6,141 research outputs found

    Further Extended Theories of Gravitation: Part I

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    We shall here propose a class of relativistic theories of gravitation, based on a foundational paper of Ehlers Pirani and Schild (EPS).All "extended theories of gravitation" (also known as f(R) theories) in Palatini formalism are shown to belong to this class. In a forthcoming paper we shall show that this class of theories contains other more general examples. EPS framework helps in the interpretation and solution of these models that however have exotic behaviours even compared to f(R) theories.Comment: 10 pages. Some refs adde

    Improved multi-user interaction in a smart environment through a preference-based conflict resolution virtual assistant

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    In this work we will examine and develop a system that can assist people in Activities of Daily Life (ADL). This study focuses on resolving conflicts for the requests from different users’ profiles, for instance - elderly, adult and young. The objective of the system is to present a dialogue manager which is able to detect multi-user semantic conflict and to resolve the conflict for improved dialogue informing about its decisions using a system interface Avatar. The system is also able to prioritize requests that occurred among the services of multiple home appliances, as well as to deal with conflicting entities involving a single device. We investigated whether the multi-user context awareness by a Virtual Assistant adds value to the Smart Home concept in recognizing multi-user conflicts dynamically. This work has proposed a preference based method for resolving conflict and evaluated the developed system in a smart home environmen

    Beam lead technology

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    Beam lead technology for microcircuit interconnections with applications to metallization, passivation, and bondin

    Geomagnetic field observations in Antarctica at the geomagnetic observatories at Terra Nova Bay and DomeC

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    During the 1986-87 austral summer a geomagnetic observatory was installed at the Italian Antarctic Base Mario Zucchelli Station (TNB, geographic coordinates:74.7S, 164.1E; corrected geomagnetic coordinates: 80.0S, 307.7E; magnetic local time MLT=UT-8). In the first years the measurements of the geomagnetic field were carried out only during summer expeditions. Since 1991 the recording was implemented with an automatic acquisition system operating through the year. More recently,after two short test surveys, from October 2004 a geomagnetic French-Italian observatory was installed on the Antarctic plateau (Dome C, DMC), very close to the geomagnetic pole (geographic coordinates: 75.1S, 123.4E; corrected geomagnetic coordinates:88.8S, 55.6E; magnetic local time MLT=UT-1). In this work we present some results obtained from TNB observations coming from almost twenty years of observations and also the preliminary results obtained from the analysis of the first year of data from DMC

    R&D results on a CsI-TTGEM based photodetector

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    The very high momentum particle identification detector proposed for the ALICE upgrade is a focusing RICH using a C4F10 gaseous radiator. For the detection of Cherenkov photons, one of the options currently under investigation is to use a CsI coated Triple-Thick-GEM (CsI-TTGEM) with metallic or resistive electrodes. We will present results from the laboratory studies as well as preliminary results of beam tests of a RICH detector prototype consisting of a CaF2 radiator coupled to a 10x10 cm2 CsI-TTGEM equipped with a pad readout and GASSIPLEX-based front-end electronics. With such a prototype the detection of Cherenkov photons simultaneously with minimum ionizing particles has been achieved for the first time in a stable operation mode

    Geomagnetic field observations in Antarctica at the geomagnetic observatories at Terra Nova Bay and DomeC

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    During the 1986-87 austral summer a geomagnetic observatory was installed at the Italian Antarctic Base Mario Zucchelli Station (TNB, geographic coordinates:74.7S, 164.1E; corrected geomagnetic coordinates: 80.0S, 307.7E; magnetic local time MLT=UT-8). In the first years the measurements of the geomagnetic field were carried out only during summer expeditions. Since 1991 the recording was implemented with an automatic acquisition system operating through the year. More recently,after two short test surveys, from October 2004 a geomagnetic French-Italian observatory was installed on the Antarctic plateau (Dome C, DMC), very close to the geomagnetic pole (geographic coordinates: 75.1S, 123.4E; corrected geomagnetic coordinates:88.8S, 55.6E; magnetic local time MLT=UT-1). In this work we present some results obtained from TNB observations coming from almost twenty years of observations and also the preliminary results obtained from the analysis of the first year of data from DMC

    Solar model with CNO revised abundances

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    Recent three-dimensional, NLTE analyses of the solar spectrum have shown a significant reduction in the C, N, O and Ne abundances leading to a Z/X ratio of the order of 0.0177. We have computed solar models with this new mixture in the OPAL opacity tables. The present He abundance we find seems rather consistent with the helioseismic value. However, the convective envelope is too shallow, and diffusion, even if it reduces the discrepancy, is not able to give the current value. We present some numerical experiments consisting in changing the diffusion velocities and/or the value of opacity at the base of the convective envelope.Comment: 3 pages, Proc. SOHO 14 - GONG 2004 Meeting, Yale, 12-16 July 2004, added reference to Basu, S., Antia, H.M., 2004, ApJ 606, L8

    I am Me:Brain systems integrate and segregate to establish a multidimensional sense of self

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    Humans experience a sense of self, which is proposed to emerge from the integration of intrinsic and extrinsic self-processing through the propagation of information across brain systems. Using a novel functional magnetic resonance imaging (fMRI) paradigm, we tested this hypothesis in a non-clinical sample by modulating the intrinsic and extrinsic self-relatedness of auditory action consequences in terms of identity and agency, respectively. In addition, the relevance of individual traits associated with altered self-experiences (e.g., psychosis-like experiences) was examined. The task-evoked fMRI results showed distinctive associations between the neural coding of identity and negative affect traits, and between agency and psychosis-like experiences. Most importantly, regarding the functional connectivity analysis, graph theoretical measures demonstrated that the simultaneous processing of identity and agency relies on the functional integration and segregation of default mode, sensorimotor, language, and executive brain networks. Finally, cross-network interactions mediated by executive and sensorimotor regions were negatively associated with psychosis-like experiences when the intrinsic and extrinsic self-relatedness of action consequences conflicted. These findings provide evidence that the self is a multidimensional phenomenon rooted in the functional interactions between large-scale neuronal networks. Such interactions may have particular relevance for self-experience alterations

    A multidisciplinary study of an exceptional prehistoric waste dump in the mountainous inland of Calabria (Italy) : implications for reconstructions of prehistoric land use and vegetation in Southern Italy

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    The mountainous inland of northern Calabria (Southern Italy) is known for its sparse prehistoric human occupation. Nevertheless, a thorough multidisciplinary approach of field walking, geophysical survey and invasive research led to the discovery of a major archaeological archive. This archive concerns a rich multi-phased dump, spanning about 3000 years (Late Neolithic to Late Imperial Roman Age) and holding two Somma-Vesuvius tephra. Of these, the younger is a distinct layer of juvenile tephra from the Pompeii eruption, while the older concerns reworked tephra from the Bronze Age AP2 eruption (ca. 1700 cal. yr BP). The large dump contains abundant ceramics, faunal remains and charcoal, and most probably originated through long-continued deposition of waste in a former gully like system of depressions. This resulted in an inversed, mound-like relief, whose anthropogenic origin had not been recognized in earlier research. The tephras were found to be important markers that support the reconstruction of the occupational history of the site. The sequence of occupational phases is very similar to that observed in a recent palaeoecological study from nearby situated former lakes (Lago Forano/Fontana Manca). This suggests that this sequence reflects the more regional occupational history of Calabria, which goes back to ca. 3000 BC. Attention is paid to the potential link between this history and Holocene climatic phases, for which no indication was found. The history deviates strongly from histories deduced from the few, but major palaeorecords elsewhere in the inlands of Southern Italy (Lago Grande di Monticchio and Lago Trifoglietti). We conclude that major regional variation occurred in prehistoric land use and its impacts on the vegetation cover of Southern Italy, and studies of additional palaeoarchives are needed to unravel this complex history. Finally, shortcomings of archaeological predictive models are discussed and the advantages of truly integrated multidisciplinary research
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