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Interprets an early engraving by Albretcht Durer, the 'Promenade,' circa 1498. Themes held in common with the 'Dances of Death' in Spreuerbrucke at Luzerne, Switzerland; Range of diverse sources and themes; Intentional ambiguities to create a composition which resists attempts to fix meaning precisely.

Hail is a major threat associated with severe thunderstorms, and estimating the hail size is important for issuing warnings to the public. For the validation of existing operational, radar-derived hail estimates, ground-based observations are necessary. Automatic hail sensors, for example within the Swiss Hail Network, record the kinetic energy of hailstones to estimate the hail sizes. Due to the small size of the observational area of these sensors (0.2 m2), the full hail size distribution (HSD) cannot be retrieved. To address this issue, we apply a state-of-the-art custom trained deep learning object detection model to drone-based aerial photogrammetric data to identify hailstones and estimate the HSD. Photogrammetric data of hail on the ground were collected for one supercell thunderstorm crossing central Switzerland from southwest to northeast in the afternoon of 20 June 2021. The hail swath of this intense right-moving supercell was intercepted a few minutes after the passage at a soccer field near Entlebuch (canton of Lucerne, Switzerland) and aerial images were taken by a commercial DJI drone, equipped with a 45 -megapixel full-frame camera system. The resulting images have a ground sampling distance (GSD) of 1.5 mm per pixel, defined by the focal length of 35 mm of the camera and a flight altitude of 12 m above the ground. A 2-dimensional orthomosaic model of the survey area (750.4 m2) is created based on 116 captured images during the first drone mapping flight. Hail is then detected using a region-based convolutional neural network (Mask R-CNN). We first characterize the hail sizes based on the individual hail segmentation masks resulting from the model detections and investigate the performance using manual hail annotations by experts to generate validation and test data sets. The final HSD, composed of 18 207 hailstones, is compared with nearby automatic hail sensor observations, the operational weather-radar-based hail product MESHS (Maximum Expected Severe Hail Size) and crowdsourced hail reports. Based on the retrieved data set, a statistical assessment of sampling errors of hail sensors is carried out. Furthermore, five repetitions of the drone-based photogrammetry mission within 18.65 min facilitate investigations into the hail-melting process on the ground. [ABSTRACT FROM AUTHOR]

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This paper analyses interactions between a host of a Swiss mountain destination and her guests. The conversations take place in a scenic gondola. The analysis is conducted in the format of an ethnographic case study and focuses on the interactants' speech style. The case study constitutes a part of a larger, applied and interdisciplinary project of the Business School of the University of Applied Sciences of Lucerne. The aim of the main project is to specify what could be defined as "hospitality" in a touristic context and to develop tools to enhance hospitality at touristic destinations in Central Switzerland. The aim of the present ethnographic case study is to analyse interactions between hosts and their guests. It seeks to find communicative elements which let the guests perceive an interaction as hospitable and to discuss if generic features of a "hospitable speech style" may be identified. [ABSTRACT FROM AUTHOR]

Copyright of Praehistorische Zeitschrift is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)