CNR Institute of Cybernetics Eduardo Caianiello

Italy

CNR Institute of Cybernetics Eduardo Caianiello

Italy

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De Gregorio M.,CNR Institute of Cybernetics Eduardo Caianiello | Giordano M.,CNR Institute for High Performance Computing and Networking
IEEE Computer Society Conference on Computer Vision and Pattern Recognition Workshops | Year: 2014

In this paper a pixel-based Weightless Neural Network (WNN) method to face the problem of change detection in the field of view of a camera is proposed. The main features of the proposed method are 1) the dynamic adaptability to background change due to the WNN model adopted and 2) the introduction of pixel color histories to improve system behavior in videos characterized by (des)appearing of objects in video scene and/or sudden changes in lightning and background brightness and shape. The WNN approach is very simple and straightforward, and it gives high rank results in competition with other approaches applied to the ChangeDetection.net 2014 benchmark dataset. © 2014 IEEE.


De Gregorio M.,CNR Institute of Cybernetics Eduardo Caianiello | Giordano M.,CNR Institute for High Performance Computing and Networking
23rd European Symposium on Artificial Neural Networks, Computational Intelligence and Machine Learning, ESANN 2015 - Proceedings | Year: 2015

DRASiW is an extension of the WiSARD Weightless NN model with the capability of storing the frequencies of seen patterns during the training stage in an internal data structure called "mental image" (MI). Due to these capability, in previous work it was demonstrated how to reversely process MIs in order to generate synthetic prototypes from training samples. In this paper we show how DRASiW-like systems are able to transfer memory between different architectures while preserving the same functionalities.


Gregorio M.D.,CNR Institute of Cybernetics Eduardo Caianiello | Giordano M.,CNR Institute for High Performance Computing and Networking
Neurocomputing | Year: 2016

Neuronal death (apoptosis) and neurogenesis in mammal adult brains indicate that neuronal turnover could be considered as a special form of neuroplasticity mostly related to memory, cognition and neurodegenerative disorders. In this work we define an algebraic theory of apoptotic and neurogenic transformations of DRASiW-like systems, and, within the proposed formalism, we discover and discuss neuroplasticity properties of DRASiW. Therefore, the main contribution of this work is theoretical with the aim of characterizing DRASiW apoptotic and neurogenic transformations by envisioning their potentialities, rather than to propose a new neural model for future biological simulations. © 2015 Elsevier B.V.


Barone C.,University of Salerno | Bellingeri E.,CNR Institute of Neuroscience | Adamo M.,CNR Institute of Cybernetics Eduardo Caianiello | Sarnelli E.,CNR Institute of Cybernetics Eduardo Caianiello | And 2 more authors.
Superconductor Science and Technology | Year: 2013

A voltage-noise analysis of FeTe0.5Se0.5 thin films has revealed the existence of nonlinear fluctuations above an electric field bias threshold. Below this threshold the fluctuations are standard and compatible with the presence of electron- and hole-type carriers, and it has been possible to evaluate the value of the Hooge noise parameter. Above the electric field bias threshold and at temperatures higher than 70 K, an increased nonlinear 1/f noise is found with a power exponent scaling with the temperature squared. Several possible theoretical interpretations are considered and discussed. © 2013 IOP Publishing Ltd.


Crescitelli A.,University of Sannio | Ricciardi A.,University of Sannio | Consales M.,University of Sannio | Esposito E.,CNR Institute of Cybernetics Eduardo Caianiello | And 4 more authors.
Advanced Functional Materials | Year: 2012

The first evidence of out-of-plane resonances in hybrid metallo-dielectric quasi-crystal (QC) nanostructures composed of metal-backed aperiodically patterned low-contrast dielectric layers is reported. Via experimental measurements and full-wave numerical simulations, these resonant phenomena are characterized with specific reference to the Ammann-Beenker (quasi- periodic, octagonal) tiling lattice geometry and the underlying physics is investigated. In particular, it is shown that, by comparison with standard periodic structures, a moderately richer spectrum of resonant modes may be excited, due to the easier achievement of phase-matching conditions endowed by its denser Bragg spectrum. Such modes are characterized by a distinctive plasmonic or photonic behavior, discriminated by their field distribution and dependence on the metal film thickness. Moreover, the response is accurately predicted via computationally affordable periodic-approximant-based numerical modeling. The enhanced capability of QCs to control number, spectral position, and mode distribution of hybrid resonances may be exploited in a variety of possible applications. To assess this aspect, label-free biosensing is studied via characterization of the surface sensitivity of the proposed structures with respect to local refractive index changes. Moreover, it is also shown that the resonance-engineering capabilities of QC nanostructures may be effectively exploited in order to enhance the absorption efficiency of thin-film solar cells. When illuminated by normally incident light, hybrid metallo-dielectric quasi-crystal nanostructures composed of metal-backed dielectric layers, aperiodically patterned according to the Ammann-Beenker octagonal tiling geometry, may exhibit a rich spectrum of resonant modes characterized by a distinctive plasmonic or photonic behavior. The ability to control the number, spectral position, and field distribution of the resonances may be exploited in label-free biosensing or in energy harvesting applications. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Consales M.,University of Sannio | Ricciardi A.,University of Sannio | Crescitelli A.,University of Sannio | Esposito E.,CNR Institute of Cybernetics Eduardo Caianiello | And 3 more authors.
ACS Nano | Year: 2012

We propose a reliable fabrication process enabling the integration of dielectric and metallic nanostructures on the tip of optical fibers, thus representing a further step in the "lab-on-fiber" technology roadmap. The proposed fabrication procedure involves conventional deposition and nanopatterning techniques, typically used for planar devices, but here adapted to directly operate on optical fiber tip. Following this approach, we demonstrate a first technological platform based on the integration onto the optical fiber tip of two-dimensional hybrid metallo-dielectric nanostructures supporting localized surface plasmon resonances. By means of experimental measurements and full-wave numerical simulations, we characterize these resonant phenomena and investigate the underlying physics. We show that resonances can be easily tuned by acting on the physical and geometrical parameters of the structure. Moreover, with a view toward possible applications, we present some preliminary results demonstrating how the proposed device can work effectively as an optical probe for label-free chemical and biological sensing as well as a microphone for acoustic wave detection. © 2012 American Chemical Society.


Lisitskiy M.P.,CNR Institute of Cybernetics Eduardo Caianiello | Lisitskiy M.P.,National Institute of Nuclear Physics, Italy | Camerlingo C.,CNR Institute of Cybernetics Eduardo Caianiello
Journal of Physics: Conference Series | Year: 2014

The high atomic number of niobium (Z=41) can be exploited to develop a high efficiency superconducting gamma-ray detector based on a novel detection principle, namely, the interaction of a single gamma-ray photon with Abrikosov vortices trapped inside a niobium bulk absorber. To study the feasibility of this principle, niobium type Josephson tunnel junctions with the aluminium oxide as a tunnel barrier and with a thick (0.3 mm) niobium base electrode have been fabricated. The devices have been tested at T = 4.2 K in terms of the current-voltage characteristic and of the magnetic field dependence of the Josephson critical current. The feasibility of the detection principle has been tested under X-ray irradiation from the 55Fe source. The time dependence of the Josephson critical current of the junction with trapped Abrikosov vortices has been recorded without and with X-ray irradiation. The data analysis of obtained experimental curves has confirmed the effect of the X-ray photon absorption on the Josephson critical current caused by jumping of Abrikosov vortices. © Published under licence by IOP Publishing Ltd.


Grieco B.P.A.,Federal University of Rio de Janeiro | Lima P.M.V.,Federal University of Rio de Janeiro | De Gregorio M.,CNR Institute of Cybernetics Eduardo Caianiello | Franca F.M.G.,Federal University of Rio de Janeiro
Neurocomputing | Year: 2010

The WiSARD (Wilkie, Stonham and Aleksander's Recognition Device) weightless neural network model has its functionality based on the collective response of RAM-based neurons. WiSARD's learning phase consists on writing at the RAM neurons' positions addressed (typically through a pseudo-random mapping) by binary training patterns. By counting the frequency of writing accesses at RAM neuron positions during the learning phase, it is possible to associate the most accessed addresses with the corresponding input field contents that defined them. The idea of associating this process with the formation of "mental" images is explored in the DRASiW model, a WiSARD extension provided with the ability of producing pattern examples, or prototypes, derived from learnt categories. This work demonstrates the equivalence of two ways of generating such prototypes: (i) via frequency counting and filtering and (ii) via formulating fuzzy rules. Moreover, it is shown, through the exploration of the MNIST database of handwritten digits as benchmark, how the process of mental images formation can improve WiSARD's classification skills. © 2010 Elsevier B.V. All rights reserved.


Pierobon P.,CNR Institute of Cybernetics Eduardo Caianiello
Journal of Experimental Biology | Year: 2015

In the presence of prey, or upon exposure to reduced glutathione (GSH), Hydra polyps open a mouth to ingest the captured prey and close it after feeding; at rest the mouth is not evident. In previous papers we have shown that GABA, glycine and NMDA modulate the mechanisms of mouth closure through ligand-gated-ion-channel receptors that are similar to their mammalian analogues in terms of biochemical and pharmacological properties. In order to study the regional distribution of these receptors, we have applied the GSH assay to polyps amputated at different levels of the body column. The response to 1-10 μmol l-1 GSH of polyps lacking either peduncle and foot or the entire body columns (heads) was not different from control, whole animals. In the presence of GABA or muscimol, duration of the response was significantly decreased in heads; the decrease was suppressed by the GABA antagonists gabazine and bicuculline. By contrast, in animals lacking peduncle and foot, duration of the response did not vary upon GABA administration. Conversely, in the presence of glycine, duration of the response in heads preparations was similar to control, whereas in footless polyps, it was significantly reduced. The decrease was mimicked by the glycine agonists taurine and β-alanine, and counteracted by strychnine. These results suggest a regional distribution of receptors to GABA and glycine in the neuromuscular circuitry modulating the feeding behaviour. © 2015, Company of Biologists Ltd. All rights reserved.


De Gregorio M.,CNR Institute of Cybernetics Eduardo Caianiello | Giordano M.,CNR Institute of Cybernetics Eduardo Caianiello
Proceedings - 1st BRICS Countries Congress on Computational Intelligence, BRICS-CCI 2013 | Year: 2013

In this paper, we present a WiSARD-based system (CwisarD) facing the problem of change detection (CD) in multiple images of the same scene taken at different time, and, in particular, motion in videos of the same view taken by a static camera. Although the proposed weightless neural approach is very simple and straightforward, it provides very good results in challenging with others approaches on the ChangeDetection.net benchmark dataset (CDnet). © 2013 IEEE.

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