Stefano Fiorucci

The use of equivalent beam models to estimate the dynamical characteristics of complex tall buildings has been investigated by several authors. The main reason is the structural response estimation to stochastic loads, such as wind and earthquake, using a reduced number of degrees of freedom, which reduces the computational costs and therefore gives the designer an effective tool to explore a number of possible structural solutions. In this paper, a novel approach to calibrate the mechanical… Visualizza altro

The use of equivalent beam models to estimate the dynamical characteristics of complex tall buildings has been investigated by several authors. The main reason is the structural response estimation to stochastic loads, such as wind and earthquake, using a reduced number of degrees of freedom, which reduces the computational costs and therefore gives the designer an effective tool to explore a number of possible structural solutions. In this paper, a novel approach to calibrate the mechanical and dynamical features of a complete 3D Timoshenko beam, i.e., describing bending, shear and torsional behavior, is proposed. This approach is based on explicitly considering the sub-structures of the tall building. In particular, the frames, shear walls and lattice sub-systems are modeled as equivalent beams, constrained by means of rigid diaphragms at different floors. The overall dynamic features of the tall building are obtained by equating the deformation energy of an equivalent sandwich beam with that of the selected sub-structures. Finally, the 3D Timoshenko equivalent beam parameters are calibrated by minimizing a suitable function of modal natural frequencies and static displacements. The closed form modal solution of the equivalent beam model is used to obtain the response to stochastic loads. Meno dettagli

In this paper, we describe and present the results of meme detection system, specifically developed and submitted for our participation to the first subtask of DANKMEMES (EVALITA 2020).
We built simple classifiers, consisting in feed forward neural networks.
They leverage existing pretrained embeddings, both for text and image representation.
Our best system (SNK1) achieves good results in meme detection (F1 = 0.8473), ranking 2nd in the competition, at a distance of 0.0028 from the… Visualizza altro

In this paper, we describe and present the results of meme detection system, specifically developed and submitted for our participation to the first subtask of DANKMEMES (EVALITA 2020).
We built simple classifiers, consisting in feed forward neural networks.
They leverage existing pretrained embeddings, both for text and image representation.
Our best system (SNK1) achieves good results in meme detection (F1 = 0.8473), ranking 2nd in the competition, at a distance of 0.0028 from the first classified. Meno dettagli

The overall dynamic behaviour of tall buildings can be estimated by means of equivalent beam models, and several ways of assessing this equivalence are presented in papers by different authors.
The most appealing benefit of this approach is that the response of the structure to stochastic
actions, such as wind loads, can be estimated using a model with a reduced number of degrees of
freedom, consequently decreasing the computational costs and therefore allowing the designer… Visualizza altro

The overall dynamic behaviour of tall buildings can be estimated by means of equivalent beam models, and several ways of assessing this equivalence are presented in papers by different authors.
The most appealing benefit of this approach is that the response of the structure to stochastic
actions, such as wind loads, can be estimated using a model with a reduced number of degrees of
freedom, consequently decreasing the computational costs and therefore allowing the designer to
explore a greater variety of possible structural solutions (Cluni et al, 2013).

In this paper, the dynamic mechanical properties of an equivalent beam able to describe the threedimensional response of a tall building are estimated with an approach which extends that proposed in Cluni et al. (2014). The resulting model can fully describe the interaction between bending, shear and torsional behaviour.
In particular, the approach here proposed explicitly uses the information on the sub-structures of the building to calibrate the mechanical characteristics of the equivalent beam. More in details, the frames, the shear walls and the lattice structures are identified and modelled as equivalent beams connected by rigid diaphragms at different floors. Thereafter, using an energetic approach the dynamic characteristics of the tall building are estimated (as shown in Potzta and Kollar, 2003) and used to calibrate the mechanic characteristics of the equivalent beam by means of the minimization of a suitable function of modal periods and static displacements. The modal shapes of the equivalent beam can be evaluated in closed form, and thereafter the response of the structure to wind actions is estimated with modal analysis and/or stochastic analysis.
The results obtained with the proposed approach are finally compared both to standard Finite Element approach and to the modal approach with approximated modal shapes presented in Potzta and Kollar (2003). Meno dettagli