Search Results for author: Ilija Bogunovic

Found 32 papers, 5 papers with code

PROSAC: Provably Safe Certification for Machine Learning Models under Adversarial Attacks

no code implementations4 Feb 2024 Ziquan Liu, Zhuo Zhi, Ilija Bogunovic, Carsten Gerner-Beuerle, Miguel Rodrigues

Our paper offers a new approach to certify the performance of machine learning models in the presence of adversarial attacks with population level risk guarantees.

Adversarial Attack Bayesian Optimization

Sample Efficient Reinforcement Learning from Human Feedback via Active Exploration

no code implementations1 Dec 2023 Viraj Mehta, Vikramjeet Das, Ojash Neopane, Yijia Dai, Ilija Bogunovic, Jeff Schneider, Willie Neiswanger

Preference-based feedback is important for many applications in reinforcement learning where direct evaluation of a reward function is not feasible.

reinforcement-learning

Robust Best-arm Identification in Linear Bandits

no code implementations8 Nov 2023 Wei Wang, Sattar Vakili, Ilija Bogunovic

To this end, we present an instance-dependent lower bound for the robust best-arm identification problem with linear rewards.

Distributionally Robust Model-based Reinforcement Learning with Large State Spaces

no code implementations5 Sep 2023 Shyam Sundhar Ramesh, Pier Giuseppe Sessa, Yifan Hu, Andreas Krause, Ilija Bogunovic

Three major challenges in reinforcement learning are the complex dynamical systems with large state spaces, the costly data acquisition processes, and the deviation of real-world dynamics from the training environment deployment.

Gaussian Processes Model-based Reinforcement Learning +1

Near-optimal Policy Identification in Active Reinforcement Learning

no code implementations19 Dec 2022 Xiang Li, Viraj Mehta, Johannes Kirschner, Ian Char, Willie Neiswanger, Jeff Schneider, Andreas Krause, Ilija Bogunovic

Many real-world reinforcement learning tasks require control of complex dynamical systems that involve both costly data acquisition processes and large state spaces.

Bayesian Optimization reinforcement-learning +1

Movement Penalized Bayesian Optimization with Application to Wind Energy Systems

no code implementations14 Oct 2022 Shyam Sundhar Ramesh, Pier Giuseppe Sessa, Andreas Krause, Ilija Bogunovic

Contextual Bayesian optimization (CBO) is a powerful framework for sequential decision-making given side information, with important applications, e. g., in wind energy systems.

Bayesian Optimization Decision Making

Graph Neural Network Bandits

no code implementations13 Jul 2022 Parnian Kassraie, Andreas Krause, Ilija Bogunovic

By establishing a novel connection between such kernels and the graph neural tangent kernel (GNTK), we introduce the first GNN confidence bound and use it to design a phased-elimination algorithm with sublinear regret.

Drug Discovery

A Robust Phased Elimination Algorithm for Corruption-Tolerant Gaussian Process Bandits

no code implementations3 Feb 2022 Ilija Bogunovic, Zihan Li, Andreas Krause, Jonathan Scarlett

We consider the sequential optimization of an unknown, continuous, and expensive to evaluate reward function, from noisy and adversarially corrupted observed rewards.

Misspecified Gaussian Process Bandit Optimization

no code implementations NeurIPS 2021 Ilija Bogunovic, Andreas Krause

Instead, we introduce a \emph{misspecified} kernelized bandit setting where the unknown function can be $\epsilon$--uniformly approximated by a function with a bounded norm in some Reproducing Kernel Hilbert Space (RKHS).

Risk-averse Heteroscedastic Bayesian Optimization

1 code implementation NeurIPS 2021 Anastasiia Makarova, Ilnura Usmanova, Ilija Bogunovic, Andreas Krause

We generalize BO to trade mean and input-dependent variance of the objective, both of which we assume to be unknown a priori.

Bayesian Optimization

Contextual Games: Multi-Agent Learning with Side Information

no code implementations NeurIPS 2020 Pier Giuseppe Sessa, Ilija Bogunovic, Andreas Krause, Maryam Kamgarpour

We formulate the novel class of contextual games, a type of repeated games driven by contextual information at each round.

Efficient Model-Based Multi-Agent Mean-Field Reinforcement Learning

no code implementations8 Jul 2021 Barna Pásztor, Ilija Bogunovic, Andreas Krause

Learning in multi-agent systems is highly challenging due to several factors including the non-stationarity introduced by agents' interactions and the combinatorial nature of their state and action spaces.

Gaussian Processes Model-based Reinforcement Learning +2

Cost-Efficient Online Hyperparameter Optimization

no code implementations17 Jan 2021 Jingkang Wang, Mengye Ren, Ilija Bogunovic, Yuwen Xiong, Raquel Urtasun

Recent work on hyperparameters optimization (HPO) has shown the possibility of training certain hyperparameters together with regular parameters.

Bayesian Optimization Hyperparameter Optimization

Learning to Play Sequential Games versus Unknown Opponents

1 code implementation NeurIPS 2020 Pier Giuseppe Sessa, Ilija Bogunovic, Maryam Kamgarpour, Andreas Krause

We consider a repeated sequential game between a learner, who plays first, and an opponent who responds to the chosen action.

Bilevel Optimization

Stochastic Linear Bandits Robust to Adversarial Attacks

no code implementations7 Jul 2020 Ilija Bogunovic, Arpan Losalka, Andreas Krause, Jonathan Scarlett

We consider a stochastic linear bandit problem in which the rewards are not only subject to random noise, but also adversarial attacks subject to a suitable budget $C$ (i. e., an upper bound on the sum of corruption magnitudes across the time horizon).

Corruption-Tolerant Gaussian Process Bandit Optimization

no code implementations4 Mar 2020 Ilija Bogunovic, Andreas Krause, Jonathan Scarlett

We consider the problem of optimizing an unknown (typically non-convex) function with a bounded norm in some Reproducing Kernel Hilbert Space (RKHS), based on noisy bandit feedback.

Mixed Strategies for Robust Optimization of Unknown Objectives

no code implementations28 Feb 2020 Pier Giuseppe Sessa, Ilija Bogunovic, Maryam Kamgarpour, Andreas Krause

We consider robust optimization problems, where the goal is to optimize an unknown objective function against the worst-case realization of an uncertain parameter.

Autonomous Vehicles Gaussian Processes +1

Distributionally Robust Bayesian Optimization

no code implementations20 Feb 2020 Johannes Kirschner, Ilija Bogunovic, Stefanie Jegelka, Andreas Krause

Attaining such robustness is the goal of distributionally robust optimization, which seeks a solution to an optimization problem that is worst-case robust under a specified distributional shift of an uncontrolled covariate.

Bayesian Optimization

Adversarially Robust Optimization with Gaussian Processes

no code implementations NeurIPS 2018 Ilija Bogunovic, Jonathan Scarlett, Stefanie Jegelka, Volkan Cevher

In this paper, we consider the problem of Gaussian process (GP) optimization with an added robustness requirement: The returned point may be perturbed by an adversary, and we require the function value to remain as high as possible even after this perturbation.

Gaussian Processes

Robust Maximization of Non-Submodular Objectives

no code implementations20 Feb 2018 Ilija Bogunovic, Junyao Zhao, Volkan Cevher

In this work, we present a new algorithm Oblivious-Greedy and prove the first constant-factor approximation guarantees for a wider class of non-submodular objectives.

High-Dimensional Bayesian Optimization via Additive Models with Overlapping Groups

1 code implementation20 Feb 2018 Paul Rolland, Jonathan Scarlett, Ilija Bogunovic, Volkan Cevher

In this paper, we consider the approach of Kandasamy et al. (2015), in which the high-dimensional function decomposes as a sum of lower-dimensional functions on subsets of the underlying variables.

Additive models Bayesian Optimization +2

Streaming Robust Submodular Maximization: A Partitioned Thresholding Approach

no code implementations NeurIPS 2017 Slobodan Mitrović, Ilija Bogunovic, Ashkan Norouzi-Fard, Jakub Tarnawski, Volkan Cevher

We study the classical problem of maximizing a monotone submodular function subject to a cardinality constraint k, with two additional twists: (i) elements arrive in a streaming fashion, and (ii) m items from the algorithm's memory are removed after the stream is finished.

Data Summarization

Robust Submodular Maximization: A Non-Uniform Partitioning Approach

no code implementations ICML 2017 Ilija Bogunovic, Slobodan Mitrović, Jonathan Scarlett, Volkan Cevher

We study the problem of maximizing a monotone submodular function subject to a cardinality constraint $k$, with the added twist that a number of items $\tau$ from the returned set may be removed.

Data Summarization

Truncated Variance Reduction: A Unified Approach to Bayesian Optimization and Level-Set Estimation

no code implementations NeurIPS 2016 Ilija Bogunovic, Jonathan Scarlett, Andreas Krause, Volkan Cevher

We present a new algorithm, truncated variance reduction (TruVaR), that treats Bayesian optimization (BO) and level-set estimation (LSE) with Gaussian processes in a unified fashion.

Bayesian Optimization Gaussian Processes

Time-Varying Gaussian Process Bandit Optimization

no code implementations25 Jan 2016 Ilija Bogunovic, Jonathan Scarlett, Volkan Cevher

We illustrate the performance of the algorithms on both synthetic and real data, and we find the gradual forgetting of TV-GP-UCB to perform favorably compared to the sharp resetting of R-GP-UCB.

Bayesian Optimization

Learning-based Compressive Subsampling

no code implementations21 Oct 2015 Luca Baldassarre, Yen-Huan Li, Jonathan Scarlett, Baran Gözcü, Ilija Bogunovic, Volkan Cevher

In this paper, we instead take a principled learning-based approach in which a \emph{fixed} index set is chosen based on a set of training signals $\mathbf{x}_1,\dotsc,\mathbf{x}_m$.

Combinatorial Optimization

Near-Optimally Teaching the Crowd to Classify

no code implementations10 Feb 2014 Adish Singla, Ilija Bogunovic, Gábor Bartók, Amin Karbasi, Andreas Krause

How should we present training examples to learners to teach them classification rules?

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