变量名称对于传达预期的程序行为至关重要。基于机器学习的程序分析方法使用变量名称表示广泛的任务，例如建议新的变量名称和错误检测。理想情况下，这些方法可以捕获句法相似性的名称之间的语义关系，例如，名称平均和均值的事实是相似的。不幸的是，以前的工作发现，即使是先前的最佳的表示方法主要是捕获相关性（是否有两个变量始终链接），而不是相似性（是否具有相同的含义）。我们提出了VarCLR，一种用于学习变量名称的语义表示的新方法，这些方法有效地捕获了这种更严格的意义上的可变相似性。我们观察到这个问题是对比学习的优秀契合，旨在最小化明确类似的输入之间的距离，同时最大化不同输入之间的距离。这需要标记的培训数据，因此我们构建了一种新颖的弱监督的变量重命名数据集，从GitHub编辑开采。我们表明VarCLR能够有效地应用BERT等复杂的通用语言模型，以变为变量名称表示，因此也是与变量名称相似性搜索或拼写校正等相关的下游任务。 varclr产生模型，显着越优于idbench的最先进的现有基准，明确地捕获可变相似度（与相关性不同）。最后，我们贡献了所有数据，代码和预先训练模型的版本，旨在为现有或未来程序分析中使用的可变表示提供的可变表示的替代品。

从几个培训示例中不断学习新课程，而不忘记以前的旧课程需要一个灵活的体系结构，而不可避免地会增加部分存储，其中可以逐步存储并有效地检索新的示例和类。一个可行的架构解决方案是将固定的深神经网络紧密融合到动态发展的明确记忆（EM）。作为该体系结构的核心，我们提出了一个EM单元，该单元在持续学习操作过程中利用节能中的内存计算（IMC）核心。我们首次证明了EM单元如何使用基于IMC Core上的操作（PCM）上的IMC核心操作，在推理期间进行了多个训练示例，扩展以适应看不见的类并进行相似性搜索。具体而言，通过PCM设备的原位进行性结晶实现了一些编码训练示例的物理叠加。与不断学习的最新完整精确基线软件模型相比，IMC核心上达到的分类精度在1.28％ - 2.5％范围内保持在2.5％之内。在60个旧课程的顶部，新颖的课程（每班只有五个示例）。

具有更多数据，计算和参数的缩放语言模型在自然语言处理方面取得了重大进展。例如，由于缩放，GPT-3能够在内心学习任务上实现强烈结果。但是，培训这些大密度模型需要大量的计算资源。在本文中，我们提出并开发了名为Glam（通用语言模型）的语言模型系列，它使用稀疏激活的专家架构来规模模型容量，同时与致密变体相比，也产生显着更少的训练成本。最大的Glam具有1.2万亿参数，比GPT-3大约为7倍。它仅消耗了用于训练GPT-3的1/3的能量，并且需要一半的计算拖鞋进行推理，同时仍然在29个NLP任务中实现更好的整体零射击和一次性性能。

We study the problem of planning under model uncertainty in an online meta-reinforcement learning (RL) setting where an agent is presented with a sequence of related tasks with limited interactions per task. The agent can use its experience in each task and across tasks to estimate both the transition model and the distribution over tasks. We propose an algorithm to meta-learn the underlying structure across tasks, utilize it to plan in each task, and upper-bound the regret of the planning loss. Our bound suggests that the average regret over tasks decreases as the number of tasks increases and as the tasks are more similar. In the classical single-task setting, it is known that the planning horizon should depend on the estimated model's accuracy, that is, on the number of samples within task. We generalize this finding to meta-RL and study this dependence of planning horizons on the number of tasks. Based on our theoretical findings, we derive heuristics for selecting slowly increasing discount factors, and we validate its significance empirically.

Underwater images are altered by the physical characteristics of the medium through which light rays pass before reaching the optical sensor. Scattering and strong wavelength-dependent absorption significantly modify the captured colors depending on the distance of observed elements to the image plane. In this paper, we aim to recover the original colors of the scene as if the water had no effect on them. We propose two novel methods that rely on different sets of inputs. The first assumes that pixel intensities in the restored image are normally distributed within each color channel, leading to an alternative optimization of the well-known \textit{Sea-thru} method which acts on single images and their distance maps. We additionally introduce SUCRe, a new method that further exploits the scene's 3D Structure for Underwater Color Restoration. By following points in multiple images and tracking their intensities at different distances to the sensor we constrain the optimization of the image formation model parameters. When compared to similar existing approaches, SUCRe provides clear improvements in a variety of scenarios ranging from natural light to deep-sea environments. The code for both approaches is publicly available at https://github.com/clementinboittiaux/sucre .

We study representation learning for efficient imitation learning over linear systems. In particular, we consider a setting where learning is split into two phases: (a) a pre-training step where a shared $k$-dimensional representation is learned from $H$ source policies, and (b) a target policy fine-tuning step where the learned representation is used to parameterize the policy class. We find that the imitation gap over trajectories generated by the learned target policy is bounded by $\tilde{O}\left( \frac{k n_x}{HN_{\mathrm{shared}}} + \frac{k n_u}{N_{\mathrm{target}}}\right)$, where $n_x > k$ is the state dimension, $n_u$ is the input dimension, $N_{\mathrm{shared}}$ denotes the total amount of data collected for each policy during representation learning, and $N_{\mathrm{target}}$ is the amount of target task data. This result formalizes the intuition that aggregating data across related tasks to learn a representation can significantly improve the sample efficiency of learning a target task. The trends suggested by this bound are corroborated in simulation.

Forecasting the state of vegetation in response to climate and weather events is a major challenge. Its implementation will prove crucial in predicting crop yield, forest damage, or more generally the impact on ecosystems services relevant for socio-economic functioning, which if absent can lead to humanitarian disasters. Vegetation status depends on weather and environmental conditions that modulate complex ecological processes taking place at several timescales. Interactions between vegetation and different environmental drivers express responses at instantaneous but also time-lagged effects, often showing an emerging spatial context at landscape and regional scales. We formulate the land surface forecasting task as a strongly guided video prediction task where the objective is to forecast the vegetation developing at very fine resolution using topography and weather variables to guide the prediction. We use a Convolutional LSTM (ConvLSTM) architecture to address this task and predict changes in the vegetation state in Africa using Sentinel-2 satellite NDVI, having ERA5 weather reanalysis, SMAP satellite measurements, and topography (DEM of SRTMv4.1) as variables to guide the prediction. Ours results highlight how ConvLSTM models can not only forecast the seasonal evolution of NDVI at high resolution, but also the differential impacts of weather anomalies over the baselines. The model is able to predict different vegetation types, even those with very high NDVI variability during target length, which is promising to support anticipatory actions in the context of drought-related disasters.

Partially observable Markov decision processes (POMDPs) provide a flexible representation for real-world decision and control problems. However, POMDPs are notoriously difficult to solve, especially when the state and observation spaces are continuous or hybrid, which is often the case for physical systems. While recent online sampling-based POMDP algorithms that plan with observation likelihood weighting have shown practical effectiveness, a general theory characterizing the approximation error of the particle filtering techniques that these algorithms use has not previously been proposed. Our main contribution is bounding the error between any POMDP and its corresponding finite sample particle belief MDP (PB-MDP) approximation. This fundamental bridge between PB-MDPs and POMDPs allows us to adapt any sampling-based MDP algorithm to a POMDP by solving the corresponding particle belief MDP, thereby extending the convergence guarantees of the MDP algorithm to the POMDP. Practically, this is implemented by using the particle filter belief transition model as the generative model for the MDP solver. While this requires access to the observation density model from the POMDP, it only increases the transition sampling complexity of the MDP solver by a factor of $\mathcal{O}(C)$, where $C$ is the number of particles. Thus, when combined with sparse sampling MDP algorithms, this approach can yield algorithms for POMDPs that have no direct theoretical dependence on the size of the state and observation spaces. In addition to our theoretical contribution, we perform five numerical experiments on benchmark POMDPs to demonstrate that a simple MDP algorithm adapted using PB-MDP approximation, Sparse-PFT, achieves performance competitive with other leading continuous observation POMDP solvers.

地震数据中的噪声来自许多来源，并且正在不断发展。使用监督的深度学习程序来降级地震数据集通常会导致性能差：这是由于缺乏无噪声的现场数据来充当训练目标以及合成数据集和现场数据集之间特性的巨大差异。自我监督，盲点网络通常通过直接在原始嘈杂的数据上训练来克服这些限制。但是，这样的网络通常依赖于随机噪声假设，并且在存在最小相关的噪声的情况下，它们的降解能力迅速降低。从盲点延伸到盲面可以有效地沿特定方向抑制连贯的噪声，但不能适应噪声的不断变化的特性。为了抢占网络预测信号并减少其学习噪声属性的机会的能力，我们在以自欺欺人的方式进行微调的方式，在节俭生成的合成数据集上对网络进行初始监督的培训。感兴趣的数据集。考虑到峰值信噪比的变化以及观察到的噪声量减少和信号泄漏的体积，我们说明了从监督的基础训练中的权重来初始化自我监督网络的明显好处。通过在字段数据集上进行的测试进一步支持，在该数据集中进行了微调网络在信号保存和降低噪声之间达到最佳平衡。最后，使用不切实际的，节俭生成的合成数据集用于监督的基础培训包括许多好处：需要最少的先验地质知识，大大降低了数据集生成的计算成本，并减少了重新训练的要求。网络应记录条件更改，仅举几例。

我们研究Claire（一种差异性多形状，多-GPU图像注册算法和软件）的性能 - 在具有数十亿素素的大规模生物医学成像应用中。在这样的分辨率下，大多数用于差异图像注册的软件包非常昂贵。结果，从业人员首先要大量删除原始图像，然后使用现有工具进行注册。我们的主要贡献是对降采样对注册性能的影响的广泛分析。我们通过将用Claire获得的全分辨率注册与合成和现实成像数据集的低分辨率注册进行比较，研究了这种影响。我们的结果表明，完全分辨率的注册可以产生卓越的注册质量 - 但并非总是如此。例如，将合成图像从$ 1024^3 $减少到$ 256^3 $将骰子系数从92％降低到79％。但是，对于嘈杂或低对比度的高分辨率图像，差异不太明显。克莱尔不仅允许我们在几秒钟内注册临床相关大小的图像，而且还可以在合理的时间内以前所未有的分辨率注册图像。考虑的最高分辨率是$ 2816 \ times3016 \ times1162 $的清晰图像。据我们所知，这是有关此类决议中图像注册质量的首次研究。