The problem of learning threshold functions is a fundamental one in machine learning. Classical learning theory implies sample complexity of $O(\xi^{-1} \log(1/\beta))$ (for generalization error $\xi$ with confidence $1-\beta$). The private version of the problem, however, is more challenging and in particular, the sample complexity must depend on the size $|X|$ of the domain. Progress on quantifying this dependence, via lower and upper bounds, was made in a line of works over the past decade. In this paper, we finally close the gap for approximate-DP and provide a nearly tight upper bound of $\tilde{O}(\log^* |X|)$, which matches a lower bound by Alon et al (that applies even with improper learning) and improves over a prior upper bound of $\tilde{O}((\log^* |X|)^{1.5})$ by Kaplan et al. We also provide matching upper and lower bounds of $\tilde{\Theta}(2^{\log^*|X|})$ for the additive error of private quasi-concave optimization (a related and more general problem). Our improvement is achieved via the novel Reorder-Slice-Compute paradigm for private data analysis which we believe will have further applications.

物体重新识别（REID）是生物识别和监视系统中最重要的问题之一，在过去几十年来通过图像处理和计算机视觉社区进行了广泛的研究。学习强大而判别的特征表示是对象REID的关键挑战。在REID中，基于无人机（UAV）的REID更具挑战性，因为图像的特征是飞行无人机的摄像机参数（例如，视角，海拔等）的连续变化。为了应对这一挑战，已经考虑了多尺度特征表示形式来表征来自不同海拔无人机飞行的图像。在这项工作中，我们提出了一种多任务学习方法，该方法采用新的多尺度体系结构，无卷积，金字塔视觉变压器（PVT），作为基于无人机的对象REID的骨干。通过对类内变化的不确定性建模，我们提出的模型可以使用不确定性感知对象ID和相机ID信息共同优化。实验结果报告了Prai和VRAI，这是两个REID数据集，从空中监视中验证我们提出的方法的有效性

最近的作品揭示了设计损失功能的基本范式，该损失功能与骨料损失不同。单个损失衡量样本上模型的质量，而总损失结合了每个训练样本的个体损失/分数。两者都有一个共同的过程，将一组单个值集合到单个数值值。排名顺序反映了设计损失时个人价值观之间最基本的关系。此外，可以将损失分解成单个术语的合奏的可分解性成为组织损失/得分的重要特性。这项调查对机器学习中的基于等级的可分解损失进行了系统的全面审查。具体而言，我们提供了损失功能的新分类法，遵循总损失和个人损失的观点。我们确定聚合器以形成此类损失，这是集合功能的示例。我们将基于等级的分解损失组织为八类。遵循这些类别，我们回顾有关基于等级的总损失和基于等级的个人损失的文献。我们描述了这些损失的一般公式，并将其与现有的研究主题联系起来。我们还建议未来的研究方向涵盖基于等级的可分解损失的未开发，剩余和新兴问题。

由不同形状和非线性形状变化引起的机器官的大变形，对医学图像配准产生了重大挑战。传统的注册方法需要通过特定变形模型迭代地优化目标函数以及细致的参数调谐，但在具有大变形的图像中具有有限的能力。虽然基于深度学习的方法可以从输入图像到它们各自的变形字段中的复杂映射，但它是基于回归的，并且容易被卡在局部最小值，特别是当涉及大变形时。为此，我们呈现随机策划者 - 演员 - 评论家（SPAC），这是一种新的加强学习框架，可以执行逐步登记。关键概念通过每次步骤连续地翘曲运动图像，以最终与固定图像对齐。考虑到在传统的强化学习（RL）框架中处理高维连续动作和状态空间有挑战性，我们向标准演员 - 评论家模型引入了一个新的概念“计划”，这是低维度，可以促进演员生成易于高维行动。整个框架基于无监督的培训，并以端到端的方式运行。我们在几个2D和3D医学图像数据集上评估我们的方法，其中一些包含大变形。我们的经验结果强调了我们的工作实现了一致，显着的收益和优于最先进的方法。

训练无模型的深度加强学习模型来解决图像到图像转换是困难的，因为它涉及高维连续状态和动作空间。在本文中，我们借鉴了最近的最大熵增强学习框架成功的灵感来设计用于挑战连续控制问题，在包括图像表示，产生和控制的高维连续空间上开发随机策略。这种方法的核心是随机演员 - 执行程序 - 批评者 - 评论家（SAEC），这是一个违法的演员 - 评论家模型，具有额外的excator来生成现实图像。具体地，该actor通过随机潜行动作侧重于高级表示和控制策略，以及明确地指示执行器生成用于操纵状态的低级动作。关于若干图像到图像转换任务的实验已经证明了在面对高维连续空间问题时所提出的SAEC的有效性和稳健性。

代码摘要可帮助开发人员理解程序并减少在软件维护过程中推断程序功能的时间。最近的努力诉诸深度学习技术，例如序列到序列模型，以生成准确的代码摘要，其中基于变压器的方法已实现了有希望的性能。但是，在此任务域中，有效地将代码结构信息集成到变压器中的情况不足。在本文中，我们提出了一种名为SG-Trans的新方法，将代码结构属性纳入变压器。具体而言，我们将局部符号信息（例如，代码令牌和语句）和全局句法结构（例如，数据流程图）注入变压器的自我发项模块中。为了进一步捕获代码的层次结构特征，局部信息和全局结构旨在分布在下层和变压器高层的注意力头中。广泛的评估表明，SG-trans的表现优于最先进的方法。与表现最佳的基线相比，SG-Trans在流星评分方面仍然可以提高1.4％和2.0％，这是一个广泛用于测量发电质量的度量，分别在两个基准数据集上。

AI-synthesized face-swapping videos, commonly known as DeepFakes, is an emerging problem threatening the trustworthiness of online information. The need to develop and evaluate DeepFake detection algorithms calls for large-scale datasets. However, current DeepFake datasets suffer from low visual quality and do not resemble Deep-Fake videos circulated on the Internet. We present a new large-scale challenging DeepFake video dataset, Celeb-DF, which contains 5, 639 high-quality DeepFake videos of celebrities generated using improved synthesis process. We conduct a comprehensive evaluation of DeepFake detection methods and datasets to demonstrate the escalated level of challenges posed by Celeb-DF.

Different people speak with diverse personalized speaking styles. Although existing one-shot talking head methods have made significant progress in lip sync, natural facial expressions, and stable head motions, they still cannot generate diverse speaking styles in the final talking head videos. To tackle this problem, we propose a one-shot style-controllable talking face generation framework. In a nutshell, we aim to attain a speaking style from an arbitrary reference speaking video and then drive the one-shot portrait to speak with the reference speaking style and another piece of audio. Specifically, we first develop a style encoder to extract dynamic facial motion patterns of a style reference video and then encode them into a style code. Afterward, we introduce a style-controllable decoder to synthesize stylized facial animations from the speech content and style code. In order to integrate the reference speaking style into generated videos, we design a style-aware adaptive transformer, which enables the encoded style code to adjust the weights of the feed-forward layers accordingly. Thanks to the style-aware adaptation mechanism, the reference speaking style can be better embedded into synthesized videos during decoding. Extensive experiments demonstrate that our method is capable of generating talking head videos with diverse speaking styles from only one portrait image and an audio clip while achieving authentic visual effects. Project Page: https://github.com/FuxiVirtualHuman/styletalk.

Nowadays, time-stamped web documents related to a general news query floods spread throughout the Internet, and timeline summarization targets concisely summarizing the evolution trajectory of events along the timeline. Unlike traditional document summarization, timeline summarization needs to model the time series information of the input events and summarize important events in chronological order. To tackle this challenge, in this paper, we propose a Unified Timeline Summarizer (UTS) that can generate abstractive and extractive timeline summaries in time order. Concretely, in the encoder part, we propose a graph-based event encoder that relates multiple events according to their content dependency and learns a global representation of each event. In the decoder part, to ensure the chronological order of the abstractive summary, we propose to extract the feature of event-level attention in its generation process with sequential information remained and use it to simulate the evolutionary attention of the ground truth summary. The event-level attention can also be used to assist in extracting summary, where the extracted summary also comes in time sequence. We augment the previous Chinese large-scale timeline summarization dataset and collect a new English timeline dataset. Extensive experiments conducted on these datasets and on the out-of-domain Timeline 17 dataset show that UTS achieves state-of-the-art performance in terms of both automatic and human evaluations.

Masked image modeling (MIM) has shown great promise for self-supervised learning (SSL) yet been criticized for learning inefficiency. We believe the insufficient utilization of training signals should be responsible. To alleviate this issue, we introduce a conceptually simple yet learning-efficient MIM training scheme, termed Disjoint Masking with Joint Distillation (DMJD). For disjoint masking (DM), we sequentially sample multiple masked views per image in a mini-batch with the disjoint regulation to raise the usage of tokens for reconstruction in each image while keeping the masking rate of each view. For joint distillation (JD), we adopt a dual branch architecture to respectively predict invisible (masked) and visible (unmasked) tokens with superior learning targets. Rooting in orthogonal perspectives for training efficiency improvement, DM and JD cooperatively accelerate the training convergence yet not sacrificing the model generalization ability. Concretely, DM can train ViT with half of the effective training epochs (3.7 times less time-consuming) to report competitive performance. With JD, our DMJD clearly improves the linear probing classification accuracy over ConvMAE by 5.8%. On fine-grained downstream tasks like semantic segmentation, object detection, etc., our DMJD also presents superior generalization compared with state-of-the-art SSL methods. The code and model will be made public at https://github.com/mx-mark/DMJD.