1,724,952 research outputs found
SISTEMA MODULARE PER LA DISTRIBUZIONE DI UNA CHIAVE QUANTISTICA E RELATIVI MODULO DI MODULAZIONE E MODULO DI DEMODULAZIONE
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Contributes to accessibility and usability: the case of the Web site of a research institute
No full textCreating a web site is a complex task which involves many aspects such as massive information structure, information daily updating, accessibility and usability issues. It is crucial to plan in details a site and its future maintainability, structuring information and, at the same time, it's important to write pages in a way suitable by assistive technologies used by people with disabilities, which represent a significant percentage of the users. Aim of this paper is to analyze specific solutions we have adopted to improve the Web site of the Institute of Information Science and Technologies ( http://www.isti.cnr.it/ ), an institute of the National Research Council (ISTI-CNR), in terms of accessibility and usability, like ordered lists for adjacent links, heading levels and hidden labels, automatic assignment of tabbing order. Some approaches to Web pages development, in order to make easy to create a site, are also discussed
Comparison of different propeller boss cap fins design for improved propeller performances
No full textThe performances of different Propeller Boss Cap Fins devices, designed with the aid of a Simulation Based Design Optimization approach, are analysed and compared. A novel configuration, i.e., a PBCF inside a nozzle, is investigated in an effort to mitigate possible side effects of conventional Propeller Boss Cap Fins, such as secondary vortical structures from the fins tip, increased pressure pulses and radiated noise, without excessive worsening of the beneficial effects (increased propulsive efficiency) provided by this energy saving device. Detailed analyses reveal, instead, the destabilizing effect of the hub vortical structures on the blade tip vortex evolution, determining a substantial increase of the radiated noise of this type of propulsors
Pseudo time reversal operators for the state of polarization
No full textThe existence of three generalized mirrors (Martinelli and Martelli, 2017) that compensate for the effects of birefringence in retracing optical circuits allows to develop a parallel with the time reversal properties. The Wigner time reversal operator for the photon spin is considered and three pseudo time reversal operators borrowed from this original operator are introduced and analysed. Their application to different birefringence situations demonstrates the validity and the fertility of the approach
Pre- and post-swirl fins design for improved propulsive performances
No full textPre- and post-swirl fins-based energy-saving devices (ESD) are designed to improve the propulsive performances of a twin-screw ship. To this aim, BEM and RANSE calculations are employed. Depending on the application, a simple actuator disc model (post-swirl) with radially varying load or a combined BEM/RANSE method for self-propulsion prediction (pre-swirl) are required. Both the approaches are included in a framework for a design by optimization, where systematic variations of the ESD geometry are used to explore the design space and maximize the energy-saving effect of the devices. Considering the particularity of the case selected for the study, results show encouraging improvements that reach a promising 5% in the case of the combined action of both devices
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