69 research outputs found
Modelling Hot Spots of Soil Loss by Wind Erosion (SoLoWind) in Western Saxony, Germany
Land Degradation and Development published by John Wiley & Sons, Ltd. While it needs yet to be assessed whether or not wind erosion in Western Saxony is a major point of concern regarding land degradation and fertility, it has already been recognized that considerable off-site effects of wind erosion in the adjacent regions of Saxony-Anhalt and Brandenburg are connected to the spread of herbicides, pesticides and dust. So far, no wind erosion assessment for Western Saxony, Germany, exists. The wind erosion model previously applied for Germany (DIN standard 19706) is considering neither changes in wind direction over time nor influences of field size. This study aims to provide a first assessment of wind erosion for Western Saxony by extending the existing DIN model to a multidirectional model on soil loss by wind (SoLoWind) with new controlling factors (changing wind directions, soil cover, mean field length and mean protection zone) combined by fuzzy logic. SoLoWind is used for a local off-site effect evaluation in combination with high-resolution wind speed and wind direction data at a section of the highway A72. The model attributes 3·6% of the arable fields in Western Saxony to the very-high-wind erosion risk class. A relationship between larger fields (greater than 116 ha) and higher proportions (51·7%) of very-high-wind erosion risk can be observed. Sections of the highway A72 might be under high risk according to the modelled off-site effects of wind erosion. The presented applications showed the potential of SoLoWind to support and consult management for protection measures on a regional scale. © 2016 The Authors. Land Degradation and Development published by John Wiley & Sons, Ltd.The authors would like to thank JĂŒrgen Heinrich and Gudrun
Mayer for the technical revision of the model conception
and the German Weather Service, the Saxon State Office for
the Environment, Agriculture and Geology, the Saxon State
Office for Road Construction and Traffic, the Saxon State
Ministry of the Environment and Agriculture, the Saxon
State Spatial Data and Land Survey Corporation, the Saxon
Road Maintenance Depots, OpenStreetMap and the National
Aeronautics and Space Administration for providing the
datasets. We would also like to thank three anonymous
reviewers for helpful comments.info:eu-repo/semantics/publishedVersio
Biomechanische Untersuchung der PrimĂ€rstabilitĂ€t von zwei winkelstabilen Implantaten fĂŒr die valgisierende Osteotomie am Tibiakopf (HTO)
Whitelegg's Octopus - Oc50 - with Dive Bomber - DB15 - photographed 1972
Speckle Classification for Sensorless Freehand 3D Ultrasound
Despite being a valuable tool for volume measurement and the analysis of complex geometry, the need for an external position sensor is holding up the clinical exploitation of freehand three-dimensional ultrasound. Some sensorless systems have been developed, using speckle decorrelation for out-of-plane distance estimation, but their accuracy is still not as good as that of sensor-based systems. Here, we examine the widely held belief that accuracy can be improved by limiting the distance measurements to patches of ultrasound data containing fully developed speckle. Without speckle detection, we observe that scan separation is systematically underestimated by 33.1 % in biological tissue. We describe a number of speckle detectors and show that they reduce the underestimate to about 25 %. We conclude that speckle classification can improve the quality of distance estimation, but not sufficiently to achieve accurate, metric reconstruction of the insonified volume
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