Search results for "cienza"

An unsupervised Learning Algorithm for Fatigue Crack Detection in Waveguides

2009

Ultrasonic guided waves (UGWs) are a useful tool in structural health monitoring (SHM) applications that can benefit from built-in transduction, moderately large inspection ranges, and high sensitivity to small flaws. This paper describes an SHM method based on UGWs and outlier analysis devoted to the detection and quantification of fatigue cracks in structural waveguides. The method combines the advantages of UGWs with the outcomes of the discrete wavelet transform (DWT) to extract defect-sensitive features aimed at performing a multivariate diagnosis of damage. In particular, the DWT is exploited to generate a set of relevant wavelet coefficients to construct a uni-dimensional or multi-di…

Outlier analysis and principal component analysis to detect fatigue cracks in waveguides

2009

Ultrasonic Guided Waves (UGWs) are a useful tool in structural health monitoring (SHM) applications that can benefit from built-in transduction, moderately large inspection ranges and high sensitivity to small flaws. This paper describes a SHM method based on UGWs, discrete wavelet transform (DWT), outlier analysis and principal component analysis (PCA) able to detect and quantify the onset and propagation of fatigue cracks in structural waveguides. The method combines the advantages of guided wave signals processed through the DWT with the outcomes of selecting defectsensitive features to perform a multivariate diagnosis of damage. The framework presented in this paper is applied to the de…

Digital signal processing for rail monitoring by means of ultrasonic guided waves

2007

Recent train accidents have reaffirmed the need for developing rail defect detection systems that are more effective than those used today. One of the recent developments in rail inspection is the use of ultrasonic guided waves (UGWs) and non-contact probing techniques to target transverse-type defects. Besides the obvious advantages of non-contact probing, that include robustness and a potential for large inspection speed, such a system can theoretically detect transverse defects under horizontal shelling or head checks. This paper demonstrates the effectiveness of digital signal processing to enhance the damage detection sensitivity of the non-contact system. The method proposed here comb…

The symmetric boundary element method for unilateral contact problems

2008

Abstract On the basis of the boundary integral equation method, in its symmetric formulation, the frictionless unilateral contact between two elastic bodies has been studied. A boundary discretization by boundary elements leads to an algebraic formulation in the form of a linear complementarity problem. In this paper the process of contact or detachment is obtained through a step by step analysis by using generalized (weighted) quantities as the check elements: the detachment or the contact phenomenon may happen when the weighted traction or the weighted displacement is greater than the weighted cohesion or weighted minimum reference gap, respectively. The applications are performed by usin…

The Line Element-less Method Analysis of orthotropic beam for the De Saint Venant torsion problem

2010

Abstract This paper deals with the extension of a novel numerical technique, labelled line element-less method (LEM), in order to provide approximate solutions of the De Saint Venant torsion problem for orthotropic beams having simply and multiply connected cross-section. A suitable transformation of coordinates allows to take full advantage of the theory of analytic complex functions as in the isotropic case. A complex potential function analytic in all the transformed domain whose real and imaginary parts are related to the shear stress components and to the orthotropic ratio is introduced and expanded in the double-ended Laurent series involving harmonic polynomials. An element-free weak…

Line element-less method (LEM) for beam torsion solution (truly no-mesh method)

2008

In this paper a new numerical method for finding approximate solutions of the torsion problem is proposed. The method takes full advantage of the theory of analytic complex function. A new potential function directly in terms of shear stresses is proposed and expanded in the double-ended Laurent series involving harmonic polynomials. A novel element-free weak form procedure, labelled Line Element-Less Method (LEM), has been developed imposing that the square of the net flux across the border is minimum with respect to coefficients expansion. Numerical implementation of the LEM results in systems of linear algebraic equations involving symmetric and positive-definite matrices without resorti…

Plasma endothelin-1 and 8-Iso-ProstaglandinF2alpha levels are related to renal function and predict estimated glomerular filtration rate in hypertens…

2008

Tra diritto e morale. saggio sulla disobbedienza civile

2008

Di nuovo schiave. Donne e distopia (2007-2022)

2022

Il saggio analizza le peculiarità e le costanti della narrativa distopica scritta da donne in Italia lungo un arco di tempo che va dal 2007 al 2022. Riallacciandosi a una tradizione mainstream che in ambito anglosassone ha prodotto libri di successo come The Handmaid’s Tale di Margaret Atwood, le distopie italiane degli ultimi anni mettono in scena un futuro in cui a dominare è una società marcatamente patriarcale che esercita un controllo violento sul corpo e sull’identità femminili. Il cupo futuro raccontato da Laura Pugno, Nicoletta Vallorani, Maria Rosa Cutrufelli, Laura Pariani e altre scrittrici italiane nasce dall’amplificazione di stereotipi sessuali radicati nel presente e vuole es…

Smart Beam Element Approach for LRPH Device

2020

LRPH (Limited Resistance Rigid Perfectly Plastic Hinge) device is a special steel device mainly usable to join beam elements of plane or spatial steel frames covered by patent n. 102017000088597 at the Italian Ministry of Economic Development and identified in the International Patent System with the number PCT/IB2018/055766. In the framework of moment (rigid) connection, the main fundamental innovation of LRPH consists in the mutual independence of its own resistance and stiffness features. The device is constituted by a sequence of three steel elements of limited length bounded by two parallel steel plates joined up with the connected structure elements. The cross-sections of the three st…