no code implementations • 11 Feb 2023 • T. Mitchell Roddenberry, Santiago Segarra
We consider the task of representing signals supported on graph bundles, which are generalizations of product graphs that allow for "twists" in the product structure.
no code implementations • 2 Feb 2023 • Fernando Gama, Nicolas Zilberstein, Martin Sevilla, Richard Baraniuk, Santiago Segarra
Thus, the crux of particle filters lies in designing sampling distributions that are both easy to sample from and lead to accurate estimators.
1 code implementation • 4 Dec 2022 • Samuel Rey, Madeline Navarro, Andrei Buciulea, Santiago Segarra, Antonio G. Marques
Motivated by this, we propose a joint graph learning method that takes into account the presence of hidden (latent) variables.
no code implementations • 19 Nov 2022 • Zhongyuan Zhao, Bojan Radojicic, Gunjan Verma, Ananthram Swami, Santiago Segarra
In this work, we improve upon the widely-used metric of hop distance (and its variants) for the shortest path bias by introducing a bias based on the link duty cycle, which we predict using a graph convolutional neural network.
no code implementations • 16 Nov 2022 • Elvin Isufi, Fernando Gama, David I. Shuman, Santiago Segarra
For time series and image data that reside on Euclidean domains, filters are the crux of many signal processing and machine learning techniques, including convolutional neural networks.
1 code implementation • 5 Nov 2022 • Negar Erfanian, Santiago Segarra, Maarten de Hoop
Predicting discrete events in time and space has many scientific applications, such as predicting hazardous earthquakes and outbreaks of infectious diseases.
1 code implementation • 27 Oct 2022 • Madeline Navarro, Santiago Segarra
Mixup is a data augmentation method to create new training data by linearly interpolating between pairs of data samples and their labels.
1 code implementation • 26 Oct 2022 • Nicolas Zilberstein, Chris Dick, Rahman Doost-Mohammady, Ashutosh Sabharwal, Santiago Segarra
We propose a multiple-input multiple-output (MIMO) detector based on an annealed version of the \emph{underdamped} Langevin (stochastic) dynamic.
1 code implementation • 17 Sep 2022 • Madeline Navarro, Santiago Segarra
The proposed joint network and graphon estimation is further enhanced with the introduction of a robust method for noisy graph sampling information.
1 code implementation • 15 Aug 2022 • Yu Zhu, Santiago Segarra
We study p-Laplacians and spectral clustering for a recently proposed hypergraph model that incorporates edge-dependent vertex weights (EDVW).
no code implementations • 11 Jul 2022 • Samuel Rey, T. Mitchell Roddenberry, Santiago Segarra, Antonio G. Marques
Guided by this, we first assume that we have a reference graph that is related to the sought graph (in the sense of having similar motif densities) and then, we exploit this relation by incorporating a similarity constraint and a regularization term in the network topology inference optimization problem.
1 code implementation • 11 May 2022 • Nicolas Zilberstein, Chris Dick, Rahman Doost-Mohammady, Ashutosh Sabharwal, Santiago Segarra
Based on the proposed MIMO detector, we also design a robust version of the method by unfolding and parameterizing one term -- the score of the likelihood -- by a neural network.
1 code implementation • 27 Mar 2022 • Zhongyuan Zhao, Ananthram Swami, Santiago Segarra
Distributed scheduling algorithms for throughput or utility maximization in dense wireless multi-hop networks can have overwhelmingly high overhead, causing increased congestion, energy consumption, radio footprint, and security vulnerability.
1 code implementation • 24 Feb 2022 • Nicolas Zilberstein, Chris Dick, Rahman Doost-Mohammady, Ashutosh Sabharwal, Santiago Segarra
Optimal symbol detection in multiple-input multiple-output (MIMO) systems is known to be an NP-hard problem.
no code implementations • 22 Feb 2022 • T. Mitchell Roddenberry, Fernando Gama, Richard G. Baraniuk, Santiago Segarra
Leveraging this, we are able to seamlessly compare graphs of different sizes and coming from different models, yielding results on the convergence of spectral densities, transferability of filters across arbitrary graphs, and continuity of graph signal properties with respect to the distribution of local substructures.
1 code implementation • 11 Feb 2022 • Madeline Navarro, Santiago Segarra
We consider the problem of estimating the topology of multiple networks from nodal observations, where these networks are assumed to be drawn from the same (unknown) random graph model.
no code implementations • 27 Jan 2022 • Boning Li, Gunjan Verma, Santiago Segarra
We develop a novel graph-based trainable framework to maximize the weighted sum energy efficiency (WSEE) for power allocation in wireless communication networks.
2 code implementations • 15 Nov 2021 • Boning Li, Ananthram Swami, Santiago Segarra
We propose a data-driven approach for power allocation in the context of federated learning (FL) over interference-limited wireless networks.
1 code implementation • 13 Nov 2021 • Zhongyuan Zhao, Gunjan Verma, Ananthram Swami, Santiago Segarra
In wireless multi-hop networks, delay is an important metric for many applications.
1 code implementation • 14 Oct 2021 • Arindam Chowdhury, Fernando Gama, Santiago Segarra
Power allocation is one of the fundamental problems in wireless networks and a wide variety of algorithms address this problem from different perspectives.
1 code implementation • 13 Oct 2021 • Nicolas Zilberstein, Chris Dick, Rahman Doost-Mohammady, Ashutosh Sabharwal, Santiago Segarra
Our method is based on hypernetworks that generate the parameters of a neural network-based detector that works well on a specific channel.
no code implementations • 7 Oct 2021 • Artun Bayer, Arindam Chowdhury, Santiago Segarra
In this context, our current work considers a challenging inductive setting where a set of labeled graphs are available for training while the unlabeled target graph is completely separate, i. e., there are no connections between labeled and unlabeled nodes.
1 code implementation • 6 Oct 2021 • Fernando Gama, Nicolas Zilberstein, Richard G. Baraniuk, Santiago Segarra
Particle filtering is used to compute good nonlinear estimates of complex systems.
1 code implementation • 5 Oct 2021 • Samuel Rey, Andrei Buciulea, Madeline Navarro, Santiago Segarra, Antonio G. Marques
Learning graphs from sets of nodal observations represents a prominent problem formally known as graph topology inference.
1 code implementation • 2 Oct 2021 • Victor M. Tenorio, Samuel Rey, Fernando Gama, Santiago Segarra, Antonio G. Marques
Graph convolutional neural networks (GCNNs) are popular deep learning architectures that, upon replacing regular convolutions with graph filters (GFs), generalize CNNs to irregular domains.
1 code implementation • 24 Sep 2021 • Samuel Rey, Santiago Segarra, Reinhard Heckel, Antonio G. Marques
This paper introduces two untrained graph neural network architectures for graph signal denoising, provides theoretical guarantees for their denoising capabilities in a simple setup, and numerically validates the theoretical results in more general scenarios.
no code implementations • 17 Sep 2021 • T. Mitchell Roddenberry, Florian Frantzen, Michael T. Schaub, Santiago Segarra
We first show that the Hodge Laplacian can be used in lieu of the graph Laplacian to construct a family of wavelets for higher-order signals on simplicial complexes.
1 code implementation • 12 Sep 2021 • Zhongyuan Zhao, Gunjan Verma, Chirag Rao, Ananthram Swami, Santiago Segarra
Test results on medium-sized wireless networks show that our centralized heuristic can reach a near-optimal solution quickly, and our distributed heuristic based on a shallow GCN can reduce by nearly half the suboptimality gap of the distributed greedy solver with minimal increase in complexity.
no code implementations • 16 Aug 2021 • Gunnar Carlsson, Facundo Mémoli, Santiago Segarra
We begin by introducing three practical properties associated with the notion of robustness in hierarchical clustering: linear scale preservation, stability, and excisiveness.
no code implementations • 14 Jun 2021 • Michael T. Schaub, Jean-Baptiste Seby, Florian Frantzen, T. Mitchell Roddenberry, Yu Zhu, Santiago Segarra
Higher-order networks have so far been considered primarily in the context of studying the structure of complex systems, i. e., the higher-order or multi-way relations connecting the constituent entities.
no code implementations • 31 May 2021 • David Ramírez, Antonio G. Marques, Santiago Segarra
When either the input or the filter coefficients are known, this is tantamount to assuming that the signals of interest live on a subspace defined by the supporting graph.
no code implementations • 27 May 2021 • T. Mitchell Roddenberry, Yu Zhu, Santiago Segarra
With the increasing popularity of graph-based methods for dimensionality reduction and representation learning, node embedding functions have become important objects of study in the literature.
1 code implementation • 19 May 2021 • Yu Zhu, Ananthram Swami, Santiago Segarra
On the other hand, we propose a matrix factorization method based on a loss function that generalizes that of the skip-gram model with negative sampling to arbitrary similarity matrices.
1 code implementation • 20 Feb 2021 • Cameron R. Wolfe, Jingkang Yang, Arindam Chowdhury, Chen Dun, Artun Bayer, Santiago Segarra, Anastasios Kyrillidis
The graph convolutional network (GCN) is a go-to solution for machine learning on graphs, but its training is notoriously difficult to scale both in terms of graph size and the number of model parameters.
1 code implementation • 19 Feb 2021 • Yu Zhu, Boning Li, Santiago Segarra
We propose a novel method to co-cluster the vertices and hyperedges of hypergraphs with edge-dependent vertex weights (EDVWs).
2 code implementations • 19 Feb 2021 • T. Mitchell Roddenberry, Nicholas Glaze, Santiago Segarra
We consider the construction of neural network architectures for data on simplicial complexes.
no code implementations • 14 Jan 2021 • Michael T. Schaub, Yu Zhu, Jean-Baptiste Seby, T. Mitchell Roddenberry, Santiago Segarra
In the context of simplicial complexes, we specifically focus on signal processing using the Hodge Laplacian matrix, a multi-relational operator that leverages the special structure of simplicial complexes and generalizes desirable properties of the Laplacian matrix in graph signal processing.
no code implementations • 24 Dec 2020 • Fernando J. Iglesias Garcia, Santiago Segarra, Antonio G. Marques
Using graphs to model irregular information domains is an effective approach to deal with some of the intricacies of contemporary (network) data.
no code implementations • 17 Dec 2020 • T. Mitchell Roddenberry, Santiago Segarra, Anastasios Kyrillidis
We study the role of the constraint set in determining the solution to low-rank, positive semidefinite (PSD) matrix sensing problems.
1 code implementation • 18 Nov 2020 • Abhishek Kumar, Gunjan Verma, Chirag Rao, Ananthram Swami, Santiago Segarra
We study the problem of adaptive contention window (CW) design for random-access wireless networks.
1 code implementation • 18 Nov 2020 • Gojko Cutura, Boning Li, Ananthram Swami, Santiago Segarra
We study the temporal reconstruction of epidemics evolving over networks.
1 code implementation • 18 Nov 2020 • Zhongyuan Zhao, Gunjan Verma, Chirag Rao, Ananthram Swami, Santiago Segarra
In small- to middle-sized wireless networks with tens of links, even a shallow GCN-based MWIS scheduler can leverage the topological information of the graph to reduce in half the suboptimality gap of the distributed greedy solver with good generalizability across graphs and minimal increase in complexity.
1 code implementation • 18 Nov 2020 • Arindam Chowdhury, Gunjan Verma, Chirag Rao, Ananthram Swami, Santiago Segarra
We study the problem of optimal power allocation in a single-hop ad hoc wireless network.
no code implementations • 21 Oct 2020 • Chiraag Kaushik, T. Mitchell Roddenberry, Santiago Segarra
We assume that signals on the nodes of the graph are regularized by the underlying graph structure via a graph filtering model, which we then leverage to distill the graph topology change-point detection problem to a subspace detection problem.
no code implementations • 16 Oct 2020 • Madeline Navarro, Yuhao Wang, Antonio G. Marques, Caroline Uhler, Santiago Segarra
Inferring graph structure from observations on the nodes is an important and popular network science task.
no code implementations • 15 Oct 2020 • T. Mitchell Roddenberry, Madeline Navarro, Santiago Segarra
In particular, we consider the case where the graph was drawn from a graphon model, and we supplement our convex optimization problem with a provably-valid regularizer on the spectrum of the graph to be recovered.
1 code implementation • 22 Sep 2020 • Arindam Chowdhury, Gunjan Verma, Chirag Rao, Ananthram Swami, Santiago Segarra
We study the problem of optimal power allocation in a single-hop ad hoc wireless network.
no code implementations • 2 Aug 2020 • Antonio G. Marques, Santiago Segarra, Gonzalo Mateos
This paper provides an overview of the current landscape of signal processing (SP) on directed graphs (digraphs).
1 code implementation • 2 Aug 2019 • Samuel Rey, Antonio G. Marques, Santiago Segarra
While deep convolutional architectures have achieved remarkable results in a gamut of supervised applications dealing with images and speech, recent works show that deep untrained non-convolutional architectures can also outperform state-of-the-art methods in several tasks such as image compression and denoising.
no code implementations • 22 May 2019 • Michael T. Schaub, Santiago Segarra, John N. Tsitsiklis
We consider a blind identification problem in which we aim to recover a statistical model of a network without knowledge of the network's edges, but based solely on nodal observations of a certain process.
1 code implementation • 17 May 2019 • Junteng Jia, Michael T. Schaub, Santiago Segarra, Austin R. Benson
The first strategy selects edges to minimize the reconstruction error bound and works well on flows that are approximately divergence-free.
no code implementations • 26 Apr 2019 • Michael T. Schaub, Santiago Segarra, Hoi-To Wai
We discuss a variant of `blind' community detection, in which we aim to partition an unobserved network from the observation of a (dynamical) graph signal defined on the network.
no code implementations • 5 Sep 2018 • Hoi-To Wai, Santiago Segarra, Asuman E. Ozdaglar, Anna Scaglione, Ali Jadbabaie
The paper shows that communities can be detected by applying a spectral method to the covariance matrix of graph signals.
no code implementations • 28 Jul 2017 • Marco Avella-Medina, Francesca Parise, Michael T. Schaub, Santiago Segarra
Using the theory of linear integral operators, we define degree, eigenvector, Katz and PageRank centrality functions for graphons and establish concentration inequalities demonstrating that graphon centrality functions arise naturally as limits of their counterparts defined on sequences of graphs of increasing size.
no code implementations • 18 Oct 2016 • Mark Eisen, Santiago Segarra, Gabriel Egan, Alejandro Ribeiro
We first study the similarity of writing styles between Early English playwrights by comparing the profile WANs.
no code implementations • 21 Jul 2016 • Gunnar Carlsson, Facundo Mémoli, Alejandro Ribeiro, Santiago Segarra
This paper considers networks where relationships between nodes are represented by directed dissimilarities.
no code implementations • 21 Jul 2016 • Gunnar Carlsson, Facundo Mémoli, Alejandro Ribeiro, Santiago Segarra
This paper characterizes hierarchical clustering methods that abide by two previously introduced axioms -- thus, denominated admissible methods -- and proposes tractable algorithms for their implementation.
no code implementations • 21 Jul 2016 • Gunnar Carlsson, Facundo Mémoli, Alejandro Ribeiro, Santiago Segarra
We introduce two practical properties of hierarchical clustering methods for (possibly asymmetric) network data: excisiveness and linear scale preservation.
no code implementations • 17 Jun 2014 • Santiago Segarra, Mark Eisen, Alejandro Ribeiro
Attribution accuracy is observed to exceed the one achieved by methods that rely on word frequencies alone.
no code implementations • 17 Apr 2014 • Gunnar Carlsson, Facundo Mémoli, Alejandro Ribeiro, Santiago Segarra
This paper introduces hierarchical quasi-clustering methods, a generalization of hierarchical clustering for asymmetric networks where the output structure preserves the asymmetry of the input data.
no code implementations • 31 Jan 2013 • Gunnar Carlsson, Facundo Mémoli, Alejandro Ribeiro, Santiago Segarra
Our construction of hierarchical clustering methods is based on defining admissible methods to be those methods that abide by the axioms of value - nodes in a network with two nodes are clustered together at the maximum of the two dissimilarities between them - and transformation - when dissimilarities are reduced, the network may become more clustered but not less.