We study a multi-factor block model for variable clustering and connect it to the regularized subspace clustering by formulating a distributionally robust version of the nodewise regression. To solve the latter problem, we derive a convex relaxation, provide guidance on selecting the size of the robust region, and hence the regularization weighting parameter, based on the data, and propose an ADMM algorithm for implementation. We validate our method in an extensive simulation study. Finally, we propose and apply a variant of our method to stock return data, obtain interpretable clusters that facilitate portfolio selection and compare its out-of-sample performance with other clustering methods in an empirical study.

Ensemble learning serves as a straightforward way to improve the performance of almost any machine learning algorithm. Existing deep ensemble methods usually naively train many different models and then aggregate their predictions. This is not optimal in our view from two aspects: i) Naively training multiple models adds much more computational burden, especially in the deep learning era; ii) Purely optimizing each base model without considering their interactions limits the diversity of ensemble and performance gains. We tackle these issues by proposing deep negative correlation classification (DNCC), in which the accuracy and diversity trade-off is systematically controlled by decomposing the loss function seamlessly into individual accuracy and the correlation between individual models and the ensemble. DNCC yields a deep classification ensemble where the individual estimator is both accurate and negatively correlated. Thanks to the optimized diversities, DNCC works well even when utilizing a shared network backbone, which significantly improves its efficiency when compared with most existing ensemble systems. Extensive experiments on multiple benchmark datasets and network structures demonstrate the superiority of the proposed method.

The role of mobile cameras increased dramatically over the past few years, leading to more and more research in automatic image quality enhancement and RAW photo processing. In this Mobile AI challenge, the target was to develop an efficient end-to-end AI-based image signal processing (ISP) pipeline replacing the standard mobile ISPs that can run on modern smartphone GPUs using TensorFlow Lite. The participants were provided with a large-scale Fujifilm UltraISP dataset consisting of thousands of paired photos captured with a normal mobile camera sensor and a professional 102MP medium-format FujiFilm GFX100 camera. The runtime of the resulting models was evaluated on the Snapdragon's 8 Gen 1 GPU that provides excellent acceleration results for the majority of common deep learning ops. The proposed solutions are compatible with all recent mobile GPUs, being able to process Full HD photos in less than 20-50 milliseconds while achieving high fidelity results. A detailed description of all models developed in this challenge is provided in this paper.

While deep reinforcement learning has proven to be successful in solving control tasks, the "black-box" nature of an agent has received increasing concerns. We propose a prototype-based post-hoc policy explainer, ProtoX, that explains a blackbox agent by prototyping the agent's behaviors into scenarios, each represented by a prototypical state. When learning prototypes, ProtoX considers both visual similarity and scenario similarity. The latter is unique to the reinforcement learning context, since it explains why the same action is taken in visually different states. To teach ProtoX about visual similarity, we pre-train an encoder using contrastive learning via self-supervised learning to recognize states as similar if they occur close together in time and receive the same action from the black-box agent. We then add an isometry layer to allow ProtoX to adapt scenario similarity to the downstream task. ProtoX is trained via imitation learning using behavior cloning, and thus requires no access to the environment or agent. In addition to explanation fidelity, we design different prototype shaping terms in the objective function to encourage better interpretability. We conduct various experiments to test ProtoX. Results show that ProtoX achieved high fidelity to the original black-box agent while providing meaningful and understandable explanations.

速度控制预测是驾驶员行为分析中一个具有挑战性的问题，旨在预测驾驶员在控制车速（例如制动或加速度）中的未来行动。在本文中，我们尝试仅使用以自我为中心的视频数据来应对这一挑战，与使用第三人称视图数据或额外的车辆传感器数据（例如GPS或两者）的文献中的大多数作品相比。为此，我们提出了一个基于新型的图形卷积网络（GCN）网络，即Egospeed-net。我们的动机是，随着时间的推移，对象的位置变化可以为我们提供非常有用的线索，以预测未来的速度变化。我们首先使用完全连接的图形图将每个类的对象之间的空间关系建模，并在其上应用GCN进行特征提取。然后，我们利用一个长期的短期内存网络将每个类别的此类特征随着时间的流逝融合到矢量中，加入此类矢量并使用多层perceptron分类器预测速度控制动作。我们在本田研究所驾驶数据集上进行了广泛的实验，并证明了Egospeed-NET的出色性能。

具有高分辨率（HR）的磁共振成像（MRI）提供了更详细的信息，以进行准确的诊断和定量图像分析。尽管取得了重大进展，但大多数现有的医学图像重建网络都有两个缺陷：1）所有这些缺陷都是在黑盒原理中设计的，因此缺乏足够的解释性并进一步限制其实际应用。可解释的神经网络模型引起了重大兴趣，因为它们在处理医学图像时增强了临床实践所需的可信赖性。 2）大多数现有的SR重建方法仅使用单个对比度或使用简单的多对比度融合机制，从而忽略了对SR改进至关重要的不同对比度之间的复杂关系。为了解决这些问题，在本文中，提出了一种新颖的模型引导的可解释的深层展开网络（MGDUN），用于医学图像SR重建。模型引导的图像SR重建方法求解手动设计的目标函数以重建HR MRI。我们通过将MRI观察矩阵和显式多对比度关系矩阵考虑到末端到端优化期间，将迭代的MGDUN算法展示为新型模型引导的深层展开网络。多对比度IXI数据集和Brats 2019数据集进行了广泛的实验，证明了我们提出的模型的优势。

我们建议\ emph {Choquet正则化器}来衡量和管理强化学习的探索水平（RL），并重新重新制定Wang等人的连续时间熵调节的RL问题。（2020年，JMLR，21（198）），其中我们用Choquet正常器代替用于正则化的差分熵。我们通过使汉密尔顿（Jacobi-Bellman方程）得出了问题的jacobi-bellman方程，并在线性 - 季度（LQ）情况下明确求解了汉密尔顿（LQ）（LQ）情况，这是通过静态上一种平均值 - 差异约束的Choquet正常制剂。在LQ设置下，我们为几个特定的Choquet正规化器提供了明确的最佳分布，相反，我们确定了产生许多广泛使用的探索性采样器的Choquet正则化器，例如$ \ epsilon $ - 果岭，指数，统一，统一和高斯。

本文报告了建立在线语言学习工具的进步，以通过使用对话系统作为对话实践伙伴为学习者提供对话体验。我们的系统可以随时适应用户的语言水平。我们还提供自动语法错误反馈，以帮助用户从错误中学习。根据我们的第一个采用者，我们的系统娱乐和有用。此外，我们将为学习技术社区提供有关语言学习和语法校正的大规模对话数据集。我们的下一步是通过使用强化学习算法使我们的系统更适应用户配置文件。

我们研究了Wang等人介绍的熵调查的，探索性扩散过程制定的Q-学习（RL）的Q-学习（RL）的持续时间对应物。 （2020）随着常规（大）Q功能在连续的时间崩溃，我们考虑其一阶近似，并在“（小）Q功能”一词中造成术语。此功能与瞬时优势率函数以及哈密顿量有关。我们围绕时间离散化独立于Q功能开发了“ Q学习”理论。鉴于随机策略，我们通过某些随机过程的martingale条件共同表征了相关的Q功能和价值函数。然后，我们将理论应用来设计不同的参与者批评算法来解决潜在的RL问题，具体取决于是否可以明确计算从Q功能产生的Gibbs测量的密度函数。我们的一种算法解释了著名的Q学习算法SARSA，另一个算法恢复了基于政策梯度（PG）在Jia和Zhou（2021）中提出的基于策略梯度（PG）。最后，我们进行了仿真实验，以将我们的算法的性能与JIA和Zhou（2021）中的PG基算法的性能以及时间消化的常规Q学习算法进行比较。

我们努力努力探索的任务很少，名为Insbestantial对象检测（IOD），该任务旨在以以下特征定位对象：（1）具有不明显的边界的无定形形状； （2）与周围环境相似； （3）颜色不存在。因此，在单个静态框架中区分不理性对象是更具挑战性的，而空间和时间信息的协作表示至关重要。因此，我们构建了一个由600个视频（141,017帧）组成的iod-video数据集，其中涵盖了各种距离，尺寸，可见性和不同光谱范围捕获的场景。此外，我们为IOD开发了一个时空聚合框架，其中部署了不同的骨架，并精心设计了时空聚合损失（Staloss），以利用沿时轴的一致性来利用一致性。在IOD-VIDEO数据集上进行的实验表明，时空聚集可以显着改善IOD的性能。我们希望我们的工作能够吸引进一步的研究，以完成这项有价值但充满挑战的任务。该代码将在：\ url {https://github.com/calayzhou/iod-video}上可用。