Numbers in the Blind's “Eye”

Background: Although lacking visual experience with numerosities, recent evidence shows that the blind perform similarly to sighted persons on numerical comparison or parity judgement tasks. In particular, on tasks presented in the auditory modality, the blind surprisingly show the same effect that appears in sighted persons, demonstrating that numbers are represented through a spatial code, i.e. the Spatial-Numerical Association of Response Codes (SNARC) effect. But, if this is the case, how is this numerical spatial representation processed in the brain of the blind? Principal Findings: Here we report that, although blind and sighted people have similarly organized numerical representations, the attentional shifts generated by numbers have different electrophysiological correlates (sensorial N100 in the sighted and cognitive P300 in the blind). Conclusions: These results highlight possible differences in the use of spatial representations acquired through modalities other than vision in the blind population

An experimental validation of the effectiveness of quasi-trivial solutions for composite laminates

In this work the problem of the least-weight design procedure of a multilayer composite plate is addressed. The proposed design method is based on an optimization strategy that uses neither simplifying hypotheses nor standard rules for determining the optimum stack. Indeed, the design task is stated as a constrained non-linear programming problem (CNLPP) wherein requirements of different nature are integrated as optimization constraints. Such constraints include mechanical requirements (i.e. material properties, first buckling load of the plate, membrane stiffness) together with geometrical and technological restrictions on the selected design variables. The proposed strategy follows a two-step approach which first selects the optimum number of plies and then searches the optimum stack in the space of the so-called quasi-trivial solutions. The quasi-trivial optimum sequences have been compared with stacking sequences developed following layup rules typically used in aeronautics: optimized non-standard plates are lighter (about 10%) than standard ones with equivalent or superior mechanical properties. The effectiveness of the developed configurations is proven through an a posteriori experimental campaign of buckling tests conducted at I2M laboratory. The experimental results are in excellent agreement with those provided by numerical simulations

Multiscale Thermal Characterization of Mechanically Loaded Ceramic Matrix Composite

International audienc

Least-weight design of composite structures: an unconventional and general approach

This work deals with the problem of the least-weight design of a multilayer composite plate introducing neither simplifying hypotheses nor standard rules for determining the optimum stack. In this context, the design task is stated as a constrained non-linear programming problem (CNLPP) wherein requirements of different nature are integrated as optimisation constraints. Such constraints include mechanical requirements (admissible material properties, first buckling load, membrane stiffness), together with geometrical and technological restrictions. A multi-scale two-level optimisation methodology (MS2L) is proposed, [1]-[2], that aims at optimising simultaneously both geometrical and material parameters at two characteristic scales: the macro and meso scales. The macroscopic behaviour of the laminate is managed by the MS2L optimisation strategy through the polar parameters (in the framework of the equivalent single layer theories) while a special hybrid algorithm (genetic + gradient-based algorithm) perform the lay-up solution search. In this context, the design problem is split into two different (but related) optimisation problems. At the first level (macroscopic scale) the goal is to find the optimum value of the laminate thickness and its polar parameters that minimise mass and meets the full set of constraints for the problem at hand. The second-level problem focuses on the laminate mesoscopic scale (i.e. the ply-level). Here the goal is to determine at least one stacking-sequence meeting the optimum value of both mechanical and geometrical design variables provided by the first-level problem. The search of the optimum stack is realised in the space of the so-called quasi-trivial solutions [1]. The MS2L approach allows to design plates that are lighter (about 10%) than those obtainable with classical approaches typically used for aerospace structures and with equivalent or superior mechanical properties. The effectiveness of the proposed configurations is proven through an experimental campaign conducted at I2M laboratory. REFERENCES [1] M. Montemurro and A. Catapano. On the effective integration of manufacturability constraints within the multi-scale methodology for designing variable angle-tow laminates. Composite Structures. Vol. 161, pp. 145159, 2017. [2] M. Montemurro. The polar analysis of the Third-order Shear Deformation Theory of laminates. Composite Structures. Vol. 131, pp. 775789, 2015

Project NeuroPros: EEG investigation of prosodic cues processing in French

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Human Voice as a Measure of Mental Load Level

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