579 research outputs found

    Generating Compact Geometric Track-Maps for Train Positioning Applications

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    In this paper, we present a method to generate compact geometric track-maps for train-borne localization applications. Therefore, we first give a brief overview on the purpose of track maps in train-positioning applications. It becomes apparent that there are hardly any adequate methods to generate suitable geometric track-maps. This is why we present a novel map generation procedure. It uses an optimization formulation to find the continuous sequence of track geometries that fits the available measurement data best. The optimization is initialized with the results from a localization filter developed in our previous work. The localization filter also provides the required information for shape identification and measurement association. The presented approach will be evaluated on simulated data as well as on real measurements

    Increasing Accuracy in Train Localization Exploiting Track-Geometry Constraints

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    Train-borne localization systems as a key component of future signalling systems are expected to offer huge economic and operational advances for the railway transportation sector. However, the reliable provision of a track-selective and constantly available location information is still unsolved and prevents the introduction of such systems so far. A contribution to overcome this issue is presented here. We show a recursive multistage filtering approach with an increased cross-track positioning accuracy, which is decisive to ensure track-selectivity. This is achieved by exploiting track-geometry constraints known in advance, as there are strict rules for the construction of railway tracks. Additionally, compact geometric track-maps can be extracted during the filtering process which are beneficial for existing train localization approaches. The filter was derived applying approximate Bayesian inference. The geometry constraints are directly incorporated in the filter design, utilizing an interacting multiple model (IMM) filter and extended Kalman filters (EKF). Throughout simulations the performance of the filter is analyzed and discussed thereafter

    Weak antilocalization and disorder-enhanced electron interactions in crystalline GeSbTe

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    Phase change materials can be reversibly switched between amorphous and crystalline states and often show strong contrast in the optical and electrical properties of these two phases. They are now in widespread use for optical data storage, and their fast switching and a pronounced change of resistivity upon crystallization are also very attractive for nonvolatile electronic data storage. Nevertheless there are still several open questions regarding the electronic states and charge transport in these compounds. In this work we study electrical transport in thin metallic films of the disordered, crystalline phase change material Ge1_1Sb2_2Te4_4. We observe weak antilocalization and disorder enhanced Coulomb interaction effects at low temperatures, and separate the contributions of these two phenomena to the temperature dependence of the resistivity, Hall effect, and magnetoresistance. Strong spin-orbit scattering causes positive magnetoresistance at all temperatures, and a careful analysis of the low-field magnetoresistance allows us to extract the temperature dependent electron dephasing rate and study other scattering phenomena. We find electron dephasing due to inelastic electron-phonon scattering at higher temperatures, electron-electron scattering dephasing at intermediate temperatures, and a crossover to weak temperature dependence below 1 K

    Generating Compact Geometric Track-Maps for Train Positioning Applications

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    In this paper, we present a method to generate compact geometric track-maps for train-borne localization applications. Therefore, we first give a brief overview on the purpose of track maps in train-positioning applications. It becomes apparent that there are hardly any adequate methods to generate suitable geometric track-maps. This is why we present a novel map generation procedure. It uses an optimization formulation to find the continuous sequence of track geometries that fits the available measurement data best. The optimization is initialized with the results from a localization filter [1] developed in our previous work. The localization filter also provides the required information for shape identification and measurement association. The presented approach will be evaluated on simulated data as well as on real measurements

    Arteriolar vasoconstrictive response: comparing the effects of arginine vasopressin and norepinephrine

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    INTRODUCTION: This study was designed to examine differences in the arteriolar vasoconstrictive response between arginine vasopressin (AVP) and norepinephrine (NE) on the microcirculatory level in the hamster window chamber model in unanesthetized, normotonic hamsters using intravital microscopy. It is known from patients with advanced vasodilatory shock that AVP exerts strong additional vasoconstriction when incremental dosage increases of NE have no further effect on mean arterial blood pressure (MAP). METHODS: In a prospective controlled experimental study, eleven awake, male golden Syrian hamsters were instrumented with a viewing window inserted into the dorsal skinfold. NE (2 μg/kg/minute) and AVP (0.0001 IU/kg/minute, equivalent to 4 IU/h in a 70 kg patient) were continuously infused to achieve a similar increase in MAP. According to their position within the arteriolar network, arterioles were grouped into five types: A0 (branch off small artery) to A4 (branch off A3 arteriole). RESULTS: Reduction of arteriolar diameter (NE, -31 ± 12% versus AVP, -49 ± 7%; p = 0.002), cross sectional area (NE, -49 ± 17% versus AVP, -73 ± 7%; p = 0.002), and arteriolar blood flow (NE, -62 ± 13% versus AVP, -80 ± 6%; p = 0.004) in A0 arterioles was significantly more pronounced in AVP animals. There was no difference in red blood cell velocities in A0 arterioles between groups. The reduction of diameter, cross sectional area, red blood cell velocity, and arteriolar blood flow in A1 to A4 arterioles was comparable in AVP and NE animals. CONCLUSION: Within the microvascular network, AVP exerted significantly stronger vasoconstriction on large A0 arterioles than NE under physiological conditions. This observation may partly explain why AVP is such a potent vasopressor hormone and can increase systemic vascular resistance even in advanced vasodilatory shock unresponsive to increases in standard catecholamine therapy

    Система мониторинга и учета энергоресурсов

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    Система предназначена для автоматизации процесса получения объективных данных о фактическом потреблении энергоресурсов на объектах жилищного и нежилого фондов с использованием домовых и/или квартирных приборов учета.The system is designed to automate the process of obtaining objective data on the actual consumption of energy resources on the objects of housing and non-residential funds using house and / or apartment accounting devices
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