New technologies and the availability of geospatial data have drawn attention to spatio-temporal biases present in society. For example: the COVID-19 pandemic highlighted disparities in the availability of broadband service and its role in the digital divide; the environmental justice movement in the United States has raised awareness to health implications for minority populations stemming from historical redlining practices; and studies have found varying quality and coverage in the collection and sharing of open-source geospatial data. Despite the extensive literature on machine learning (ML) fairness, few algorithmic strategies have been proposed to mitigate such biases. In this paper we highlight the unique challenges for quantifying and addressing spatio-temporal biases, through the lens of use cases presented in the scientific literature and media. We envision a roadmap of ML strategies that need to be developed or adapted to quantify and overcome these challenges -- including transfer learning, active learning, and reinforcement learning techniques. Further, we discuss the potential role of ML in providing guidance to policy makers on issues related to spatial fairness.

In large-scale machine learning, recent works have studied the effects of compressing gradients in stochastic optimization in order to alleviate the communication bottleneck. These works have collectively revealed that stochastic gradient descent (SGD) is robust to structured perturbations such as quantization, sparsification, and delays. Perhaps surprisingly, despite the surge of interest in large-scale, multi-agent reinforcement learning, almost nothing is known about the analogous question: Are common reinforcement learning (RL) algorithms also robust to similar perturbations? In this paper, we investigate this question by studying a variant of the classical temporal difference (TD) learning algorithm with a perturbed update direction, where a general compression operator is used to model the perturbation. Our main technical contribution is to show that compressed TD algorithms, coupled with an error-feedback mechanism used widely in optimization, exhibit the same non-asymptotic theoretical guarantees as their SGD counterparts. We then extend our results significantly to nonlinear stochastic approximation algorithms and multi-agent settings. In particular, we prove that for multi-agent TD learning, one can achieve linear convergence speedups in the number of agents while communicating just $\tilde{O}(1)$ bits per agent at each time step. Our work is the first to provide finite-time results in RL that account for general compression operators and error-feedback in tandem with linear function approximation and Markovian sampling. Our analysis hinges on studying the drift of a novel Lyapunov function that captures the dynamics of a memory variable introduced by error feedback.

The goal of this paper is to detect objects by exploiting their interrelationships. Rather than relying on predefined and labeled graph structures, we infer a graph prior from object co-occurrence statistics. The key idea of our paper is to model object relations as a function of initial class predictions and co-occurrence priors to generate a graph representation of an image for improved classification and bounding box regression. We additionally learn the object-relation joint distribution via energy based modeling. Sampling from this distribution generates a refined graph representation of the image which in turn produces improved detection performance. Experiments on the Visual Genome and MS-COCO datasets demonstrate our method is detector agnostic, end-to-end trainable, and especially beneficial for rare object classes. What is more, we establish a consistent improvement over object detectors like DETR and Faster-RCNN, as well as state-of-the-art methods modeling object interrelationships.

We present a machine-learning framework to accurately characterize morphologies of Active Galactic Nucleus (AGN) host galaxies within $z<1$. We first use PSFGAN to decouple host galaxy light from the central point source, then we invoke the Galaxy Morphology Network (GaMorNet) to estimate whether the host galaxy is disk-dominated, bulge-dominated, or indeterminate. Using optical images from five bands of the HSC Wide Survey, we build models independently in three redshift bins: low $(0<z<0.25)$, medium $(0.25<z<0.5)$, and high $(0.5<z<1.0)$. By first training on a large number of simulated galaxies, then fine-tuning using far fewer classified real galaxies, our framework predicts the actual morphology for $\sim$ $60\%-70\%$ host galaxies from test sets, with a classification precision of $\sim$ $80\%-95\%$, depending on redshift bin. Specifically, our models achieve disk precision of $96\%/82\%/79\%$ and bulge precision of $90\%/90\%/80\%$ (for the 3 redshift bins), at thresholds corresponding to indeterminate fractions of $30\%/43\%/42\%$. The classification precision of our models has a noticeable dependency on host galaxy radius and magnitude. No strong dependency is observed on contrast ratio. Comparing classifications of real AGNs, our models agree well with traditional 2D fitting with GALFIT. The PSFGAN+GaMorNet framework does not depend on the choice of fitting functions or galaxy-related input parameters, runs orders of magnitude faster than GALFIT, and is easily generalizable via transfer learning, making it an ideal tool for studying AGN host galaxy morphology in forthcoming large imaging survey.

是否可以指导基础模型执行涉及法律推理的任务？我们认为，建立一个基准来回答这个问题将需要计算机科学与法律社区之间持续的合作努力。为此，这份简短的纸张有三个目的。首先，我们描述了IRAC-A框架法律学者如何用来区分不同类型的法律推理 - can指导基础模型的基础基准。其次，我们介绍了根据此框架构建的44个任务的种子集。我们讨论初始发现，并突出显示新任务的方向。最终，由开放科学运动引起的启发 - 我们呼吁法律和计算机科学社区通过贡献新任务来加入我们的努力。这项工作正在进行中，我们的进度可以在此处跟踪：https：//github.com/hazyresearch/legalbench。

与训练数据中心的训练传统机器学习（ML）模型相反，联合学习（FL）训练ML模型，这些模型在资源受限的异质边缘设备上包含的本地数据集上。现有的FL算法旨在为所有参与的设备学习一个单一的全球模型，这对于所有参与培训的设备可能没有帮助，这是由于整个设备的数据的异质性。最近，Hanzely和Richt \'{A} Rik（2020）提出了一种新的配方，以培训个性化的FL模型，旨在平衡传统的全球模型与本地模型之间的权衡，该模型可以使用其私人数据对单个设备进行培训只要。他们得出了一种称为无环梯度下降（L2GD）的新算法，以解决该算法，并表明该算法会在需要更多个性化的情况下，可以改善沟通复杂性。在本文中，我们为其L2GD算法配备了双向压缩机制，以进一步减少本地设备和服务器之间的通信瓶颈。与FL设置中使用的其他基于压缩的算法不同，我们的压缩L2GD算法在概率通信协议上运行，在概率通信协议中，通信不会按固定的时间表进行。此外，我们的压缩L2GD算法在没有压缩的情况下保持与香草SGD相似的收敛速率。为了验证算法的效率，我们在凸和非凸问题上都进行了多种数值实验，并使用各种压缩技术。

随着图像识别中深度学习模型的快速发展和使用的增加，安全成为其在安全至关重要系统中的部署的主要关注点。由于深度学习模型的准确性和鲁棒性主要归因于训练样本的纯度，因此，深度学习体系结构通常容易受到对抗性攻击的影响。对抗性攻击通常是通过对正常图像的微妙扰动而获得的，正常图像对人类最不可感知，但可能会严重混淆最新的机器学习模型。我们提出了一个名为Apudae的框架，利用DeNoing AutoCoders（DAES）通过以自适应方式使用这些样品来纯化这些样本，从而提高了已攻击目标分类器网络的分类准确性。我们还展示了如何自适应地使用DAE，而不是直接使用它们，而是进一步提高分类精度，并且更强大，可以设计自适应攻击以欺骗它们。我们在MNIST，CIFAR-10，Imagenet数据集上展示了我们的结果，并展示了我们的框架（Apudae）如何在净化对手方面提供可比性和在大多数情况下的基线方法。我们还设计了专门设计的自适应攻击，以攻击我们的净化模型，并展示我们的防御方式如何强大。

大型语言模型已经证明了能够在自然语言和编程语言文本上进行条件和生成的能力。这样的模型打开了多语言代码生成的可能性：代码生成模型是否可以将知识从一种语言推广到另一种语言？尽管当代代码生成模型可以生成语义上正确的Python代码，但对它们使用其他语言的能力知之甚少。我们通过提出Multipl-E来促进该主题的探索，这是自然语言到代码生成的第一个多语言平行基准。 Multipl-E扩展了HumaneVal基准（Chen等，2021），以支持另外18种编程语言，涵盖了一系列编程范式和受欢迎程度。我们在Multipl-E：Codex和Incoder上评估了两个最先进的代码生成模型。我们发现，在几种语言上，法典匹配，甚至超过了其在Python上的性能。在多型E中表示的编程语言范围使我们能够探索语言频率和语言功能对模型性能的影响。最后，将代码生成基准分配给新编程语言的多重方法既可扩展又可扩展。我们描述了一种通用方法，可以轻松地增加对新基准和语言的支持。

组合优化的硬度（CO）问题阻碍收集用于监督学习的解决方案。但是，由于缺乏标记的数据，因此很难学习CO问题的神经网络，因为训练很容易被捕获到本地Optima。在这项工作中，我们为CO问题提出了一个简单但有效的退火培训框架。特别是，我们将CO问题转化为公正的基于能量的模型（EBM）。我们仔细选择了罚款条款，以使EBM尽可能平滑。然后，我们训练图形神经网络以近似EBM。为了防止训练在初始化附近被卡在本地Optima上，我们引入了退火损失功能。实验评估表明，我们的退火训练框架获得了实质性改进。在四种类型的CO问题中，我们的方法在合成图和现实世界图上都比其他无监督神经方法更好地达到了性能。

听觉事件的感知固有地依赖于音频和视觉提示。许多现有的多模式方法使用模式特异性模型处理每种模式，然后融合嵌入以编码关节信息。相反，我们采用异质图来明确捕获模态之间的空间和时间关系，并表示有关基础信号的详细信息。使用异质图方法来解决视觉感知的声学事件分类的任务，该任务是一种紧凑，有效且可扩展的方式，以图形形式表示数据。通过异质图，我们显示了在空间和时间尺度上有效地建模模式和模式间关系。我们的模型可以通过相关的超参数轻松适应不同的事件规模。在Audioset上进行的实验（一个大型基准）表明，我们的模型实现了最先进的性能。