Explainable Artificial Intelligence (AI) in the form of an interpretable and semiautomatic approach to stage grading ocular pathologies such as Diabetic retinopathy, Hypertensive retinopathy, and other retinopathies on the backdrop of major systemic diseases. The experimental study aims to evaluate an explainable staged grading process without using deep Convolutional Neural Networks (CNNs) directly. Many current CNN-based deep neural networks used for diagnosing retinal disorders might have appreciable performance but fail to pinpoint the basis driving their decisions. To improve these decisions' transparency, we have proposed a clinician-in-the-loop assisted intelligent workflow that performs a retinal vascular assessment on the fundus images to derive quantifiable and descriptive parameters. The retinal vessel parameters meta-data serve as hyper-parameters for better interpretation and explainability of decisions. The semiautomatic methodology aims to have a federated approach to AI in healthcare applications with more inputs and interpretations from clinicians. The baseline process involved in the machine learning pipeline through image processing techniques for optic disc detection, vessel segmentation, and arteriole/venule identification.

Differentially private deep learning has recently witnessed advances in computational efficiency and privacy-utility trade-off. We explore whether further improvements along the two axes are possible and provide affirmative answers leveraging two instantiations of \emph{group-wise clipping}. To reduce the compute time overhead of private learning, we show that \emph{per-layer clipping}, where the gradient of each neural network layer is clipped separately, allows clipping to be performed in conjunction with backpropagation in differentially private optimization. This results in private learning that is as memory-efficient and almost as fast per training update as non-private learning for many workflows of interest. While per-layer clipping with constant thresholds tends to underperform standard flat clipping, per-layer clipping with adaptive thresholds matches or outperforms flat clipping under given training epoch constraints, hence attaining similar or better task performance within less wall time. To explore the limits of scaling (pretrained) models in differentially private deep learning, we privately fine-tune the 175 billion-parameter GPT-3. We bypass scaling challenges associated with clipping gradients that are distributed across multiple devices with \emph{per-device clipping} that clips the gradient of each model piece separately on its host device. Privately fine-tuning GPT-3 with per-device clipping achieves a task performance at $\epsilon=1$ better than what is attainable by non-privately fine-tuning the largest GPT-2 on a summarization task.

In reinforcement learning (RL), the ability to utilize prior knowledge from previously solved tasks can allow agents to quickly solve new problems. In some cases, these new problems may be approximately solved by composing the solutions of previously solved primitive tasks (task composition). Otherwise, prior knowledge can be used to adjust the reward function for a new problem, in a way that leaves the optimal policy unchanged but enables quicker learning (reward shaping). In this work, we develop a general framework for reward shaping and task composition in entropy-regularized RL. To do so, we derive an exact relation connecting the optimal soft value functions for two entropy-regularized RL problems with different reward functions and dynamics. We show how the derived relation leads to a general result for reward shaping in entropy-regularized RL. We then generalize this approach to derive an exact relation connecting optimal value functions for the composition of multiple tasks in entropy-regularized RL. We validate these theoretical contributions with experiments showing that reward shaping and task composition lead to faster learning in various settings.

Causal phenomena associated with rare events frequently occur across a wide range of engineering and mathematical problems, such as risk-sensitive safety analysis, accident analysis and prevention, and extreme value theory. However, current methods for causal discovery are often unable to uncover causal links between random variables that manifest only when the variables first experience low-probability realizations. To address this issue, we introduce a novel algorithm that performs statistical independence tests on data collected from time-invariant dynamical systems in which rare but consequential events occur. We seek to understand if the state of the dynamical system causally affects the likelihood of the rare event. In particular, we exploit the time-invariance of the underlying data to superimpose the occurrences of rare events, thus creating a new dataset, with rare events are better represented, on which conditional independence tests can be more efficiently performed. We provide non-asymptotic bounds for the consistency of our algorithm, and validate the performance of our algorithm across various simulated scenarios, with applications to traffic accidents.

Chest X-ray (CXR) datasets hosted on Kaggle, though useful from a data science competition standpoint, have limited utility in clinical use because of their narrow focus on diagnosing one specific disease. In real-world clinical use, multiple diseases need to be considered since they can co-exist in the same patient. In this work, we demonstrate how federated learning (FL) can be used to make these toy CXR datasets from Kaggle clinically useful. Specifically, we train a single FL classification model (`global`) using two separate CXR datasets -- one annotated for presence of pneumonia and the other for presence of pneumothorax (two common and life-threatening conditions) -- capable of diagnosing both. We compare the performance of the global FL model with models trained separately on both datasets (`baseline`) for two different model architectures. On a standard, naive 3-layer CNN architecture, the global FL model achieved AUROC of 0.84 and 0.81 for pneumonia and pneumothorax, respectively, compared to 0.85 and 0.82, respectively, for both baseline models (p>0.05). Similarly, on a pretrained DenseNet121 architecture, the global FL model achieved AUROC of 0.88 and 0.91 for pneumonia and pneumothorax, respectively, compared to 0.89 and 0.91, respectively, for both baseline models (p>0.05). Our results suggest that FL can be used to create global `meta` models to make toy datasets from Kaggle clinically useful, a step forward towards bridging the gap from bench to bedside.

Tuberculosis (TB), an infectious bacterial disease, is a significant cause of death, especially in low-income countries, with an estimated ten million new cases reported globally in $2020$. While TB is treatable, non-adherence to the medication regimen is a significant cause of morbidity and mortality. Thus, proactively identifying patients at risk of dropping off their medication regimen enables corrective measures to mitigate adverse outcomes. Using a proxy measure of extreme non-adherence and a dataset of nearly $700,000$ patients from four states in India, we formulate and solve the machine learning (ML) problem of early prediction of non-adherence based on a custom rank-based metric. We train ML models and evaluate against baselines, achieving a $\sim 100\%$ lift over rule-based baselines and $\sim 214\%$ over a random classifier, taking into account country-wide large-scale future deployment. We deal with various issues in the process, including data quality, high-cardinality categorical data, low target prevalence, distribution shift, variation across cohorts, algorithmic fairness, and the need for robustness and explainability. Our findings indicate that risk stratification of non-adherent patients is a viable, deployable-at-scale ML solution.

我们提出了一种基于神经辐射场（NERF）的单个$ 360^\ PANORAMA图像合成新视图的方法。在类似环境中的先前研究依赖于多层感知的邻居插值能力来完成由遮挡引起的丢失区域，这导致其预测中的伪像。我们提出了360Fusionnerf，这是一个半监督的学习框架，我们介绍几何监督和语义一致性，以指导渐进式培训过程。首先，将输入图像重新投影至$ 360^\ Circ $图像，并在其他相机位置提取辅助深度图。除NERF颜色指导外，深度监督还改善了合成视图的几何形状。此外，我们引入了语义一致性损失，鼓励新观点的现实渲染。我们使用预先训练的视觉编码器（例如剪辑）提取这些语义功能，这是一个视觉变压器，经过数以千计的不同2D照片，并通过自然语言监督从网络中挖掘出来。实验表明，我们提出的方法可以在保留场景的特征的同时产生未观察到的区域的合理完成。 360fusionnerf在各种场景中接受培训时，转移到合成结构3D数据集（PSNR〜5％，SSIM〜3％lpips〜13％）时，始终达到最先进的性能，SSIM〜3％LPIPS〜9％）和replica360数据集（PSNR〜8％，SSIM〜2％LPIPS〜18％）。

语言模型是使用大量通用数据（如Book Copus，Common Crawl和Wikipedia）进行预训练的，这对于模型了解语言的语言特征至关重要。新的研究建议将域自适应预训练（DAPT）和任务自适应预训练（TAPT）作为最终填充任务之前的中间步骤。此步骤有助于涵盖目标域词汇，并改善下游任务的模型性能。在这项工作中，我们仅研究训练在TAPT和特定于任务的填充过程中嵌入层对模型性能的影响。基于我们的研究，我们提出了一种简单的方法，以通过对BERT层进行选择性预训练，使基于BERT的模型的中间步骤更有效。我们表明，在TAPT期间仅训练BERT嵌入层足以适应目标域的词汇并实现可比的性能。我们的方法在计算上是有效的，在TAPT期间训练了78％的参数。所提出的嵌入层列式方法也可以是一种有效的域适应技术。

在本文中，我们研究了以马尔可夫决策过程（MDP）为模型的随机系统中的计划，其偏好比时间扩展的目标。偏好的时间计划上的先前工作假定用户偏好形成总订单，这意味着每对结果彼此相当。在这项工作中，我们考虑了对可能结果的偏好是部分顺序而不是总订单的情况。我们首先引入了确定性有限自动机的变体，称为偏好DFA，用于指定用户对时间扩展目标的偏好。基于顺序理论，我们将偏好DFA转化为与标记为MDP中概率计划的策略相比的偏好关系。在这种处理中，最优选的策略会在MDP中的有限路径上引起弱化的非主导概率分布。拟议的计划算法取决于建造多目标MDP。我们证明，考虑到偏好规范的弱化的非主导政策在构建的多目标MDP中是帕特托最佳的，反之亦然。在整篇论文中，我们采用一个运行的示例来演示提出的偏好规范和解决方案方法。我们使用该示例和详细分析显示了算法的功效，然后讨论可能的未来方向。

我们将图形神经网络训练来自小工具N体模拟的光晕目录的神经网络，以执行宇宙学参数的无现场级别可能的推断。目录包含$ \ Lessim $ 5,000 HAROS带质量$ \ gtrsim 10^{10} 〜h^{ - 1} m_ \ odot $，定期卷为$（25〜H^{ - 1} {\ rm mpc}）{\ rm mpc}） ^3 $;目录中的每个光环都具有多种特性，例如位置，质量，速度，浓度和最大圆速度。我们的模型构建为置换，翻译和旋转的不变性，不施加最低限度的规模来提取信息，并能够以平均值来推断$ \ omega _ {\ rm m} $和$ \ sigma_8 $的值$ \ sim6 \％$的相对误差分别使用位置加上速度和位置加上质量。更重要的是，我们发现我们的模型非常强大：他们可以推断出使用数千个N-n-Body模拟的Halo目录进行测试时，使用五个不同的N-进行测试时，在使用Halo目录进行测试时，$ \ omega _ {\ rm m} $和$ \ sigma_8 $身体代码：算盘，Cubep $^3 $ M，Enzo，PKDGrav3和Ramses。令人惊讶的是，经过培训的模型推断$ \ omega _ {\ rm m} $在对数千个最先进的骆驼水力动力模拟进行测试时也可以使用，该模拟使用四个不同的代码和子网格物理实现。使用诸如浓度和最大循环速度之类的光环特性允许我们的模型提取更多信息，而牺牲了模型的鲁棒性。这可能会发生，因为不同的N体代码不会在与这些参数相对应的相关尺度上收敛。