132,727 research outputs found
D-NAV – Dynamic Navigator
No full textNavigatore satellitare dinamico con logica client-server per dispositivi di telefonia mobile, fondato su un approccio partecipativo in cui gli utenti fungono anche da veicoli sonda che possono contribuire ad alimentare OPTIMA; registrato presso la SIAE in data 17.02.2009 con il n. 707
Spazio Ricerca, Anno IV, n. 7, "luci e ombre" (a cura di) Santuccio S., Dardi D., giugno 2006, edizioni Kappa, Roma.
No full textAn approach towards the construction of a Digital Atlas for the documentation of cloister and courtyards in Ascoli Piceno
No full textThe following article aims to present the results of a research experience that defines a geographic information system oriented at the architecture of closed areas of cloisters and courtyards of the historic center of Ascoli Piceno. This experimentation is part of the scenery of documentation's activities for the management and the enhancement of urban environmental improvements through the use of integrated technologies closed and open source. Therefore the main object of the analysis was the architectural one, in its different, articulated and individual features, but always considered in relation to the same geographical location, in this case the urban space, consequently focused not only on the object itself, but also on the relationship between this and any other similar ones. In this sense, the tested geographic information system is intentionally hybrid. We wanted to check the possibility of binding different shape and nature data to the "map" by structuring in a well organized manner different information – drawings, videos, photos, 3D, etc.. – in order to realize a GIS that would allow to analyze the architecture of cloisters and courtyards both in its relations to the urban context and in its specific spatial qualities
Effects of mitral chordae tendineae on the flow in the left heart ventricle
No full textAbstract.: In this paper a computational model for the ventricular flow with a mitral valve and modeled chordae tendineae is presented. The results are compared with an analogous case in which the chordae are not included and their presence is replaced by kinematic boundary conditions. The problem is studied using direct numerical simulation of the Navier-Stokes equations, two-way coupled with a structural solver for the ventricle and mitral valve dynamics. An experimental validation of the model is performed by a comparison of the results with a companion dedicated experiment. It is found that the inclusion of the chordae tendineae makes the model self-consistent thus avoiding the use of ad hoc kinematic constraints to mimic their effect. In this way it is possible to simulate the correct system dynamics without user-defined parameters. More in detail, the results have shown that the mitral valve dynamics can be described also without chordae with the help of ad hoc kinematic constrains, whereas the changes produced in the intra-ventricular flow need the explicit consideration of the chordae in the model. On the other hand, the computational load increases owing to the presence of additional structures that, being thin filaments, are also demanding for the spatial resolution requirements. Since the presence of the chordae tendineae produces only specific differences in the overall flow structure, we conclude that their explicit modeling should be limited to those cases in which their presence is unavoidable. Graphical abstract: [Figure not available: see fulltext.]
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Modeling and analysis of the tritium fuel cycle for ARC- and STEP-class D-T fusion power plants
No full textThe limited tritium resources available for the first fusion power plants (FPPs) make fuel self-sufficiency and tritium inventory minimization leading issues in FPP design. This work builds on the model proposed by Abdou et al (2020 Nucl. Fusion 61 013001), which analyzed the fuel cycle (FC) of a DEMOnstration nuclear FPP-class FPP with a time-dependent system-level model. Here, we use a modified version of their model to analyze the FC of an Affordable, Robust, Compact (ARC)-class tokamak and two versions of a Spherical Tokamak for Energy Production (STEP)-class tokamak. The ARC-class tokamak breeds tritium in a 2LiF + BeF2 liquid immersion blanket, while the STEP-class tokamak breeds tritium utilizing either a liquid-lithium blanket design or an encapsulated breeding blanket. A time-dependent system-level model is developed in Matlab Simulink® to simulate the evolution of tritium flows and tritium inventories in the FC. The main goals of this work are to assess tritium self-sufficiency of the ARC- and STEP-class designs and to determine quantitative design requirements that can be used to analyze the adequacy of a proposed FC system. These design requirements are aimed at achieving a low tritium inventory doubling time ( t d ) and a low start-up inventory ( I s t a r t u p ) while keeping the required tritium breeding ratio (TBR r ) as low as possible. We also consider how improvements in FC technology and POs affect TBR r and I s t a r t u p . The model results show that TBR r for ARC- and STEP-class FPPs should be achievable if the tritium burn efficiency (TBE) reaches 0.5%-1% (TBR r 70%, tritium processing time < 4 h, and the implementation of direct internal recycling (DIR). If future research yields major improvements to achievable TBE, it may be possible to achieve tritium self-sufficiency while operating at lower availability and without implementing DIR
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Radiological source terms estimation for the Divertor Tokamak Test (DTT) facility
No full textThe Divertor Tokamak Test (DTT) facility will start its operations in 2026. DTT will operate with D-D fuel only, for an expected operational period of 25 years. Nevertheless, tritium will be produced by the D(d,p)T reaction. A mandatory step in the safety assessment of the machine is the estimation of the different source terms. Major contributions to the source terms are due to tritium and to activated dust. The amount of tritium in the vacuum chamber, in co-deposited tungsten layers and implanted in the bulk of the first wall is computed in this work. Also, a preliminary estimation of dust production due to inter and intra ELMs sputtering is carried out. Results report small amount of source terms related to tritium, below 1 mg after one year of full power operations, and less than 300 g of activated dust at the end of life
Methodology for O-D matrix estimation using the revealed paths of floating car data on large-scale networks
No full textThe increasing availability of historical floating car data (FCD) represents a relevant chance to improve the accuracy of model-based traffic forecasting systems. A more precise estimation of origin-destination (O-D) matrices is a critical issue for the successful application of traffic assignment models. The authors developed a methodology for obtaining demand matrices without any prior information, but just starting from a data set of vehicle trajectories, and without using any assignment model, as traditional correction approaches do. Several steps are considered. A data-driven approach is applied to determine both observed departure shares from origins to destinations and static assignment matrices. Then the O-D matrix estimation problem is formulated as a scaling problem of the observed FCD demand and carried out using as inputs: a set of traffic counts, the FCD revealed assignment matrix and the observed departure shares as an a-priori matrix. Four different optimisation solutions are proposed. The methodology was successfully tested on the network of Turin. The results highlight the concrete opportunity to perform a data-driven methodology that, independently from the reliability of the reference demand, minimises manual and specialised effort to build and calibrate the transportation demand models
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