1,843 research outputs found

    The highD Dataset: A Drone Dataset of Naturalistic Vehicle Trajectories on German Highways for Validation of Highly Automated Driving Systems

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    Scenario-based testing for the safety validation of highly automated vehicles is a promising approach that is being examined in research and industry. This approach heavily relies on data from real-world scenarios to derive the necessary scenario information for testing. Measurement data should be collected at a reasonable effort, contain naturalistic behavior of road users and include all data relevant for a description of the identified scenarios in sufficient quality. However, the current measurement methods fail to meet at least one of the requirements. Thus, we propose a novel method to measure data from an aerial perspective for scenario-based validation fulfilling the mentioned requirements. Furthermore, we provide a large-scale naturalistic vehicle trajectory dataset from German highways called highD. We evaluate the data in terms of quantity, variety and contained scenarios. Our dataset consists of 16.5 hours of measurements from six locations with 110 000 vehicles, a total driven distance of 45 000 km and 5600 recorded complete lane changes. The highD dataset is available online at: http://www.highD-dataset.comComment: IEEE International Conference on Intelligent Transportation Systems (ITSC) 201

    Development of a regional-scale library of near infrared reflectance soil spectra for alternative assessment of soil characteristics in Southern Belgium

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    In Walloon Region (Southern Belgium), five routine soil laboratories are grouped within a network promoting a better quality in analysis (www.requasud.be). The harmonization of protocols as well as methodological or technical prospective are realized under scientifically supervision of our research laboratory. In this context, a study was conducted to evaluate the ability of the NIRS to predict some soil properties: CEC, TOC, TN and clay content. The initial models were elaborated upon local PLS regression on set of 1 300 soil samples. The local PLS calibration used allows an accurate prediction of the soil properties and precision of NIRS technique is comparable to reference analytical metho

    Valorisation de la Carte des Sols dans un cadre inattendu - Le tourisme à caractère scientifique

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    Patrimoine géologique et pédologique en Province de Namur - 500 millions d'années de façonnement de notre paysag

    A high signal to noise ratio map of the Sunyaev-Zel'dovich increment at 1.1 mm wavelength in Abell 1835

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    We present an analysis of an 8 arcminute diameter map of the area around the galaxy cluster Abell 1835 from jiggle map observations at a wavelength of 1.1 mm using the Bolometric Camera (Bolocam) mounted on the Caltech Submillimeter Observatory (CSO). The data is well described by a model including an extended Sunyaev-Zel'dovich (SZ) signal from the cluster gas plus emission from two bright background submm galaxies magnified by the gravitational lensing of the cluster. The best-fit values for the central Compton value for the cluster and the fluxes of the two main point sources in the field: SMM J140104+0252, and SMM J14009+0252 are found to be y0=(4.34±0.52±0.69)×10−4y_{0}=(4.34\pm0.52\pm0.69)\times10^{-4}, 6.5±2.0±0.7\pm{2.0}\pm0.7 mJy and 11.3±1.9±1.1\pm{1.9}\pm1.1 mJy, where the first error represents the statistical measurement error and the second error represents the estimated systematic error in the result. This measurement assumes the presence of dust emission from the cluster's central cD galaxy of 1.8±0.51.8\pm0.5 mJy, based on higher frequency observations of Abell 1835. The cluster image represents one of the highest-significance SZ detections of a cluster in the positive region of the thermal SZ spectrum to date. The inferred central intensity is compared to other SZ measurements of Abell 1835 and this collection of results is used to obtain values for y0=(3.60±0.24)×10−4y_{0} = (3.60\pm0.24)\times10^{-4} and the cluster peculiar velocity vz=−226±275v_{z} = -226\pm275 km/s.Comment: 9 pages, 5 figure

    Characterisation of Herschel-SPIRE flight model optical performances

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    The Spectral and Photometric Imaging Receiver (SPIRE) is one of three scientific instruments on ESA's Herschel Space Observatory. This long wavelength instrument covers 200 to 670μm with a three band photometric camera and a two band imaging Fourier Transform Spectrometer (IFTS). Following first results reported in a previous paper, we discuss the in-band optical performances of the flight model as measured extensively during several dedicated test campaigns. Complementary to the experimentally probed spectral characteristics of the instrument detailed in an accompanying paper (see L.D. Spencer et al., in these proceedings), attention is focused here on a set of standard but key tests aimed at measuring the spatial response of the Photometer and Spectrometer end-to-end optical chain, including detector. Effects of defocus as well as source size extent, in-band wavelength, and polarization are also investigated over respective Photometer and Spectrometer field-of-views. Comparison with optical modelling, based on instrument design knowledge and some of the internal component measured characteristics, is performed. Beyond the specific characterisation of each effect, this allows estimating in each band where optical behaviour and detector behaviour respectively dominates and also reconstructing some of the contributors to the instrument throughput. Based on this analysis, retrieved optical performances are finally assessed against the related science-driven instrument requirements

    How can long-term experimental plots can help us to understand the sustainability of different phosphorus inputs ?

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    During the last twenty years, we observed a constant reduction of mineral fertilizer use, due to prices increase and environmental awareness, and an increase of crop removal, leading to a phosphorus (P) budget decrease. These changes are feared for a decrease of soil P content, which is already observed in some regions in Wallonia. However, P being an essential element for plant growth, is a such management compatible with yield maintaining? Are the current cropping systems sustainable? To answer to the questions, different studies are made. However, long-term data are rarely available to understand the influence of cropping systems on the soil behavior, leaching risks or to choose adequate indicators of P. To answer to these questions in our soils, 2 experimental plots of the Walloon Agricultural Research Center. These experimental plots were established in 1967 and 1959 in order to evaluate the effect of, respectively, 3 P and K input levels and different organic inputs on the production. Soils samples were taken in plots and analyzed in laboratory. So, different P indicators and edaphic parameters were determined. This study showed that all indicators are coherent with P levels and correlated with yields but no many differences can be shown between fertilizer types. Meanly, zero P-input engenders a decrease of yield of 7%, while a double input increases yield of 2% in comparison to plots with an input corresponding to crop export. So, financially, the zero P-input option is rarely profitable in the long-term and double input of P removed is never financially sustainable. Leaching into deeper soils levels was studied with analysis of deeper horizons which indicated any leaching , even in plots with double inputs. Indeed, soil P contents in depth were similar in these plots than those with no P-inputs or soils under forest cover. So, to conclude, these plots help to study the sustainability of cropping systems in real situations and to determine appropriate management of P
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