49 research outputs found
Optimizing network robustness via Krylov subspaces
We consider the problem of attaining either the maximal increase or reduction
of the robustness of a complex network by means of a bounded modification of a
subset of the edge weights. We propose two novel strategies combining Krylov
subspace approximations with a greedy scheme and an interior point method
employing either the Hessian or its approximation computed via the
limited-memory Broyden-Fletcher-Goldfarb-Shanno algorithm (L-BFGS). The paper
discusses the computational and modeling aspects of our methodology and
illustrates the various optimization problems on networks that can be addressed
within the proposed framework. Finally, in the numerical experiments we compare
the performances of our algorithms with state-of-the-art techniques on
synthetic and real-world networks
WEARABLE MIXED REALITY SOLUTIONS FOR INDUSTRIAL PLANTS AND PRODUCTION LINES
In the present research project, the authors developed wearable and portable solutions capable to improve safety in production lines by taking advantages of availability of exhaustive and reliable data in modern industrial plants. Indeed, the synergy between Industry 4.0 and cutting edge devices, such as smartphones and headsets for Mixed Reality demonstrated to be potentially used to assist personnel on the shop floor,
especially during critical and most dangerous operations. In this paper it is presented an ongoing project devoted to develop such support systems and to evaluate their efficiency in multiple industrial environments
Disasters and emergency management in chemical and industrial plants: Drones simulation for education and training
The use of simulation for training is proven to be extremely effective both in term of costs and in term of its flexibility for different uses and applications, such as building situation awareness and creating scenarios for training scopes. The aim of the project proposed is to demonstrate the powerful rule of simulation in UAV pilots\u2019 cooperative training; the project presented makes use of a 3D simulation environment in order to build a realistic condition of an emergency situation in a chemical plant for the first responders. The model proposed makes use of HLA (High Level Architecture) standards in order to be potentially federated with other existing simulators. In the solution proposed, the pilot of the drone must accomplish the mission in a given time piloting a UAV; the scenario is based inside a chemical plant where a disaster is newly occurred. Then ability of the pilot is measured by the system and several constraints are reproduced to provide a realistic training scenario (such as small spaces and barriers to overcome, battery durations, risks of damages due to high temperatures zones, etc.); the system records and tracks all the actions of the pilot and gives a feedback to the user at the end of the simulation time
Left atrial strain in patients with β-thalassemia major: a cross-sectional CMR study
Objectives The aim of this cross-sectional study was to investigate the association of left atrial (LA) strain parameters
with demographics, clinical data, cardiovascular magnetic resonance (CMR) fndings, and cardiac complications (heart
failure and arrhythmias) in a cohort of patients with β-thalassemia major (β-TM).
Materials and methods We considered 264 β-TM patients (133 females, 36.79 ± 11.95 years) consecutively enrolled
in the Extension-Myocardial Iron Overload in Thalassemia (E-MIOT) project. Moreover, we included 35 sex- and agematched healthy controls (14 females, mean age 37.36 ± 17.52 years). Reservoir, conduit, and booster LA functions
were analysed by CMR feature tracking using dedicated software.
Results Compared to the healthy control group, β-TM patients demonstrated lower LA reservoir strain and booster
strains, as well as LA reservoir and booster strain rates. However, no diferences were found in LA conduit deformation parameters. In β-TM patients, ageing, sex, and left ventricle (LV) volume indexes were independent determinants
of LA strain parameters. The number of segments with late gadolinium enhancement (LGE) signifcantly correlated
with all LA strain parameters, with the exception of the LA conduit rate. Patients with cardiac complications exhibited
signifcantly impaired strain parameters compared to patients without cardiac complications.
Conclusion In patients with β-TM, LA strain parameters were impaired compared to control subjects, and they exhibited a signifcant correlation with the number of LV segments with LGE. Furthermore, patients with cardiac complications had impaired left atrial strain parameters.
Clinical relevance statement
In patients with β-thalassemia major, left atrial strain parameters were impaired compared to control subjects
and emerged as a sensitive marker of cardiac complications, stronger than cardiac iron levels
AUTONOMOUS SYSTEMS & SAFETY ISSUES: THE ROADMAP TO ENABLE NEW ADVANCES IN INDUSTRIAL APPLICATIONS
The paper addresses the safety issues related to the development of new solutions based on autonomous systems for industrial applications and the necessity to develop experimental environments for investigating these cases; a set of examples is proposed in order to provide cases and challenges as well as to suggest approaches to address these problems
Roe and fallow deer: are they compatible neighbours?
International audienceThe analysis of the relationships between population density and habitat features is important to evaluate the ecological needs of a species, its potential impact on ecosystems and its interspecific interactions. We analysed the spatial variation of roe deer and fallow deer densities in a Mediterranean area in summer 2007 and winter 2007/2008. Previous research has shown that fallow deer can actively displace and exclude roe deer from natural feeding sites. Here we show that both species have the greatest densities in ecotone habitats between wood and open fields (abandoned olive groves and pastures), but with contrasting geographic patterns. The fallow deer showed the greatest densities in the central northern part of the study area near to local historical release sites. The densities of roe deer were great where fallow deer were rare and low where fallow deer were abundant. Spatial overlap was great at the habitat scale, indicating a high potential for competition, but was low at the plot scale, suggesting that partitioning of space occurred at a fine scale. Supporting great numbers of deer, the ecotone areas are crucial for the management of ecosystems. We suggest that roe deer avoid areas with great densities of fallow deer and that interspecific interference from the latter affects the density and distribution of the former both at a fine and at a large scale
La sostenibilità in azienda e le sue interrelazioni con il controllo di gestione ed i sistemi di misurazione delle performance.
Il presente lavoro si concentra sul ruolo della sostenibilità all'interno della vita aziendale, prendendo in considerazione le interrelazioni delle dinamiche socio-ambientali con il controllo di gestione ed i sistemi di misurazione delle performance. Alla luce dell'importanza sempre più crescente di questi concetti tra gli stakeholders, le aziende hanno la necessità di implementare e costituire meccanismi e sistemi che permettano di monitorare non più solo le variabili economiche-finanziarie ma, anche, tutto ciò che è connesso al tema della sostenibilità. All'interno del presente lavoro, dopo aver passato in rassegna i principali filoni di studio relativi alla sostenibilità, verrà proposti alcuni cruscotti dediti al monitoraggio di tale variabile, per poi terminare con due casi studio.
This paper focuses on the role of sustainability within corporate life, considering the interrelationship of socio-environmental dynamics with management control and performance measurement systems. In light of the ever-increasing importance of these concepts among stakeholders, companies need to implement and set up mechanisms and systems that enable them to monitor not only economic-financial variables but also everything related to the issue of sustainability. In this paper, after reviewing the main lines of study related to sustainability, some dashboards dedicated to monitoring this variable will be proposed, ending with two case studies
Modeling and performance simulation of EPC Gen2 RFID on OPNET
The proliferation of the RFID (Radio-Frequency IDentification) technology in the last decade shows its importance as effective solution for a large variety of applications. Actually, an accurate RFID modeling and the associated performance analysis via simulation is strongly desired. In this paper, the authors present the modeling and performance simulation of EPC Gen 2 RFID on OPNET Modeler, a popular, comprehensive and industry's leading network modeling and simulation platform. Thanks to these accurate reader and tag models is possible to accurately analyze the tag collision problem, to quickly evaluate the performance in both static and dynamic application scenarios, as well as to justify some technical configurations. Moreover, such models represent a fundamental tool for the development of innovative tag anti-collision algorithms