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Vincenzo Consalvo,Francesca D’Auria,Vincenzo Salsano 대한대장항문학회 2019 Annals of Coloproctolgy Vol.35 No.3
Purpose: Despite the minimally invasive nature of transanal hemorrhoidal dearterialization (THD) with Doppler arterial identification procedures, hemorrhoidectomy is still considered the gold standard procedure for hemorrhoidal disease. However, the classical techniques of hemorrhoidectomy have a high rate of postoperative complications. The main purpose of this study is to demonstrate the efficacy and complications of these techniques used for grades II and III hemorrhoids. Methods: A retrospective (case-control) study was carried out from January 2009 to May 2014, and all patients undergoing surgical procedures for hemorrhoidal disease in two French clinics were considered. Application of inclusion and exclusion criteria identified 270 eligible patients (163 undergoing Doppler THD and 107 treated with Milligan Morgan hemorrhoidectomy). Statistical analysis was calculated considering immediate postoperative complications, functional results, chronic complications, and recurrences. Results: Analysis of primary outcomes showed a significant difference between the 2 groups concerning postoperative pain, which had a lower rate in THD (P = 0.0001) and in postoperative bleeding (P = 0.02) than hemorrhoidectomy. However, long-term follow-up at three years showed a superior rate of recurrence in the THD group (P = 0.009). Conclusion: The THD technique is a safe and effective procedure for grades II and III hemorrhoids, has lower rates of post-operative pain and bleeding, and allows faster hospital discharge; however, it also shows a higher rate of recurrence at three years of follow-up.
Vincenzo Alfieri,Giuseppe Conte,Carmen Pedicini 한국자동차공학회 2018 International journal of automotive technology Vol.19 No.3
The objective of this study is to investigate a nonlinear model-based multivariable (MIMO, Multi Input Multi Output) technique to decouple actuators interaction and to reduce the calibration effort, while increasing control performances, above all in transient conditions, and robustness with respect to model uncertainties and system parameter variations. The presented control technique is based on the development of a nonlinear dynamical physical model of the diesel air and charging system. Feedback Linearization control is then applied to decouple actuators’ interactions and compensate for nonlinearities. A new set of virtual inputs are defined inverting the system differential equations. Relation among the new virtual inputs and the outputs is purely linear and decoupled, meaning that each virtual input affects linearly only one output. Moreover, a linear control block is added to guarantee transient and steady state performances and closed loop robustness. The proposed control approach has been validated through small diesel engine dyno and vehicle activities. Transient test bench maneuvers show that the control is able to coordinate the actuators in order to fulfill the targets and to guarantee similar performances in different operating points. In addition the robustness to environmental changes has been demonstrated by vehicle tests at different ambient conditions.
The overall motion sickness incidence applied to catamarans
Vincenzo Piscopo,Antonio Scamardella 대한조선학회 2015 International Journal of Naval Architecture and Oc Vol.7 No.4
The Overall Motion Sickness Incidence is applied to the hull form optimization of a wave piercing highspeed catamaran vessel. Parametric hull modelling is applied to generate two families of derived hull forms, the former varying the prismatic coefficient and the position of longitudinal centre of buoyancy, the latter instead the demi-hull separation. Several heading angles are analysed in a seaway, considering all combinations of significant wave height and zero-crossing period under two operating scenarios. The optimum hull is generated and vertical accelerations at some critical points on main deck are compared with the parent ones. Finally a comparative analysis with the results obtained for a similarly sized monohull passenger ship is carried out, in order to quantify, by the OMSI, the relative goodness in terms of wellness onboard of monohulls and catamarans, as a function of sea states and operating scenarios.
Modelling of aluminium foam sandwich panels
Vincenzo D’Alessandro,Giuseppe Petrone,Sergio De Rosa,Francesco Franco 국제구조공학회 2014 Smart Structures and Systems, An International Jou Vol.13 No.4
applications thanks to the excellent combination of mechanical properties, high strength and stiffness, with functional ones, thermo-acoustic isolation and vibration damping. These properties strongly depend on the density of the foam, the morphology of the pores, the type (open or closed cells) and the size of the gas bubbles enclosed in the solid material. In this paper, the vibrational performances of two classes of sandwich panels with an Alulight R foam core are studied. Experimental tests, in terms of frequency response function and modal analysis, are performed in order to investigate the effect of different percentage of porosity in the foam, as well as the effect of the random distribution of the gas bubbles. Experimental results are used as a reference for developing numerical models using finite element approach. Firstly, a sensitivity analysis is performed in order to obtain a limit-but-bounded dynamic response, modelling the foam core as a homogeneous one. The experimental-numerical correlation is evaluated in terms of natural frequencies and mode shapes. Afterwards, an update of the previous numerical model is presented, in which the core is not longer modelled as homogeneous. Mass and stiffness are randomly distributed in the core volume, exploring the space of the eigenvectors.
A NOTE ON SKEW DERIVATIONS IN PRIME RINGS
Vincenzo De Filippis,Ajda Fonsner 대한수학회 2012 대한수학회보 Vol.49 No.4
Let m, n, r be nonzero fixed positive integers, R a 2-torsion free prime ring, Q its right Martindale quotient ring, and L a non-central Lie ideal of R. Let D : $R{\rightarrow}R$ be a skew derivation of R and $E(x)=D(x^{m+n+r})-D(x^m)x^{n+r}-x^mD(x^n)x^r-x^{m+n}D(x^r)$. We prove that if $E(x)=0$ for all $x{\in}L$, then D is a usual derivation of R or R satisfies $s_4(x_1,{\ldots},x_4)$, the standard identity of degree 4.
GENERALIZED SKEW DERIVATIONS AS JORDAN HOMOMORPHISMS ON MULTILINEAR POLYNOMIALS
Vincenzo De Filippis 대한수학회 2015 대한수학회지 Vol.52 No.1
Let R be a prime ring of characteristic different from 2, Qr be its right Martindale quotient ring and C be its extended cen- troid. Suppose that G is a nonzero generalized skew derivation of R, is the associated automorphism of G, f(x1, . . . , xn) is a non-central multilinear polynomial over C with n non-commuting variables and S = {f(r1, . . . , rn) | r1, . . . , rn ∈ R}. If G acts as a Jordan homomorphism on S, then either G(x) = x for all x ∈ R, or G = α.