基于概念的解释允许通过用户指定的概念镜头来了解深神经网络（DNN）的预测。现有方法假设说明概念的示例是在DNN潜在空间的固定方向上映射的。当这种情况下，该概念可以用指向该方向的概念激活向量（CAV）表示。在这项工作中，我们建议通过允许概念示例散布在DNN潜在空间中的不同群集中来放松这一假设。然后，每个概念都由DNN潜在空间的区域表示，该区域包括这些簇，我们称为概念激活区域（CAR）。为了使这个想法形式化，我们介绍了基于内核技巧和支持向量分类器的CAV形式主义的扩展。这种汽车形式主义产生了基于全球概念的解释和基于本地概念的特征重要性。我们证明，用径向核建造的汽车解释在潜在空间等法下是不变的。这样，汽车将相同的解释分配给具有相同几何形状的潜在空间。我们进一步证明汽车提供（1）更准确地描述了概念如何散布在DNN的潜在空间中； （2）更接近人类概念注释和（3）基于概念的特征的重要性重要性的全球解释，这些特征的重要性是有意义地相互关联的。最后，我们使用汽车表明DNN可以自主重新发现已知的科学概念，例如前列腺癌分级系统。

估计治疗的个性化影响是一个复杂但普遍存在的问题。为了解决这个问题，机器学习（ML）关于异质治疗效果估计的最新发展引起了许多复杂的，但不透明的工具：由于它们的灵活性，模块化和学习受限的表示的能力，尤其是神经网络，因此已成为中心对此文学。不幸的是，这种黑匣子的资产是有代价的：模型通常涉及无数的非平凡操作，因此很难理解他们所学到的知识。然而，理解这些模型可能至关重要 - 例如，在医学背景下，发现有关治疗效果的知识异质性可以在临床实践中为治疗处方提供信息。因此，在这项工作中，我们使用事后特征重要性方法来识别影响模型预测的功能。这使我们能够评估沿着先前工作中忽略的新重要维度的治疗效应估计量：我们构建了一个基准测试环境，以经验研究个性化治疗效果模型鉴定预测协变量的能力 - 确定治疗差异反应的协变量。然后，我们的基准测量环境使我们能够对不同类型的治疗效果模型的优势和劣势提供新的见解，因为我们调节了针对治疗效果估计的不同挑战 - 例如预后与预测信息的比率，潜在结果的可能非线性以及混杂的存在和类型。

无监督的黑盒模型要挑战。实际上，大多数现有的解释性方法都要求标签来选择要解释的黑框输出的组件。在没有标签的情况下，黑框输出通常是表示向量，其组件的分量与任何有意义的数量不符。因此，选择哪些组件在无标签的无监督/自我监督的设置中是一个重要但未解决的问题。为了弥合文献中的这一差距，我们介绍了事后解释技术的两个关键扩展：（1）无标签的功能重要性以及（2）无标签的示例分别重要的示例，这些示例分别强调了黑盒的有影响力的特征和训练示例在推理时间构建表示。我们证明，我们的扩展可以成功实现，以围绕许多现有功能和示例重要性方法的简单包装器实现。我们通过定性和定量的比较来说明我们无标记的解释性范式的实用性，该范式对经过不同无监督任务的各种自动编码器学到的表示空间进行了定量比较。

数据质量的系统量化对于一致的模型性能至关重要。先前的工作集中在分发数据上。取而代之的是，我们解决了一个研究了一个研究的且同样重要的问题，即表征不协调的区域（ID）数据，这可能是由特征空间异质性引起的。为此，我们提出了使用数据套件的范式转移：一个以数据为中心的AI框架来识别这些区域，而与特定于任务的模型无关。数据套件利用Copula建模，表示学习和共形预测，以基于一组培训实例来构建功能置信区间估计器。这些估计器可用于评估有关培训集的测试实例的一致性，以回答两个实际有用的问题：（1）通过培训培训实例培训的模型可以可靠地预测哪些测试实例？ （2）我们可以确定功能空间的不协调区域，以便数据所有者了解数据的局限性还是指导未来数据收集？我们从经验上验证了数据套件的性能和覆盖范围保证，并在跨站点的医疗数据，有偏见的数据以及具有概念漂移的数据上证明，数据套件最能确定下游模型可能是可靠的ID区域（与所述模型无关）。我们还说明了这些确定的区域如何为数据集提供见解并突出其局限性。

Accurate determination of a small molecule candidate (ligand) binding pose in its target protein pocket is important for computer-aided drug discovery. Typical rigid-body docking methods ignore the pocket flexibility of protein, while the more accurate pose generation using molecular dynamics is hindered by slow protein dynamics. We develop a tiered tensor transform (3T) algorithm to rapidly generate diverse protein-ligand complex conformations for both pose and affinity estimation in drug screening, requiring neither machine learning training nor lengthy dynamics computation, while maintaining both coarse-grain-like coordinated protein dynamics and atomistic-level details of the complex pocket. The 3T conformation structures we generate are closer to experimental co-crystal structures than those generated by docking software, and more importantly achieve significantly higher accuracy in active ligand classification than traditional ensemble docking using hundreds of experimental protein conformations. 3T structure transformation is decoupled from the system physics, making future usage in other computational scientific domains possible.

Adversarial imitation learning (AIL) has become a popular alternative to supervised imitation learning that reduces the distribution shift suffered by the latter. However, AIL requires effective exploration during an online reinforcement learning phase. In this work, we show that the standard, naive approach to exploration can manifest as a suboptimal local maximum if a policy learned with AIL sufficiently matches the expert distribution without fully learning the desired task. This can be particularly catastrophic for manipulation tasks, where the difference between an expert and a non-expert state-action pair is often subtle. We present Learning from Guided Play (LfGP), a framework in which we leverage expert demonstrations of multiple exploratory, auxiliary tasks in addition to a main task. The addition of these auxiliary tasks forces the agent to explore states and actions that standard AIL may learn to ignore. Additionally, this particular formulation allows for the reusability of expert data between main tasks. Our experimental results in a challenging multitask robotic manipulation domain indicate that LfGP significantly outperforms both AIL and behaviour cloning, while also being more expert sample efficient than these baselines. To explain this performance gap, we provide further analysis of a toy problem that highlights the coupling between a local maximum and poor exploration, and also visualize the differences between the learned models from AIL and LfGP.

Many problems in machine learning involve bilevel optimization (BLO), including hyperparameter optimization, meta-learning, and dataset distillation. Bilevel problems consist of two nested sub-problems, called the outer and inner problems, respectively. In practice, often at least one of these sub-problems is overparameterized. In this case, there are many ways to choose among optima that achieve equivalent objective values. Inspired by recent studies of the implicit bias induced by optimization algorithms in single-level optimization, we investigate the implicit bias of gradient-based algorithms for bilevel optimization. We delineate two standard BLO methods -- cold-start and warm-start -- and show that the converged solution or long-run behavior depends to a large degree on these and other algorithmic choices, such as the hypergradient approximation. We also show that the inner solutions obtained by warm-start BLO can encode a surprising amount of information about the outer objective, even when the outer parameters are low-dimensional. We believe that implicit bias deserves as central a role in the study of bilevel optimization as it has attained in the study of single-level neural net optimization.

The Covid-19 pandemic induced a vast increase in adolescents diagnosed with eating disorders and hospitalized due to eating disorders. This immense growth stemmed partially from the stress of the pandemic but also from increased exposure to content that promotes eating disorders via social media, which, within the last decade, has become plagued by pro-eating disorder content. This study aimed to create a deep learning model capable of determining whether a given social media post promotes eating disorders based solely on image data. Tweets from hashtags that have been documented to promote eating disorders along with tweets from unrelated hashtags were collected. After prepossessing, these images were labeled as either pro-eating disorder or not based on which Twitter hashtag they were scraped from. Several deep-learning models were trained on the scraped dataset and were evaluated based on their accuracy, F1 score, precision, and recall. Ultimately, the vision transformer model was determined to be the most accurate, attaining an F1 score of 0.877 and an accuracy of 86.7% on the test set. The model, which was applied to unlabeled Twitter image data scraped from "#selfie", uncovered seasonal fluctuations in the relative abundance of pro-eating disorder content, which reached its peak in the summertime. These fluctuations correspond not only to the seasons, but also to stressors, such as the Covid-19 pandemic. Moreover, the Twitter image data indicated that the relative amount of pro-eating disorder content has been steadily rising over the last five years and is likely to continue increasing in the future.

We introduce a pivot for exact selective inference with randomization. Not only does our pivot lead to exact inference in Gaussian regression models, but it is also available in closed form. We reduce the problem of exact selective inference to a bivariate truncated Gaussian distribution. By doing so, we give up some power that is achieved with approximate inference in Panigrahi and Taylor (2022). Yet we always produce narrower confidence intervals than a closely related data-splitting procedure. For popular instances of Gaussian regression, this price -- in terms of power -- in exchange for exact selective inference is demonstrated in simulated experiments and in an HIV drug resistance analysis.

Using geometric landmarks like lines and planes can increase navigation accuracy and decrease map storage requirements compared to commonly-used LiDAR point cloud maps. However, landmark-based registration for applications like loop closure detection is challenging because a reliable initial guess is not available. Global landmark matching has been investigated in the literature, but these methods typically use ad hoc representations of 3D line and plane landmarks that are not invariant to large viewpoint changes, resulting in incorrect matches and high registration error. To address this issue, we adopt the affine Grassmannian manifold to represent 3D lines and planes and prove that the distance between two landmarks is invariant to rotation and translation if a shift operation is performed before applying the Grassmannian metric. This invariance property enables the use of our graph-based data association framework for identifying landmark matches that can subsequently be used for registration in the least-squares sense. Evaluated on a challenging landmark matching and registration task using publicly-available LiDAR datasets, our approach yields a 1.7x and 3.5x improvement in successful registrations compared to methods that use viewpoint-dependent centroid and "closest point" representations, respectively.