103,279 research outputs found
Time-relevant stability of 2D systems
No full textFor many 2D systems, one of the independent variables plays a distinct role in the evolution of the trajectories; since often this special independent variable is time, we call such systems 'time-relevant'. In this paper, we introduce a stability notion for time-relevant systems described by higher-order difference equations. We give algebraic tests in terms of the location of the zeros of the determinant of a polynomial matrix describing the system. We also give an LMI characterization of time-relevant stability involving only constant matrices
Identification and data-driven model reduction of state-space representations of lossless and dissipative systems from noise-free data
No full textWe illustrate procedures to identify a state-space representation of a lossless- or dissipative system from a given noise-free trajectory; important special cases are passive- and bounded-real systems. Computing a rank-revealing factorization of a Gramian-like matrix constructed from the data, a state sequence can be obtained; state-space equations are then computed solving a system of linear equations. This idea is also applied to perform model reduction by obtaining a balanced realization directly from data and truncating it to obtain a reduced-order mode
Autonomy, forward non-Zenoness and quadratic stability of bimodal higher-order piecewise linear systems
No full textWe consider bimodal higher-order piecewise linear systems, i.e. the sets of solutions of two higher-order linear differential equations, coupled with inequality constraints involving a polynomial differential operator acting on the trajectories of the system. Under suitable assumptions on the characteristic polynomials of the differential equations and the polynomial associated with the inequality constraint, we prove that a solution always exists and is unique given the initial conditions, that no forward Zeno-behavior is possible, and that the system is quadratically stable. Moreover, we provide an algorithm based on polynomial algebra to compute a Lyapunov function for the system
Gender stereotypes in occupational choice: a cross-sectional study on a group of Italian adolescents [Erratum]
No full textRamaci T, Pellerone M, Ledda C, Presti G, Squatrito V, Rapisarda V. Psychol Res Behav Manag. 2017;10:109–117. On page 116, Reference section, an error was introduced in the numbering regarding reference 44. The correct reference details are:44. Wraga M, Duncan L, Jacobs EC, Helt M, Church J. Stereotype susceptibility narrows the gender gap in imagined self-rotation performance. Psychon Bull Rev. 2006;13(5):813–819.The reference citation in the main text is correct.Read the original articl
On positive-realness and stability of switched linear differential systems
No full textWe present some results regarding the stability of switched linear differential systems (SLDS) in the behavioral framework. Positive-realness is studied as a sufficient condition for stability and some implications derived from the use of positive-real completions are discussed
HUB PER BORGO VAL DI TARO. Un crocevia turistico-culturale nell’ex area FNET
No full textIn una prospettiva di recupero e di rilancio delle strutture edilizie
preesistenti della città di Borgo Val di Taro, la mostra “Hub per Borgo Val
di Taro. Un crocevia turistico-culturale” presenta una sperimentazione
didattica sulla riconversione d’uso di una parte dell’ex area FNET.
Nell’ambito del Laboratorio di Progettazione dell’Architettura degli Interni
(Corso di Laurea in Progettazione dell’Architettura, Politecnico di Milano),
guidato dalle proff.sse Imma Forino e Francesca Rapisarda con le
arch.tte Greta Allegretti e Carola D’Ambros, alcuni giovani progettisti
hanno progettato il riuso e la riqualificazione tre piccoli capannoni industriali
e un edificio a torre, ormai in disuso e in parte in stato di abbandono, vicino
alla Stazione ferroviaria, nei pressi di Piazzale Guglielmo Marconi.
I progetti di riqualificazione hanno previsto la riconversione d’uso dell’ex
area FNET in un hub polivalente a carattere culturale e turistico per i
cittadini e coloro che visitano a piedi o in bicicletta la città, i suoi monumenti
e i suggestivi luoghi naturalistici adiacenti. Gli edifici sono stati destinati
a spazi espositivi, una sala musica per corsi o prove, una sala per prove
teatrali, spazi di accoglienza, co-working e fab lab, quali incubatori di
start up per i giovani. Per ciò che riguarda i servizi al turismo sono stati
previsti un’area di ristoro, una ciclofficina e noleggio biciclette, servizi con
docce e deposito bagaglio, una foresteria/ostello, un bar a disposizione
dei vari utenti della struttura.
Gli ambienti sono stati organizzati secondo criteri di flessibilità e
adattabilità. Pur nel rispetto della volumetria esistente e delle strutture
portanti degli edifici, i progetti hanno reinterpretato in modo differente
le preesistenze, integrandole con le aree verdi di pertinenza e talora
catturando inediti scorci panoramici. In coerenza con i Sustainable
Development Goals dell’Agenda ONU 2030 (in particolare SDG3-Good
Health & Well-being; SDG5-Gender Equality; SDG8-Decent Work &
Economic Growth), i progetti si sono proposti di costruire relazioni di
inclusività sociale e opportunità di formazione e lavoro creativo
Stabilization, Lyapunov functions, and dissipation
No full textFor linear time-invariant systems any stabilizing controller for a given plant can be associated with a supply rate with respect to which the plant in open-loop is half-line dissipative. We also prove the equivalence between stability of the interconnection of two systems and their half-line dissipativity with respect to a supply rate and its negative
Autonomous linear lossless systems
No full textWe define a lossless autonomous system as one having a quadratic differential form associated with it called an energy function, which is positive and which is conserved. We define an oscillatory system as one which has all its trajectories bounded on the entire time axis. In this paper, we show that an autonomous system is lossless if and only if it is oscillatory. Next we discuss a few properties of energy functions of autonomous lossless systems and a suitable way of splitting a given energy function into its kinetic and potential energy components
Higher-order linear lossless systems
No full textWe define a lossless autonomous system as one having a quadratic differential form associated with it called the total energy, which obeys the property of positivity and which is conserved. In this paper, we show that an autonomous system is lossless if and only if it is oscillatory. Next we discuss a suitable way of splitting the total energy function into its kinetic and potential energy components. We also extend the investigation to the case of open systems
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