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Alexia Atsidakou

5 accepted papers

2024

Contextual Pandora’s Box

AAAI 2024technical

Pandora’s Box is a fundamental stochastic optimization problem, where the decision-maker must find a good alternative, while minimizing the search cost of exploring the value of each alternative. In the original formulation, it is assumed that accurate distributions are given for the values of all t…

Cited by 6SourcePDFScholar
2023

Finite-Time Logarithmic Bayes Regret Upper Bounds

NeurIPS 2023poster

We derive the first finite-time logarithmic Bayes regret upper bounds for Bayesian bandits. In a multi-armed bandit, we obtain $O(c_\Delta \log n)$ and $O(c_h \log^2 n)$ upper bounds for an upper confidence bound algorithm, where $c_h$ and $c_\Delta$ are constants depending on the prior distribution…

Cited by 1SourcePDFScholar
2022

Towards Statistical and Computational Complexities of Polyak Step Size Gradient Descent

AISTATS 2022poster

We study the statistical and computational complexities of the Polyak step size gradient descent algorithm under generalized smoothness and {Ł}ojasiewicz conditions of the population loss function, namely, the limit of the empirical loss function when the sample size goes to infinity, and the stabil…

Cited by 10SourcePDFScholar
2021

Combinatorial Blocking Bandits with Stochastic Delays

ICML 2021spotlight

Recent work has considered natural variations of the {\em multi-armed bandit} problem, where the reward distribution of each arm is a special function of the time passed since its last pulling. In this direction, a simple (yet widely applicable) model is that of {\em blocking bandits}, where an arm…

Cited by 16SourcePDFScholar