Search results for " Geology"
showing 10 items of 533 documents
Comparative Analysis of Four New Alternative Types of Roundabouts: “Turbo”, “Flower”, “Target” and “Four-Flyover” Roundabou
2016
Analysis of literature shows that “modern roundabouts” nowadays exist in all European countries, as well as in more than 60 countries elsewhere in the world. Nowadays, a growing number of studies, presented in scientific and professional literature, point out a poor traffic safety characteristics of “standard” two-lane roundabouts and lower capacity then was expected. These problems are resolved in more ways in different countries; however the solution, whereby the number of conflict spots is diminished has proven to be the most successful. Lower number of conflict spots is one of characteristics of the alternative types of roundabouts. The alternative types of roundabouts are usually more …
Analysis of the chemical and microstructural modifications effects on the hydro-mechanical behaviour of a lime-treated clay
2019
The paper presents the results of a characterization of kinetic characteristics of pozzolanic reaction with the aim to investigate the time-dependent modification of clay properties as a consequence of mixing with lime. Results of chemical analyses are in agreement with the increase of mechanical properties and with the observed microstructure modifications up to one year of curing time. The rate of development of pozzolanic reactions seems to be almost constant while the time required for their completion is dependent on the lime content. Pozzolanic products are responsible for the time reduction of swelling strain upon saturation as well as for the increases of yielding stress, stiffness …
Drones - New technologies for geophysics?
2015
Drones, also referred as Unmanned Aircraft Systems (UAS), Unmanned Aerial Vehicles (UAV) or Remotely Piloted Aircraft (RPA), are aircraft without pilot on board. USA is today the leading country in the field of UAS but recently, seven European countries have pledged to launch joint programs for drones, with the aim of producing the next generation of UAS before 2020. According to some studies on the potential market of UAS in Europe, the geoscience sector is definitely one of the most promising. In this paper, we bring a short description and classification of drones, according to their sized and shaped, with particular attention to the advantages and drawbacks of each type in reference to …
The reaction structure of the LEDA research centre: Development and design
2017
In the last twenty years, the field of earthquake engineering experienced a noticeable improvement. The results of experimental and theoretical researches have contributed to the development of modern technical codes, which provide innovative solutions for the structural assessment and new design approaches. Despite this large amount of improvements, several open questions are still open, and the need for large scale testing has been deeply proved and discussed. A new research facility, namely the Laboratory of Earthquake engineering and Dynamic Analysis (LEDA), has been recently completed at the University of Enna "Kore". This research centre, funded with a grant from Italian Ministry of E…
Gastropod evidence against the Early Triassic Lilliput effect
2010
4 pages; International audience; Size reduction in the aftermath of the Permian-Triassic mass extinction event has repeatedly been described for various marine organisms, including gastropods (the Lilliput effect). A Smithian gastropod assemblage from Utah, USA, reveals numerous large-sized specimens of different genera as high as 70 mm, the largest ever reported from the Early Triassic. Other gastropods reported from Serbia and Italy are also as large as 35 mm. Size frequency distributions of the studied assemblages indicate that they were not unusually small when compared with later Mesozoic and modern faunas. The occurrence of large-sized gastropods less than 2 Ma after the Permian-Trias…
Vladimir P. Amalitsky and Dmitry N. Sobolev – late nineteenth/ early twentieth century pioneers of modern concepts of palaeobiogeography, biosphere e…
2017
The great palaeontological achievements of the Russian scientists Amalitsky and Sobolev, who worked in Russia and Poland at the turn of nineteenth and twentieth centuries, have previously been outlined in detail. However, their original and surprisingly modern concepts of the development of life on earth have received far less attention. Amalitsky was one of the first scholars who considered the intimate relationship between floral and faunal evolution and the interdependence between a developing biosphere and geological processes. In fact, he documented, for the first time, the existence of a single palaeobiogeographical province during the Permian Period, which we now refer to as the supe…
Efficient Nonlinear RX Anomaly Detectors
2020
Current anomaly detection algorithms are typically challenged by either accuracy or efficiency. More accurate nonlinear detectors are typically slow and not scalable. In this letter, we propose two families of techniques to improve the efficiency of the standard kernel Reed-Xiaoli (RX) method for anomaly detection by approximating the kernel function with either {\em data-independent} random Fourier features or {\em data-dependent} basis with the Nystr\"om approach. We compare all methods for both real multi- and hyperspectral images. We show that the proposed efficient methods have a lower computational cost and they perform similar (or outperform) the standard kernel RX algorithm thanks t…
Accounting for Input Noise in Gaussian Process Parameter Retrieval
2020
Gaussian processes (GPs) are a class of Kernel methods that have shown to be very useful in geoscience and remote sensing applications for parameter retrieval, model inversion, and emulation. They are widely used because they are simple, flexible, and provide accurate estimates. GPs are based on a Bayesian statistical framework which provides a posterior probability function for each estimation. Therefore, besides the usual prediction (given in this case by the mean function), GPs come equipped with the possibility to obtain a predictive variance (i.e., error bars, confidence intervals) for each prediction. Unfortunately, the GP formulation usually assumes that there is no noise in the inpu…
Warped Gaussian Processes in Remote Sensing Parameter Estimation and Causal Inference
2018
This letter introduces warped Gaussian process (WGP) regression in remote sensing applications. WGP models output observations as a parametric nonlinear transformation of a GP. The parameters of such a prior model are then learned via standard maximum likelihood. We show the good performance of the proposed model for the estimation of oceanic chlorophyll content from multispectral data, vegetation parameters (chlorophyll, leaf area index, and fractional vegetation cover) from hyperspectral data, and in the detection of the causal direction in a collection of 28 bivariate geoscience and remote sensing causal problems. The model consistently performs better than the standard GP and the more a…
Effect of FRP strengthening on the flexural behaviour of calcarenite masonry walls
2017
The use of fiber-reinforced polymers (FRP) for structural strengthening has become increasingly popular in recent years. Several applications of FRP have been proposed and applied, depending on the target of the technique, kind and/or material of the structural member. In particular, because of their great tensile strength, FRP materials are commonly used to enhance the out-of-plane behaviour of masonry walls, allowing to increase their strength, ductility and improving safety against overturning. For these reasons, FRP laminates are often applied in vulnerable ancient buildings in seismic areas to reinforce façades and walls with poor structural features. However, some issues arise when a…