Search Results for author: Bruno Ribeiro

Found 40 papers, 20 papers with code

Zero-shot Logical Query Reasoning on any Knowledge Graph

2 code implementations10 Apr 2024 Mikhail Galkin, Jincheng Zhou, Bruno Ribeiro, Jian Tang, Zhaocheng Zhu

Complex logical query answering (CLQA) in knowledge graphs (KGs) goes beyond simple KG completion and aims at answering compositional queries comprised of multiple projections and logical operations.

Knowledge Graphs

GraphMETRO: Mitigating Complex Graph Distribution Shifts via Mixture of Aligned Experts

no code implementations7 Dec 2023 Shirley Wu, Kaidi Cao, Bruno Ribeiro, James Zou, Jure Leskovec

Graph data are inherently complex and heterogeneous, leading to a high natural diversity of distributional shifts.

MIST: Defending Against Membership Inference Attacks Through Membership-Invariant Subspace Training

no code implementations2 Nov 2023 Jiacheng Li, Ninghui Li, Bruno Ribeiro

Most MI attacks in the literature take advantage of the fact that ML models are trained to fit the training data well, and thus have very low loss on training instances.

Representation Learning

Efficient Subgraph GNNs by Learning Effective Selection Policies

1 code implementation30 Oct 2023 Beatrice Bevilacqua, Moshe Eliasof, Eli Meirom, Bruno Ribeiro, Haggai Maron

Subgraph GNNs are provably expressive neural architectures that learn graph representations from sets of subgraphs.

A Multi-Task Perspective for Link Prediction with New Relation Types and Nodes

1 code implementation12 Jul 2023 Jincheng Zhou, Beatrice Bevilacqua, Bruno Ribeiro

The task of inductive link prediction in (discrete) attributed multigraphs infers missing attributed links (relations) between nodes in new test multigraphs.

Inductive Link Prediction Relation +1

MetaPhysiCa: OOD Robustness in Physics-informed Machine Learning

no code implementations6 Mar 2023 S Chandra Mouli, Muhammad Ashraful Alam, Bruno Ribeiro

A fundamental challenge in physics-informed machine learning (PIML) is the design of robust PIML methods for out-of-distribution (OOD) forecasting tasks.

Meta-Learning Physics-informed machine learning

Double Equivariance for Inductive Link Prediction for Both New Nodes and New Relation Types

1 code implementation2 Feb 2023 Jianfei Gao, Yangze Zhou, Jincheng Zhou, Bruno Ribeiro

We then show how double-equivariant architectures are able to self-supervise pre-train on distinct KG domains and zero-shot predict links on a new KG domain (with completely new entities and new relation types).

Inductive Link Prediction Logical Reasoning +2

Causal Lifting and Link Prediction

no code implementations2 Feb 2023 Leonardo Cotta, Beatrice Bevilacqua, Nesreen Ahmed, Bruno Ribeiro

Existing causal models for link prediction assume an underlying set of inherent node factors -- an innate characteristic defined at the node's birth -- that governs the causal evolution of links in the graph.

Knowledge Base Completion Link Prediction

Bias Challenges in Counterfactual Data Augmentation

no code implementations12 Sep 2022 S Chandra Mouli, Yangze Zhou, Bruno Ribeiro

Deep learning models tend not to be out-of-distribution robust primarily due to their reliance on spurious features to solve the task.

counterfactual Data Augmentation

OOD Link Prediction Generalization Capabilities of Message-Passing GNNs in Larger Test Graphs

1 code implementation30 May 2022 Yangze Zhou, Gitta Kutyniok, Bruno Ribeiro

This work provides the first theoretical study on the ability of graph Message Passing Neural Networks (gMPNNs) -- such as Graph Neural Networks (GNNs) -- to perform inductive out-of-distribution (OOD) link prediction tasks, where deployment (test) graph sizes are larger than training graphs.

Link Prediction

Contextual Unsupervised Outlier Detection in Sequences

no code implementations6 Nov 2021 Mohamed A. Zahran, Leonardo Teixeira, Vinayak Rao, Bruno Ribeiro

This work proposes an unsupervised learning framework for trajectory (sequence) outlier detection that combines ranking tests with user sequence models.

Outlier Detection

Reconstruction for Powerful Graph Representations

no code implementations NeurIPS 2021 Leonardo Cotta, Christopher Morris, Bruno Ribeiro

Empirically, we show how reconstruction can boost GNN's expressive power -- while maintaining its invariance to permutations of the vertices -- by solving seven graph property tasks not solvable by the original GNN.

Graph Reconstruction Graph Representation Learning +1

Asymmetry Learning for Counterfactually-invariant Classification in OOD Tasks

no code implementations ICLR 2022 S Chandra Mouli, Bruno Ribeiro

Generalizing from observed to new related environments (out-of-distribution) is central to the reliability of classifiers.

Classification

Neural Networks for Learning Counterfactual G-Invariances from Single Environments

1 code implementation20 Apr 2021 S Chandra Mouli, Bruno Ribeiro

In order to endow neural networks with the ability to extrapolate over group transformations, we introduce a learning framework counterfactually-guided by the learning hypothesis that any group invariance to (known) transformation groups is mandatory even without evidence, unless the learner deems it inconsistent with the training data.

counterfactual

On the Equivalence Between Temporal and Static Graph Representations for Observational Predictions

1 code implementation12 Mar 2021 Jianfei Gao, Bruno Ribeiro

This work formalizes the associational task of predicting node attribute evolution in temporal graphs from the perspective of learning equivariant representations.

Attribute

Size-Invariant Graph Representations for Graph Classification Extrapolations

1 code implementation8 Mar 2021 Beatrice Bevilacqua, Yangze Zhou, Bruno Ribeiro

In general, graph representation learning methods assume that the train and test data come from the same distribution.

General Classification Graph Classification +1

Neural Network Extrapolations with G-invariances from a Single Environment

no code implementations ICLR 2021 S Chandra Mouli, Bruno Ribeiro

In order to endow neural networks with the ability to extrapolate over group transformations, we introduce a learning framework guided by a new learning hypothesis: Any invariance to transformation groups is mandatory even without evidence, unless the learner deems it inconsistent with the training data.

counterfactual Counterfactual Inference

Sequential Stratified Regeneration: MCMC for Large State Spaces with an Application to Subgraph Count Estimation

1 code implementation7 Dec 2020 Carlos H. C. Teixeira, Mayank Kakodkar, Vinícius Dias, Wagner Meira Jr., Bruno Ribeiro

This work considers the general task of estimating the sum of a bounded function over the edges of a graph, given neighborhood query access and where access to the entire network is prohibitively expensive.

Social and Information Networks Data Structures and Algorithms

Unsupervised Joint k-node Graph Representations with Compositional Energy-Based Models

no code implementations NeurIPS 2020 Leonardo Cotta, Carlos H. C. Teixeira, Ananthram Swami, Bruno Ribeiro

Existing Graph Neural Network (GNN) methods that learn inductive unsupervised graph representations focus on learning node and edge representations by predicting observed edges in the graph.

Node Classification

Unsupervised Joint $k$-node Graph Representations with Compositional Energy-Based Models

no code implementations8 Oct 2020 Leonardo Cotta, Carlos H. C. Teixeira, Ananthram Swami, Bruno Ribeiro

Existing Graph Neural Network (GNN) methods that learn inductive unsupervised graph representations focus on learning node and edge representations by predicting observed edges in the graph.

Node Classification

Deceptive Deletions for Protecting Withdrawn Posts on Social Platforms

no code implementations28 May 2020 Mohsen Minaei, S Chandra Mouli, Mainack Mondal, Bruno Ribeiro, Aniket Kate

Our mechanism injects decoy deletions, hence creating a two-player minmax game between an adversary that seeks to classify damaging content among the deleted posts and a challenger that employs decoy deletions to masquerade real damaging deletions.

A Collective Learning Framework to Boost GNN Expressiveness

no code implementations26 Mar 2020 Mengyue Hang, Jennifer Neville, Bruno Ribeiro

Graph Neural Networks (GNNs) have recently been used for node and graph classification tasks with great success, but GNNs model dependencies among the attributes of nearby neighboring nodes rather than dependencies among observed node labels.

General Classification Graph Classification +2

Membership Inference Attacks and Defenses in Classification Models

1 code implementation27 Feb 2020 Jiacheng Li, Ninghui Li, Bruno Ribeiro

We study the membership inference (MI) attack against classifiers, where the attacker's goal is to determine whether a data instance was used for training the classifier.

Classification General Classification

Infinity Learning: Learning Markov Chains from Aggregate Steady-State Observations

no code implementations11 Feb 2020 Jianfei Gao, Mohamed A. Zahran, Amit Sheoran, Sonia Fahmy, Bruno Ribeiro

We consider the task of learning a parametric Continuous Time Markov Chain (CTMC) sequence model without examples of sequences, where the training data consists entirely of aggregate steady-state statistics.

On the Equivalence between Positional Node Embeddings and Structural Graph Representations

1 code implementation ICLR 2020 Balasubramaniam Srinivasan, Bruno Ribeiro

This work provides the first unifying theoretical framework for node (positional) embeddings and structural graph representations, bridging methods like matrix factorization and graph neural networks.

Link Prediction Node Classification +1

Deep Lifetime Clustering

1 code implementation1 Oct 2019 S Chandra Mouli, Leonardo Teixeira, Jennifer Neville, Bruno Ribeiro

The goal of lifetime clustering is to develop an inductive model that maps subjects into $K$ clusters according to their underlying (unobserved) lifetime distribution.

Clustering

Are Graph Neural Networks Miscalibrated?

1 code implementation7 May 2019 Leonardo Teixeira, Brian Jalaian, Bruno Ribeiro

Graph Neural Networks (GNNs) have proven to be successful in many classification tasks, outperforming previous state-of-the-art methods in terms of accuracy.

Decision Making General Classification

Relational Pooling for Graph Representations

1 code implementation6 Mar 2019 Ryan L. Murphy, Balasubramaniam Srinivasan, Vinayak Rao, Bruno Ribeiro

This work generalizes graph neural networks (GNNs) beyond those based on the Weisfeiler-Lehman (WL) algorithm, graph Laplacians, and diffusions.

General Classification Graph Classification

Random Spiking and Systematic Evaluation of Defenses Against Adversarial Examples

1 code implementation5 Dec 2018 Huangyi Ge, Sze Yiu Chau, Bruno Ribeiro, Ninghui Li

Image classifiers often suffer from adversarial examples, which are generated by strategically adding a small amount of noise to input images to trick classifiers into misclassification.

Graph Pattern Mining and Learning through User-defined Relations (Extended Version)

1 code implementation14 Sep 2018 Carlos H. C. Teixeira, Leonardo Cotta, Bruno Ribeiro, Wagner Meira Jr

In this work we propose R-GPM, a parallel computing framework for graph pattern mining (GPM) through a user-defined subgraph relation.

Stochastic Optimization

A Deep Learning Approach for Survival Clustering without End-of-life Signals

no code implementations ICLR 2018 S Chandra Mouli, Bruno Ribeiro, Jennifer Neville

The goal of survival clustering is to map subjects (e. g., users in a social network, patients in a medical study) to $K$ clusters ranging from low-risk to high-risk.

Clustering

Detecting Anomalies in Sequential Data with Higher-order Networks

1 code implementation27 Dec 2017 Jian Xu, Mandana Saebi, Bruno Ribeiro, Lance M. Kaplan, Nitesh V. Chawla

A major branch of anomaly detection methods relies on dynamic networks: raw sequence data is first converted to a series of networks, then critical change points are identified in the evolving network structure.

Social and Information Networks Physics and Society

From Monte Carlo to Las Vegas: Improving Restricted Boltzmann Machine Training Through Stopping Sets

1 code implementation22 Nov 2017 Pedro H. P. Savarese, Mayank Kakodkar, Bruno Ribeiro

We propose a Las Vegas transformation of Markov Chain Monte Carlo (MCMC) estimators of Restricted Boltzmann Machines (RBMs).

Stochastic Gradient Descent for Relational Logistic Regression via Partial Network Crawls

no code implementations24 Jul 2017 Jiasen Yang, Bruno Ribeiro, Jennifer Neville

Research in statistical relational learning has produced a number of methods for learning relational models from large-scale network data.

regression Relational Reasoning

Selective Harvesting over Networks

no code implementations15 Mar 2017 Fabricio Murai, Diogo Rennó, Bruno Ribeiro, Gisele L. Pappa, Don Towsley, Krista Gile

We find that it is possible to collect a much larger set of targets by using multiple classifiers, not by combining their predictions as an ensemble, but switching between classifiers used at each step, as a way to ease the tunnel vision effect.

Multi-Armed Bandits

Bayesian Inference of Online Social Network Statistics via Lightweight Random Walk Crawls

no code implementations19 Oct 2015 Konstantin Avrachenkov, Bruno Ribeiro, Jithin K. Sreedharan

Online social networks (OSN) contain extensive amount of information about the underlying society that is yet to be explored.

Bayesian Inference

Estimating and Sampling Graphs with Multidimensional Random Walks

1 code implementation ‏‏‎ ‎ 2020 Bruno Ribeiro, Don Towsley

We show that the proposed sampling method, which we call Frontier sampling, exhibits all of the nice sampling properties of a regular random walk.

Data Structures and Algorithms Networking and Internet Architecture G.3

Cannot find the paper you are looking for? You can Submit a new open access paper.