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  • Copernicus GmbH  (7)
  • 2020-2024  (7)
  • 1
    Online Resource
    Online Resource
    Copernicus GmbH ; 2020
    In:  Earth System Science Data Vol. 12, No. 4 ( 2020-12-23), p. 3641-3652
    In: Earth System Science Data, Copernicus GmbH, Vol. 12, No. 4 ( 2020-12-23), p. 3641-3652
    Abstract: Abstract. Strontium isotope ratios (87Sr ∕ 86Sr) of biogenic material such as bones and teeth reflect the local sources of strontium ingested as food and drink during their formation. This has led to the use of strontium isotope ratios as a geochemical tracer in a wide range of fields including archaeology, ecology, food studies and forensic sciences. In order to utilise strontium as a geochemical tracer, baseline data of bioavailable 87Sr ∕ 86Sr in the region of interest are required, and a growing number of studies have developed reference maps for this purpose in various geographic regions, and over varying scales. This study presents a new data set of bioavailable strontium isotope ratios from rock and soil samples across Israel, as well as from sediment layers from seven key archaeological sites. This data set may be viewed and accessed both in an Open Science Framework repository (https://doi.org/10.17605/OSF.IO/XKJ5Y, Moffat et al., 2020) or via the IRHUM (Isotopic Reconstruction of Human Migration) database.
    Type of Medium: Online Resource
    ISSN: 1866-3516
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2020
    detail.hit.zdb_id: 2475469-9
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  • 2
    Online Resource
    Online Resource
    Copernicus GmbH ; 2020
    In:  The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences Vol. XLIII-B2-2020 ( 2020-08-12), p. 977-984
    In: The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Copernicus GmbH, Vol. XLIII-B2-2020 ( 2020-08-12), p. 977-984
    Abstract: Abstract. Systematic errors may result from the adoption of an incomplete functional model that is not able to properly incorporate all the effects involved in the image formation process. These errors very likely appear as systematic residual patterns in image observations and produce deformations of the photogrammetric model in object space. The Brown/Beyer model of self-calibration is often adopted in underwater photogrammetry, although it does not take into account the refraction introduced by the passage of the optical ray through different media, i.e. air and water. This reduces the potential accuracy of photogrammetry underwater. In this work, we investigate through simulations the depth-dependent systematic errors introduced by unmodelled refraction effects when both flat and dome ports are used. The importance of camera geometry to reduce the deformation in the object space is analyzed and mitigation measures to reduce the systematic patterns in image observations are investigated. It is shown how, for flat ports, the use of a stochastic approach, consisting in radial weighting of image observations, improves the accuracy in object space up to 50%. Iterative look-up table corrections are instead adopted to reduce the evident systematic residual patterns in the case of dome ports.
    Type of Medium: Online Resource
    ISSN: 2194-9034
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2020
    detail.hit.zdb_id: 2874092-0
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  • 3
    Online Resource
    Online Resource
    Copernicus GmbH ; 2022
    In:  ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences Vol. V-2-2022 ( 2022-05-17), p. 343-350
    In: ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Copernicus GmbH, Vol. V-2-2022 ( 2022-05-17), p. 343-350
    Abstract: Abstract. Regular monitoring activities are important for assessing the influence of unfavourable factors on corals and tracking subsequent recovery or decline. Deep learning-based underwater photogrammetry provides a comprehensive solution for automatic large-scale and precise monitoring. It can quickly acquire a large range of underwater coral reef images, and extract information from these coral images through advanced image processing technology and deep learning methods. This procedure has three major components: (a) Generation of 3D models, (b) understanding of relevant corals in the images, and (c) tracking of those models over time and spatial change analysis. This paper focusses on issue (b), it applies five state-of-the-art neural networks to the semantic segmentation of coral images, compares their performance, and proposes a new coral semantic segmentation method. Finally, in order to quantitatively evaluate the performance of neural networks for semantic segmentation in these experiments, this paper uses mean class-wise Intersection over Union (mIoU), the most commonly used accuracy measure in semantic segmentation, as the standard metric. Meanwhile, considering that the coral boundary is very irregular and the evaluation index of IoU is not accurate enough, a new segmentation evaluation index based on boundary quality, Boundary IoU, is also used to evaluate the segmentation effect. The proposed trained network can accurately distinguish living from dead corals, which could reflect the health of the corals in the area of interest. The classification results show that we achieve state-of-the-art performance compared to other methods tested on the dataset provided in this paper on underwater coral images.
    Type of Medium: Online Resource
    ISSN: 2194-9050
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2022
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  • 4
    Online Resource
    Online Resource
    Copernicus GmbH ; 2021
    In:  The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences Vol. XLIII-B2-2021 ( 2021-06-28), p. 673-679
    In: The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Copernicus GmbH, Vol. XLIII-B2-2021 ( 2021-06-28), p. 673-679
    Abstract: Abstract. Uncontrolled refraction of optical rays in underwater photogrammetry is known to reduce its accuracy potential. Several strategies have been proposed aiming at restoring the accuracy to levels comparable with photogrammetry applied in air. These methods are mainly based on rigours modelling of the refraction phenomenon or empirical iterative refraction corrections. The authors of this contribution have proposed two mitigation strategies of image residuals systematic patterns in the image plane: (i) empirical weighting of image observations as function of their radial position; (ii) iterative look-up table corrections computed in a squared grid. Here, a novel approach is developed. It explicitly takes into account the object point-to-camera distance dependent error introduced by refraction in multimedia photogrammetry. A polynomial correction function is iteratively computed to correct the image residuals clustered in radial slices in the image plane as function of the point-to-camera distance. The effectiveness of the proposed method is demonstrated by simulations that allow to: (i) separate the geometric error under investigation from other effects not easily modellable and (ii) have reliable reference data against which to assess the accuracy of the result.
    Type of Medium: Online Resource
    ISSN: 2194-9034
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2021
    detail.hit.zdb_id: 2874092-0
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  • 5
    Online Resource
    Online Resource
    Copernicus GmbH ; 2021
    In:  ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences Vol. VIII-4/W1-2021 ( 2021-09-03), p. 17-24
    In: ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Copernicus GmbH, Vol. VIII-4/W1-2021 ( 2021-09-03), p. 17-24
    Abstract: Abstract. In the face of climate change and the energy transition that the German federal government is aiming for, all renewable energy potentials need to be tapped. Unfortunately, small wind turbines play a niche role in Germany and most other countries despite the fact, that although they offer advantages as e.g. almost seasonal independent energy production in close proximity to the consumer on the same low-voltage grid level. One reason beside the lower wind speeds that can be expected closer to the ground is, that in comparison to PV (photovoltaic), for which good yield forecasts can be made using global radiation measurements from nearby weather stations or online databases, the yield of small wind turbines, especially in urban areas, can only be forecasted using on-site measurements due to the influence of the surrounding buildings and topography. This method is time-consuming and costly. To address this, within this work a Computational Fluid Dynamics (CFD) simulation based visualization framework for the investigation of the small wind turbine potential is presented. In this specific case the energy supply company EnBW is planning to refurbish the “Neuer Stöckach” urban quarter on the former “Stöckach” company site. As part of the redevelopment, a comprehensive energy concept is planned to integrate renewable energies. In this context the integration of small wind turbines into the energy concept is examined according to this new methodology.
    Type of Medium: Online Resource
    ISSN: 2194-9050
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2021
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  • 6
    Online Resource
    Online Resource
    Copernicus GmbH ; 2020
    In:  The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences Vol. XLIII-B2-2020 ( 2020-08-12), p. 435-441
    In: The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Copernicus GmbH, Vol. XLIII-B2-2020 ( 2020-08-12), p. 435-441
    Abstract: Abstract. Objects and structures realized by connecting and bending wires are common in modern architecture, furniture design, metal sculpting, etc. The 3D reconstruction of such objects with traditional range- or image-based methods is very difficult and poses challenges due to their unique characteristics such as repeated structures, slim elements, holes, lack of features, self-occlusions, etc. Complete 3D models of such complex structures are normally reconstructed with lots of manual intervention as automated processes fail in providing detailed and accurate 3D reconstruction results.This paper presents the image-based 3D reconstruction of the Shukhov hyperboloid tower in Moscow, a wire structure built in 1922, composed of a series of hyperboloid sections stacked one to another to approximate an overall conical shape. A deep learning approach for image segmentation was developed in order to robustly detect wire structures in images and provide the basis for accurate corresponding problem solutions. The developed WireNet convolution neural network (CNN) model has been used to aid the multi-view stereo (MVS) process and to improve robustness and accuracy of the image-based 3D reconstruction approach, otherwise not feasible without masking the images automatically.
    Type of Medium: Online Resource
    ISSN: 2194-9034
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2020
    detail.hit.zdb_id: 2874092-0
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  • 7
    In: Magnetic Resonance, Copernicus GmbH, Vol. 2, No. 1 ( 2021-05-11), p. 291-320
    Abstract: Abstract. The review describes the application of nuclear magnetic resonance (NMR) spectroscopy to study kinetics of folding, refolding and aggregation of proteins, RNA and DNA. Time-resolved NMR experiments can be conducted in a reversible or an irreversible manner. In particular, irreversible folding experiments pose large requirements for (i) signal-to-noise due to the time limitations and (ii) synchronising of the refolding steps. Thus, this contribution discusses the application of methods for signal-to-noise increases, including dynamic nuclear polarisation, hyperpolarisation and photo-CIDNP for the study of time-resolved NMR studies. Further, methods are reviewed ranging from pressure and temperature jump, light induction to rapid mixing to induce rapidly non-equilibrium conditions required to initiate folding.
    Type of Medium: Online Resource
    ISSN: 2699-0016
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2021
    detail.hit.zdb_id: 2998533-X
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