1,298 research outputs found
Plug-and-Play Model Predictive Control based on robust control invariant sets
In this paper we consider a linear system represented by a coupling graph
between subsystems and propose a distributed control scheme capable to
guarantee asymptotic stability and satisfaction of constraints on system inputs
and states. Most importantly, as in Riverso et al., 2012 our design procedure
enables plug-and-play (PnP) operations, meaning that (i) the addition or
removal of subsystems triggers the design of local controllers associated to
successors to the subsystem only and (ii) the synthesis of a local controller
for a subsystem requires information only from predecessors of the subsystem
and it can be performed using only local computational resources. Our method
hinges on local tube MPC controllers based on robust control invariant sets and
it advances the PnP design procedure proposed in Riverso et al., 2012 in
several directions. Quite notably, using recent results in the computation of
robust control invariant sets, we show how critical steps in the design of a
local controller can be solved through linear programming. Finally, an
application of the proposed control design procedure to frequency control in
power networks is presented
Plug-and-Play Decentralized Model Predictive Control
In this paper we consider a linear system structured into physically coupled
subsystems and propose a decentralized control scheme capable to guarantee
asymptotic stability and satisfaction of constraints on system inputs and
states. The design procedure is totally decentralized, since the synthesis of a
local controller uses only information on a subsystem and its neighbors, i.e.
subsystems coupled to it. We first derive tests for checking if a subsystem can
be plugged into (or unplugged from) an existing plant without spoiling overall
stability and constraint satisfaction. When this is possible, we show how to
automatize the design of local controllers so that it can be carried out in
parallel by smart actuators equipped with computational resources and capable
to exchange information with neighboring subsystems. In particular, local
controllers exploit tube-based Model Predictive Control (MPC) in order to
guarantee robustness with respect to physical coupling among subsystems.
Finally, an application of the proposed control design procedure to frequency
control in power networks is presented.Comment: arXiv admin note: text overlap with arXiv:1210.692
Plug-and-play distributed state estimation for linear systems
This paper proposes a state estimator for large-scale linear systems
described by the interaction of state-coupled subsystems affected by bounded
disturbances. We equip each subsystem with a Local State Estimator (LSE) for
the reconstruction of the subsystem states using pieces of information from
parent subsystems only. Moreover we provide conditions guaranteeing that the
estimation errors are confined into prescribed polyhedral sets and converge to
zero in absence of disturbances. Quite remarkably, the design of an LSE is
recast into an optimization problem that requires data from the corresponding
subsystem and its parents only. This allows one to synthesize LSEs in a
Plug-and-Play (PnP) fashion, i.e. when a subsystem gets added, the update of
the whole estimator requires at most the design of an LSE for the subsystem and
its parents. Theoretical results are backed up by numerical experiments on a
mechanical system
Moving horizon partition-based state estimation of large-scale systems -- Revised version
This report presents three Moving Horizon Estimation (MHE) methods for
discrete-time partitioned linear systems, i.e. systems decomposed into coupled
subsystems with non-overlapping states. The MHE approach is used due to its
capability of exploiting physical constraints on states in the estimation
process. In the proposed algorithms, each subsystem solves reduced-order MHE
problems to estimate its own state and different estimators have different
computational complexity, accuracy and transmission requirements among
subsystems. In all cases, conditions for the convergence of the estimation
error to zero are analyzed
Compiler Design for Distributed Quantum Computing
In distributed quantum computing architectures, with the network and communications functionalities provided by the Quantum Internet, remote quantum processing units (QPUs) can communicate and cooperate for executing computational tasks that single NISQ devices cannot handle by themselves. To this aim, distributed quantum computing requires a new generation of quantum compilers, for mapping any quantum algorithm to any distributed quantum computing architecture. With this perspective, in this paper, we first discuss the main challenges arising with compiler design for distributed quantum computing. Then, we analytically derive an upper bound of the overhead induced by quantum compilation for distributed quantum computing. The derived bound accounts for the overhead induced by the underlying computing architecture as well as the additional overhead induced by the sub-optimal quantum compiler--expressly designed through the paper to achieve three key features, namely, general-purpose, efficient and effective. Finally, we validate the analytical results and we confirm the validity of the compiler design through an extensive performance analysis
Le nuove Information and Communication Technologies per la conoscenza e l’accessibilità del patrimonio culturale. Il progetto INCEPTION - Inclusive Cultural Heritage in Europe through 3D semantic modelling
A un anno dal suo avvio, il progetto “INCEPTION - Inclusive Cultural Heritage in Europe through 3D semantic modelling” porta al Salone del Restauro le più recenti innovazioni tecnologiche per il rilievo tridimensionale del patrimonio culturale, frutto delle prime attività di ricerca.
Il progetto, finanziato dalla Commissione Europea nell’ambito del Work Programme "Europe in a changing world – inclusive, innovative and reflective Societies" (Call Reflective-7-2014, Advanced 3D modelling for accessing and understanding European cultural assets), a partire da metodologie innovative per il rilievo e la modellazione tridimensionale, si propone di sviluppare nuovi strumenti per l’interoperabilità e la condivisione inclusiva dei modelli tridimensionali verso nuove forme di accessibilità e conoscenza dell’identità del patrimonio culturale europeo
Long-term cropland abandonment does not lead per se to the recovery of semi-natural herb communities deemed habitats of community interest
Abandoned croplands can be considered a new category of »scattered elements« of mountain landscapes. To gain a deeper understanding of the conservation status (sensu EEC Directive 92/43) of abandoned cropland in the northern Apennines, we used the concept of the social behavior type (SBT) of plant communities. SBTs refer to the behaviour and ecological attributes of species at a given observation level and allow the understanding of the plant community conservation status. We found that topographic and soil conditions drive species assemblage in pastures after crop abandonment, but that long-term abandonment does not lead per se to the recovery of the semi-natural grassland communities deemed worthy of conservation in the EEC Directive. It was mainly the lack of appropriate disturbance regimes that allowed the spread of dominant tall herbs, which, in turn, reduced site suitability for subordinate plants. Moreover, their spread fostered the presence of elements such as ruderals and fringe species. We concluded that these abandoned croplands had a good potential to develop into a Habitat as defined in the EU Directive but without appropriate management plans they would remain of low representativeness
The Coexistence of asthma and Chronic Ostructive Pulmonary Disease (COPD): prevalence and risk factors in young, middle-aged and elderly people from the general population
Background: The joint distribution of asthma and chronic obstructive pulmonary disease (COPD) has not been well described. This study aims at determining the prevalence of self-reported physician diagnoses of asthma, COPD and of the asthma-COPD overlap syndrome and to assess whether these conditions share a common set of risk factors.
Methods: A screening questionnaire on respiratory symptoms, diagnoses and risk factors was administered by mail or phone to random samples of the general Italian population aged 20–44 (n = 5163) 45–64 (n = 2167) and 65–84 (n = 1030) in the frame of the multicentre Gene Environment Interactions in Respiratory Diseases (GEIRD) study.
Results: A physician diagnosis of asthma or COPD (emphysema/chronic bronchitis/COPD) was reported by 13% and 21% of subjects aged <65 and 65–84 years respectively. Aging was associated with a marked decrease in the prevalence of diagnosed asthma (from 8.2% to 1.6%) and with a marked increase in the prevalence of diagnosed COPD (from 3.3% to 13.3%). The prevalence of the overlap of asthma and COPD was 1.6% (1.3%–2.0%), 2.1% (1.5%–2.8%) and 4.5% (3.2%–5.9%) in the 20–44, 45–64 and 65–84 age groups. Subjects with both asthma and COPD diagnoses were more likely to have respiratory symptoms, physical impairment, and to report hospital admissions compared to asthma or COPD alone (p<0.01). Age, sex, education and smoking showed different and sometimes opposite associations with the three conditions.
Conclusion: Asthma and COPD are common in the general population, and they coexist in a substantial proportion of subjects. The asthma-COPD overlap syndrome represents an important clinical phenotype that deserves more medical attention and further research.</br
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