As one of the most important psychic stress reactions, micro-expressions (MEs), are spontaneous and transient facial expressions that can reveal the genuine emotions of human beings. Thus, recognizing MEs (MER) automatically is becoming increasingly crucial in the field of affective computing, and provides essential technical support in lie detection, psychological analysis and other areas. However, the lack of abundant ME data seriously restricts the development of cutting-edge data-driven MER models. Despite the recent efforts of several spontaneous ME datasets to alleviate this problem, it is still a tiny amount of work. To solve the problem of ME data hunger, we construct a dynamic spontaneous ME dataset with the largest current ME data scale, called DFME (Dynamic Facial Micro-expressions), which includes 7,526 well-labeled ME videos induced by 671 participants and annotated by more than 20 annotators throughout three years. Afterwards, we adopt four classical spatiotemporal feature learning models on DFME to perform MER experiments to objectively verify the validity of DFME dataset. In addition, we explore different solutions to the class imbalance and key-frame sequence sampling problems in dynamic MER respectively on DFME, so as to provide a valuable reference for future research. The comprehensive experimental results show that our DFME dataset can facilitate the research of automatic MER, and provide a new benchmark for MER. DFME will be published via https://mea-lab-421.github.io.

Adversarial attacks on thermal infrared imaging expose the risk of related applications. Estimating the security of these systems is essential for safely deploying them in the real world. In many cases, realizing the attacks in the physical space requires elaborate special perturbations. These solutions are often \emph{impractical} and \emph{attention-grabbing}. To address the need for a physically practical and stealthy adversarial attack, we introduce \textsc{HotCold} Block, a novel physical attack for infrared detectors that hide persons utilizing the wearable Warming Paste and Cooling Paste. By attaching these readily available temperature-controlled materials to the body, \textsc{HotCold} Block evades human eyes efficiently. Moreover, unlike existing methods that build adversarial patches with complex texture and structure features, \textsc{HotCold} Block utilizes an SSP-oriented adversarial optimization algorithm that enables attacks with pure color blocks and explores the influence of size, shape, and position on attack performance. Extensive experimental results in both digital and physical environments demonstrate the performance of our proposed \textsc{HotCold} Block. \emph{Code is available: \textcolor{magenta}{https://github.com/weihui1308/HOTCOLDBlock}}.

Recently, due to the increasing requirements of medical imaging applications and the professional requirements of annotating medical images, few-shot learning has gained increasing attention in the medical image semantic segmentation field. To perform segmentation with limited number of labeled medical images, most existing studies use Proto-typical Networks (PN) and have obtained compelling success. However, these approaches overlook the query image features extracted from the proposed representation network, failing to preserving the spatial connection between query and support images. In this paper, we propose a novel self-supervised few-shot medical image segmentation network and introduce a novel Cycle-Resemblance Attention (CRA) module to fully leverage the pixel-wise relation between query and support medical images. Notably, we first line up multiple attention blocks to refine more abundant relation information. Then, we present CRAPNet by integrating the CRA module with a classic prototype network, where pixel-wise relations between query and support features are well recaptured for segmentation. Extensive experiments on two different medical image datasets, e.g., abdomen MRI and abdomen CT, demonstrate the superiority of our model over existing state-of-the-art methods.

Pessimism is of great importance in offline reinforcement learning (RL). One broad category of offline RL algorithms fulfills pessimism by explicit or implicit behavior regularization. However, most of them only consider policy divergence as behavior regularization, ignoring the effect of how the offline state distribution differs with that of the learning policy, which may lead to under-pessimism for some states and over-pessimism for others. Taking account of this problem, we propose a principled algorithmic framework for offline RL, called \emph{State-Aware Proximal Pessimism} (SA-PP). The key idea of SA-PP is leveraging discounted stationary state distribution ratios between the learning policy and the offline dataset to modulate the degree of behavior regularization in a state-wise manner, so that pessimism can be implemented in a more appropriate way. We first provide theoretical justifications on the superiority of SA-PP over previous algorithms, demonstrating that SA-PP produces a lower suboptimality upper bound in a broad range of settings. Furthermore, we propose a new algorithm named \emph{State-Aware Conservative Q-Learning} (SA-CQL), by building SA-PP upon representative CQL algorithm with the help of DualDICE for estimating discounted stationary state distribution ratios. Extensive experiments on standard offline RL benchmark show that SA-CQL outperforms the popular baselines on a large portion of benchmarks and attains the highest average return.

Large language models (LLMs) have been shown to be able to perform new tasks based on a few demonstrations or natural language instructions. While these capabilities have led to widespread adoption, most LLMs are developed by resource-rich organizations and are frequently kept from the public. As a step towards democratizing this powerful technology, we present BLOOM, a 176B-parameter open-access language model designed and built thanks to a collaboration of hundreds of researchers. BLOOM is a decoder-only Transformer language model that was trained on the ROOTS corpus, a dataset comprising hundreds of sources in 46 natural and 13 programming languages (59 in total). We find that BLOOM achieves competitive performance on a wide variety of benchmarks, with stronger results after undergoing multitask prompted finetuning. To facilitate future research and applications using LLMs, we publicly release our models and code under the Responsible AI License.

Models should be able to adapt to unseen data during test-time to avoid performance drops caused by inevitable distribution shifts in real-world deployment scenarios. In this work, we tackle the practical yet challenging test-time adaptation (TTA) problem, where a model adapts to the target domain without accessing the source data. We propose a simple recipe called \textit{Data-efficient Prompt Tuning} (DePT) with two key ingredients. First, DePT plugs visual prompts into the vision Transformer and only tunes these source-initialized prompts during adaptation. We find such parameter-efficient finetuning can efficiently adapt the model representation to the target domain without overfitting to the noise in the learning objective. Second, DePT bootstraps the source representation to the target domain by memory bank-based online pseudo-labeling. A hierarchical self-supervised regularization specially designed for prompts is jointly optimized to alleviate error accumulation during self-training. With much fewer tunable parameters, DePT demonstrates not only state-of-the-art performance on major adaptation benchmarks VisDA-C, ImageNet-C, and DomainNet-126, but also superior data efficiency, i.e., adaptation with only 1\% or 10\% data without much performance degradation compared to 100\% data. In addition, DePT is also versatile to be extended to online or multi-source TTA settings.

Although Deep Neural Networks (DNNs) have achieved impressive results in computer vision, their exposed vulnerability to adversarial attacks remains a serious concern. A series of works has shown that by adding elaborate perturbations to images, DNNs could have catastrophic degradation in performance metrics. And this phenomenon does not only exist in the digital space but also in the physical space. Therefore, estimating the security of these DNNs-based systems is critical for safely deploying them in the real world, especially for security-critical applications, e.g., autonomous cars, video surveillance, and medical diagnosis. In this paper, we focus on physical adversarial attacks and provide a comprehensive survey of over 150 existing papers. We first clarify the concept of the physical adversarial attack and analyze its characteristics. Then, we define the adversarial medium, essential to perform attacks in the physical world. Next, we present the physical adversarial attack methods in task order: classification, detection, and re-identification, and introduce their performance in solving the trilemma: effectiveness, stealthiness, and robustness. In the end, we discuss the current challenges and potential future directions.

在过去的几年中，用于计算机视觉的深度学习技术的快速发展极大地促进了医学图像细分的性能（Mediseg）。但是，最近的梅赛格出版物通常集中于主要贡献的演示（例如，网络体系结构，培训策略和损失功能），同时不知不觉地忽略了一些边缘实施细节（也称为“技巧”），导致了潜在的问题，导致了潜在的问题。不公平的实验结果比较。在本文中，我们为不同的模型实施阶段（即，预培训模型，数据预处理，数据增强，模型实施，模型推断和结果后处理）收集了一系列Mediseg技巧，并在实验中探索了有效性这些技巧在一致的基线模型上。与仅关注分割模型的优点和限制分析的纸驱动调查相比，我们的工作提供了大量的可靠实验，并且在技术上更可操作。通过对代表性2D和3D医疗图像数据集的广泛实验结果，我们明确阐明了这些技巧的效果。此外，根据调查的技巧，我们还开源了一个强大的梅德西格存储库，其每个组件都具有插件的优势。我们认为，这项里程碑的工作不仅完成了对最先进的Mediseg方法的全面和互补的调查，而且还提供了解决未来医学图像处理挑战的实用指南，包括但不限于小型数据集学习，课程不平衡学习，多模式学习和领域适应。该代码已在以下网址发布：https：//github.com/hust-linyi/mediseg

最近，视觉变压器及其变体在人类和多视图人类姿势估计中均起着越来越重要的作用。将图像补丁视为令牌，变形金刚可以对整个图像中的全局依赖项进行建模或其他视图中的图像。但是，全球关注在计算上是昂贵的。结果，很难将这些基于变压器的方法扩展到高分辨率特征和许多视图。在本文中，我们提出了代币螺旋的姿势变压器（PPT）进行2D人姿势估计，该姿势估计可以找到粗糙的人掩模，并且只能在选定的令牌内进行自我注意。此外，我们将PPT扩展到多视图人类姿势估计。我们建立在PPT的基础上，提出了一种新的跨视图融合策略，称为人类区域融合，该策略将所有人类前景像素视为相应的候选者。可可和MPII的实验结果表明，我们的PPT可以在减少计算的同时匹配以前的姿势变压器方法的准确性。此外，对人类360万和滑雪姿势的实验表明，我们的多视图PPT可以有效地从多个视图中融合线索并获得新的最新结果。

在智能决策系统的核心上，如何代表和优化政策是一个基本问题。这个问题的根源挑战是政策空间的大规模和高复杂性，这加剧了政策学习的困难，尤其是在现实世界中。对于理想的替代政策领域，最近在低维潜在空间中的政策表示表明其在改善政策的评估和优化方面的潜力。这些研究所涉及的关键问题是，我们应根据哪些标准抽象出所需的压缩和泛化的政策空间。但是，文献中对政策抽象的理论和政策表示学习方法的研究较少。在这项工作中，我们做出了最初的努力来填补空缺。首先，我们提出了一个统一的政策抽象理论，其中包含与不同级别的政策特征相关的三种类型的策略抽象。然后，我们将它们推广到三个策略指标，以量化政策的距离（即相似性），以便在学习策略表示方面更方便使用。此外，我们建议基于深度度量学习的政策表示学习方法。对于实证研究，我们研究了拟议的政策指标和代表的功效，分别表征政策差异和传达政策概括。我们的实验均在政策优化和评估问题中进行，其中包含信任区域政策优化（TRPO），多样性引导的进化策略（DGES）和非政策评估（OPE）。自然而然地，实验结果表明，对于所有下游学习问题，都没有普遍的最佳抽象。虽然影响力 - 反应抽象可以是通常的首选选择。