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Many real world applications today are built on analyses of movement and related features. Examples of such applications include transportation management, urban planning, tourism services, and animal migration monitoring, among others. Recent database modeling and management research prototypes have the capability to store and manipulate movement data in terms of point or region geometries that evolve over time (moving point or moving and deforming region). This captures the spatio‐temporal trace left by a moving object, but ignores its links with non‐geometric information that enable a semantic interpretation of the movement of moving objects. The concept of trajectory has been introduced to express a more semantic understanding of movement, taking it closer to the perception of applications. This article describes a framework for a semantics‐oriented structuring, modeling and querying of trajectory data. The framework relies on the definition of trajectory‐related ontologies, addressing domain‐independent and application‐specific geometric and semantic facets. Last we briefly discuss how the proposed approach has been applied for a traffic management application.  相似文献   
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The load of pathogenic bacteria, their fate and their dangerousness in the Tietê River were assessed along 100 km starting from the city of São Paulo, Brazil. The data were compared with those from two German rivers. High loads of pathogens were found in the Tietê River near the city of São Paulo (Escherichia coli O157:H7, Shigella flexneri, and Shigella boydii), which were absent 30 km downstream of São Paulo. The antibiotic resistances observed in the Tietê river were rather low and decreased after the major input in São Paulo to significantly lower levels about 30 km downstream. While the Brazilian isolates were more susceptible for ampicillin than the German ones, the reverse was observed for gentamycin. For optimal control of infections in humans critical areas where these bacteria survived longer and their elimination mechanisms should be identified as well as the extent and the origin of antibiotic resistance should be determined.  相似文献   
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Leach tests carried out on tektite specimens (indochinites and australites) under high-dilution conditions show a common behavior characterized by low leach rates (1.8 × 10?5g · m?2 · d?1or 7.2 × 10?12m · d?1 at 23°C) and an activation energy of (79.6 ± 0.7) × 103J · mol?1. The extent of selective leaching is very small, of the order of 10?8 m. Extrapolation of test results over the lifetime of the tektites gives an excellent agreement with field observations on the extent of corrosion, and this is an important step in establishing the validity of laboratory tests as a basis for the development of models and predictions concerning long-term durabilities at least in the limiting case of high dilution or rapid flow. The results are also shown to be in agreement with various previous observations on the corrosion resistance of tektites. The chemical durability of tektites is observed to be consistent with their composition, highlighting requirements for high corrosion resistance in glasses; these requirements include a silica content in excess of 67 mol%, an extremely low water content and an alkali content which is low both absolutely and relative to the di- and poly-valent metal oxide levels. It is shown that artificial glasses which fulfil these criteria are no less corrosion-resistant than the corresponding natural glasses. These conclusions have bearing on the development as well as on the evaluation of glasses intended for very long service, such as radioactive waste vitrification media.  相似文献   
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GIS techniques have been used in the evaluation of favorability for base-metal mineralization in an area comprising the Cerro Azul and Apiaí quadrangles (SG.22-X-B-IV and V, scale 1:100.000), Ribeira Valley, São Paulo and Paraná States, Brazil. Methods have been employed for selection and weighting of prospective variables when applying GIS techniques to a digital database consisting of geological, geochemical and airborne geophysics, and mineral occurrence information. The exploration variable selection and analysis were based on two mineralization models: (1) Panelas type, vein-type carbonate hosted, and (2) Perau type, sedimentary-exhalative. The overlay was performed by weighted linear combination (WLC) and order weighted average (OWA) methods. Both methods proved suitable for the study area, yielding similar results. The ordered weighted averaging analysis provided the best results, with favorability maps showing a large number of classes occupying relatively minor areas. In comparison, the weighted linear combination analysis produced more coherent results but without details for minor areas. The prospective parameters obtained are considered suitable for both Perau and Panelas types. Both methods are inexpensive, and are suitable for selection of prospective areas during geological surveys in areas similar to the studied one.  相似文献   
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Theoretical and Applied Climatology - The climate change endangers many species of the Amazon Forest. An example, in the endangered medicinal species Pilocarpus microphyllus (popularly known as...  相似文献   
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Anisotropy of magnetic susceptibility (AMS) applied to an alkaline granite from Meruoca (NE Brazil) recorded weak anisotropies, typically below 4%, and a considerable dispersion of the AMS axes. Red-clouded feldspars and clots of metasomatic minerals enclosed in magmatic crystals indicate that hydrothermal fluids altered the granite. U–Pb isotopic data show high-common Pb on zircons but allowed the calculation of a mean SHRIMP age of 523 ± 9 Ma attributed to the magmatic crystallization. Growth of fine oxides by late fluid–rock interactions was responsible for the scattering of AMS. Rock magnetic data indicate they consist mainly of an oxidized magnetite and (titano)hematite. Shape preferred orientation of mafic aggregates measured in granite quarries shows that the pluton preserves a gently dipping magmatic foliation. AMS in some quarries with a well-defined magmatic fabric, however, remains highly dispersed. When AMS mimics the mafic shape fabric, only magnetic foliations share a common orientation. Locally, AMS grounded in coarse Ti-poor magnetite associated with titanite develops a consistent subhorizontal oblate fabric that agrees with tectonic models suggesting that the cupola of the pluton has been exposed by erosion.  相似文献   
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The construction and method of operation of an all-metal system for KAr and U-He dating is described in detail. The system is capable of handling samples in batches of about 15 g total weight. Blanks are typically 6 × 10?9 cm3 STP for40Aratmos, <1.2 × 10?9 cm3 STP for4He, and ~2 × 10?9 STP for40Arradiogenic. The last of these quantities is independent of the quantity of40Arradiogenic processed in the preceding run because vapor transport of the sample out of the hottest region of the crucible is very substantial and release of the rare gases in the sample is therefore almost complete. The system is very stable manometrically; monitoring of spike peaks therefore permits detection of any gas loss which amounts to more than a few percent. The system is not very suitable for analysis of large samples.  相似文献   
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