206 research outputs found

    LIMO: Lidar-Monocular Visual Odometry

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    Higher level functionality in autonomous driving depends strongly on a precise motion estimate of the vehicle. Powerful algorithms have been developed. However, their great majority focuses on either binocular imagery or pure LIDAR measurements. The promising combination of camera and LIDAR for visual localization has mostly been unattended. In this work we fill this gap, by proposing a depth extraction algorithm from LIDAR measurements for camera feature tracks and estimating motion by robustified keyframe based Bundle Adjustment. Semantic labeling is used for outlier rejection and weighting of vegetation landmarks. The capability of this sensor combination is demonstrated on the competitive KITTI dataset, achieving a placement among the top 15. The code is released to the community.Comment: Accepted at IROS 201

    Extraction of routing relevant geodata using telemetry sensor data of agricultural vehicles

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    The mechanization of processes in agriculture is growing within the last hundred years. Within the last decades, the information technology in this sector constantly grew and data is one of the key factors for process optimization. For planning and execution of logistic processes and harvest campaigns, road maps and field geometries are essential to guide the large vehicles to their work places and to optimize harvest chains. Through nowadays available telemetry data of these vehicles, a new data source generates new opportunities. Mining geographic data from these movement data, that can improve agricultural work processes is one of the main objectives of this thesis. As a first step, data cleaning processes, and further preprocessing steps are shown. With classification algorithms, the continuous movement data will be separated into different work processes. Based on this data, algorithms to generate geographic geographic features, such as field boundaries have been analyzed and improved. As quality metric to compare the results, the Jaccard-Distance has been established. With the classified road representing measurements, the rural road networks were created and the results of different algorithmic approaches have been compared. The usability of volunteered geographic information to route the heterogeneous set of agricultural vehicles is shown in a third step. Due to the fact, that routes for e.g. harvesters are not ending at the field boundary, solutions for infield route graph generation have been given. The presented components provide the content and the services within a framework structure. The concluding prototype, a web based routing system demonstrates the interaction of all components and provides a consecutive routing from farm to field and within the field

    Continuous fusion of motion data using an axis-angle rotation representation with uniform B-spline

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    The fusion of motion data is key in the fields of robotic and automated driving. Most existing approaches are filter-based or pose-graph-based. By using filter-based approaches, parameters should be set very carefully and the motion data can usually only be fused in a time forward direction. Pose-graph-based approaches can fuse data in time forward and backward directions. However, pre-integration is needed by applying measurements from inertial measurement units. Additionally, both approaches only provide discrete fusion results. In this work, we address this problem and present a uniform B-spline-based continuous fusion approach, which can fuse motion measurements from an inertial measurement unit and pose data from other localization systems robustly, accurately and efficiently. In our continuous fusion approach, an axis-angle is applied as our rotation representation method and uniform B-spline as the back-end optimization base. Evaluation results performed on the real world data show that our approach provides accurate, robust and continuous fusion results, which again supports our continuous fusion concept

    Atomic Force Microscopy-Based Screening of Drug-Excipient Miscibility and Stability of Solid Dispersions

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    ABSTRACT: Purpose: Development of a method to assess the drug/polymer miscibility and stability of solid dispersions using a melt-based mixing method. Methods: Amorphous fractured films are prepared and characterized with Raman Microscopy in combination with Atomic Force Microscopy to discriminate between homogenously and heterogeneously mixed drug/polymer combinations. The homogenous combinations are analyzed further for physical stability under stress conditions, such as increased humidity or temperature. Results: Combinations that have the potential to form a molecular disperse mixture are identified. Their potential to phase separate is determined through imaging at molecular length scales, which results in short observation time. De-mixing is quantified by phase separation analysis, and the drug/polymer combinations are ranked to identify the most stable combinations. Conclusions: The presented results demonstrate that drug/polymer miscibility and stability of solid dispersions, with many mechanistic details, can be analyzed with Atomic Force Microscopy. The assay allows to identify well-miscible and stable combinations within hours or a few day

    Sign of inverse spin Hall voltages generated by ferromagnetic resonance and temperature gradients in yttrium iron garnet|platinum bilayers

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    We carried out a concerted effort to determine the absolute sign of the inverse spin Hall effect voltage generated by spin currents injected into a normal metal. We focus on yttrium iron garnet (YIG)|platinum bilayers at room temperature, generating spin currents by microwaves and temperature gradients. We find consistent results for different samples and measurement setups that agree with theory. We suggest a right-hand-rule to define a positive spin Hall angle corresponding to with the voltage expected for the simple case of scattering of free electrons from repulsive Coulomb charges.Comment: incorporated additions from the published versio

    Wie Unternehmen des Baugewerbes die Corona-Krise bewerten

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    Die wirtschaftliche Situation der Unternehmen stellt sich im Baugewerbe besser dar als in den anderen Industrien. Gleichzeitig haben die Unternehmen des Baugewerbes weniger staatliche Maßnahmen in Anspruch genommen. Zur Kompensation der Mehrbelastung greifen die meisten von ihnen auf eine Reduktion von Löhnen und Boni zurück. Innerhalb des Baugewerbes werden zwischen Ausbau- und Bauhauptgewerbe starke Unterschiede in der krisenbedingten Belastung deutlich. Dies betrifft die Erwartungen zur Umsatzentwicklung sowie die Inanspruchnahme staatlicher Maßnahmen

    Atomic Force Microscopy-Based Screening of Drug-Excipient Miscibility and Stability of Solid Dispersions

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    PURPOSE: Development of a method to assess the drug/polymer miscibility and stability of solid dispersions using a melt-based mixing method. METHODS: Amorphous fractured films are prepared and characterized with Raman Microscopy in combination with Atomic Force Microscopy to discriminate between homogenously and heterogeneously mixed drug/polymer combinations. The homogenous combinations are analyzed further for physical stability under stress conditions, such as increased humidity or temperature. RESULTS: Combinations that have the potential to form a molecular disperse mixture are identified. Their potential to phase separate is determined through imaging at molecular length scales, which results in short observation time. De-mixing is quantified by phase separation analysis, and the drug/polymer combinations are ranked to identify the most stable combinations. CONCLUSIONS: The presented results demonstrate that drug/polymer miscibility and stability of solid dispersions, with many mechanistic details, can be analyzed with Atomic Force Microscopy. The assay allows to identify well-miscible and stable combinations within hours or a few days

    Infrared Radiofluorescence (IR-RF) of K-Feldspar:An Interlaboratory Comparison

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    Infrared Radiofluorescence (IR-RF) is a relatively new method for dosimetric dating of the depositional timing of sediments. This contribution presents an interlaboratory comparison of IR-RF measurements of sedimentary feldspar from eight laboratories. A comparison of the variability of instrumental background, bleaching, saturation, and initial rise behaviour of the IR-RF signal was carried out. Two endmember samples, a naturally bleached modern dune sand sample with a zero dose and a naturally saturated sample from a Triassic sandstone (~250 Ma), were used for this interlaboratory comparison. The major findings of this study are that (1) the observed IR-RF signal keeps decreasing beyond 4000 Gy, (2) the saturated sample gives an apparent palaeodose of 1265 ± 329 Gy and (3) in most cases, the natural IR-RF signal of the modern analogue sample (resulting from natural bleaching) is higher than the signal from laboratory-induced bleaching of 6 h, using a solar simulator (SLS). In other words, the laboratory sample bleaching was unable to achieve the level of natural bleaching. The results of the investigations are discussed in detail, along with possible explanations

    Infrared radiofluorescence (IR-RF) dating:A review

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    International audienceLuminescence dating methods on natural minerals such as quartz and feldspars are indispensable for establishing chronologies in Quaternary Science. Commonly applied sediment dating methods are optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). In 1999, Trautmann et al. (1999a, b) proposed a new related technique called infrared radiofluorescence (IR-RF). IR-RF denotes the infrared luminescence signal of feldspar resulting from exposure to ionizing radiation and potentially offers a significant methodological advance compared to OSL and IRSL regarding luminescence signal stability, dating range and required measurement time. The method has rarely been applied due to a lack of commercially available measurement equipment but experienced a revival during the last years. The present article provides a state-of-the-art overview of the physical background of IR-RF, its challenges, applications and the potential as a dating method. The paper particularly addresses practical considerations for applying IR-RF dating, including signal bleachability and saturation behaviour, and summarizes proposed solutions

    Hypoxia drives glucose transporter 3 expression through HIF-mediated induction of the long non-coding RNA NICI

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    Hypoxia inducible transcription factors (HIFs) directly dictate the expression of multiple RNA species including novel and as yet uncharacterized long non-coding transcripts with unknown function. We used pan-genomic HIF-binding and transcriptomic data to identify a novel long non-coding RNA NICI (Non-coding Intergenic Co-Induced transcript) on chromosome 12p13.31 which is regulated by hypoxia via HIF-1 promoter-binding in multiple cell types. CRISPR/Cas9-mediated deletion of the hypoxia-response element revealed co-regulation of NICI and the neighboring protein-coding gene, solute carrier family 2 member 3 (SLC2A3) which encodes the high-affinity glucose transporter 3 (GLUT3). Knock-down or knock-out of NICI attenuated hypoxic induction of SLC2A3 indicating a direct regulatory role of NICI in SLC2A3 expression, which was further evidenced by CRISPR/Cas9-VPR mediated activation of NICI expression. We also demonstrate that regulation of SLC2A3 is mediated through transcriptional activation rather than post-transcriptional mechanisms since knock-out of NICI leads to reduced recruitment of RNA polymerase 2 to the SLC2A3 promoter. Consistent with this we observe NICI-dependent regulation of glucose consumption and cell proliferation. Furthermore, NICI expression is regulated by the VHL tumour suppressor and is highly expressed in clear cell renal cancer, where SLC2A3 expression is associated with patient prognosis, implying an important role for the HIF/NICI/SLC2A3 axis in this malignancy
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