1,721,318 research outputs found
Sea state and wind speed
No full textMonitoring of sea state and sea surface wind is certainly of fundamental importance for studies on climatology, meteorology, weather forecast, and ocean circulation. However, it has a great relevance also in the framework of maritime surveillance, particularly for navigation safety. In fact, of course navigation safety strongly depends on weather forecasts; in addition, knowledge of sea surface winds and sea currents allows predicting paths followed by fl oating sea ice and icebergs, which constitute a serious danger for navigation. Also, knowledge of wind speed and surface currents allows predicting the spreading and movements of oil spills over the sea surface. Microwave remote sensing systems, such as synthetic aperture radar (SAR) systems, have been recognized since their fi rst operational uses as the ideal sensors for the monitoring of sea state and sea surface winds
Keel bone lesions in laying hens: occurrence and risk factors
Full text linkIn Europe, farms for laying hens are housing the highest number of caged animals, whereas a transition towards cage-free systems is expected based on the Initiative of the European Citizens “End the Cage Age” and the corresponding Resolution of the European Parliament to provide hens with more possibility of movement, besides other improvements with respect to animal welfare. On the other side, navigation ability of laying hens in alternative systems, with special reference to multi-level aviary systems, may be associated to collisions with equipment and other animals which can produce injuries to animals where and if other risk factors are present. In fact, the latest Scientific Opinion of EFSA about the welfare of laying hens on farm has identified several highly-relevant welfare consequences for these animals based on severity, duration and occurrence, with bone lesions at the top of the list. Among these latter, keel bone fractures have been proved to produce negative states such as pain, distress, and/or discomfort, whereas less data are available on the occurrence of keel bone deviations and their impact on animal welfare and health. In this context, the present contribution aims to provide an overview of the available data about the occurrence of keel bone fractures and deviations in laying hens kept in different rearing systems, discussing the ontogenetic, management and housing factors that have been identified as risk factors, and, finally, to provide information about the animal-based indicators both on farm and slaughterhouse
Introduction
No full textThis book is divided into two parts. The first one deals with models and techniques, thus focusing on the SAR system viewpoint. This part provides the necessary background for a complete understanding of the second part, which is devoted to maritime surveillance applications. In the following, a brief description of book chapters is provided
What to show on the wine labels: a hedonic analysis of price drivers of Sicilian wines
No full textUnlike previous literature, we construct a hedonic model of wine price that incorporates all the main categories of variables simultaneously to enable a better evaluation of their importance on wine price formation. A comprehensive model has the advantage of providing more reliable estimates of the attributes' implicit prices thereby facilitating firms' pricing and improving effectiveness of wine production and marketing decisions. We utilize two different datasets of Sicilian wines collecting data from influential wine guides. Our results suggest that wine price strongly depends on objective features such as vintage, alcoholic content, geographical origin, grape variety, producer size and cellaring potential. In addition, use of containers like tonneaux and barrique positively affects prices, whereas use of concrete containers has a negative influence. No univocal indications emerge with regard to the effect of the type of company, type of viticulture and firm age. As for sensorial ch..
Closed-Form Anisotropic Polarimetric Two-Scale Model for Fast Evaluation of Sea Surface Backscattering
No full textThe polarimetric two-scale model (PTSM) was
introduced a few years ago as an electromagnetic scattering
model to be used within algorithms for soil moisture
retrieval from polarimetric synthetic aperture radar (SAR) data.
PTSM inherits the ability to account for depolarization effects
from the original two-scale model (TSM), and, with respect to
the latter, it has the advantage to provide closed-form expressions
of the elements of the covariance matrix that hold for moderate
large-scale surface slopes. This allows a very fast evaluation of
scattering, since numerical integration needed by the original
TSM is avoided. The TSM, also called composite model (CM),
has been extensively used to study scattering from the sea
surface, so that it is natural to explore the use of PTSM
for the same purpose. However, in its current formulation,
PTSM assumes that large-scale surface slope distribution and
small-scale roughness spectrum are isotropic. This is not realistic
for the sea surface, for which anisotropy is dictated by the wind
direction. Accordingly, we here extend PTSM to account for
surface roughness anisotropy, so obtaining the anisotropic PTSM
(A-PTSM). In addition, as a second contribution, we provide
A-PTSM expressions also in the circular polarization basis, which
may be useful for some SAR sensor polarimetric configurations.
Finally, we compare A-PTSM results with sea surface scattering
measurements available in the literature and with results of the
second-order small-slope approximation (SSA2). In particular,
as a third original contribution of this paper, an analytical
closed-form expression of the ratio of crosspolarized normalized
radar cross sections (NRCSs) obtained by SSA2 and A-PTSM is
provided
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