no code implementations • 19 May 2023 • Yibo Wang, Wenhao Yang, Wei Jiang, Shiyin Lu, Bing Wang, Haihong Tang, Yuanyu Wan, Lijun Zhang
Specifically, we first provide a novel dynamic regret analysis for an existing projection-free method named $\text{BOGD}_\text{IP}$, and establish an $\mathcal{O}(T^{3/4}(1+P_T))$ dynamic regret bound, where $P_T$ denotes the path-length of the comparator sequence.
no code implementations • NeurIPS 2021 • Lijun Zhang, Wei Jiang, Shiyin Lu, Tianbao Yang
Moreover, when the hitting cost is both convex and $\lambda$-quadratic growth, we reduce the competitive ratio to $1 + \frac{2}{\sqrt{\lambda}}$ by minimizing the weighted sum of the hitting cost and the switching cost.
no code implementations • 6 Feb 2020 • Lijun Zhang, Shiyin Lu, Tianbao Yang
To address this limitation, new performance measures, including dynamic regret and adaptive regret have been proposed to guide the design of online algorithms.
no code implementations • 5 Sep 2019 • Shiyin Lu, Lijun Zhang
The first algorithm achieves a second-order tracking regret bound, which improves existing first-order bounds.
no code implementations • 30 May 2019 • Shiyin Lu, Guanghui Wang, Yao Hu, Lijun Zhang
In this paper, we study the multi-objective bandits (MOB) problem, where a learner repeatedly selects one arm to play and then receives a reward vector consisting of multiple objectives.
no code implementations • 15 May 2019 • Guanghui Wang, Shiyin Lu, Lijun Zhang
In this paper, we study adaptive online convex optimization, and aim to design a universal algorithm that achieves optimal regret bounds for multiple common types of loss functions.
1 code implementation • ICLR 2020 • Guanghui Wang, Shiyin Lu, Wei-Wei Tu, Lijun Zhang
In this paper, we give an affirmative answer by developing a variant of Adam (referred to as SAdam) which achieves a data-dependant $O(\log T)$ regret bound for strongly convex functions.
no code implementations • NeurIPS 2018 • Lijun Zhang, Shiyin Lu, Zhi-Hua Zhou
In this paper, we study online convex optimization in dynamic environments, and aim to bound the dynamic regret with respect to any sequence of comparators.