Search results for "COSTRUZIONE"
showing 10 items of 669 documents
A probabilistic compressive sensing framework with applications to ultrasound signal processing
2019
Abstract The field of Compressive Sensing (CS) has provided algorithms to reconstruct signals from a much lower number of measurements than specified by the Nyquist-Shannon theorem. There are two fundamental concepts underpinning the field of CS. The first is the use of random transformations to project high-dimensional measurements onto a much lower-dimensional domain. The second is the use of sparse regression to reconstruct the original signal. This assumes that a sparse representation exists for this signal in some known domain, manifested by a dictionary. The original formulation for CS specifies the use of an l 1 penalised regression method, the Lasso. Whilst this has worked well in l…
Lock-In Signal Post-Processing Techniques in Infra-Red Thermography for Materials Structural Evaluation
2013
This paper describes the potential of off-line thermographic signal processing by means of Lock-In Correlation algorithms, in order to implement structural health monitoring and stress analysis techniques. Thermal datasets acquired by infrared thermocameras are locked-in and correlated numerically with opportune reference signals, and amplitude and phase values of various harmonics retrieved by means of a Fast Fourier Transform and time averaging based filtering. This information is then processed for NDT defect probing and for evaluating the Thermoelastic Effect induced temperature changes. Two case studies in particular are discussed, implementing the proposed signal lock-in processing: a…
Quantitative thermoelastic stress analysis by means of low-cost setups
2020
Abstract A low-cost Thermoelastic Stress Analysis (TSA) experimental setup is proposed which uses an ordinary micro-bolometer and in-house developed signal processing scripts. The setup is evaluated by analysing the thermoelastic signal from a tensile and a SENT specimen made of stainless steel AISI 304L, and the bolometer performances are compared with those of a state of the art photon detector. Signal processing is based on off-line cross-correlation, using a self-reference signal which is retrieved from the acquired thermal data. Procedures are in particular developed to recognise, quantify and correct errors due to spectral leakage and loss of streamed frames. The thermoelastic signal …
Il secondo concorso per il Parlamento di Ernesto Basile. Analisi e ricostruzione congetturale
2020
Lo studio si inquadra nel settore delle ricostruzioni congetturali di progetti a partire da disegni di archivio. Nel caso specifico, si tratta del progetto di Ernesto Basile per il secondo concorso per il Parlamento del Regno d’Italia, conclusosi nel 1889. È un progetto molto maturo, premiato dalla Commissione giudicatrice ex aequo insieme ad altri quattro, e conclude la fase dei concorsi romani (1882-89), segnata da un linguaggio classicista che permea i progetti per le sedi istituzionali. I disegni originari dell’opera, non realizzata, sono conservati presso la Dotazione Basile-Ducrot del Dipartimento di Architettura dell’Università di Palermo, e sono stati utilizzati per il rilievo, la v…
Architettura altomedievale nel Santuario di San Michele: analisi stratigrafica degli elevati e studio ricostruttivo 3D
2012
Il Santuario di San Michele a Monte Sant’Angelo (FG) costituisce uno dei più importanti e antichi luoghi della cristianità occidentale. La sede del culto riservato all’Angelo è posta all’interno di una Caverna situata a metà del fianco settentrionale del rilievo montuoso sul cui pianoro si estende il centro abitato. Il contributo riguarda lo studio architettonico, dal rilievo alla lettura stratigrafica muraria fino alla ricostruzione virtuale, del monumento di età longobarda The Sanctuary of San Michele in Monte Sant’Angelo (FG) is one of the most important and ancient places of Western Christianity. The seat of the cult reserved for the Angel is placed inside a Cave located in the middle o…
Active magnetic bearing design study
2012
The purpose of this paper is to propose a useful method to implement active magnetic bearings (AMBs) on an existing rotating shaft which rotates on conventional bearings. This is feasible if AMBs can produce the same reaction loads of conventional ones and if the size of vane is large enough to host an AMB. As this substitution could offer some difficulties due to the different size between magnetic bearings and conventional ones, a set of equations are performed to show that a variation of some parameters can solve this problem. The journal ratio is the geometrical parameter introduced to develop the present analysis. The variation of journal ratio does not produce a variation of the pole…
Measuring Multiple Residual-Stress Components using the Contour Method and Multiple Cuts
2009
The conventional contour method determines one component of residual stress over the cross section of a part. The part is cut into two, the contour (topographic shape) of the exposed surface is measured, and Bueckner’s superposition principle is analytically applied to calculate stresses. In this paper, the contour method is extended to the measurement of multiple residual-stress components by making multiple cuts with subsequent applications of superposition. The theory and limitations are described. The theory is experimentally tested on a 316L stainless steel disk with residual stresses induced by plastically indenting the central portion of the disk. The multiple-cut contour method resu…
Investigation on the influence of the surface resin rich layer on the thermoelastic signal from different composite laminate lay-ups
2006
This work presents a set of experimental results based on the measured thermoelastic signal from GRP composite coupons adopting different lay-ups. A comparison is made with the thermoelastic signal predicted by two different analytical models: one based on the classical law of the thermoelastic effect for orthotropic materials, and the other based on a novel theory accounting for the presence of a resin layer on the external surface of the composite structure. The composite coupons were designed such to determine a significant difference in the predictions made by the two theoretical models. Experimental results have shown a far better match with the predictions based on the novel theory ac…
Ripartire dalla crisi. Nuovi modelli di sviluppo urbano
2010
[TESI SOSTENUTA] Ripartire dalla crisi, piuttosto che resistervi perpetuando i medesimi modelli di sviluppo, appare ormai atteggiamento condiviso tra tutti i settori dell’economia, della cultura e della ricerca. Mettere a fuoco i meccanismi o i passaggi che hanno portato al crollo dei sistemi è condizione necessaria, ed il conseguente passaggio obbligato riguarda l’individuazione di soluzioni alternative, i cui spunti possono essere attinti dallo storico ciclico ripetersi delle recessioni. Lezioni dalle crisi sono a disposizione nel recente passato (dal giovedì nero del 24 ottobre ‘29 a Wall Strett all’11 dicembre ‘97 a Kyoto) attraversando tutti i settori, dall’economia all’ambiente. Le at…