2,558 research outputs found

    The magnetic reversal in dot arrays recognized by the self-organized adaptive neural network

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    The remagnetization dynamics of monolayer dot array superlattice XY 2-D spin model with dipole-dipole interactions is simulated. Within the proposed model of array, the square dots are described by the spatially modulated exchange-couplings. The dipole-dipole interactions are approximated by the hierarchical sums and spin dynamics is considered in regime of the Landau-Lifshitz equation. The simulation of reversal for 4000040 000 spins exhibits formation of nonuniform intra-dot configurations with nonlinear wave/anti-wave pairs developed at intra-dot and inter-dot scales. Several geometric and parametric dependences are calculated and compared with oversimplified four-spin model of reversal. The role of initial conditions and the occurrence of coherent rotation mode is also investigated. The emphasis is on the classification of intra-dot or inter-dot (interfacial) magnetic configurations done by adaptive neural network with varying number of neurons.Comment: 16 figure

    Federated User Clustering for non-IID Federated Learning

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    Federated Learning (FL) is one of the leading learning paradigms for enabling a more significant presence of intelligent applications in networking considering highly distributed environments while preserving user privacy.However, FL has the significant shortcoming of requiring user data to be Independent Identically Distributed (IID) to make reliable predictions for a given group of users.We present a Neural Network-based Federated Clustering mechanism capable of clustering the local models trained by users of the network with no access to their raw data.We also present an alternative to the FedAvg aggregation algorithm used in traditional FL, which significantly increases the aggregated models' reliability in Mean Square Error by creating several training models over IID users

    Threading Granules in Freiburg : 2nd International Symposium on "One Mitochondrion, Many Diseases – Biological and Molecular Perspectives", a FRIAS Junior Researcher Conference, Freiburg im Breisgau, Germany, March 9th/10th, 2016

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    Altered mitochondrial activities play an important role in many different human disorders, including cancer and neurodegeneration. At the Freiburg Institute of Advanced Studies (FRIAS) Junior Researcher Conference “One Mitochondrion, Many Diseases – Biological and Molecular Perspectives” (University of Freiburg, Freiburg, Germany), junior and experienced researches discussed common and distinct mechanisms of mitochondrial contributions to various human disorders

    Diagnostic accuracy of inflammatory back pain for axial spondyloarthritis in rheumatological care

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    Objective: Inflammatory back pain (IBP), the key symptom of axial spondyloarthritis (axSpA), including ankylosing spondylitis, has been proposed as a screening test for patients presenting with chronic back pain in primary care. The diagnostic accuracy of IBP in the rheumatology setting is unknown. Methods: Six rheumatology centres, representing secondary and tertiary rheumatology care, included routinely referred patients with consecutive chronic back pain with suspicion of axSpA. IBP (diagnostic test) was assessed in each centre by an independent (blinded) rheumatologist; a second (unblinded) rheumatologist made the diagnosis (axSpA or no-axSpA), which served as reference standard. Results: Of 461 routinely referred patients, 403 received a final diagnosis. IBP was present in 67.3%, and 44.6% (180/403) were diagnosed as axSpA. The sensitivity of IBP according to various definitions (global judgement, Calin, Berlin, Assessment of SpondyloArthritis international Society criteria for IBP) was 74.4%-81.1 % and comparable to published figures, whereas the specificity was unexpectedly low (25.1%-43.9%). The resulting positive likelihood ratios (LR+) were 1.1-1.4 and without major differences between sets of IBP criteria. The presence of IBP according to various definitions increased the probability of axSpA by 2.5%-8.4% only (from 44.6% to 47.1%-53.0%). Conclusions: The diagnostic utility of IBP in the rheumatology setting was smaller than expected. However, this was counterbalanced by a high prevalence of IBP among referred patients, demonstrating the effective usage of IBP in primary care as selection parameter for referral to rheumatology. Notably, this study illustrates potential shifts in specificity and LR+ of diagnostic tests if these tests are used to select patients for referral

    Coherent Interaction of Spins Induced by Thermal Bosonic Environment

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    We obtain and analyze the indirect exchange interaction between two two-state systems, e.g., spins, in a formulation that also incorporates the quantum noise that they experience, due to a bosonic environment, for instance, phonons. We utilize a perturbative approach to obtain a quantum evolution equation for the two-spin dynamics. A non-perturbative approach is used to study the onset of the induced interaction, which is calculated exactly. We predict that for low enough temperatures the interaction is coherent over time scales sufficient to create entanglement, dominated by the zero-point quantum fluctuations of the environment. We identify the time scales for which the spins develop entanglement for various spatial separations.Comment: 10 pages, 3 figures; typos correcte

    SMaRT-OnlineWDN: A Franco-German Project For The Online Security Management Of Water Distribution Networks

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    Water Distribution Networks (WDNs) are critical infrastructures that are exposed to deliberate or accidental chemical, biological or radioactive contamination which need to be detected in due time. However, until now, no monitoring system is capable of protecting a WDN in real time. Powerful online sensor systems are currently developed and the prototypes are able to detect a small change in water quality. In the immediate future, water service utilities will install their networks with water quantity and water quality sensors. For taking appropriate decisions and countermeasures, WDN operators will need to dispose of: 1) a fast and reliable detection of abnormal events in the WDNs; 2) reliable online models both for the hydraulics and water quality predictions; 3) methods for contaminant source identification backtracking from the data history. Actually, in general none of these issues (1) – (3) are available at the water suppliers. Consequently, the main objective of the project SMaRT-OnlineWDN is the development of an online security management toolkit for WDNs that is based on sensor measurements of water quality as well as water quantity. Its main innovations are the detection of abnormal events with a binary classifier of high accuracy and the generation of real-time, reliable (i) flow and pressure predictions, (ii) water quality indicator predictions of the whole water network. Detailed information regarding contamination sources (localization and intensity) will be explored by means of the online running model, which is automatically calibrated to the measured sensor data. Its field of application ranges from the detection of deliberate contamination including source identification and decision support for effective countermeasures to improved operation and control of a WDN under normal and abnormal conditions (dual benefit).In this project, the technical research work is completed with a sociological, economical and management analysis

    Long-term efficacy and safety of secukinumab 150 mg in ankylosing spondylitis : 5-year results from the phase III MEASURE 1 extension study

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    Objective: This study aimed to report end-of-study results on efficacy and safety of secukinumab 150 mg through 5 years in patients with ankylosing spondylitis (AS; MEASURE 1 extension trial (NCT01863732)). Methods: After the 2-year core trial, 274 patients receiving subcutaneous secukinumab 150 or 75 mg (following intravenous loading or initial placebo treatment to 16/24 weeks) every 4 weeks were invited to enter the 3-year extension study. Dose escalation from 75 to 150 mg (approved dose) was allowed at or after week 156 based on the judgement of the treating physician. Assessments at week 260 (5 years) included Assessment of SpondyloArthritis international Society (ASAS) 20/40 and other efficacy outcomes. Data are presented as observed. Safety assessment included all patients who received >= 1 dose of study treatment. Results: Of the 274 patients who entered the extension study, 84% (230/274) completed 5 years of treatment. ASAS20/40 responses were 78.6/65.2%, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) 50 response was 63.4% and mean (+/- SD) BASDAI total score was 2.6 +/- 1.76 with secukinumab 150 mg at 5 years. Improvements in efficacy outcomes were sustained through 5 years. A total of 82 patients on secukinumab 75 mg (56.2%) had their dose escalated to 150 mg after week 168; ASAS40, ASAS-PR, ASAS 5/6 and BASDAI50 responses were improved in patients whose dose was escalated from secukinumab 75 to 150 mg. Secukinumab was well tolerated with a safety profile consistent over the course of the study. Conclusions: Secukinumab 150 mg provided sustained efficacy across multiple domains of AS with a favourable and consistent safety profile through 5-year treatment. Over 50% of patients required dose escalation from 75 to 150 mg and efficacy improved in these patients

    Five-Brane Superpotentials and Heterotic/F-theory Duality

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    Under heterotic/F-theory duality it was argued that a wide class of heterotic five-branes is mapped into the geometry of an F-theory compactification manifold. In four-dimensional compactifications this identifies a five-brane wrapped on a curve in the base of an elliptically fibered Calabi-Yau threefold with a specific F-theory Calabi-Yau fourfold containing the blow-up of the five-brane curve. We argue that this duality can be reformulated by first constructing a non-Calabi-Yau heterotic threefold by blowing up the curve of the five-brane into a divisor with five-brane flux. Employing heterotic/F-theory duality this leads us to the construction of a Calabi-Yau fourfold and four-form flux. Moreover, we obtain an explicit map between the five-brane superpotential and an F-theory flux superpotential. The map of the open-closed deformation problem of a five-brane in a compact Calabi-Yau threefold into a deformation problem of complex structures on a dual Calabi-Yau fourfold with four-form flux provides a powerful tool to explicitly compute the five-brane superpotential.Comment: 43 pages, v2: minor correction
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