POD-based representation of the alongwind Equivalent Static Force for long-span bridges

Fiore, Alessandra,Monaco, Pietro Techno-Press 2009 Wind and Structures, An International Journal (WAS Vol.12 No.3

This paper develops and discusses a method by which it is possible to evaluate the Equivalent Static Force (ESF) of wind in the case of long-span bridges. Attention is focused on the alongwind direction. The study herein carried out deals with the classical problems of determining the maximum effects due to the alongwind action and the corresponding ESFs. The mean value of the maximum alongwind displacement of the deck is firstly obtained both by the spectral analysis and the Gust Response Factor (GRF) technique. Successively, in order to derive the other wind-induced effects acting on the deck, the Gust Effect Factor (GEF) technique is extended to long-span bridges. By adopting the GRF technique, it is possible to define the ESF that applied on the structure produces the maximum alongwind displacement. Nevertheless the application of the ESF so obtained does not furnish the correct maximum values of other wind-induced effects acting on the deck such as bending moments or shears. Based on this observation, a new technique is proposed which allows to define an ESF able to simultaneously reproduce the maximum alongwind effects of the bridge deck. The proposed technique is based on the GEF and the POD techniques and represents a valid instrument of research for the understanding of the wind excitation mechanism.

Functional Outcome after Reimplantation in Patients Treated with and without an Antibiotic-Loaded Cement Spacers for Hip Prosthetic Joint Infections

Michele Fiore,Claudia Rondinella,Azzurra Paolucci,Lorenzo Morante,Massimiliano De Paolis,Andrea Sambri 대한고관절학회 2023 Hip and Pelvis Vol.35 No.1

Purpose: A staged revision with placement of a temporary antibiotic-loaded cement spacer after removal of the implant is the “gold standard” for treatment of chronic prosthetic joint infection (PJI). It enables local delivery of antibiotics, maintenance of limb-length and mobility, easier reimplantation. However, bacterial colonization of spacers and mechanical complications can also occur. The aim of this study is to evaluate functional results and infection control in two-stage treatment of total hip arthroplasty (THA) PJI with and without a spacer. Materials and Methods: A retrospective review of 64 consecutive patients was conducted: 34 underwent twostage revision using a cement spacer (group A), 30 underwent two-stage revision without a spacer (group B). At the final follow-up, functional evaluation of patients with a THA in site, without PJI recurrence, was performed using the Harris hip score (HHS). Measurement of limb-length and off-set discrepancies was performed using anteroposterior pelvic X-rays. Results: Most patients in group B were older with more comorbidities preoperatively. Thirty-three patients (97.1%) in group A underwent THA reimplantation versus 22 patients (73.3%) in group B (P<0.001). No significant differences in limb-length and off-set were observed. The results of functional evaluation performed during the final follow-up (mean, 41 months) showed better function in patients in group A (mean HHS, 76.3 vs. 55.9;P<0.001). Conclusion: The use of antibiotic-loaded cement spacer seems superior in terms of functional outcomes and reimplantation rate. Resection arthroplasty might be reserved as a first-stage procedure in patients who are unfit, who might benefit from a definitive procedure.

A Case of Ralstonia pickettii Bloodstream Infection and the Growing Problem of Healthcare Associated Infections in Frail Older Adults

Francesca Fiore,Stefano Cacciatore,Salvatore Tupputi,Clara Agostino,Rossella Montenero,Giovanni Spaziani,Daniele Elmi,Martina Medei,Manuela Antocicco,Federica Mammarella,Eleonora Taddei,Ester Manes-Gr 대한노인병학회 2022 Annals of geriatric medicine and research Vol.26 No.4

Frailty is a clinically measurable state of vulnerability to developing increased dependency and/or mortality when exposed to a stressor. Chronic diseases, aggressive treatments, antibiotic overuse, microbiota changes, immune senescence, and increased use of medical devices and implants (i.e., central lines and catheters) expose modern patients to healthcare-associated infections (HAIs), multidrug-resistant bacteria, and new and unusual opportunistic pathogens. Older adults are among the main victims of HAIs and are associated with high costs, disability, morbidity, and mortality. Ralstonia pickettii is an emerging opportunistic pathogen that causes rare nosocomial infections in frail individuals. Herein, we present a case of bloodstream infection caused by R. pickettii in an 88-year-old woman with a relatively mild course. In addition to describing this unusual finding, this report discusses the problem of HAIs in older adults. Older age, comorbidities, and hospital admissions were among the main risk factors for HAIs. Adherence to guidelines, training, auditing, and surveillance is crucial for reducing the burden of HAIs in acute settings. Furthermore, avoiding incongruous hospitalizations would have positive implications both for preventing HAIs and improving patient quality of life.

POD-based representation of the alongwind Equivalent Static Force for long-span bridges

Alessandra Fiore,Pietro Monaco 한국풍공학회 2009 Wind and Structures, An International Journal (WAS Vol.12 No.3

This paper develops and discusses a method by which it is possible to evaluate the Equivalent Static Force (ESF) of wind in the case of long-span bridges. Attention is focused on the alongwind direction. The study herein carried out deals with the classical problems of determining the maximum effects due to the alongwind action and the corresponding ESFs. The mean value of the maximum alongwind displacement of the deck is firstly obtained both by the spectral analysis and the Gust Response Factor (GRF) technique. Successively, in order to derive the other wind-induced effects acting on the deck, the Gust Effect Factor (GEF) technique is extended to long-span bridges. By adopting the GRF technique, it is possible to define the ESF that applied on the structure produces the maximum alongwind displacement. Nevertheless the application of the ESF so obtained does not furnish the correct maximum values of other wind-induced effects acting on the deck such as bending moments or shears. Based on this observation, a new technique is proposed which allows to define an ESF able to simultaneously reproduce the maximum alongwind effects of the bridge deck. The proposed technique is based on the GEF and the POD techniques and represents a valid instrument of research for the understanding of the wind excitation mechanism.

Viscoelastic behaviour of non-homogeneous variable-section beams with post-poned restraints

Alessandra Fiore,Pietro Monaco,Domenico Raffaele 사단법인 한국계산역학회 2012 Computers and Concrete, An International Journal Vol.9 No.5

The aim of this paper is to develop a procedure able to calculate the long-term stress and strain patterns in modern prestressed composite structures which are largely influenced by creep and shrinkage and whose final static configuration is the result of many phases of loading and restraints conditions. The introduction of equivalent moduli, depending on the viscous and elastic features of materials, can guarantee a significant simplification of the problem presented above. The proposed calculation model has been used to design the “Quattroquercie Viaduct” located on the highway “A3”Salerno-Reggio Calabria, Italy.

Structural Optimization of Hollow-section Steel Trusses by Differential Evolution Algorithm

Alessandra Fiore,Giuseppe Carlo Marano,Rita Greco,Erika Mastromarino 한국강구조학회 2016 International Journal of Steel Structures Vol.16 No.2

This paper deals with the weight minimization of planar steel trusses by adopting a differential evolution-based algorithm. Square hollow sections are considered. The design optimization refers to size, shape and topology. The design variables are represented by the geometrical dimensions of the cross sections of the different components of the truss, directly involving the size of the structure, and by some geometrical parameters affecting the outer shape of the truss. The topology is included in the optimization search in a particular way, since the designer at different runs of the algorithm can change the number of bays keeping constant the total length of the truss, to successively choose the best optimal solution. The minimum weight optimum design is posed as a single-objective optimization problem subject to constraints formulated in accordance with the current Eurocode 3. The optimal solution is obtained by a Differential Evolutionary (DE) algorithm. In the DE algorithm, a particular combination of mutation and crossover operators is adopted in order to achieve the best solutions and a specific way for dealing with constraints is introduced. The effectiveness of the proposed approach is shown with reference to two case-studies. The analysis results prove the versatility of the optimizer algorithm with regard to the three optimization categories of sizing, shape, topology as well as its high computational performances and its efficacy for practical applications. In particular useful practical indications concerning the geometrical dimensions of the various involved structural elements can be deduced by the optimal solutions: in a truss girder the cross section of the top chord should be bigger than the one of the bottom chord as well as diagonals should be characterized by smaller cross sections with respect to the top and bottom chords in order to simultaneously optimize the weight and ensure an optimal structural behaviour.

스텔라 피오레

스텔라 피오레(Stella Fiore) 현대건축사 2018 마루 Vol.- No.200

스텔라 피오레

스텔라 피오레(Stella Fiore) 현대건축사 2018 (월간)Maru Vol.- No.200

A method to evaluate the frequencies of free transversal vibrations in self-anchored cable-stayed bridges

Pietro Monaco,Alessandra Fiore 한국계산역학회 2005 Computers and Concrete, An International Journal Vol.2 No.2

The objective of this paper is setting out, for a cable-stayed bridge with a curtain suspension, a method to determine the modes of vibration of the structure. The system of differential equations governing the vibrations of the bridge, derived by means of a variational formulation in a nonlinear field, is reported in Appendix C. The whole analysis results from the application of Hamilton's principle, using the expressions of potential and kinetic energies and of the virtual work made by viscous damping forces of the various parts of the bridge (Monaco and Fiore 2003). This paper focuses on the equation concerning the transversal motion of the girder of the cable-stayed bridge and in particular on its final form obtained, restrictedly to the linear case, neglecting some quantities affecting the solution in a non-remarkable way. In the hypotheses of normal mode of vibration and of steady-state, we propose the resolution of this equation by a particular method based on a numerical approach. Respecting the boundary conditions, we derive, for each mode of vibration, the corresponding frequency, both natural and damped, the shape-function of the girder axis and the exponential function governing the variability of motion amplitude in time. Finally the results so obtained are compared with those deriving from the dynamic analysis performed by a finite elements calculation program.

SPARK: A Smart Parametric Online RWA Algorithm

Palmieri, Francesco,Fiore, Ugo,Ricciardi, Sergio The Korea Institute of Information and Commucation 2007 Journal of communications and networks Vol.9 No.4

The large potential bandwidth available in wavelength-division multiplexed optical networks makes this technology of crucial importance for satisfying the ever increasing capacity requirements of the next-generation Internet. In this scenario, the routing and wavelength assignment(RWA) problem that concerns determining the optical paths and wavelengths to be used for connection establishment in a wavelength-routed network, is still one of the most important open issues. In this paper we propose a new online dynamic grooming-capable RWA heuristic scheme working on wavelength division multiplexing(WDM) networks as a multistage selection process. The proposed algorithm is transparent with respect to the presence of wavelength converters, achieves very low connection rejection ratios with minimal computational complexity and is appropriate for the modern multilayer optical circuit and wavelength switched networks with sparse wavelength conversion capability.