Search results for " Wind"
showing 10 items of 403 documents
Energy and economic assessment of a small domestic wind turbine in Palermo
2016
The cost effectiveness of micro-wind technology is closely linked to the annual energy production plants, which strongly depends on the wind characteristics and on the morphological properties of the installation site. The power curve of a wind turbine, supplied by manufacturers, characterizes the theoretical energy performance that it should have at a particular site. The behavior of a wind turbine in the field is affected by the speed but also by wind direction variations. At each change of direction and speed, the turbine will try to adapt to new conditions and the phase transition negatively influences the energy production. In order to experimentally confirm what above mentioned, the a…
Determination of the Time Window of Event-Related Potential Using Multiple-Set Consensus Clustering
2020
Clustering is a promising tool for grouping the sequence of similar time-points aimed to identify the attention blocks in spatiotemporal event-related potentials (ERPs) analysis. It is most likely to elicit the appropriate time window for ERP of interest if a suitable clustering method is applied to spatiotemporal ERP. However, how to reliably estimate a proper time window from entire individual subjects’ data is still challenging. In this study, we developed a novel multiset consensus clustering method in which several clustering results of multiple subjects were combined to retrieve the best fitted clustering for all the subjects within a group. Then, the obtained clustering was processed…
Determination of the Time Window of Event-Related Potential Using Multiple-Set Consensus Clustering
2020
Clustering is a promising tool for grouping the sequence of similar time-points aimed to identify the attention blocks in spatiotemporal event-related potentials (ERPs) analysis. It is most likely to elicit the appropriate time window for ERP of interest if a suitable clustering method is applied to spatiotemporal ERP. However, how to reliably estimate a proper time window from entire individual subjects’ data is still challenging. In this study, we developed a novel multiset consensus clustering method in which several clustering results of multiple subjects were combined to retrieve the best fitted clustering for all the subjects within a group. Then, the obtained clustering was processed…
Modelling the effect of porosity on the mechanical properties of unidirectional composites. The case of thick-walled pressure vessels
2018
International audience; The present article highlights morphological features present in composite pressure vessels. The use of X-ray microtomography provides three-dimensional information about the voids in a large thick-walled type 3 pressure vessel at the mesoscopic scale. The observations show that the porosity structure depends strongly on composite thickness and orientation. A numerical approach is proposed to model realistically the damage phenomena in pressure vessels.
Rain on building façades
2006
Rain is one of the main causes of moisture damage to the building envelope, leading to problems such as rain penetration, frost and salt damage, discoloration by leaching, soiling by differential washing, etc. The potential of deterioration due to rain depends on the façade material, the junction of building envelope components, the overall geometry of the building, but also the presence or absence of modulation on the façade. In this paper, Computational fluid dynamics (CFD) simulations are used to analyze these effects and illustrated with examples taken in Sicily. It is firstly shown that buildings protect themselves from driving rain due to the wind blocking effect, but that façade open…
Nano-graphite cold cathodes for electric solar wind sail
2015
The nanographite (NG) films consisting of tiny graphite crystallites (nanowalls) are produced by carbon condensation from methane–hydrogen gas mixture activated by a direct current discharge. High aspect ratio and structural features of the NG crystallites provides efficient field electron emission (FE). Applicability and performance of the NG films in an electron gun (E-gun) of a solar wind thruster system with an electric sail (E-sail) is tested. The long-term tests are demonstrated suitability of E-gun assembly with the NG cathodes for the real space missions. The results of the tests are analyzed and physical mechanisms of the cathode aging and practical methods for improvement performa…
Modeling foreign exchange market activity around macroeconomic news: Hawkes-process approach
2015
We present a Hawkes-model approach to the foreign exchange market in which the high-frequency price dynamics is affected by a self-exciting mechanism and an exogenous component, generated by the pre-announced arrival of macroeconomic news. By focusing on time windows around the news announcement, we find that the model is able to capture the increase of trading activity after the news, both when the news has a sizable effect on volatility and when this effect is negligible, either because the news in not important or because the announcement is in line with the forecast by analysts. We extend the model by considering noncausal effects, due to the fact that the existence of the news (but not…
Impact of pharmacological and environmental manipulations on neuronal structural plasticity and dynamics
2017
El sistema nervioso de vertebrados es uno de los más estudiados, aunque peor comprendidos, del organismo de mamíferos. Desde que Ramón y Cajal postuló su teoría celular de este sistema (Ramón y Cajal 1909), la neurona se ha postulado como su unidad funcional. Sin embargo, durante las últimas décadas se ha revolucionado la visión que se tenía de éste. Una de las percepciones más asentadas era que, tras el desarrollo embrionario, el sistema nervioso se mantenía inmutable. Sin embargo, ahora sabemos que diferentes formas de plasticidad gobiernan su adaptación, que son necesarias para importantes procesos del día a día, tales como el aprendizaje y la memoria (Smythies 2002; Berlucchi and Buchte…
Usage des organisateurs anti-entropique dans les documents électroniques : approche expérimentale des fenêtres ponctuelles
1999
International audience; Les documents électroniques permettent de nombreuses manières d'organiser, de présenter et d'accéder à l'information. Une utilisation pertinente de ces options par les auteurs requiert une bonne connaissance des effets que ces choix ont sur la représentation cognitive et les traitements faits par l'utilisateur. Cette approche des documents électroniques, sur la base du concept de représentation mentale, fournit un cadre d'analyse des structures et signaux propres à ce type d'écriture. Parmi ces signaux que nous appelons « organisateurs para-linguistiques » pour les distinguer de leurs équivalents purement textuels, un ensemble est destiné à réduire l'entropie due à l…
Intégrer des informations en escamots dans les textes techniques : quels effets sur les processus cognitifs ?
1998
Though computerized sytems now offer a wide range of options for accessing and displaying text or text-picture information, little is known about their effects on the user's cognitive processes. In this paper, we investigate the effect of a computer-specific display (pop-up window) which consists in displaying some pieces of information in windows that appear only under user's action. Experiments were carried out to compare the pop-up window device with other devices used on paper. The experiments dealt with text only as well as text-picture documents and involved various tasks. Results are discussed from a theoretical and a practical point of view.