1
|
Piersanti M, Ubertini P, Battiston R, Bazzano A, D'Angelo G, Rodi JG, Diego P, Zeren Z, Ammendola R, Badoni D, Bartocci S, Beolè S, Bertello I, Burger WJ, Campana D, Cicone A, Cipollone P, Coli S, Conti L, Contin A, Cristoforetti M, De Angelis F, De Donato C, De Santis C, Di Luca A, Fiorenza E, Follega FM, Gebbia G, Iuppa R, Lega A, Lolli M, Martino B, Martucci M, Masciantonio G, Mergè M, Mese M, Morbidini A, Neubüser C, Nozzoli F, Nuccilli F, Oliva A, Osteria G, Palma F, Palmonari F, Panico B, Papini E, Parmentier A, Perciballi S, Perfetto F, Perinelli A, Picozza P, Pozzato M, Rebustini G, Recchiuti D, Ricci E, Ricci M, Ricciarini SB, Russi A, Sahnoun Z, Savino U, Scotti V, Shen X, Sotgiu A, Sparvoli R, Tofani S, Vertolli N, Vilona V, Vitale V, Zannoni U, Zoffoli S, Zuccon P. Author Correction: Evidence of an upper ionospheric electric field perturbation correlated with a gamma ray burst. Nat Commun 2023; 14:8513. [PMID: 38129406 PMCID: PMC10739859 DOI: 10.1038/s41467-023-44224-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2023] Open
Affiliation(s)
- Mirko Piersanti
- Department of Physical and Chemical Sciences, University of L'Aquila, 67100, L'Aquila, Italy.
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy.
| | - Pietro Ubertini
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | - Roberto Battiston
- Department of Physics, University of Trento, Povo, Italy
- TIFPA-INFN, Povo, 38123, Trento, Italy
| | - Angela Bazzano
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | - Giulia D'Angelo
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | - James G Rodi
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | - Piero Diego
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | - Zhima Zeren
- National Institute of Natural Hazards, Ministry of Emergency Management of China, Beijing, 100085, People's Republic of China
| | | | - Davide Badoni
- INFN, University of Rome Tor Vergata, Rome, 00133, Italy
| | | | | | - Igor Bertello
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | | | | | - Antonio Cicone
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
- Dipartimento di Ingegneria e Scienze dell'Informazione e Matematica, University of L'Aquila, 67100, L'Aquila, Italy
| | | | - Silvia Coli
- INFN - Sezione di Torino, 10125, Torino, Italy
| | - Livio Conti
- INFN, University of Rome Tor Vergata, Rome, 00133, Italy
- Uninettuno University, 00186, Rome, Italy
| | - Andrea Contin
- University of Bologna, Bologna, 40127, Italy
- INFN - Sezione di Bologna, 40127, Bologna, Italy
| | - Marco Cristoforetti
- TIFPA-INFN, Povo, 38123, Trento, Italy
- Fondazione Bruno Kessler, 38123, Povo, TN, Italy
| | | | | | | | - Andrea Di Luca
- Department of Physics, University of Trento, Povo, Italy
- TIFPA-INFN, Povo, 38123, Trento, Italy
| | | | - Francesco Maria Follega
- Department of Physics, University of Trento, Povo, Italy
- TIFPA-INFN, Povo, 38123, Trento, Italy
| | - Giuseppe Gebbia
- Department of Physics, University of Trento, Povo, Italy
- TIFPA-INFN, Povo, 38123, Trento, Italy
| | - Roberto Iuppa
- Department of Physics, University of Trento, Povo, Italy
- TIFPA-INFN, Povo, 38123, Trento, Italy
| | - Alessandro Lega
- Department of Physics, University of Trento, Povo, Italy
- TIFPA-INFN, Povo, 38123, Trento, Italy
| | - Mauro Lolli
- INFN - Sezione di Bologna, 40127, Bologna, Italy
| | - Bruno Martino
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
- CNR, V. Fosso del Cavaliere 100, 00133, Rome, Italy
| | | | | | - Matteo Mergè
- INFN, University of Rome Tor Vergata, Rome, 00133, Italy
- Agenzia Spaziale Italia, Rome, 00133, Italy
| | - Marco Mese
- INFN-Sezione di Napoli, Naples, 80126, Italy
- Università degli Studi di Napoli Federico II, 80126, Naples, Italy
| | | | | | | | | | - Alberto Oliva
- University of Bologna, Bologna, 40127, Italy
- INFN - Sezione di Bologna, 40127, Bologna, Italy
| | | | | | - Federico Palmonari
- University of Bologna, Bologna, 40127, Italy
- INFN - Sezione di Bologna, 40127, Bologna, Italy
| | - Beatrice Panico
- INFN-Sezione di Napoli, Naples, 80126, Italy
- Università degli Studi di Napoli Federico II, 80126, Naples, Italy
| | - Emanuele Papini
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | - Alexandra Parmentier
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
- INFN, University of Rome Tor Vergata, Rome, 00133, Italy
| | | | | | - Alessio Perinelli
- Department of Physics, University of Trento, Povo, Italy
- TIFPA-INFN, Povo, 38123, Trento, Italy
| | - Piergiorgio Picozza
- INFN, University of Rome Tor Vergata, Rome, 00133, Italy
- Department of Physics, University of Rome Tor Vergata, Rome, 00133, Italy
| | | | | | - Dario Recchiuti
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
- Department of Physics, University of Trento, Povo, Italy
| | - Ester Ricci
- Department of Physics, University of Trento, Povo, Italy
- TIFPA-INFN, Povo, 38123, Trento, Italy
| | | | | | - Andrea Russi
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | | | | | - Valentina Scotti
- INFN-Sezione di Napoli, Naples, 80126, Italy
- Università degli Studi di Napoli Federico II, 80126, Naples, Italy
| | - Xuhui Shen
- National Space Science Center, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China
| | | | - Roberta Sparvoli
- INFN, University of Rome Tor Vergata, Rome, 00133, Italy
- Department of Physics, University of Rome Tor Vergata, Rome, 00133, Italy
| | - Silvia Tofani
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | - Nello Vertolli
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | | | | | - Ugo Zannoni
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | | | - Paolo Zuccon
- Department of Physics, University of Trento, Povo, Italy
- TIFPA-INFN, Povo, 38123, Trento, Italy
| |
Collapse
|
2
|
Piersanti M, Ubertini P, Battiston R, Bazzano A, D'Angelo G, Rodi JG, Diego P, Zeren Z, Ammendola R, Badoni D, Bartocci S, Beolè S, Bertello I, Burger WJ, Campana D, Cicone A, Cipollone P, Coli S, Conti L, Contin A, Cristoforetti M, De Angelis F, De Donato C, De Santis C, Di Luca A, Fiorenza E, Follega FM, Gebbia G, Iuppa R, Lega A, Lolli M, Martino B, Martucci M, Masciantonio G, Mergè M, Mese M, Morbidini A, Neubüser C, Nozzoli F, Nuccilli F, Oliva A, Osteria G, Palma F, Palmonari F, Panico B, Papini E, Parmentier A, Perciballi S, Perfetto F, Perinelli A, Picozza P, Pozzato M, Rebustini G, Recchiuti D, Ricci E, Ricci M, Ricciarini SB, Russi A, Sahnoun Z, Savino U, Scotti V, Shen X, Sotgiu A, Sparvoli R, Tofani S, Vertolli N, Vilona V, Vitale V, Zannoni U, Zoffoli S, Zuccon P. Evidence of an upper ionospheric electric field perturbation correlated with a gamma ray burst. Nat Commun 2023; 14:7013. [PMID: 37963921 PMCID: PMC10646044 DOI: 10.1038/s41467-023-42551-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 10/13/2023] [Indexed: 11/16/2023] Open
Abstract
Earth's atmosphere, whose ionization stability plays a fundamental role for the evolution and endurance of life, is exposed to the effect of cosmic explosions producing high energy Gamma-ray-bursts. Being able to abruptly increase the atmospheric ionization, they might deplete stratospheric ozone on a global scale. During the last decades, an average of more than one Gamma-ray-burst per day were recorded. Nevertheless, measurable effects on the ionosphere were rarely observed, in any case on its bottom-side (from about 60 km up to about 350 km of altitude). Here, we report evidence of an intense top-side (about 500 km) ionospheric perturbation induced by significant sudden ionospheric disturbance, and a large variation of the ionospheric electric field at 500 km, which are both correlated with the October 9, 2022 Gamma-ray-burst (GRB221009A).
Collapse
Affiliation(s)
- Mirko Piersanti
- Department of Physical and Chemical Sciences, University of L'Aquila, 67100, L'Aquila, Italy.
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy.
| | - Pietro Ubertini
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | - Roberto Battiston
- Department of Physics, University of Trento, Povo, Italy
- TIFPA-INFN, Povo, 38123, Trento, Italy
| | - Angela Bazzano
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | - Giulia D'Angelo
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | - James G Rodi
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | - Piero Diego
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | - Zhima Zeren
- National Institute of Natural Hazards, Ministry of Emergency Management of China, Beijing, 100085, People's Republic of China
| | | | - Davide Badoni
- INFN, University of Rome Tor Vergata, Rome, 00133, Italy
| | | | | | - Igor Bertello
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | | | | | - Antonio Cicone
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
- Dipartimento di Ingegneria e Scienze dell'Informazione e Matematica, University of L'Aquila, 67100, L'Aquila, Italy
| | | | - Silvia Coli
- INFN - Sezione di Torino, 10125, Torino, Italy
| | - Livio Conti
- INFN, University of Rome Tor Vergata, Rome, 00133, Italy
- Uninettuno University, 00186, Rome, Italy
| | - Andrea Contin
- University of Bologna, Bologna, 40127, Italy
- INFN - Sezione di Bologna, 40127, Bologna, Italy
| | - Marco Cristoforetti
- TIFPA-INFN, Povo, 38123, Trento, Italy
- Fondazione Bruno Kessler, 38123, Povo, TN, Italy
| | | | | | | | - Andrea Di Luca
- Department of Physics, University of Trento, Povo, Italy
- TIFPA-INFN, Povo, 38123, Trento, Italy
| | | | - Francesco Maria Follega
- Department of Physics, University of Trento, Povo, Italy
- TIFPA-INFN, Povo, 38123, Trento, Italy
| | - Giuseppe Gebbia
- Department of Physics, University of Trento, Povo, Italy
- TIFPA-INFN, Povo, 38123, Trento, Italy
| | - Roberto Iuppa
- Department of Physics, University of Trento, Povo, Italy
- TIFPA-INFN, Povo, 38123, Trento, Italy
| | - Alessandro Lega
- Department of Physics, University of Trento, Povo, Italy
- TIFPA-INFN, Povo, 38123, Trento, Italy
| | - Mauro Lolli
- INFN - Sezione di Bologna, 40127, Bologna, Italy
| | - Bruno Martino
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
- CNR, V. Fosso del Cavaliere 100, 00133, Rome, Italy
| | | | | | - Matteo Mergè
- INFN, University of Rome Tor Vergata, Rome, 00133, Italy
- Agenzia Spaziale Italia, Rome, 00133, Italy
| | - Marco Mese
- INFN-Sezione di Napoli, Naples, 80126, Italy
- Università degli Studi di Napoli Federico II, 80126, Naples, Italy
| | | | | | | | | | - Alberto Oliva
- University of Bologna, Bologna, 40127, Italy
- INFN - Sezione di Bologna, 40127, Bologna, Italy
| | | | | | - Federico Palmonari
- University of Bologna, Bologna, 40127, Italy
- INFN - Sezione di Bologna, 40127, Bologna, Italy
| | - Beatrice Panico
- INFN-Sezione di Napoli, Naples, 80126, Italy
- Università degli Studi di Napoli Federico II, 80126, Naples, Italy
| | - Emanuele Papini
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | - Alexandra Parmentier
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
- INFN, University of Rome Tor Vergata, Rome, 00133, Italy
| | | | | | - Alessio Perinelli
- Department of Physics, University of Trento, Povo, Italy
- TIFPA-INFN, Povo, 38123, Trento, Italy
| | - Piergiorgio Picozza
- INFN, University of Rome Tor Vergata, Rome, 00133, Italy
- Department of Physics, University of Rome Tor Vergata, Rome, 00133, Italy
| | | | | | - Dario Recchiuti
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
- Department of Physics, University of Trento, Povo, Italy
| | - Ester Ricci
- Department of Physics, University of Trento, Povo, Italy
- TIFPA-INFN, Povo, 38123, Trento, Italy
| | | | | | - Andrea Russi
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | | | | | - Valentina Scotti
- INFN-Sezione di Napoli, Naples, 80126, Italy
- Università degli Studi di Napoli Federico II, 80126, Naples, Italy
| | - Xuhui Shen
- National Space Science Center, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China
| | | | - Roberta Sparvoli
- INFN, University of Rome Tor Vergata, Rome, 00133, Italy
- Department of Physics, University of Rome Tor Vergata, Rome, 00133, Italy
| | - Silvia Tofani
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | - Nello Vertolli
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | | | | | - Ugo Zannoni
- National Institute of Astrophysics, IAPS, Rome, 00133, Italy
| | | | - Paolo Zuccon
- Department of Physics, University of Trento, Povo, Italy
- TIFPA-INFN, Povo, 38123, Trento, Italy
| |
Collapse
|
3
|
Alfonsi L, Ambroglini F, Ambrosi G, Ammendola R, Assante D, Badoni D, Belyaev V, Burger W, Cafagna A, Cipollone P, Consolini G, Conti L, Contin A, Angelis E, Donato C, Franceschi G, Santis A, Santis C, Diego P, Durante M, Fornaro C, Guandalini C, Laurenti G, Laurenza M, Lazzizzera I, Lolli M, Manea C, Marcelli L, Marcucci F, Masciantonio G, Osteria G, Palma F, Palmonari F, Panico B, Patrizii L, Picozza P, Pozzato M, Rashevskaya I, Ricci M, Rovituso M, Scotti V, Sotgiu A, Sparvoli R, Spataro B, Spogli L, Tommasino F, Ubertini P, Vannaroni G, Xuhui S, Zoffoli S. The HEPD particle detector and the EFD electric field detector for the CSES satellite. Radiat Phys Chem Oxf Engl 1993 2017. [DOI: 10.1016/j.radphyschem.2016.12.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
4
|
Lucci M, Badoni D, Merlo V, Ottaviani I, Salina G, Cirillo M, Ustinov AV, Winkler D. Experimental Study of Spectral Properties of a Frenkel-Kontorova System. Phys Rev Lett 2015; 115:107002. [PMID: 26382697 DOI: 10.1103/physrevlett.115.107002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Indexed: 06/05/2023]
Abstract
We report on microwave emission from linear parallel arrays of underdamped Josephson junctions, which are described by the Frenkel-Kontorova (FK) model. Electromagnetic radiation is detected from the arrays when biased on current singularities (steps) appearing at voltages V(n)=Φ(0)(nc̅/L), where Φ(0)=2.07×10(-15) Wb is the magnetic flux quantum, and c̅, L, and n are, respectively, the speed of light in the transmission line embedding the array, L its physical length, and n an integer. The radiation, detected at fundamental frequency c̅/2L when biased on different singularities, indicates shuttling of bunched 2π kinks (magnetic flux quanta). Resonance of flux-quanta motion with the small-amplitude oscillations induced in the arrays gives rise to fine structures in the radiation spectrum, which are interpreted on the basis of the FK model describing the resonance. The impact of our results on design and performances of new digital circuit families is discussed.
Collapse
Affiliation(s)
- M Lucci
- Dipartimento di Fisica and MINAS Lab, Università di Roma Tor Vergata, 00133 Roma, Italy and INFN sezione "Tor Vergata", via della Ricerca Scientifica, 00133 Roma, Italy
| | - D Badoni
- Dipartimento di Fisica and MINAS Lab, Università di Roma Tor Vergata, 00133 Roma, Italy and INFN sezione "Tor Vergata", via della Ricerca Scientifica, 00133 Roma, Italy
| | - V Merlo
- Dipartimento di Fisica and MINAS Lab, Università di Roma Tor Vergata, 00133 Roma, Italy and INFN sezione "Tor Vergata", via della Ricerca Scientifica, 00133 Roma, Italy
| | - I Ottaviani
- Dipartimento di Fisica and MINAS Lab, Università di Roma Tor Vergata, 00133 Roma, Italy and INFN sezione "Tor Vergata", via della Ricerca Scientifica, 00133 Roma, Italy
| | - G Salina
- Dipartimento di Fisica and MINAS Lab, Università di Roma Tor Vergata, 00133 Roma, Italy and INFN sezione "Tor Vergata", via della Ricerca Scientifica, 00133 Roma, Italy
| | - M Cirillo
- Dipartimento di Fisica and MINAS Lab, Università di Roma Tor Vergata, 00133 Roma, Italy and INFN sezione "Tor Vergata", via della Ricerca Scientifica, 00133 Roma, Italy
| | - A V Ustinov
- Physikalisches Institut, Karlsruhe Institute of Technology, D-76128 Karlsruhe, Germany and National University of Science and Technology MISIS, Leninsky prosp. 4, Moscow 119049, Russia
| | - D Winkler
- Department of Microtechnology and Nanoscience-MC2, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
| |
Collapse
|
5
|
Abstract
In this article we describe the electronic implementation of an attractor neural network with plastic analog synapses. The project for a 27 neurons fully connected network will be shown together with the most important electronic tests we have carried out on a smaller network.
Collapse
Affiliation(s)
- Davide Badoni
- INFN, Sezione di Roma, Istituto di Fisica, Università di Roma “Tor Vergata”, V.le della Ricerca Scientifica 1, 00173, Roma, Italy
| | - Roberto Riccardi
- INFN, Sezione di Roma, Istituto di Fisica, Università di Roma “Tor Vergata”, V.le della Ricerca Scientifica 1, 00173, Roma, Italy
| | - Gaetano Salina
- INFN, Sezione di Roma, Istituto di Fisica, Università di Roma “Tor Vergata”, V.le della Ricerca Scientifica 1, 00173, Roma, Italy
| |
Collapse
|
6
|
Giulioni M, Pannunzi M, Badoni D, Dante V, Del Giudice P. Classification of correlated patterns with a configurable analog VLSI neural network of spiking neurons and self-regulating plastic synapses. Neural Comput 2009; 21:3106-29. [PMID: 19686067 DOI: 10.1162/neco.2009.08-07-599] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
We describe the implementation and illustrate the learning performance of an analog VLSI network of 32 integrate-and-fire neurons with spike-frequency adaptation and 2016 Hebbian bistable spike-driven stochastic synapses, endowed with a self-regulating plasticity mechanism, which avoids unnecessary synaptic changes. The synaptic matrix can be flexibly configured and provides both recurrent and external connectivity with address-event representation compliant devices. We demonstrate a marked improvement in the efficiency of the network in classifying correlated patterns, owing to the self-regulating mechanism.
Collapse
|
7
|
Chicca E, Badoni D, Dante V, D'Andreagiovanni M, Salina G, Carota L, Fusi S, Del Giudice P. A vlsi recurrent network of integrate-and-fire neurons connected by plastic synapses with long-term memory. ACTA ACUST UNITED AC 2003; 14:1297-307. [DOI: 10.1109/tnn.2003.816367] [Citation(s) in RCA: 135] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
8
|
Abstract
We present a model for spike-driven dynamics of a plastic synapse, suited for aVLSI implementation. The synaptic device behaves as a capacitor on short timescales and preserves the memory of two stable states (efficacies) on long timescales. The transitions (LTP/LTD) are stochastic because both the number and the distribution of neural spikes in any finite (stimulation) interval fluctuate, even at fixed pre- and postsynaptic spike rates. The dynamics of the single synapse is studied analytically by extending the solution to a classic problem in queuing theory (Takacs process). The model of the synapse is implemented in aVLSI and consists of only 18 transistors. It is also directly simulated. The simulations indicate that LTP/LTD probabilities versus rates are robust to fluctuations of the electronic parameters in a wide range of rates. The solutions for these probabilities are in very good agreement with both the simulations and measurements. Moreover, the probabilities are readily manipulable by variations of the chip's parameters, even in ranges where they are very small. The tests of the electronic device cover the range from spontaneous activity (3-4 Hz) to stimulus-driven rates (50 Hz). Low transition probabilities can be maintained in all ranges, even though the intrinsic time constants of the device are short (approximately 100 ms). Synaptic transitions are triggered by elevated presynaptic rates: for low presynaptic rates, there are essentially no transitions. The synaptic device can preserve its memory for years in the absence of stimulation. Stochasticity of learning is a result of the variability of interspike intervals; noise is a feature of the distributed dynamics of the network. The fact that the synapse is binary on long timescales solves the stability problem of synaptic efficacies in the absence of stimulation. Yet stochastic learning theory ensures that it does not affect the collective behavior of the network, if the transition probabilities are low and LTP is balanced against LTD.
Collapse
Affiliation(s)
- S Fusi
- INFN Sezione RM1, University of Rome La Sapienza, Roma, Italy
| | | | | | | | | |
Collapse
|
9
|
Del Giudice P, Fusi S, Badoni D, Dante V, Amit DJ. Learning attractors in an asynchronous, stochastic electronic neural network. Network 1998; 9:183-205. [PMID: 9861985 DOI: 10.1088/0954-898x/9/2/003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
LANN27 is an electronic device implementing in discrete electronics a fully connected (full feedback) network of 27 neurons and 351 plastic synapses with stochastic Hebbian learning. Both neurons and synapses are dynamic elements, with two time constants--fast for neurons and slow for synapses. Learning, synaptic dynamics, is analogue and is driven in a Hebbian way by neural activities. Long-term memorization takes place on a discrete set of synaptic efficacies and is effected in a stochastic manner. The intense feedback between the nonlinear neural elements, via the learned synaptic structure, creates in an organic way a set of attractors for the collective retrieval dynamics of the neural system, akin to Hebbian learned reverberations. The resulting structure of the attractors is a record of the large-scale statistics in the uncontrolled, incoming flow of stimuli. As the statistics in the stimulus flow changes significantly, the attractors slowly follow it and the network behaves as a palimpsest--old is gradually replaced by new. Moreover, the slow learning creates attractors which render the network a prototype extractor: entire clouds of stimuli, noisy versions of a prototype, used in training, all retrieve the attractor corresponding to the prototype upon retrieval. Here we describe the process of studying the collective dynamics of the network, before, during and following learning, which is rendered complex by the richness of the possible stimulus streams and the large dimensionality of the space of states of the network. We propose sampling techniques and modes of representation for the outcome.
Collapse
Affiliation(s)
- P Del Giudice
- Istituto Superiore di Sanità, Physics Laboratory, Rome, Italy
| | | | | | | | | |
Collapse
|