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排序方式: 共有358条查询结果,搜索用时 15 毫秒
1.
Gustavo?Bastos?Lyra Tamíres?Partelli?Correia José?Francisco?de?Oliveira-Júnior Marcelo?ZeriEmail authorView authors OrcID profile 《Theoretical and Applied Climatology》2018,134(3-4):955-965
Five deterministic methods of spatial interpolation of monthly rainfall were compared over the state of Rio de Janeiro, southeast Brazil. The methods were the inverse distance weight (IDW), nearest neighbor (NRN), triangulation with linear interpolation (TLI), natural neighbor (NN), and spline tension (SPT). A set of 110 weather stations was used to test the methods. The selection of stations had two criteria: time series longer than 20 years and period of data from 1960 to 2009. The methods were evaluated using cross-validation, linear regression between values observed and interpolated, root mean square error (RMSE), coefficient of determination (r 2), coefficient of variation (CV, %), and the Willmott index of agreement (d). The results from different methods are influenced by the meteorological systems and their seasonality, as well as by the interaction with the topography. The methods presented higher precision (r 2) and accuracy (d, RMSE) during the summer and transition to autumn, in comparison with the winter or spring months. The SPT had the highest precision and accuracy in relation to other methods, in addition to having a good representation of the spatial patterns expected for rainfall over the complex terrain of the state and its high spatial variability. 相似文献
2.
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
3.
Ruiz-Salcines Pablo Appendini Christian M. Salles Paulo Rey Wilmer Vigh Jonathan L. 《Natural Hazards》2021,105(1):431-459
Natural Hazards - This study presents a new approach to assess storm surge risk from tropical cyclones under climate change by direct calculation of the local flood levels using a limited number of... 相似文献
4.
Castilho Tayane Westermann Rodrigues Roger Augusto Lodi Paulo César 《Geotechnical and Geological Engineering》2021,39(8):5943-5955
Geotechnical and Geological Engineering - Many studies have investigated polyethylene terephthalate (PET) and polypropylene fibers in soil improvement. However, there is a lack of research using... 相似文献
5.
Costa Lus R. D. Hugman Rui T. Stigter Tibor Y. Monteiro Jos Paulo 《Hydrogeology Journal》2021,29(7):2501-2516
Hydrogeology Journal - The dynamics related to evolution of nitrate-contaminated groundwater are analyzed with focus on the impact of intrinsic aquifer properties, agricultural activities and... 相似文献
6.
Franco JL Posser T Mattos JJ Sánchez-Chardi A Trevisan R Oliveira CS Carvalho PS Leal RB Marques MR Bainy AC Dafre AL 《Marine environmental research》2008,66(1):88-89
The aim of this study was to investigate biochemical changes in juvenile carp (Cyprinus carpio) exposed to zinc chloride (10, 30 and 100 microM) for a period of 48 h. Zinc exposure caused a concentration-dependent reduction in glutathione reductase (GR) activity in gills, liver and brain. Gill glutathione S-transferase (GST) was reduced when animals were exposed to the highest concentration of 100 microM zinc. The phosphorylation of p38(MAPK) increased in the brain of fish exposed to zinc 100 microM, while phosphorylation of the extracellular signal-regulated protein kinase 1/2 (ERK1/2) and c-Jun N-terminal protein kinase 1/2 (JNK1/2) remained unchanged. Expression of proteins HSP60 and HSP70 were not affected by zinc exposure. Considering the significant concentration-dependent inhibition of GR in all tissues analyzed, this enzyme could be a potential biomarker of exposure to zinc, which has to be confirmed. 相似文献
7.
8.
The morphosedimentary evolution of a sector of the southern Espinhaco range (northern Minas Gerais State, Brazil) and its
regional neotectonic setting are presented herein. The studied site is a stream at base level flowing along the western border
of the range. Its identification was accomplished by using remote sensing techniques including the analysis of 3D slope models
generated with shuttle radar topography mission images. The main geomorphological features of the identified site were surveyed
in a 1:500 scale. In addition, seven stratigraphic logs are described. A regional geologic compilation and facies diagrams
were used as a basis for the integration of the geomorphological and stratigraphic data, which produced some conclusions about
the recent tectonic reactivations at the eastern border of Sao Francisco Craton. The results point to a local eastward tilting
of the Espinhaco range. This fact is in accordance with previous findings in neighboring areas and results in the asymmetric
evolution of the fluvial valley, as well as the regional relief. 相似文献
9.
Mrio Neto Cavalcanti de Araújo Fernando Csar Alves da Silva Emanuel Ferraz Jardim de S Rodney J. Holcombe Paulo Marcos de Vasconcelos 《Journal of Structural Geology》2003,25(12):2089-2107
The polyphase evolution of the Seridó Belt (NE-Brazil) includes D1 crust formation at 2.3–2.1 Ga, D2 thrust tectonics at 1.9 Ga and crustal reworking by D3 strike-slip shear zones at 600 Ma. Microstructural investigations within mylonites associated with D2 and D3 events were used to constrain the tectono-thermal evolution of the belt. D2 shear zones commenced at deeper crustal levels and high amphibolite facies conditions (600–650 °C) through grain boundary migration, subgrain rotation and operation of quartz c-prism slip. Continued shearing and exhumation of the terrain forced the re-equilibration of high-T fabrics and the switching of slip systems from c-prism to positive and negative a-rhombs. During D3, enhancement of ductility by dissipation of heat that came from syn-D3 granites developed wide belts of amphibolite facies mylonites. Continued shearing, uplift and cooling of the region induced D3 shear zones to act in ductile-brittle regimes, marked by fracturing and development of thinner belts of greenschist facies mylonites. During this event, switching from a-prism to a-basal slip indicates a thermal path from 600 to 350 °C. Therefore, microstructures and quartz c-axis fabrics in polydeformed rocks from the Seridó Belt preserve the record of two major events, which includes contrasting deformation mechanisms and thermal paths. 相似文献
10.
Michael Joseph Carr Pedro Pina Avelino Paulo Mauricio de Carvalho 《Astrophysics and Space Science》1998,261(1-4):335-336
As an alternative to computationally expensive N-body simulations for gravitional clustering, the Zel'dovich approximation
(ZA) was studied in 3D, 2D and 1D. Plots of the density contrast were compared against linear theory and the exact solution.
The ZA was found to perform very well in the linear regime, better than linear theory, and to give a good approximation well
into the non-linear regime.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献