activity
20212026
collaborators

10 papers

cs.LG2026

Risk-Aware General-Utility Markov Decision Processes

Pedro P. Santos, Fábio Vital, Alberto Sardinha +1

We study general-utility Markov decision processes (GUMDPs) with risk-aware objectives. In this framework, an agent aims to optimize a risk measure of the distribution of objective…

cs.LG2026

Entropic Risk-Aware Monte Carlo Tree Search

Pedro P. Santos, Jacopo Silvestrin, Alberto Sardinha +1

We propose a provably correct Monte Carlo tree search (MCTS) algorithm for solving risk-aware Markov decision processes (MDPs) with entropic risk measure (ERM) objectives. We provi…

cs.MA2025

RecBayes: Recurrent Bayesian Ad Hoc Teamwork in Large Partially Observable Domains

João G. Ribeiro, Yaniv Oren, Alberto Sardinha +2

This paper proposes RecBayes, a novel approach for ad hoc teamwork under partial observability, a setting where agents are deployed on-the-fly to environments where pre-existing te…

cs.LG2025

Solving General-Utility Markov Decision Processes in the Single-Trial Regime with Online Planning

Pedro P. Santos, Alberto Sardinha, Francisco S. Melo

In this work, we contribute the first approach to solve infinite-horizon discounted general-utility Markov decision processes (GUMDPs) in the single-trial regime, i.e., when the ag…

cs.LG2025

Implicit Repair with Reinforcement Learning in Emergent Communication

Fábio Vital, Alberto Sardinha, Francisco S. Melo

Conversational repair is a mechanism used to detect and resolve miscommunication and misinformation problems when two or more agents interact. One particular and underexplored form…

cs.LG2025

Distributed Value Decomposition Networks with Networked Agents

Guilherme S. Varela, Alberto Sardinha, Francisco S. Melo

We investigate the problem of distributed training under partial observability, whereby cooperative multi-agent reinforcement learning agents (MARL) maximize the expected cumulativ…

cs.LG2025

Networked Agents in the Dark: Team Value Learning under Partial Observability

Guilherme S. Varela, Alberto Sardinha, Francisco S. Melo

We propose a novel cooperative multi-agent reinforcement learning (MARL) approach for networked agents. In contrast to previous methods that rely on complete state information or j…

cs.LG2024

The Number of Trials Matters in Infinite-Horizon General-Utility Markov Decision Processes

Pedro P. Santos, Alberto Sardinha, Francisco S. Melo

The general-utility Markov decision processes (GUMDPs) framework generalizes the MDPs framework by considering objective functions that depend on the frequency of visitation of sta…

cs.MA2023

Making Friends in the Dark: Ad Hoc Teamwork Under Partial Observability

João G. Ribeiroa, Cassandro Martinhoa, Alberto Sardinhaa +1

This paper introduces a formal definition of the setting of ad hoc teamwork under partial observability and proposes a first-principled model-based approach which relies only on pr…

cs.LG2021

The Impact of Data Distribution on Q-learning with Function Approximation

Pedro P. Santos, Diogo S. Carvalho, Alberto Sardinha +1

We study the interplay between the data distribution and Q-learning-based algorithms with function approximation. We provide a unified theoretical and empirical analysis as to how…