1,720,992 research outputs found
DISPLAY - Distributed hybrIdSimulation PLAtform for ATM and VTS sYstems
No full textThe distributed nature and huge complexity of modern systems which are required to provide integrated services and functiona lities, move industry to achieve interoperability among heterogeneous subsystems, even spread among different countries, envisaged as the best way to allow them interoperating and to dominate overall systems’ complexity.
Such an ambitious goal, which is currently addressed by several academic and industrial European wide research initiatives, makes definitely more complicated for designers and developers the task of facing and solving integration and configuration issues of both pre-existing and under development systems. Indeed, integration among components may introduce unexpected system behaviors that usually manifest late, i.e., during systems installation and execution time, thus impacting on systems dependability and performance. Additionally, as they cannot be detected earlier, they require on-site maintenance operations resulting in increased maintenance costs and overspending in terms of personnel resources.
For this reason, industries need novel methodologies and tools to face the paradigm migration from centralized and monolithic systems to open, distributed an interconnected Systems of Systems (SoS) safely, i.e., to dominate systems complexity and to prevent costs exponential increase. If the former exhibited predictable behavior and were easier to control, since they were almost always developed in- house, the latter open new scenarios in which the companies have to deal with both third party (COTS, Commercial Off-The Shelf)and in-house (named target hereafter) developed components. A promising way to cope with these new systems, and to lower maintenance costs, is to reproduce such complex and distributed systems locally, and let them run prior to the actual execution on-site in order to get knowledge about their real behavior and define mitigation means and improvement actions. This would also represent a boost to industry competitiveness on the reference market in that it would allow to deliver higher quality solutions, in terms of both dependability and performance.
Academic and industrial research are striving significant effort in this direction, especially in the field of mission and safety critical systems which are required to exhibit predictable dependability behaviour, and for which higher complexity means complicated fault activation patterns and higher failure probabilities. Hybrid and distributed simulation strategies, supported by novel technologies for resources virtualization and working environment reproduction, represent the most promising way to define the needed strategies to actually support such paradigm shift. The aim of this project is twofold. First, it aims to follow such research trend to improve skills and renew industrial processes by investigating the existing technologies for hybrid and distributed simulation, as well as data distribution strategies on wide scale and the most advanced techniques for systems emulation. Second, it aims to realize a distributed and hybrid simulation platform, compliant with the reference standards, which is intended to provide effective support to the daily industry work in all the phases of systems lifecycle. The platform will allow reproducing on local testbeds, by combining simulation and emulation techniques, hardware and software working environments in which real systems are intended to run. On the one hand, this will enable systems designers to evaluate potential actions to undertake both for refining existing systems or designing new ones, considering system requirements evolution and operational environment changes. On the other, it will allow trying out maintenance operations needed to mitigate occurred system failures and/or to prevent estimated potential faults and security threats. This will result in two main benefits i) a significant reduction of costs in all the system life phases and ii), an increased system dependability and security level to get the ultimate in of software product quality. Also, the actual development of this platform would bring a deep innovation into industrial design and development processes, especially with respect to very large and critical systems, thus consolidating company placement on reference market sectors and boosting its penetration into new ones.
In the context of this project a system is meant as made up of a real target in charge of interoperating with COTS components through emulated network and hardware resources. The former will be simulated according to distributedsimulation pillars, whereas the latter will be emulated to reproduce their real behavior. Virtualization strategies and technique will be used, if possible, to optimize computational and communication resources in charge of connecting different parts of the system. The platform, then, will act as a glue layer among simulated components and targets, providing configuration and emulation facilities as well as virtualization capabilities to be exploited in order to reproduce the overall, distributed system, on a local testbed. Using such a platform will allow i) to perform early analysis of design and development decisions on real targets, ii) to change and adapt taken decisions according to system workload changes, iii) to plan and verify the effectiveness of maintenance operation for foreseen or already known faults, both spontaneous and malicious, thus optimizing maintenance time and costs. This will be achieved not only on the real target but also at the overall system scope thus allowing also to undertake dependability analysis and define improving solutions in terms of dependability and performances.
The platform will be validated on real world industrial case studies provided by SELEX in the field of VTS, as well as training systems for both military and civil applications. Leveraging the skills and know how gained from the COSMIC project experience, it will be developed open source, against high performance and low overhead requirements, and will aim to overcome the limitations of existing, general purpose, solutions which stand in the way of their introduction into daily industrial processes. Indeed, to the best of our knowledge, do not exist any hybrid simulation platforms able to completely fulfill SELEX needs.
The innovation introduced by the project is expected to impact on all the industry market divisions, from strategic planning and marketing, through system design and development and up to risk management sector. Then, the increased quality of delivered solutions, which will be sided by such innovative support methodologies and tools, will open new business opportunities and will enable SELEX to face next future market needs successfully.
Additionally, projects results and outcomes will boost industries competitiveness on the target region (i.e., regione di convergenza)
Finite-difference approximation of energies in fracture mechanics
No full textWe provide a variational approximation by finite-difference energies of free-discontinuity functionals depending on the symmetrized gradient, which are related to variational models in fracture mechanics for linearly-elastic materials. We perform this approximation in dimension 2 via both discrete and continuous functionals. In the discrete scheme we treat also boundary value problems and we give an extension of the approximation result to dimension 3
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Dynamic simulation of the structural behaviour of aluminium carbodies for the analysis of ride comfort in rail vehicles
No full textAppropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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