Supraglacial lakes in the Arctic undergo seasonal and glacial-activity-induced changes, providing profound insights into ice dynamics and climate changes in these sensitive regions. However, the morphological complexity of these lakes, compounded by the environmental obstructions like clouds and slush fields, poses significant challenges to accurate lake detection. The 31st ACM SIGSPATIAL 2023 initiated a competition, GISCUP 2023, focusing on supraglacial lake detection based on multipart, multi-temporal satellite imagery. This paper, distinguished as the 3rd place winner, introduces a pioneering dual-attention U-net algorithm. This approach synergizes deep learning with spectral and spatial knowledge, ensuring a streamlined pipeline structure that upholds methodological soundness and yields satisfying results.

Dynamic pricing is a fast-moving research area in machine learning and operations management. A lot of work has been done for this problem with known noise. In this paper, we consider a contextual dynamic pricing problem under a linear customer valuation model with an unknown market noise distribution $F$. This problem is very challenging due to the difficulty in balancing three tangled tasks of revenue-maximization, estimating the linear valuation parameter $\theta_{0}$, and learning the nonparametric $F$. To address this issue, we develop a novel {\it Explore-then-UCB} (ExUCB) strategy that includes an exploration for $\theta_{0}$-learning and a followed UCB procedure of joint revenue-maximization and $F$-learning. Under Lipschitz and 2nd-order smoothness assumptions on $F$, ExUCB is the first approach to achieve the $\tilde{O}(T^{2/3})$ regret rate. Under the Lipschitz assumption only, ExUCB matches the best existing regret of $\tilde{O}(T^{3/4})$ and is computationally more efficient. Furthermore, for regret lower bounds under the nonparametric $F$, not much work has been done beyond only assuming Lipschitz. To fill this gap, we provide the first $\tilde{\Omega}(T^{3/5})$ lower bound under Lipschitz and 2nd-order smoothness assumptions.