Collaborating Authors


AAAI Conferences

Stackelberg equilibrium is a solution concept prescribing for a player an optimal strategy to commit to, assuming the opponent knows this commitment and plays the best response. Although this solution concept is a cornerstone of many security applications, the existing works typically do not consider situations where the players can observe and react to the actions of the opponent during the course of the game. We extend the existing algorithmic work to extensive-form games and introduce novel algorithm for computing Stackelberg equilibria that exploits the compact sequence-form representation of strategies. Our algorithm reduces the size of the linear programs from exponential in the baseline approach to linear in the size of the game tree. Experimental evaluation on randomly generated games and a security-inspired search game demonstrates significant improvement in the scalability compared to the baseline approach.

A Bandit Approach to Sequential Experimental Design with False Discovery Control

Neural Information Processing Systems

We propose a new adaptive sampling approach to multiple testing which aims to maximize statistical power while ensuring anytime false discovery control. We consider $n$ distributions whose means are partitioned by whether they are below or equal to a baseline (nulls), versus above the baseline (true positives). In addition, each distribution can be sequentially and repeatedly sampled. Using techniques from multi-armed bandits, we provide an algorithm that takes as few samples as possible to exceed a target true positive proportion (i.e. Our sample complexity results match known information theoretic lower bounds and through simulations we show a substantial performance improvement over uniform sampling and an adaptive elimination style algorithm.

r/MachineLearning - [N] Stable-Baselines v2.0.0 Released


Has anyone tried to use Stable-Baselines? How does it compare to the official Baselines from OpenAI in your experience? Stable Baselines is a set of improved implementations of reinforcement learning algorithms based on OpenAI Baselines. You can read a detailed presentation of Stable Baselines in the Medium article. These algorithms will make it easier for the research community and industry to replicate, refine, and identify new ideas, and will create good baselines to build projects on top of.

Extending Word Highlighting in Multiparticipant Chat

AAAI Conferences

We describe initial work on extensions to word highlighting for multiparticipant chat to aid users in finding messages of interest, especially during times of high traffic in chat rooms. We have annotated a corpus of chat messages from a technical chat domain (Ubuntu’s technical support), indicating whether they are related to Ubuntu’s new desktop environment Unity. We also created an unsupervised learning algorithm, in which relations are represented with a graph, and applied this to find words related to Unity so they can be highlighted in new, unseen chat messages. On the task of finding relevant messages, our approach outperformed two baseline approaches that are similar to current state-of-the-art word highlighting methods in chat clients.

Safe Policy Improvement by Minimizing Robust Baseline Regret

Neural Information Processing Systems

An important problem in sequential decision-making under uncertainty is to use limited data to compute a safe policy, i.e., a policy that is guaranteed to perform at least as well as a given baseline strategy. In this paper, we develop and analyze a new model-based approach to compute a safe policy when we have access to an inaccurate dynamics model of the system with known accuracy guarantees. Our proposed robust method uses this (inaccurate) model to directly minimize the (negative) regret w.r.t. the baseline policy. Contrary to the existing approaches, minimizing the regret allows one to improve the baseline policy in states with accurate dynamics and seamlessly fall back to the baseline policy, otherwise. We show that our formulation is NP-hard and propose an approximate algorithm.