1 code implementation • 5 Jan 2019 • Filippo Maria Bianchi, Daniele Grattarola, Lorenzo Livi, Cesare Alippi
Popular graph neural networks implement convolution operations on graphs based on polynomial spectral filters.
Ranked #4 on Skeleton Based Action Recognition on SBU
1 code implementation • NeurIPS 2021 • Daniele Grattarola, Lorenzo Livi, Cesare Alippi
Cellular automata (CA) are a class of computational models that exhibit rich dynamics emerging from the local interaction of cells arranged in a regular lattice.
1 code implementation • 21 Jun 2017 • Daniele Zambon, Cesare Alippi, Lorenzo Livi
Graph representations offer powerful and intuitive ways to describe data in a multitude of application domains.
1 code implementation • 24 Oct 2019 • Filippo Maria Bianchi, Daniele Grattarola, Lorenzo Livi, Cesare Alippi
In graph neural networks (GNNs), pooling operators compute local summaries of input graphs to capture their global properties, and they are fundamental for building deep GNNs that learn hierarchical representations.
Ranked #1 on Graph Classification on Bench-hard
1 code implementation • 16 May 2018 • Daniele Grattarola, Daniele Zambon, Cesare Alippi, Lorenzo Livi
A common approach is to use embedding techniques to represent graphs as points in a conventional Euclidean space, but non-Euclidean spaces have often been shown to be better suited for embedding graphs.
1 code implementation • ICML 2020 • Daniele Zambon, Cesare Alippi, Lorenzo Livi
We present Graph Random Neural Features (GRNF), a novel embedding method from graph-structured data to real vectors based on a family of graph neural networks.
1 code implementation • 11 Dec 2018 • Daniele Grattarola, Lorenzo Livi, Cesare Alippi
Constant-curvature Riemannian manifolds (CCMs) have been shown to be ideal embedding spaces in many application domains, as their non-Euclidean geometry can naturally account for some relevant properties of data, like hierarchy and circularity.
1 code implementation • 27 Mar 2019 • Pietro Verzelli, Cesare Alippi, Lorenzo Livi
Finding such a region requires searching in hyper-parameter space in a sensible way: hyper-parameter configurations marginally outside such a region might yield networks exhibiting fully developed chaos, hence producing unreliable computations.
2 code implementations • 18 Mar 2019 • Daniele Zambon, Daniele Grattarola, Lorenzo Livi, Cesare Alippi
This paper proposes an autoregressive (AR) model for sequences of graphs, which generalises traditional AR models.
no code implementations • 18 May 2018 • Daniele Zambon, Cesare Alippi, Lorenzo Livi
Given a finite sequence of graphs, e. g., coming from technological, biological, and social networks, the paper proposes a methodology to identify possible changes in stationarity in the stochastic process generating the graphs.
no code implementations • 9 May 2018 • Filippo Maria Bianchi, Lorenzo Livi, Karl Øyvind Mikalsen, Michael Kampffmeyer, Robert Jenssen
In this work, we propose a novel autoencoder architecture based on recurrent neural networks to generate compressed representations of MTS.
no code implementations • 3 May 2018 • Daniele Zambon, Lorenzo Livi, Cesare Alippi
The proposed methodology consists in embedding graphs into a geometric space and perform change detection there by means of conventional methods for numerical streams.
no code implementations • 21 Jan 2018 • Filippo Maria Bianchi, Lorenzo Livi, Alberto Ferrante, Jelena Milosevic, Miroslaw Malek
We tackle the problem of classifying Electrocardiography (ECG) signals with the aim of predicting the onset of Paroxysmal Atrial Fibrillation (PAF).
no code implementations • 22 Aug 2014 • Lorenzo Livi
Representing patterns as labeled graphs is becoming increasingly common in the broad field of computational intelligence.
no code implementations • 8 Feb 2017 • Michael Kampffmeyer, Sigurd Løkse, Filippo Maria Bianchi, Robert Jenssen, Lorenzo Livi
In this paper we introduce the deep kernelized autoencoder, a neural network model that allows an explicit approximation of (i) the mapping from an input space to an arbitrary, user-specified kernel space and (ii) the back-projection from such a kernel space to input space.
no code implementations • 10 Sep 2016 • Filippo Maria Bianchi, Lorenzo Livi, Cesare Alippi, Robert Jenssen
We show that topological properties of such a multiplex reflect important features of RNN dynamics and are used to guide the tuning procedure.
1 code implementation • 24 Oct 2015 • Enrico Maiorino, Filippo Maria Bianchi, Lorenzo Livi, Antonello Rizzi, Alireza Sadeghian
We assume that such a dynamical process is predictable to a certain degree by means of a class of recurrent networks called Echo State Network (ESN), which are capable to model a generic dynamical process.
no code implementations • 11 Mar 2016 • Lorenzo Livi, Filippo Maria Bianchi, Cesare Alippi
In this paper, we aim at addressing this issue by proposing a theoretically motivated, unsupervised method based on Fisher information for determining the edge of criticality in recurrent neural networks.
no code implementations • 8 Apr 2016 • Lorenzo Livi, Cesare Alippi
The final partition is derived by exploiting a criterion based on mutual information minimization.
no code implementations • 26 Jan 2016 • Filippo Maria Bianchi, Lorenzo Livi, Cesare Alippi
We verify that the determination of the edge of stability provided by such RQA measures is more accurate than two well-known criteria based on the Jacobian matrix of the reservoir.
no code implementations • 30 Jul 2014 • Lorenzo Livi, Alessandro Giuliani, Alireza Sadeghian
This paper deals with the relations among structural, topological, and chemical properties of the E. Coli proteome from the vantage point of the solubility/aggregation propensity of proteins.
no code implementations • 10 Apr 2015 • Lorenzo Livi, Alireza Sadeghian, Hamid Sadeghian
The subjects belong to two different groups, formed by four and eight subjects with, respectively, high- and low-amplitude rest tremors.
no code implementations • 28 Jul 2014 • Lorenzo Livi, Alessandro Giuliani, Antonello Rizzi
This paper builds upon the fundamental work of Niwa et al. [34], which provides the unique possibility to analyze the relative aggregation/folding propensity of the elements of the entire Escherichia coli (E. coli) proteome in a cell-free standardized microenvironment.
no code implementations • 26 Jul 2014 • Lorenzo Livi, Alireza Sadeghian
The proposed framework is conceived (i) to offer a guideline for the synthesis of information granules and (ii) to build a groundwork to compare and quantitatively judge over different data granulation procedures.
no code implementations • 20 Oct 2014 • Lorenzo Livi, Guido Del Vescovo, Antonello Rizzi, Fabio Massimo Frattale Mascioli
This paper presents the SPARE C++ library, an open source software tool conceived to build pattern recognition and soft computing systems.
no code implementations • 19 Jan 2015 • Francesca Possemato, Maurizio Paschero, Lorenzo Livi, Antonello Rizzi, Alireza Sadeghian
In this paper, we face the problem of joint optimization of both topology and network parameters in a real smart grid.
no code implementations • 17 Aug 2014 • Lorenzo Livi, Antonello Rizzi, Alireza Sadeghian
We evaluate a version of the recently-proposed classification system named Optimized Dissimilarity Space Embedding (ODSE) that operates in the input space of sequences of generic objects.
no code implementations • 28 Jul 2014 • Lorenzo Livi, Alireza Sadeghian, Witold Pedrycz
The one-class classification problem is a well-known research endeavor in pattern recognition.
no code implementations • 25 Jul 2014 • Enrico De Santis, Lorenzo Livi, Alireza Sadeghian, Antonello Rizzi
Modern electric power grids (smart grids) are equipped with smart sensors that allow to gather real-time information regarding the physical status of all the component elements belonging to the whole infrastructure (e. g., cables and related insulation, transformers, breakers and so on).
no code implementations • 17 Sep 2014 • Filippo Maria Bianchi, Enrico Maiorino, Lorenzo Livi, Antonello Rizzi, Alireza Sadeghian
We propose a multi-agent algorithm able to automatically discover relevant regularities in a given dataset, determining at the same time the set of configurations of the adopted parametric dissimilarity measure yielding compact and separated clusters.
no code implementations • 19 Jul 2018 • Michael Kampffmeyer, Sigurd Løkse, Filippo M. Bianchi, Robert Jenssen, Lorenzo Livi
Autoencoders learn data representations (codes) in such a way that the input is reproduced at the output of the network.
no code implementations • 27 Jul 2018 • Andrea Ceni, Peter Ashwin, Lorenzo Livi
Simulations conducted on a controlled benchmark task confirm the relevance of these attractors for interpreting the behaviour of recurrent neural networks, at least for tasks that involve learning a finite number of stable states and transitions between them.
no code implementations • 3 Oct 2018 • Pietro Verzelli, Lorenzo Livi, Cesare Alippi
Echo State Networks (ESNs) are simplified recurrent neural network models composed of a reservoir and a linear, trainable readout layer.
no code implementations • 13 Feb 2019 • Michael Kampffmeyer, Sigurd Løkse, Filippo M. Bianchi, Lorenzo Livi, Arnt-Børre Salberg, Robert Jenssen
A promising direction in deep learning research consists in learning representations and simultaneously discovering cluster structure in unlabeled data by optimizing a discriminative loss function.
no code implementations • 24 Mar 2020 • Pietro Verzelli, Cesare Alippi, Lorenzo Livi, Peter Tino
Reservoir computing is a popular approach to design recurrent neural networks, due to its training simplicity and approximation performance.
no code implementations • 6 Oct 2020 • Pietro Verzelli, Cesare Alippi, Lorenzo Livi
In recent years, the machine learning community has seen a continuous growing interest in research aimed at investigating dynamical aspects of both training procedures and machine learning models.
no code implementations • 31 Mar 2022 • Sajjad Heydari, Lorenzo Livi
Hypergraph representations are both more efficient and better suited to describe data characterized by relations between two or more objects.
no code implementations • 6 May 2022 • Sajjad Heydari, Stefano Raniolo, Lorenzo Livi, Vittorio Limongelli
Predicting structural and energetic properties of a molecular system is one of the fundamental tasks in molecular simulations, and it has use cases in chemistry, biology, and medicine.
no code implementations • 4 Jan 2023 • Daniele Zambon, Andrea Cini, Lorenzo Livi, Cesare Alippi
State-space models constitute an effective modeling tool to describe multivariate time series and operate by maintaining an updated representation of the system state from which predictions are made.