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41.
The availability of miniaturized sensors with enhanced capabilities, new methods for image processing, and easy access to small and low-weight airborne platforms for data acquisition, including unmanned vehicles, opens new possibilities for geodetic navigation applications and developing new developments in sensor fusion. In this context, the development of efficient methods, based on low-cost sensors, to extract precise georeferenced information from digital cameras is of utmost interest. We present a method to improve the performance of the integration of GNSS/low-cost IMU by exploiting the orientation changes retrieved from digital images. In this work, a robust-adaptive Kalman filter is also introduced to further improve the performance of the method deployed. The adaptive factor and the robust factor accomplished are determined by innovation information and the threshold value of orientation changes between consecutive images. Results from airborne tests used to assess the performance of the method are presented. The results show that using a non-metric camera, the Euler angle estimation accuracy of the GNSS/low-cost IMU integration can be improved to be close to 0.5 degree and an additional improvement, which can reach 59%, can be achieved after using the robust-adaptive Kalman filter. 相似文献
42.
Pablo Fernández José Pablo Suárez Agustín Trujillo Conrado Domínguez José Miguel Santana 《Journal of Geographical Systems》2018,20(2):139-157
Many organizations of all kinds are using new technologies to assist the acquisition and analysis of data. Seaports are a good example of this trend. Seaports generate data regarding the management of marine traffic and other elements, as well as environmental conditions given by meteorological sensors and buoys. However, this enormous amount of data, also known as Big Data, is useless without a proper system to organize, analyze and visualize it. SmartPort is an online platform for the visualization and management of a seaport data that has been built as a GIS application. This work offers a Rich Internet Application that allows the user to visualize and manage the different sources of information produced in a port environment. The Big Data management is based on the FIWARE platform, as well as “The Internet of Things” solutions for the data acquisition. At the same time, Glob3 Mobile (G3M) framework has been used for the development of map requirements. In this way, SmartPort supports 3D visualization of the ports scenery and its data sources. 相似文献
43.
de Arruda Gomes Mayara Maria de Melo Verçosa Lívia Fragoso Cirilo José Almir 《Natural Hazards》2021,108(3):3121-3157
Natural Hazards - Floods are the most frequent natural disaster and pose a very challenging threat to many cities worldwide. Understanding the flood dynamic is essential for developing strategies... 相似文献
44.
Gianni Gallello Mirco Ramacciotti Oreto García-Puchol Simon Chenery Alfredo Cortell-Nicolau MARíA Luisa Cervera Agustin Diez-Castillo Agustín Pastor Sarah B. McClure 《Boreas: An International Journal of Quaternary Research》2021,50(4):1190-1208
This study investigates the stratigraphical sequence of Cocina Cave (Spain) employing and testing for the first time the capability of rare earth elements as markers of human activities in caves. Located in Dos Aguas (Valencian Community, Spain), Cocina Cave is characterized by the presence of several Holocene archaeological deposits from the final Mesolithic to the present day and is a pivotal site for understanding the socio-ecological dynamics of the last hunter-gatherer inhabitants of the Iberian Peninsula and the transition to pastoral and agricultural economies in the Western Mediterranean. However, the identification of strata from particular time-periods in the cave is often difficult due to the homogeneity of layers, the poor archaeological record in some strata and the presence of severe disturbance phenomena. The methodological approach of this study consisted of cross-referencing rare earth elements and other chemical markers with the archaeological stratigraphical interpretation, in an attempt to not only support the identification of the anthropic contribution to the formation of Cocina Cave strata, but also to characterize and confirm different natural and occupational episodes, particularly those associated with hunter-gatherer, early agriculturalist, and shepherd activities. Sediments were collected from different excavation areas and analysed for major elements, trace elements, rare earth elements (REE), soil organic matter (SOM) amounts and pH. Multivariate statistics were employed to group samples according to their elemental profile, and these were then compared to the archaeological temporal interpretation. The obtained results showed that REE amount and fractionation geochemical processes were regulated by carbonates, phosphates and pH. The use of REE as markers was particularly useful as their concentrations and their calculated ratios and anomaly distributions were demonstrated to be highly consistent with the archaeological stratigraphical interpretation. 相似文献
45.
Bianca D. Lima Elba C. Teixeira James C. Hower Matheus S. Civeira Omar Ramírez Cheng-Xue Yang Marcos L.S. Oliveira Luis F.O. Silva 《地学前缘(英文版)》2021,12(3):101129
Having a better understanding of air pollutants in railway systems is crucial to ensure a clean public transport. This study measured, for the first time in Brazil, nanoparticles (NPs) and black carbon (BC) on two ground-level platforms and inside trains of the Metropolitan Area of Porto Alegre (MAPA). An intense sampling campaign during thirteen consecutive months was carried out and the chemical composition of NPs was examined by advanced microscopy techniques. The results showed that highest concentrations of the pollutants occur in colder seasons and influenced by variables such as frequency of the trains and passenger densities. Also, internal and external sources of pollution at the stations were identified. The predominance of NPs enriched with metals that increase oxidative stress like Cd, Fe, Pb, Cr, Zn, Ni, V, Hg, Sn, and Ba both on the platforms and inside trains, including Fe-minerals as hematite and magnetite, represents a critical risk to the health of passengers and employees of the system. This interdisciplinary and multi-analytical study aims to provide an improved understanding of reported adverse health effects induced by railway system aerosols. 相似文献
46.
Glacial lake outburst floods(GLOFs)represent one of the most serious hazard and risk in deglaciating high mountain regions worldwide and the need for GLOF hazard and risk assessment is apparent.As a consequence,numerous region-and nation-wide GLOF assessment studies have been published recently.These studies cover large areas and consider hundreds to thousands of lakes,prioritizing the hazard posed by them.Clearly,certain simplification is required for executing such studies,often resulting in neglecting qualitative characteristics which would need manual assignment.Different lake dam types(e.g.,bedrock-dammed,moraine-dammed)are often not distinguished,despite they control GLOF mechanism(dam overtopping/dam breach)and thus GLOF magnitude.In this study,we explore the potential of easily measurable quantitative characteristics and four ratios to approximate the lake dam type.Our dataset of 851 lakes of the Cordillera Blanca suggests that while variances and means of these characteristics of individual lake types differ significantly(F-test,t-test),value distribution of different geometrical properties can’t be used for the originally proposed purpose along the spectra.The only promising results are obtained for extreme values(selected bins)of the ratios.For instance,the low width to length ratio indicates likely morainedammed lake while the high value of ratio indicating round-shape of the lake indicates increased likelihood of bedrock-dammed lake.Overall,we report a negative result of our experiment since there are negligible differences of relative frequencies in most of the bins along the spectra. 相似文献
47.
A general overview of some of the problems involved in earthquake catalogue handling is given as part of the works carried out into the ESC/SC8-TERESA project related with the seismic hazard assessment in two selected test areas: Sannio-Matese in Italy and the northern Rhine region (BGN). Furthermore, the necessary input data to be used in the calculation of seismic hazard has been obtained, including earthquake source zones and their seismic hazard parameters.The importance is pointed out of detailed analysis of seismic catalogues, mainly in relation to the use of aftershock information, the historical records of the region, and the possible temporal and spatial variation of seismicity, which could have an important influence on short-term hazard assessment. 相似文献
48.
Zusammenfassung Bei dem Versuch, die Kristallstruktur von Bonchevit zu bestimmen, stellte sich heraus, daß dieses Mineral—bis dahin PbBi4S7—aus zwei Phasen besteht. Der Hauptanteil wurde eindeutig als Galenobismutit identifiziert. Der Rest wies nach den Gitterkonstanten (a0=13,58±0,02 Å, b0=20,51±0,07 Å, c0=4,09±0,07 Å) auf ein bisher unbekanntes Mineral hin. Die Raumgruppe ist Bbmm. Ein indiziertes Pulverdiagramm und die dazugehörigen d-Werte werden angegeben.Die Emissionsspektralanalyse zeigt Pb und Bi als Hauptkomponenten, Cu und Ag als Nebenkomponenten und Spuren von Zn und Sn. Die Strukturanalyse führte zu der Formel Me5S6, wobei die Me-Atome etwa gleich schwer sind, so daß als chemischo Formel nur Pb3Bi2S6 mit Z=4 in Frage kommt.Strukturell gehört das Mineral in die Gruppe Andorit-Ramdohrit-Fizelyit. Die Verwandtschaft bzw. Identität des Minerals mit anderen Mineralen und synthetischen Verbindungen wird diskutiert.
Mineralogical data on a sulphosalt from the Rhodope mountains, Bulgaria
Summary During an attempt to determine the crystal structure of bonchevite, this mineral was found to consist of two phases. Previously it was thought to have the composition PbBi4S7. The main constituent could unambiguously be identified as galenobismutite. For the rest the lattice constants (a0=13.58±0,02 Å, b0=20.51±0,07 Å, c0=4.09±0.07 Å), indicated a new mineral. Space group is Bbmm. An indexed powder diagram (with d-values) is given.The emission spectrographic analysis shows Pb and Bi to be main components, Cu and Ag to be minor components, and traces only of Zn and Sn. The structure analysis has led to the formula Me5S6, with Me-atoms of approximately the same atomic number; therefore, the chemical formula has to be Pb3Bi2S6, with Z=4.In a structural classification the mineral belongs to the andoriteramdohrite-fizelyite-group. The relationships to or the identity with other minerals and synthetic compounds are discussed.相似文献
49.
María Teresa Rodríguez-Salazar Ofelia Morton-Bermea Elizabeth Hernández-Álvarez Rufino Lozano Victor Tapia-Cruz 《Environmental Earth Sciences》2011,62(5):899-905
This research presents and discusses information concerning the spatial distribution of heavy metals (Pb, Cu, Zn, Ba, Co,
Cr, Ni and V) in the urban environments of Mexico City using geographical information system and statistical analysis. Superficial
soil samples (n = 146) were analyzed. The highest contamination indices were found in the north and center zone of the metropolitan area.
In contrast, the surrounding rural fields show a lower impact grade. The higher concentrations of Pb, Cu, Zn and Ba were observed
as being related to high vehicular traffic, nevertheless other elements such as Co, Cr, Ni and V do not show anthropogenic
influence and their content can be attributed to the parental rock. The results are compared with previous surveys carried
out in 2003 in order to evaluate temporal deposition trends. No changes were found on reported concentrations except for Cu
and Zn, whose concentration has increased in later years. The results suggest that spatial distribution analysis and results
in comparison with previous studies could be useful for the management and sustainable development of the metropolitan area
of Mexico City. 相似文献
50.
Idael Francisco Blanco-Quintero C. Lázaro A. García-Casco J. A. Proenza Y. Rojas-Agramonte 《Contributions to Mineralogy and Petrology》2011,162(2):395-413
Whole-rock compositions of muscovite-bearing amphibolite, trondhjemite, pegmatite and quartz-muscovite rocks from Sierra del
Convento and La Corea mélanges (eastern Cuba), as well as mineralogy, record complex circulation of Ba-rich fluids and melts
in the subduction environment. Partial melting of fluid-fluxed, MORB-derived amphibolite produced trondhjemite magmas that
crystallized at depth, in some cases evolving into pegmatites. Qtz-Ms rocks probably crystallized from primary fluids derived
from subducted sediments. All these rocks have elevated concentrations of large-ion lithophile elements, especially Ba (up
to 11,810 ppm), presumably released from slab sediments by fluids and/or melts. Fluid–rock interaction produced crystallization
of phengite in parental amphibolites. The phengite crystallized in all types of rocks is rich in Ba, with concentric zoning,
characterized by Ba-rich cores and Ba-poor rims, indicating a compatible behaviour of Ba in the studied systems. Zoning in
phengite is governed primarily by the celadonite (tschermak) exchange vector ((Mg,Fe)Si-(Al)-2), with more moderate contributions of the celsian (BaAl-(KSi)-1) and paragonite (NaK-1) exchange vectors. Late remobilization of Ba at relatively low temperature formed retrograde celsian. The compatible behaviour
of Ba in the studied rocks strengthens the importance of the stability of phengite for the transfer of LIL elements from the
subduction to the volcanic arc environments. 相似文献