410 research outputs found
Safe Distributed Control of Wireless Power Transfer Networks
No full textWireless power transfer networks (WPTNs) are composed of dedicated energy transmitters (ETs) that charge energy receivers (ERs) via radio frequency waves. A safe-charging WPTN should keep electromagnetic radiation below predetermined limits meanwhile maximizing the transmitted power. In this paper, we consider this requirement as an optimization problem: the maximization of harvested power by ERs subject to the electro-magnetic safety constraints. In order to provide an approximated solution to this problem, we introduce a dual ascent-like distributed charging algorithm that enables ETs to work without global information and satisfy safety constraints asymptotically. We provide an in-depth theoretical analysis of our algorithm which is supported by numerical simulations.Accepted author manuscriptEmbedded System
L'Enigma del Girasole - lettura critica di un'opera di architettura di Luigi Moretti/The enigma of the 'Sunflower' - critical reading of an architectural masterpiece by Luigi Moretti (prefazione/preface F. Purini, introduzione/introduction A. Muntoni, postfazione/postface C. Conforti) Italian and English texts
No full text“Secondo Ruggero Lenci, Luigi Moretti nel Girasole, forte di un’appassionata conoscenza delle leggi compositive e aggregative dell’arte barocca, fa esplodere il virtuale volume della palazzina e ricomincia il progetto da un vuoto. Un canyon al quale imprime un vigore centripeto che riattira le schegge sparse dall'esplosione iniziale, aggregandole secondo piani di luce librati come schermi scintillanti di tessere vitree, o secondo volumi turgidi come i panneggi degli Angeli che calano vorticando dal cielo a difesa del ponte tra la Roma laica e il sacro Borgo.”
“According to Ruggero Lenci, Luigi Moretti in the ‘Sunflower’, strong of a passionate knowledge of the laws of composition and aggregation of the Baroque art, blows up its virtual volume, restarting from a vacuum. A canyon which acts as a centripetal force that attracts the shrapnel scattered by the initial explosion, integrating them in planes of light hovering like screens of sparkling glass tiles, or according to the turgid volumes as the draperies of the angels who descend from the sky in a vortex, to defend the bridge between the secular Rome and the sacred Borgo.”
Claudia Conforti... .
“Ruggero Lenci guarda questa palazzina come un crittogramma da decifrare: la macchina enigma, da cui il titolo del saggio che del resto ce lo conferma. Una decrittazione impigliata in tantissime allusioni e ossessioni che Moretti potrebbe aver avuto presenti, di fronte a nessuna delle quali l’autore del libro arretra, anzi ne intreccia le implicazioni fino al limite dell’immaginario possibile. Evidentemente, non ha ‘yeux qui ne voient pas’, ma forse occhi che vedono troppo.”
“Ruggero Lenci looks at this building as a cryptogram to be deciphered: the enigma machine, from which the title of the book derives and confirms it. A decryption that catches so many allusions and obsessions, that Moretti could have had, in front of none of which the author of the book makes a step back, rather weaving the implications up to the possible limits of imagination. Evidently, he has no ‘eyes that do not see’, but maybe eyes that see too much.”
Alessandra Muntoni... .
“Ruggero Lenci sostiene che la genesi di questa opera magistrale deve essere ricercata in una traslazione poetica del tema berniniano della transizione tra natura e architettura. Un tema materializzato in particolare nella Fontana dei Quattro Fiumi a Piazza Navona. L’autore del libro individua in questa opera il luogo di un contrasto tra la forma e l’informe, forse l’esito principale del processo metamorfico... Le argomentazioni proposte si susseguono con una forte consequenzialità in un testo che si avvale di un’avvincente attitudine narrativa.”
“Ruggero Lenci argues that the genesis of this masterly work must be sought in a poetic translation of the Bernini's theme of transition between nature and architecture. A theme that materializes especially in the Fountain of the Four Rivers in Piazza Navona. The author of the book identifies in this work of art the presence of a contrast between the form and the formless, perhaps the main result of the metamorphic process. The proposed topics follow one another with a strong consequentiality, in a text that benefits from a compelling narrative attitude.” Franco Purin
Distributed partition-based optimization via dual decomposition
No full textIn this paper we consider a novel partition-based framework for distributed optimization in peer-to-peer networks. In several important applications the agents of a network system have to solve an optimization problem with two important features: (i) the dimension of the decision variable is a function of the network size, and (ii) the cost function and the constraints have a sparsity structure that is related to the sparsity of the graph. For this class of problems a straightforward application of existing methods would result in all the nodes reaching consensus on the minimizer. This approach has two inefficiencies: poor scalability and redundancy of shared information. Indeed, the dimension of the vector stored by each node and the size of the local problem to be solved depend on the network size. Furthermore, all the nodes compute the entire solution. In this paper we provide a preliminary contribution in developing and analyzing novel partition based algorithms. We propose a partition-based algorithm based on dual decomposition. We show that, exploiting the problem structure, the solution can be partitioned among the nodes so that each node stores a local copy of just a portion of the decision variable (rather than a copy of the entire decision vector) and solves a small scale local problem
Topics on the Average Consensus Problems
No full textDriven by fundamental technological achievements like the digital revolution in communication and computing and the miniaturization of electronic components, a growing interest in the field of networked systems has appeared, in recent years, in different scientific areas like physics, communication and control engineering, economy, and lately, mathematics. Besides
differences among the various approaches, the basic model consists of a certain number of agents, namely, systems living in a common environment and which communicate among each other according to some pre-specified communication pattern. Such a pattern may be fixed or varying according to their physical position, to their internal state and can possibly be affected by noises. The evolution law of each system typically depends on the information obtained through its communication links and is, in general, modeled by a difference or differential equation. For this type of models, the interest is, in general, in studying time evolution, asymptotic behaviors, and in formulating and solving related control problem. In particular, a fundamental issue is understanding the emerging of a group behavior from the individual dynamics and the communication pattern. While many models have already been proposed, the mechanisms which determine how the various individual actions get reflect in the group behavior are, in general, hard to understand and, up to now, few results are known.
In this thesis we will focus on the so-called consensus problem, where the group of agents has to reach an agreement on key pieces of information or on a common decision (represented by scalar or vector values) that enable them to cooperate in a coordinate fashion. We will consider a standard algorithm proposed in literature to solve this problem. We will provide some theoretical developments by
• characterizing the speed of convergence of this algorithm for particular communication pattern exhibiting symmetries,
• investigating the realistic and practical situation in which the systems can communicate each other only through digital channels and hence can exchange only quantized information,
• proposing the application of this algorithm to a problem of distributed estimation
Distributed state estimation for independent linear systems with relative and absolute measurements
No full text
Plug and play partition-based state estimation based on Kalman filter
No full textIn the last years, the distributed state estimation issue has gained great importance in the framework of
distributed monitoring and control of large-scale systems. It consists of estimating, through a network of sensors endowed with computational capabilities, the state of a large scale system, characterized by the interconnection of a number of subsystems. In this paper we focus on partition-based distributed estimation and we propose a novel scheme for non-overlapping subsystems based on Kalman filter. The online implementation of the proposed estimation scheme is scalable, as far as both the computation requirements and communication effort are concerned, and convergence results are provided. A simulation example is finally shown, to test the performance of the distributed Kalman filter proposed
- …
