Patterns in Biodiversity. Spatial Organisation of Biodiversity in the Netherlands - by Marieke A Schouten     

Diego  Fontaneto 《The Geographical journal》2009,175(2):165-165

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Prediction of modified Mercalli intensity from PGA, PGV, moment magnitude, and epicentral distance using several nonlinear statistical algorithms     

Diego A. Alvarez  Jorge E. Hurtado  Daniel Alveiro Bedoya-Ruíz 《Journal of Seismology》2012,16(3):489-511

Despite technological advances in seismic instrumentation, the assessment of the intensity of an earthquake using an observational scale as given, for example, by the modified Mercalli intensity scale is highly useful for practical purposes. In order to link the qualitative numbers extracted from the acceleration record of an earthquake and other instrumental data such as peak ground velocity, epicentral distance, and moment magnitude on the one hand and the modified Mercalli intensity scale on the other, simple statistical regression has been generally employed. In this paper, we will employ three methods of nonlinear regression, namely support vector regression, multilayer perceptrons, and genetic programming in order to find a functional dependence between the instrumental records and the modified Mercalli intensity scale. The proposed methods predict the intensity of an earthquake while dealing with nonlinearity and the noise inherent to the data. The nonlinear regressions with good estimation results have been performed using the ??Did You Feel It??? database of the US Geological Survey and the database of the Center for Engineering Strong Motion Data for the California region.  相似文献   

Observing high-redshift galaxy clusters through lensing of the Ostriker–Vishniac effect     

J. M. Diego  D. Herranz 《Monthly notices of the Royal Astronomical Society》2008,383(2):791-802

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Triplets of quasars at high redshift – I. Photometric data     

M. Victoria Alonso  Georgina V. Coldwell  Ilona Söchting  Carlos Bornancini  Malcolm G. Smith  Diego García Lambas  Armin Rest 《Monthly notices of the Royal Astronomical Society》2008,385(4):2254-2260

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A novel simple procedure to consider seismic soil structure interaction effects in 2D models     

Juan Diego Jaramillo  Juan David Gómez  Doriam Restrepo  Santiago Rivera 《地震工程与工程振动(英文版)》2014,13(3):535-543

A method is proposed to estimate the seismic soil-structure-interaction (SSI) effects for use in engineering practice. It is applicable to 2D structures subjected to vertically incident shear waves supported by homogenous half-spaces. The method is attractive since it keeps the simplicity of the spectral approach, overcomes some of the difficulties and inaccuracies of existing classical techniques and yet it considers a physically consistent excitation. This level of simplicity is achieved through a response spectra modification factor that can be applied to the free-field 5%-damped response spectra to yield design spectral ordinates that take into account the scattered motions introduced by the interaction effects. The modification factor is representative of the Transfer Function (TF) between the structural relative displacements and the free-field motion, which is described in terms of its maximum amplitude and associated frequency. Expressions to compute the modification factor by practicing engineers are proposed based upon a parametric study using 576 cases representative of actual structures. The method is tested in 10 cases spanning a wide range of common fundamental vibration periods.  相似文献   

Possible correlation between miocene global climatic changes and magnetic proxies,using neuro fuzzy logic analysis in a stratigraphic well at the Llanos foreland basin,Colombia     

Ana Da Silva  Vincenzo Costanzo-Álvarez  Nuri Hurtado  Milagrosa Aldana  Germán Bayona  Oswaldo Guzmán  Diego López-Rodríguez 《Studia Geophysica et Geodaetica》2010,54(4):607-631

In this work we have assessed the hybrid algorithm of NeuroFuzzy logic (NFL), to establish a correlation between global climatic changes (benthic foraminiferal δ¹⁸O data), experimental S-ratio (factor characterizing stability of remanent magnetization) and magnetic susceptibility (κ). Magnetic proxies have been measured in 44 samples of the Colombian stratigraphic well Saltarín 1A (distal Llanos foreland basin). κ and Sratios were linked to global δ¹⁸O data assuming a constant accumulation rate for a 305 meters thick stratigraphic interval flanked by the two palynological age constrains available. This interval encompasses, from top to base, the bottom of the Guayabo formation, the León, and the upper unit of the Carbonera formations (lower to middle Miocene). The best inference is accomplished applying a Takagi-Sugeno-Kan (TSK) fuzzy model with four fuzzy rules and the δ¹⁸O, S-ratios and κ data used in a linear form to train the system. These results are interpreted as the outcome of a significant influence of global climatic changes upon magnetic proxies. A stronger correlation is perhaps prevented by the likely influence of local and regional tectonic events and climatic changes that could have affected the distal segment of the Colombian Llanos foreland basin during Miocene times. We argue that late diagenesis of primary magnetic minerals and the assumption of a constant accumulation rate might have a minor influence on these results.  相似文献   

Non-parametric inversion of strong lensing systems     

J. M. Diego †  P. Protopapas †  H. B. Sandvik †  M. Tegmark † 《Monthly notices of the Royal Astronomical Society》2005,360(2):477-491

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The influence of salinity on seagrass growth,survivorship, and distribution within Biscayne Bay,Florida: Field,experimental, and modeling studies   总被引：1，自引：0，他引：1  

Diego?LirmanEmail author  Wendell?P.?Cropper 《Estuaries and Coasts》2003,26(1):131-141

We evaluate if the distribution and abundance ofThalassia testudinum, Syringodium filiforme, andHalodule wrightii within Biscayne Bay, Florida, are influenced by salinity regimes using, a combination of field surveys, salinity exposure experiments, and a seagrass simulation model. Surveys conducted in June 2001 revealed that whileT. testudinum is found throughout Biscayne Bay (84% of sites surveyed),S. filiforme andH wrightii have distributions limited mainly to the Key Biscayne area.H. wrightii can also be found in areas influenced by canal discharge. The exposure of seagrasses to short-term salinity pulses (14 d, 5–45‰) within microcosms showed species-specific susceptibility to the salinity treatments. Maximum growth rates forT testudinum were observed near oceanic salinity values (30–40‰) and lowest growth rates at extreme values (5‰ and 45‰).S. filiforme was the most susceptible seagrass species; maximum growth rates for this species were observed at 25‰ and dropped dramatically at higher and lower salinity.H. wrightii was the most tolerant, growing well at all salinity levels. Establishing the relationship between seagrass abundance and distribution and salinity is especially relevant in South Florida where freshwater deliveries into coastal bays are influenced by water management practices. The seagrass model developed by Fong and Harwell (1994) and modified here to include a shortterm salinity response function suggests that freshwater inputs and associated decreases in salinity in nearshore areas influence the distribution and growth of single species as well as modify competitive interactions so that species replacements may occur. Our simulations indicate that although growth rates ofT. testudinum decrease when salinity is lowered, this species can still be a dominant component of nearshore communities as confirmed by our surveys. Only when mean salinity values are drastically lowered in a hypothetical restoration scenario isH. wrightii able to outcompeteT. testudinum.  相似文献   

The Numidian Sequence between Guelma and Constantine (Eastern Tell,Algeria)*     

E. Moretti  R. Coccioni  F. Guerrera  Jean-Claude Lahondre  Francesco Loiacono  Diego Puglisi 《地学学报》1991,3(2):153-165

The Numidian Sequence represents one of the main tectono-stratigraphic units involved in the geological evolution of the Maghrebian orogen during the Upper Oligocene-Lower Miocene. Geo-structural aqalysis led to the reconstruction of tectonc-stratigraphic units and recognition of two main tectonic phases (Eocene and Lower Miocene). Sedimentological analysis of the studied sections has resulted in the distinction of arenaceous and conglomeratic facies generated by debris flows or high-density turbidity currents on a submarine slope, present within the pelitic-arenaceous and arenaceous-pelitic sequences which also contain slumped units in places. Previous and new micropalaeontological data indicate Late Oligocene-Early Burdigalian ages for the Numidian sequences of the Constantine Mountains. On the basis of petrographic study the Numidian rocks can be classified as poorly sorted quartzarenites containing siliciclastic matrix. The overall petrographic data indicate that the Continental intercalaire (Hoggar, Tassili and Fezzan) and Series Pharusienne (Hoggar and Eglab) are possible supply areas for the Numidian quartz.  相似文献   

Crustal deformation in northern Central America     

Diego Cceres  David Monterroso  Behrooz Tavakoli 《Tectonophysics》2005,404(1-2):119-131

Evaluation of the seismic moment tensor for earthquakes on plate boundary is a standard procedure to determine the relative velocity of plates, which controls the seismic deformation rate predicted from the slip on a single fault. The moment tensor is also decomposed into an isotropic and a deviatoric part to discover the relationship between the average strain rate and the relative velocity between two plates. We utilize this procedure to estimate the rates of deformation in northern Central America where plate boundaries are seismically well defined. Four different tectonic environments are considered for modelling of the plate motions. The deformation rates obtained here compare well with those predicted from the plate motions models and are in good agreement with actual observations. Deformation rates on faults are increasingly being used to estimate earthquake recurrence from information on fault slip rate and more on how we can incorporate our current understanding into seismic hazard analyses.  相似文献