在过去的两年中，从2020年到2021年，Covid-19在包括越南在内的许多国家 /地区都破坏了预防疾病措施，并对人类生活和社会社区的各个方面产生了负面影响。此外，社区中的误导性信息和有关大流行的虚假新闻也是严重的情况。因此，我们提出了第一个基于越南社区的问题答复数据集，用于开发COVID-19的问题答案系统，称为UIT-VICOV19QA。该数据集包括从可信赖的医疗来源收集的4,500对提问，至少有一个答案，每个问题最多有四个独特的解释答案。除数据集外，我们还建立了各种深度学习模型作为基线，以评估数据集的质量，并通过BLEU，Meteor和Rouge-l等常用指标来进一步研究基准结果，以进行进一步的研究。我们还说明了对这些模型进行多个解释答案的积极影响，尤其是在变压器上 - 研究领域的主要结构。

在视频中利用时空冗余的自适应抽样对于在有限的计算机和电池资源的可穿戴设备上始终进行动作识别至关重要。常用的固定采样策略不是上下文感知的，并且可能会在视觉内容下进行样本，从而对计算效率和准确性产生不利影响。受到人类视觉感知机制的动脉视觉和动力前处理的概念的启发，我们引入了一种新型的自适应时空抽样方案，以进行有效的动作识别。我们的系统以低分辨率为扫描前扫视全球场景上下文，并决定跳过或要求在显着区域的高分辨率功能进行进一步处理。我们在Epic-Kitchens和UCF-101数据集上验证该系统以进行动作识别，并表明我们所提出的方法可以大大加快与最先进基线相比的准确性丧失的推断。

来自RGB视频的多人姿势理解包括三个复杂的任务：姿势估计，跟踪和运动预测。在这三个任务中，姿势估计和跟踪是相关的，跟踪对于运动预测至关重要。大多数现有作品要么专注于单个任务，要么采用级联方法来分别解决每个任务。在本文中，我们提出了狙击手，这是一个框架，以同时进行单个推断，同时进行多人3D姿势估计，跟踪和运动预测。具体而言，我们首先提出了一种可变形的注意机制，以从视频片段中汇总时空信息。基于这种可变形的注意力，学会了视觉变压器来编码从多框架图像中的时空特征，并解码信息性姿势功能以更新多人姿势查询。最后，对这些查询进行了回归，以预测一个正向传球中的多人姿势轨迹和未来动作。在实验中，我们显示了狙击手对三个具有挑战性的公共数据集的有效性，在该数据集中，通用模型竞争对手专门的姿势估计，跟踪和预测的最先进基线。代码可在\ href {https://github.com/jimmyzou/snipper} {https://github.com/jimmyzou/snipper}中获得。

基于坐标的体积表示有可能从图像中生成光真实的虚拟化身。但是，即使是可能未观察到的新姿势，虚拟化身也需要控制。传统技术（例如LBS）提供了这样的功能；但是，通常需要手工设计的车身模板，3D扫描数据和有限的外观模型。另一方面，神经表示在表示视觉细节方面具有强大的作用，但在变形的动态铰接式参与者方面受到了探索。在本文中，我们提出了TAVA，这是一种基于神经表示形式创建无象光动画体积参与者的方法。我们仅依靠多视图数据和跟踪的骨骼来创建演员的体积模型，该模型可以在给定的新颖姿势的测试时间中进行动画。由于塔瓦不需要身体模板，因此它适用于人类以及其他动物（例如动物）。此外，Tava的设计使其可以恢复准确的密集对应关系，从而使其适合于内容创建和编辑任务。通过广泛的实验，我们证明了所提出的方法可以很好地推广到新颖的姿势以及看不见的观点和展示基本的编辑功能。

铰接式3D形状重建的事先工作通常依赖于专用传感器（例如，同步的多摄像机系统）或预先构建的3D可变形模型（例如，Smal或SMPL）。这些方法无法在野外扩展到不同的各种物体。我们呈现Banmo，这是一种需要专用传感器的方法，也不需要预定义的模板形状。 Banmo在可怜的渲染框架中从许多单眼休闲视频中建立高保真，铰接式的3D模型（包括形状和动画皮肤的重量）。虽然许多视频的使用提供了更多的相机视图和对象关节的覆盖范围，但它们在建立不同背景，照明条件等方面建立了重大挑战。我们的主要洞察力是合并三所思想学校; （1）使用铰接骨骼和混合皮肤的经典可变形形状模型，（2）可容纳基于梯度的优化，（3）在像素之间产生对应关系的规范嵌入物模型。我们介绍了神经混合皮肤模型，可允许可微分和可逆的铰接变形。与规范嵌入式结合时，这些模型允许我们在跨越可通过循环一致性自我监督的视频中建立密集的对应。在真实和合成的数据集上，Banmo显示比人类和动物的先前工作更高保真3D重建，具有从新颖的观点和姿势的现实图像。项目网页：Banmo-www.github.io。

We propose a new causal inference framework to learn causal effects from multiple, decentralized data sources in a federated setting. We introduce an adaptive transfer algorithm that learns the similarities among the data sources by utilizing Random Fourier Features to disentangle the loss function into multiple components, each of which is associated with a data source. The data sources may have different distributions; the causal effects are independently and systematically incorporated. The proposed method estimates the similarities among the sources through transfer coefficients, and hence requiring no prior information about the similarity measures. The heterogeneous causal effects can be estimated with no sharing of the raw training data among the sources, thus minimizing the risk of privacy leak. We also provide minimax lower bounds to assess the quality of the parameters learned from the disparate sources. The proposed method is empirically shown to outperform the baselines on decentralized data sources with dissimilar distributions.

The number of international benchmarking competitions is steadily increasing in various fields of machine learning (ML) research and practice. So far, however, little is known about the common practice as well as bottlenecks faced by the community in tackling the research questions posed. To shed light on the status quo of algorithm development in the specific field of biomedical imaging analysis, we designed an international survey that was issued to all participants of challenges conducted in conjunction with the IEEE ISBI 2021 and MICCAI 2021 conferences (80 competitions in total). The survey covered participants' expertise and working environments, their chosen strategies, as well as algorithm characteristics. A median of 72% challenge participants took part in the survey. According to our results, knowledge exchange was the primary incentive (70%) for participation, while the reception of prize money played only a minor role (16%). While a median of 80 working hours was spent on method development, a large portion of participants stated that they did not have enough time for method development (32%). 25% perceived the infrastructure to be a bottleneck. Overall, 94% of all solutions were deep learning-based. Of these, 84% were based on standard architectures. 43% of the respondents reported that the data samples (e.g., images) were too large to be processed at once. This was most commonly addressed by patch-based training (69%), downsampling (37%), and solving 3D analysis tasks as a series of 2D tasks. K-fold cross-validation on the training set was performed by only 37% of the participants and only 50% of the participants performed ensembling based on multiple identical models (61%) or heterogeneous models (39%). 48% of the respondents applied postprocessing steps.

Video understanding is a growing field and a subject of intense research, which includes many interesting tasks to understanding both spatial and temporal information, e.g., action detection, action recognition, video captioning, video retrieval. One of the most challenging problems in video understanding is dealing with feature extraction, i.e. extract contextual visual representation from given untrimmed video due to the long and complicated temporal structure of unconstrained videos. Different from existing approaches, which apply a pre-trained backbone network as a black-box to extract visual representation, our approach aims to extract the most contextual information with an explainable mechanism. As we observed, humans typically perceive a video through the interactions between three main factors, i.e., the actors, the relevant objects, and the surrounding environment. Therefore, it is very crucial to design a contextual explainable video representation extraction that can capture each of such factors and model the relationships between them. In this paper, we discuss approaches, that incorporate the human perception process into modeling actors, objects, and the environment. We choose video paragraph captioning and temporal action detection to illustrate the effectiveness of human perception based-contextual representation in video understanding. Source code is publicly available at https://github.com/UARK-AICV/Video_Representation.

Video anomaly detection (VAD) -- commonly formulated as a multiple-instance learning problem in a weakly-supervised manner due to its labor-intensive nature -- is a challenging problem in video surveillance where the frames of anomaly need to be localized in an untrimmed video. In this paper, we first propose to utilize the ViT-encoded visual features from CLIP, in contrast with the conventional C3D or I3D features in the domain, to efficiently extract discriminative representations in the novel technique. We then model long- and short-range temporal dependencies and nominate the snippets of interest by leveraging our proposed Temporal Self-Attention (TSA). The ablation study conducted on each component confirms its effectiveness in the problem, and the extensive experiments show that our proposed CLIP-TSA outperforms the existing state-of-the-art (SOTA) methods by a large margin on two commonly-used benchmark datasets in the VAD problem (UCF-Crime and ShanghaiTech Campus). The source code will be made publicly available upon acceptance.

Protein structure prediction is a fundamental problem in computational molecular biology. Classical algorithms such as ab-initio or threading as well as many learning methods have been proposed to solve this challenging problem. However, most reinforcement learning methods tend to model the state-action pairs as discrete objects. In this paper, we develop a reinforcement learning (RL) framework in a continuous setting and based on a stochastic parametrized Hamiltonian version of the Pontryagin maximum principle (PMP) to solve the side-chain packing and protein-folding problem. For special cases our formulation can be reduced to previous work where the optimal folding trajectories are trained using an explicit use of Langevin dynamics. Optimal continuous stochastic Hamiltonian dynamics folding pathways can be derived with use of different models of molecular energetics and force fields. In our RL implementation we adopt a soft actor-critic methodology however we can replace this other RL training based on A2C, A3C or PPO.