225 research outputs found

    Where do bicyclists interact with other road users?: Delineating potential risk zones in HD-maps.

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    International crash statistics indicate a decrease of bicycle crashes, but at a slower pace compared to total crash numbers. The share of crashes with involved cyclists is above the modal share (see [1] for an overview). Depending on sources, types of analyses, and geographic regions, crash statistics suggest high rates of singlebike crashes and crashes between cyclists and other vulnerable road users (VRUs) [2], while cars are opponents in more than half of all fatal crashes in the European Union [3]. The design of th.e road environment is of particular relevance for crash risks. A study from London found three times higher injury odds for cyclists at intersections [4]. Connected and automated vehicles (CAV) are frequently said to increase the safety level in road traffic since they are less prone to human errors [5]. This might hold true in transport systems with little complexity, such as highways [6]. However, when it comes to complex situations in multimodal systems with multiple interactions between different road users, such as intersections in urban environments, existing solutions are not sufficient yet in terms of protecting VRUs. ... In order to contribute to the safety of VRUs in the interplay with CAVs in current systems, we propose a geospatial model, which delineates potential interaction risk zones from high definition (HD) maps and enriching these zones with additional information. These enriched risk zones are then provided as standardized OGC web service, which can be integrated in V2X systems. With this, we contribute to the visibility, and thus the safety of VRUs in connected transport systems. From a methodological point of view, the proposed model is a first step in integrating spatial context and semantic information explicitly into V2X communication. [From: Introduction

    Urban Emotions and Cycling Experience – Enriching Traffic Planning for Cyclists with Human Sensor Data

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    Even though much research has been conducted on the safety of cycling infrastructures, most previous approaches only make use of traditional and proven methods based upon datasets such as accident statistics, road infrastructure data, or questionnaires. Apart from typical surveys, which are known to face numerous limitations from a psychological and sociological viewpoints, the question of how perceived safety can best be assessed is still widely unexplored. Thus, this paper presents an approach for bio-physiological sensing to identify places in urban environments which are perceived as unsafe by cyclists. Specifically, a number of physiological parameters like ECG, skin conductance, skin temperature and heart rate variability are analysed to identify moments of stress. Together with data gathered through a People as Sensors app, these stress levels can be mapped to specific emotions. This method was tested in a pilot study in Cambridge, MA (USA), which is presented in this paper. Our findings show that our method can identify places with emotional peaks, particularly fear and anger. Although our results can be qualitatively interpreted and used in urban planning, more research is necessary to quantitatively and automatically generate recommendations from the measurements for urban planners

    Mysteries of supercooled water elucidated by studies of aqueous solutions

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    The most abundant form of water in the universe probably is its supercooled state, staying non-crystalline down to lowest temperatures. The many peculiarities of liquid water, like its partly negative thermal expansion, have been traced back to prominent anomalies occurring in its supercooled form - especially under elevated pressure - and to the presence of two variants of supercooled water and of amorphous, glassy ice. However, the bare existence of these different liquid states and of a related liquid-liquid crossover at ambient pressure are controversially debated since decades, just as the absolute value of water's glass-transition temperature. Their direct experimental detection is hampered by the inevitable crystallization of pure water in a certain temperature range, termed "no-man's land". To tackle these problems, we have applied dielectric spectroscopy and differential scanning calorimetry to aqueous LiCl solutions. By covering a frequency range of up to 14 decades and by quenching some of the solutions to avoid crystallization, here we show that there are indeed strong hints at two forms of water, occurring in different temperature ranges and having different glass-transition temperatures, even at ambient pressure: A so-called "fragile" liquid, characterized by super-Arrhenius temperature dependence of the molecular dynamics at high temperatures, and a "strong" liquid, nearly following Arrhenius behaviour, at low temperatures.Comment: 7 pages, 4 figures + Supplementary Information (9 pages, 7 figures

    Magnetic Microcalorimeters for Primary Activity Standardization Within the EMPIR Project PrimA-LTD

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    The precision of existing decay data of radionuclides for activity determination is often a limitation for actual applications in science, society and industry. For this reason, the EMPIR project PrimA-LTD aims to introduce an advanced primary activity standardization technique that is based on magnetic microcalorimeters (MMCs) and that will offer very low energy threshold of few eV and a decay scheme-independent detection efficiency close to 100 %. As a proof of concept, we developed two MMC-based detector types in order to standardize an -decaying, a -decaying and an electron capture decaying isotope. One detector type aims to introduce a reusable detector setup, while the other aims to provide highly accurate decay spectra by high-resolution measurements with high statistics. We present the designs, fabrication status and first characterization measurements of both detectors types and outline next steps

    Phonon-Metamorphosis in Ferromagnetic Manganite Films: Probing the Evolution of an Inhomogeneous State

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    The analysis of phonon anomalies provides valuable information about the cooperative dynamics of lattice, spin and charge degrees of freedom. Significant is the anomalous temperature dependence of the external modes observed in La2/3_{2/3}Sr1/3_{1/3}MnO3_{3} (LSMO) films. The two external modes merge close to the ferromagnetic to paramagnetic transition at TCT_C and, moreover, two new modes evolve in this temperature range with strong resonances at slightly higher frequencies. We propose that this observed phonon metamorphosis probes the inhomogeneous Jahn-Teller distortion, manifest on the temperature scale TCT_C. The analysis is based on the first observation of all eight phonon modes in the metallic phase of LSMO and on susceptibility measurements which identify a Griffiths-like phase.Comment: 4 pages, 4 figure

    Safety / Mapping Bicycle Crash Risk Patterns on the Local Scale

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    Currently, mainly aggregated statistics are used for bicycle crash risk calculations. Thus, the understanding of spatial patterns at local scale levels remains vague. Using an agent-based flow model and a bicycle crash database covering 10 continuous years of observation allows us to calculate and map the crash risk on various spatial scales for the city of Salzburg (Austria). In doing so, we directly account for the spatial heterogeneity of crash occurrences. Additionally, we provide a measure for the statistical robustness on the level of single reference units and consider modifiable areal unit problem (MAUP) effects in our analysis. This study is the first of its kind. The results facilitate a better understanding of spatial patterns of bicycle crash rates on the local scale. This is especially important for cities that strive to improve the safety situation for bicyclists in order to address prevailing safety concerns that keep people from using the bicycle as a utilitarian mode of (urban) transport.(VLID)166373
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