1,147 research outputs found
A method for describing the uncertainty in geophysical models
Geophysical models are more and more complex and can describe, in a very careful way, the geodynamical processes. These models depend on several geometrical and physical parameters, which characterize the models behaviour. These parameters are not errorless since they are known with some uncertainties. Thus, model predictions are affected by these parameter uncertainties. Usually, the model errors are not taken into account and are not propagated to the estimated quantities. This can cause improper hypothesis testing when geodetic data and model predictions are compared. In this paper, a method is presented which allows considering the model errors through the definition of the spatial covariance function of the model. A simulation is set up to prove the method feasibility
Is landscape of fear of macroinvertebrate communities a major determinant of mesopredator and prey activity?
Macroinvertebrate foragers play an important role on the trophic structures of freshwater environments, and multiple trophic levels occur among macroinvertebrate communities providing very interesting scenarios for testing scientific hypotheses. One of the most intriguing aspect to understand is the role played by the landscape of fear (LOF) on macrobenthos density and activity. With this pilot study we wanted to test if LOF at the macrobenthos community levels plays a role in determining the density of both prey and mesopredators. During two consecutive years, we evaluated, with both day and night surveys, the density of two mesopredator triclad species and of one detritivore prey crustacean species, and we compared them to the number of respective predators occurring in the macroinvertebrate community. LOF levels at the macroinvertebrate community did not reduce the abundance of the target taxa. One of the triclad species was instead positively related to the levels of LOF assessed for it on the basis of the available knowledge. The broad implication of the research is that the abundance of freshwater macroinvertebrates is not mainly linked to the predation risk at the community level, suggesting that also for researches on macrobenthos LOF analyses should take in consideration the role of top predators
Applicazione delle spettroscopie ERS ed ENDOR allo studio dei moti intra- ed intermolecolari relativi alle asociazioni ioniche di substrati organici con metalli alcalini
Following a previous review on the subject, the advanced spectroscopic techniques employed to investigate the intra and intermolecular motions in ion pairs are critically examined by considering the most important systems studied into the literature. In particular the application of ENDOR (Electron Nuclear Doublc Resonance) spectroscopy to investigate the dynanics of ion pairs is widely discussed
The worldwide physical height datum project
AbstractThe definition of a common global vertical coordinate system is nowadays one of the key points in Geodesy. With the advent of GNSS, a coherent global height has been made available to users. The ellipsoidal height can be obtained with respect to a given geocentric ellipsoid in a fast and precise way using GNSS techniques. On the other hand, the traditional orthometric height is not coherent at global scale. Spirit levelling allows the estimation of height increments so that orthometric heights of surveyed points can be obtained starting from a benchmark of known orthometric heights. As it is well known, this vertical coordinate refers to the geoid, which is assumed to be coincident to the mean sea level. By means of a tide gauge, the mean sea level is estimated and thus a point of known orthometric height is defined. This assumption, which was acceptable in the past, became obsolete given the level of precision which is now required. Based on the altimetry observation, one can precisely quantify the existing discrepancy between geoid and mean sea level that can amount to 1 ÷ 2 m at global scale. Therefore, different tide gauges provide biased estimates of the geoid, given the discrepancy between this equipotential surface and the mean sea level. Also, in the last years, another vertical coordinate was used, the normal height that was introduced in the context of the Molodensky theory. In this paper, a review of the existing different height systems is given and the relationships among them are revised. Furthermore, an approach for unifying normal height referring to different tide gauges is presented and applied to the Italian test case. Finally, a method for defining a physical height system that is globally coherent is discussed in the context of the definition of the International Height Reference System/Frame, a project supported by the Global Geodetic Observing System of the International Association of Geodesy (IAG). This project was established in 2015 during the XXVI IAG General Assembly in Prague as described in IAG Resolution no. 1 that was presented and adopted there
GNSS methods in dam monitoring: case studies and future perspectives
GNSS receivers are nowadays commonly used in monitoring applications, e.g. in estimating crustal and infrastructure deformations. This is basically due to the recent improvements in GNSS instruments and methodologies that allow high precision positioning, 24h availability, semiautomatic data processing.
In this paper, we use GNSS technique to monitor dam deformation behaviour comparing results with outcomes from pendulum observations that thanks to their reliability and high accuracy can be considered as reference. The study has been carried out for two dams in Sardinia: the Genna Is Abis on Rio Cixerri, and the Eleonora D’Arborea called also Cantoniera dam. Appropriate analytical models of dam deformation depending on time, reservoir water level, air and water temperature have been estimated using pendulum data (for Genna Is Abis dam) and GNSS data (for Cantoniera dam). Both reference models were able to properly fit respectively pendulum data and GNSS data, with standard deviation of residuals lower than one
millimeter. Furthermore the Genna Is Abis reference deformation model deduced by pendulum was compared with estimated displacement from GNSS observations and standard deviation of the residuals was still lower than one millimeter. For the send model estimated at Cantoniera dam the comparison with pendulum data gave residual with mean around zero and standard deviation of lower than two millimiter.
These encouraging outcomes open new perspectives in the study of deformations of structures that foresee the GNSS technique as complementary monitoring instrumentation especially for medium-long time intervals
Il pianeta delle scimmie: una discussione critica delle nozioni di “neuromania” e “darwinite” in Raymond Tallis
Riassunto: Il presente articolo discute criticamente il volume di Raymond Tallis Aping Mankind. Neuromania, Darwinitis and the Misrepresentation of Humanity. I temi principali sono qui riassunti e commentati brevemente. Tallis descrive alcune delle interpretazioni più strettamente riduzioniste dei risultati delle neuroscienze contemporanee, definendole “neuromania” e “darwinite”. L’autore del libro in esame difende invece un naturalismo filosofico non riduzionista, in grado di valorizzare i guadagni scientifici più recenti, senza per questo sminuire la significatività di altre discipline umanistiche.Parole chiave: Naturalismo; Neuroscienza; Filosofia della biologia; Raymond Tallis; Scientismo. Planet of the Apes: A Critical Examination of Raymond Tallis’ Idea of “Neuromania” and “Darwinitis”Abstract: This paper presents a critical examination of Raymond Tallis’ Aping Mankind. Neuromania, Darwinitis and the Misrepresentation of Humanity. The main themes are summarized and briefly discussed. Tallis presents some of the most extreme reductionist interpretations of contemporary neurosciences, and labels them “neuromania” and “darwinitis”. He proposes instead a non-reductionist philosophical naturalism, one that, according to him, is able to value the latest scientific achievements, without reducing the importance of other humanistic branches of knowledge.Keywords: Naturalism; Neuroscience; Philosophy of Biology; Raymond Tallis; Scientism
Um bolero sobre ruínas: respostas poéticas do Mapa Teatro frente à renovação urbana
This paper presents some works from Mapa Teatro artists’ laboratory carried out in response to an urban renewal project in the late 1990s in Bogotá. The project of Parque Tercer Milenio, which displaced around 12,000 people living in the city center, led the group to collaborate with former residents of the neighborhood, forming an experimental community. The interventions by Mapa Teatro are brought here as a way to contemplate how it is possible to respond poetically to the brutalization of urban spaces.Este artigo apresenta algumas obras do laboratório de artistas Mapa Teatro realizadas como resposta a um projeto de renovação urbana no final dos anos 1990 em Bogotá. O projeto do Parque Tercer Milenio, que desalojou cerca de 12 mil pessoas vivendo no Centro da cidade, levou o grupo a trabalhar com antigos moradores do bairro, constituindo uma comunidade experimental. As intervenções do Mapa Teatro são trazidas aqui como forma de pensar como é possível responder poeticamente à brutalização dos espaços urbanos
A shared database of underground utility lines for 3D mapping and GIS applications
For the purpose of facility management it is very important to have detailed and up-to-date databases of underground utility lines,
but such data are not always available with adequate accuracy. Hence, the need of collecting and organizing suitable information on
underground services is a fundamental issue when dealing with urban data. Besides, by analyzing the process of designing and laying
new underground infrastructures it is possible to implement an efficient and cost-effective approach to integrate and update existing
maps by exploiting the surveying required for the installation of new facilities. It is also important to underline that collecting all the
data in a unique integrated database (and GIS) gives the possibility to share (at least at a local level) the cartographic and thematic
information for an optimal management of underground networks. In this paper, a database (DB) model for archiving the
underground lines data is presented. The structure of the DB has been designed by following the standard methodology for the
modelling of a relational DB, going through successive phases and originating the external, conceptual and logical model. Finally,
preliminary tests have been carried on for parts of the DB to verify quality parameters
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