both). After 1 week of treatment, hindlimb perfusion was assessed by perfusion scintigraphy using Tc-99m-MIBI. Results: The strongest improvement of regional perfusion was achieved by simultaneous activation of VEGFR-1 and VEGFR-2, using either VEGF-A or VEGF-A plus PlGF-2, with elevation of relative perfusion in the ischemic limbs from 0.61 to 0.83. The partial restoration in perfusion was associated with morphological changes typical for arteriogenesis. Moreover, specific inhibition of both VEGF-receptors using ZK 202650 resulted in a significant inhibition of arteriogenesis, indicating an active role of the VEGF system in compensatory arteriogenesis. Conclusion: The coordinated activation of both VEGFR-1 and VEGFR-2 represents a more potent arteriogenic stimulus compared to the isolated activation of either one of these two receptors. These data imply that the activation of both monocytes and endothelial cells is necessary to obtain a maximal VEGF-induced activation of arteriogenesi

    Driven electronic bridge processes via defect states in 229^{229}Th-doped crystals

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    The electronic defect states resulting from doping 229^{229}Th in CaF2_2 offer a unique opportunity to excite the nuclear isomeric state 229m^{229m}Th at approximately 8 eV via electronic bridge mechanisms. We consider bridge schemes involving stimulated emission and absorption using an optical laser. The role of different multipole contributions, both for the emitted or absorbed photon and nuclear transition, to the total bridge rates are investigated theoretically. We show that the electric dipole component is dominant for the electronic bridge photon. In contradistinction, the electric quadrupole channel of the 229^{229}Th isomeric transition plays the dominant role for the bridge processes presented. The driven bridge rates are discussed in the context of background signals in the crystal environment and of implementation methods. We show that inverse electronic bridge processes quenching the isomeric state population can improve the performance of a solid-state nuclear clock based on 229m^{229m}Th

    An automatic parameter extraction method for the 7x50m Stroke Efficiency Test

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    We developed an automatic method to extract the parameters of the 7 x 50m Stroke Eficiency Test for swimming based on a wrist worn acceleration sensor device. In the wrist acceleration signal we detect characteristic swim events such as wall push-offs, wall-strikes and strokes. Based on this information we compute the distance per stroke and the swimming velocity. The upper error bounds of our automatic method are 1.67% for the velocity and 1.33% for the time per stroke. The velocity measurement accuracy is of comparable order to the manual accuracy. The automatic method clearly outperforms the manual measurement for the time per stroke extraction

    PyPSA-Earth. A New Global Open Energy System Optimization Model Demonstrated in Africa

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    Macro-energy system modelling is used by decision-makers to steer the global energy transition toward an affordable, sustainable and reliable future. Closed-source models are the current standard for most policy and industry decisions. However, open models have proven to be competitive alternatives that promote science, robust technical analysis, collaboration and transparent policy decision-making. Yet, two issues slow the adoption: open models are often designed with limited geographic scope, hindering synergies from collaboration, or are based on low spatially resolved data, limiting their use. Here we introduce PyPSA-Earth, the first open-source global energy system model with data in high spatial and temporal resolution. It enables large-scale collaboration by providing a tool that can model the world energy system or any subset of it. This work is derived from the European PyPSA-Eur model using new data and functions. It is suitable for operational as well as combined generation, storage and transmission expansion studies. The model provides two main features: (1) customizable data extraction and preparation scripts with global coverage and (2) a PyPSA energy modelling framework integration. The data includes electricity demand, generation and medium to high-voltage networks from open sources, yet additional data can be further integrated. A broad range of clustering and grid meshing strategies help adapt the model to computational and practical needs. A data validation for the entire African continent is performed and the optimization features are tested with a 2060 net-zero planning study for Nigeria. The demonstration shows that the presented developments can build a highly detailed energy system model for energy planning studies to support policy and technical decision-making. We welcome joining forces to address the challenges of the energy transition together.Comment: 36 pages, 14 figures, 3 table
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