English
Related papers

Related papers: Unconstrained Dynamic Regret via Sparse Coding

200 papers

We study the problem of dynamic batch learning in high-dimensional sparse linear contextual bandits, where a decision maker, under a given maximum-number-of-batch constraint and only able to observe rewards at the end of each batch, can…

Machine Learning · Statistics 2022-07-19 Zhimei Ren , Zhengyuan Zhou

In the classic expert problem, $\Phi$-regret measures the gap between the learner's total loss and that achieved by applying the best action transformation $\phi \in \Phi$. A recent work by Lu et al., [2025] introduces an adaptive algorithm…

Machine Learning · Computer Science 2025-12-16 Soumita Hait , Ping Li , Haipeng Luo , Mengxiao Zhang

We develop parameter-free algorithms for unconstrained online learning with regret guarantees that scale with the gradient variation $V_T(u) = \sum_{t=2}^T \|\nabla f_t(u)-\nabla f_{t-1}(u)\|^2$. For $L$-smooth convex loss, we provide…

Machine Learning · Computer Science 2026-04-14 Yuheng Zhao , Andrew Jacobsen , Nicolò Cesa-Bianchi , Peng Zhao

In online convex optimization (OCO), a decision-maker is confronted with an unknown environment and seeks to play an optimal sequence of decisions on a short time-scale using only past information. Recent advances in second-order OCO…

Optimization and Control · Mathematics 2026-05-28 Jean-Luc Lupien , Yuen-Man Pun , Youssef Diouane , Iman Shames , Antoine Lesage-Landry

Recently, there has been a growing research interest in the analysis of dynamic regret, which measures the performance of an online learner against a sequence of local minimizers. By exploiting the strong convexity, previous studies have…

Machine Learning · Computer Science 2017-11-03 Lijun Zhang , Tianbao Yang , Jinfeng Yi , Rong Jin , Zhi-Hua Zhou

We propose and study an online version of min-max optimization based on cumulative saddle points under a variety of performance measures beyond convex-concave settings. After first observing the incompatibility of (static) Nash equilibrium…

Machine Learning · Computer Science 2026-02-12 Abhijeet Vyas , Brian Bullins

To deal with changing environments, a new performance measure -- adaptive regret, defined as the maximum static regret over any interval, was proposed in online learning. Under the setting of online convex optimization, several algorithms…

Machine Learning · Computer Science 2021-05-17 Lijun Zhang , Guanghui Wang , Wei-Wei Tu , Zhi-Hua Zhou

We present new algorithms for online convex optimization over unbounded domains that obtain parameter-free regret in high-probability given access only to potentially heavy-tailed subgradient estimates. Previous work in unbounded domains…

Machine Learning · Statistics 2023-02-28 Jiujia Zhang , Ashok Cutkosky

Recent literature has made much progress in understanding \emph{online LQR}: a modern learning-theoretic take on the classical control problem in which a learner attempts to optimally control an unknown linear dynamical system with fully…

Machine Learning · Computer Science 2020-10-06 Max Simchowitz

We study monotone submodular maximization under general matroid constraints in the online setting. We prove that online optimization of a large class of submodular functions, namely, weighted threshold potential functions, reduces to online…

Machine Learning · Computer Science 2024-01-09 Tareq Si Salem , Gözde Özcan , Iasonas Nikolaou , Evimaria Terzi , Stratis Ioannidis

In Online Convex Optimization (OCO), when the stochastic gradient has a finite variance, many algorithms provably work and guarantee a sublinear regret. However, limited results are known if the gradient estimate has a heavy tail, i.e., the…

Machine Learning · Computer Science 2026-03-20 Zijian Liu

Projection operations are a typical computation bottleneck in online learning. In this paper, we enable projection-free online learning within the framework of Online Convex Optimization with Memory (OCO-M) -- OCO-M captures how the history…

Machine Learning · Computer Science 2023-04-03 Hongyu Zhou , Zirui Xu , Vasileios Tzoumas

Time-varying systems are a challenge in many scientific and engineering areas. Usually, estimation of time-varying parameters or signals must be performed online, which calls for the development of responsive online algorithms. In this…

Optimization and Control · Mathematics 2018-09-10 Sophie M. Fosson

Continuous-time adaptive controllers for systems with a matched uncertainty often comprise an online parameter estimator and a corresponding parameterized controller to cancel the uncertainty. However, such methods are often impossible to…

Systems and Control · Electrical Eng. & Systems 2025-03-18 Aren Karapetyan , Efe C. Balta , Anastasios Tsiamis , Andrea Iannelli , John Lygeros

In the convex optimization approach to online regret minimization, many methods have been developed to guarantee a $O(\sqrt{T})$ bound on regret for subdifferentiable convex loss functions with bounded subgradients, by using a reduction to…

Machine Learning · Computer Science 2016-09-20 Arthur Flajolet , Patrick Jaillet

We investigate the contextual bandits with knapsack (CBwK) problem in a high-dimensional linear setting, where the feature dimension can be very large. Our goal is to harness sparsity to obtain sharper regret guarantees. To this end, we…

Machine Learning · Computer Science 2025-08-05 Wanteng Ma , Dong Xia , Jiashuo Jiang

In this paper, we study a class of online optimization problems with long-term budget constraints where the objective functions are not necessarily concave (nor convex) but they instead satisfy the Diminishing Returns (DR) property.…

Optimization and Control · Mathematics 2019-07-02 Omid Sadeghi , Maryam Fazel

We investigate the problem of online convex optimization with unknown delays, in which the feedback of a decision arrives with an arbitrary delay. Previous studies have presented a delayed variant of online gradient descent (OGD), and…

Machine Learning · Computer Science 2021-03-23 Yuanyu Wan , Wei-Wei Tu , Lijun Zhang

Decentralized online convex optimization (D-OCO), where multiple agents within a network collaboratively learn optimal decisions in real-time, arises naturally in applications such as federated learning, sensor networks, and multi-agent…

Machine Learning · Statistics 2026-01-14 Hao Qiu , Mengxiao Zhang , Juliette Achddou

We study Constrained Online Convex Optimization (COCO), where a learner chooses actions iteratively, observes both unanticipated convex loss and convex constraint, and accumulates loss while incurring penalties for constraint violations. We…

Machine Learning · Computer Science 2026-01-27 Ricardo N. Ferreira , João Xavier , Cláudia Soares