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Yang Haiqing Nikafshan Rad Hima Hasanipanah Mahdi Bakhshandeh Amnieh Hassan Nekouie Atefeh 《Natural Resources Research》2020,29(2):807-830
Natural Resources Research - Ground vibration generated from blasting is a detrimental side effect of the use of explosives to break the rock mass in mines. Therefore, accurately predicting ground... 相似文献
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Hooshang H. Asadi Atefeh Sansoleimani Moslem Fatehi Emmanuel John M. Carranza 《Natural Resources Research》2016,25(4):417-429
The Salafchegan area in central Iran is a greenfield region of high porphyry Cu–Au potential, for which a sound prospectivity model is required to guide mineral exploration. Satellite imagery, geological geochemical, geophysical, and mineral occurrence datasets of the area were used to run an innovative integration model for porphyry Cu–Au exploration. Five favorable multi-class evidence maps, representing diagnostic porphyry Cu–Au recognition criteria (intermediate igneous intrusive and sub-volcanic host rocks, structural controls, hydrothermal alterations, stream sediment Cu anomalies, magnetic signatures), were combined using analytic hierarchy process and technique for order preference by similarity to ideal solution to calculate a final map of porphyry Cu–Au potential in the Salafchegan area. 相似文献
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Ocean Dynamics - Third-generation models employ a host of parameterization schemes to consider the input wind forcing and the wave energy dissipation under different physical settings and... 相似文献
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All numerical weather prediction (NWP) models inherently have substantial biases, especially in the forecast of near-surface weather variables. Statistical methods can be used to remove the systematic error based on historical bias data at observation stations. However, many end users of weather forecasts need bias corrected forecasts at locations that scarcely have any historical bias data. To circumvent this limitation, the bias of surface temperature forecasts on a regular grid covering Iran is removed, by using the information available at observation stations in the vicinity of any given grid point. To this end, the running mean error method is first used to correct the forecasts at observation stations, then four interpolation methods including inverse distance squared weighting with constant lapse rate (IDSW-CLR), Kriging with constant lapse rate (Kriging-CLR), gradient inverse distance squared with linear lapse rate (GIDS-LR), and gradient inverse distance squared with lapse rate determined by classification and regression tree (GIDS-CART), are employed to interpolate the bias corrected forecasts at neighboring observation stations to any given location. The results show that all four interpolation methods used do reduce the model error significantly, but Kriging-CLR has better performance than the other methods. For Kriging-CLR, root mean square error (RMSE) and mean absolute error (MAE) were decreased by 26% and 29%, respectively, as compared to the raw forecasts. It is found also, that after applying any of the proposed methods, unlike the raw forecasts, the bias corrected forecasts do not show spatial or temporal dependency. 相似文献
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Experiments were carried out over a 2-dimentional pool with a constant length of 1.5 m and four different slopes.The distributions of velocity,Reynolds stress and turbulence intensities have been studied in this paper.Results show that as flow continues up the exit slope,the flow velocity increases near the channel bed and decreases near the water surface.The flow separation was not observed by ADV at the crest of the bed-form.In addition,the length of the separation zone increases with the increasing of entrance and exit slopes.The largest slope angle causes the maximum normalized shear stress.Based on the experiments,it is concluded that the shape of Reynolds stress distribution is generally dependent on the entrance and exit slopes of the pool.Also,the shape of Reynolds stress distribution is affected by both decelerating and accelerating flows.Additionally,with the increase in the slope angle,secondary currents are developed and become more stable.Results of the quadrant analysis show that the momentum between flow and bed-form is mostly transferred by sweep and ejection events. 相似文献
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Atefeh Abdolhay Bahram Saghafian Mohd Amin Mohd Soom Abdul Halim B. Ghazali 《Natural Hazards》2012,61(3):1427-1442
Estimation of flood in basins with poor condition of hydrometric stations as in quantity and quality is a dominant problem
around the world, mainly in developing country where lack of funds and human resources cause more limitation in number of
gauging stations. One of the areas that experience frequent floods and also suffer from small number of stations in Iran is
Gorganrood basin. So there is a great need for the estimation and prediction of runoff in this area to prevent any future
floods. Due to insufficient station in this area, direct prediction of flood is not applicable. Regional flood frequency analysis
is a practical and widely used solution for these situations, which involves the identification of homogenous regions. Gorganrood
region was hydrologically homogenized according to the extracted parameters that influence the floods. One of these parameters
was Normalized Difference Vegetation Index (NDVI) driven from MODIS images. Curvature is another parameter that relates to
topographic attributes. From factor analysis, the most appropriate variables were selected. According to these parameters
(NDVI, curvature, area, slope…), the regions were classified into homogenous regions. For the purpose of homogenization, hierarchical
(wards) clustering, fuzzy clustering and Kohonen method were applied. L-moment technique was used for the investigation of
the results. The heterogeneity measure for one of the groups (Group 1) was more than two; therefore some modifications were
applied. The region was grouped into two homogenous subregions. All of the clustering methods showed same results. The models
showed that class 4 of NDVI is influential on flood in some return periods. The resulted models can be applied in future studies
in different aspects of practical hydrology. 相似文献
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Rajesh P. Dhakal Atefeh Pourali Ali Sahin Tasligedik Trevor Yeow Andrew Baird Gregory MacRae Stefano Pampanin Alessandro Palermo 《地震工程与工程振动(英文版)》2016,15(1):1-17
This paper summarizes the research on non-structural elements and building contents being conducted at University of Canterbury in New Zealand. Since the 2010-2011 series of Canterbury earthquakes, in which damage to non-structural components and contents contributed heavily to downtime and overall financial loss, attention to seismic performance and design of non-structural components and contents in buildings has increased exponentially in NZ. This has resulted in an increased allocation of resources to research leading to development of more resilient non-structural systems in buildings that would incur substantially less damage and cause little downtime during earthquakes. In the last few years, NZ researchers have made important developments in understanding and improving the seismic performance of secondary building elements such as partitions, facades, ceilings and contents. 相似文献
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