我们详细介绍了一种开发Stein方法的方法,该方法是针对Riemannian歧管$ \ Mathbf M $界定的概率度量界定整体指标的。我们的方法利用了$ \ mathbf m $扩散的生成器与目标不变度度量及其表征Stein运算符之间的关系。我们考虑了一对具有不同起点的扩散,并通过对两对之间的距离过程进行分析,得出了Stein因子,该因子将解决方案绑定到Stein方程及其衍生物。Stein因子包含曲率依赖性的术语,并减少到当前可用于$ \ Mathbb r^m $的因子,此外,暗示$ \ Mathbb r^m $的界限在$ \ Mathbf M $时保持有效
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Nonconvex minimax problems have attracted wide attention in machine learning, signal processing and many other fields in recent years. In this paper, we propose a primal dual alternating proximal gradient (PDAPG) algorithm and a primal dual proximal gradient (PDPG-L) algorithm for solving nonsmooth nonconvex-strongly concave and nonconvex-linear minimax problems with coupled linear constraints, respectively. The corresponding iteration complexity of the two algorithms are proved to be $\mathcal{O}\left( \varepsilon ^{-2} \right)$ and $\mathcal{O}\left( \varepsilon ^{-3} \right)$ to reach an $\varepsilon$-stationary point, respectively. To our knowledge, they are the first two algorithms with iteration complexity guarantee for solving the two classes of minimax problems.
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我们研究了离线模仿学习(IL)的问题,在该问题中,代理商旨在学习最佳的专家行为政策,而无需其他在线环境互动。取而代之的是,该代理来自次优行为的补充离线数据集。解决此问题的先前工作要么要求专家数据占据离线数据集的大部分比例,要么需要学习奖励功能并在以后执行离线加强学习(RL)。在本文中,我们旨在解决问题,而无需进行奖励学习和离线RL培训的其他步骤,当时示范包含大量次优数据。基于行为克隆(BC),我们引入了一个额外的歧视者,以区分专家和非专家数据。我们提出了一个合作框架,以增强这两个任务的学习,基于此框架,我们设计了一种新的IL算法,其中歧视者的输出是BC损失的权重。实验结果表明,与基线算法相比,我们提出的算法可获得更高的回报和更快的训练速度。
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虚拟试验旨在在店内服装和参考人员图像的情况下产生光真实的拟合结果。现有的方法通常建立多阶段框架来分别处理衣服翘曲和身体混合,或严重依赖基于中间解析器的标签,这些标签可能嘈杂甚至不准确。为了解决上述挑战,我们通过开发一种新型的变形注意流(DAFLOF)提出了一个单阶段的尝试框架,该框架将可变形的注意方案应用于多流量估计。仅将姿势关键点作为指导,分别为参考人员和服装图像估计了自我和跨跨性别的注意力流。通过对多个流场进行采样,通过注意机制同时提取并合并了来自不同语义区域的特征级和像素级信息。它使衣服翘曲和身体合成,同时以端到端的方式导致照片真实的结果。在两个尝试数据集上进行的广泛实验表明,我们提出的方法在定性和定量上都能达到最先进的性能。此外,其他两个图像编辑任务上的其他实验说明了我们用于多视图合成和图像动画方法的多功能性。
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跨域冷启动推荐是推荐系统越来越新兴的问题。现有的作品主要专注于解决跨域用户推荐或冷启动内容推荐。但是,当新域在早期发展时,它具有类似于源域的潜在用户,但互动较少。从源域中学习用户的偏好并将其转移到目标域中是至关重要的,特别是在具有有限用户反馈的新到达内容上。为了弥合这一差距,我们提出了一个自训练的跨域用户偏好学习(夫妻)框架,针对具有各种语义标签的冷启动推荐,例如视频的项目或视频类型。更具体地,我们考虑三个级别的偏好,包括用户历史,用户内容和用户组提供可靠的推荐。利用由域感知顺序模型表示的用户历史,将频率编码器应用于用于用户内容偏好学习的底层标记。然后,建议具有正交节点表示的分层存储器树以进一步概括域域的用户组偏好。整个框架以一种对比的方式更新,以先进先出(FIFO)队列获得更具独特的表示。两个数据集的广泛实验展示了用户和内容冷启动情况的夫妇效率。通过部署在线A / B一周测试,我们表明夫妇的点击率(CTR)优于淘宝应用程序的其他基线。现在该方法在线为跨域冷微视频推荐服务。
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最近,由于这些问题与一些新兴应用的相关性,最近有许多研究工作用于开发有效算法,以解决理论收敛的保证。在本文中,我们提出了一种统一的单环交替梯度投影(AGP)算法,用于求解平滑的非convex-(强烈)凹面和(强烈)凸出 - 非concave minimax问题。 AGP采用简单的梯度投影步骤来更新每次迭代时的原始变量和双变量。我们表明,它可以在$ \ MATHCAL {O} \ left(\ Varepsilon ^{ - 2} \ right)$(rep. $ \ Mathcal {O} \ left)中找到目标函数的$ \ VAREPSILON $ -STAIMATARY点。 (\ varepsilon ^{ - 4} \ right)$)$迭代,在nonconvex-strongly凹面(resp。nonconvex-concave)设置下。此外,获得目标函数的$ \ VAREPSILON $ -STAIMATARY的梯度复杂性由$ \ Mathcal {o} \ left(\ varepsilon ^{ - 2} \ right)界限O} \ left(\ varepsilon ^{ - 4} \ right)$在强烈的convex-nonconcave(resp。,convex-nonconcave)设置下。据我们所知,这是第一次开发出一种简单而统一的单环算法来解决非convex-(强烈)凹面和(强烈)凸出 - 非concave minimax问题。此外,在文献中从未获得过解决后者(强烈)凸线 - 非孔孔的最小问题的复杂性结果。数值结果表明所提出的AGP算法的效率。此外,我们通过提出块交替近端梯度(BAPG)算法来扩展AGP算法,以求解更通用的多块非块非conmooth nonmooth nonmooth noncovex-(强)凹面和(强烈)convex-nonconcave minimax问题。我们可以在这四个不同的设置下类似地建立所提出算法的梯度复杂性。
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In this paper, we propose a novel technique, namely INVALIDATOR, to automatically assess the correctness of APR-generated patches via semantic and syntactic reasoning. INVALIDATOR reasons about program semantic via program invariants while it also captures program syntax via language semantic learned from large code corpus using the pre-trained language model. Given a buggy program and the developer-patched program, INVALIDATOR infers likely invariants on both programs. Then, INVALIDATOR determines that a APR-generated patch overfits if: (1) it violates correct specifications or (2) maintains errors behaviors of the original buggy program. In case our approach fails to determine an overfitting patch based on invariants, INVALIDATOR utilizes a trained model from labeled patches to assess patch correctness based on program syntax. The benefit of INVALIDATOR is three-fold. First, INVALIDATOR is able to leverage both semantic and syntactic reasoning to enhance its discriminant capability. Second, INVALIDATOR does not require new test cases to be generated but instead only relies on the current test suite and uses invariant inference to generalize the behaviors of a program. Third, INVALIDATOR is fully automated. We have conducted our experiments on a dataset of 885 patches generated on real-world programs in Defects4J. Experiment results show that INVALIDATOR correctly classified 79% overfitting patches, accounting for 23% more overfitting patches being detected by the best baseline. INVALIDATOR also substantially outperforms the best baselines by 14% and 19% in terms of Accuracy and F-Measure, respectively.
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Non-linear state-space models, also known as general hidden Markov models, are ubiquitous in statistical machine learning, being the most classical generative models for serial data and sequences in general. The particle-based, rapid incremental smoother PaRIS is a sequential Monte Carlo (SMC) technique allowing for efficient online approximation of expectations of additive functionals under the smoothing distribution in these models. Such expectations appear naturally in several learning contexts, such as likelihood estimation (MLE) and Markov score climbing (MSC). PARIS has linear computational complexity, limited memory requirements and comes with non-asymptotic bounds, convergence results and stability guarantees. Still, being based on self-normalised importance sampling, the PaRIS estimator is biased. Our first contribution is to design a novel additive smoothing algorithm, the Parisian particle Gibbs PPG sampler, which can be viewed as a PaRIS algorithm driven by conditional SMC moves, resulting in bias-reduced estimates of the targeted quantities. We substantiate the PPG algorithm with theoretical results, including new bounds on bias and variance as well as deviation inequalities. Our second contribution is to apply PPG in a learning framework, covering MLE and MSC as special examples. In this context, we establish, under standard assumptions, non-asymptotic bounds highlighting the value of bias reduction and the implicit Rao--Blackwellization of PPG. These are the first non-asymptotic results of this kind in this setting. We illustrate our theoretical results with numerical experiments supporting our claims.
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Machine Reading Comprehension has become one of the most advanced and popular research topics in the fields of Natural Language Processing in recent years. The classification of answerability questions is a relatively significant sub-task in machine reading comprehension; however, there haven't been many studies. Retro-Reader is one of the studies that has solved this problem effectively. However, the encoders of most traditional machine reading comprehension models in general and Retro-Reader, in particular, have not been able to exploit the contextual semantic information of the context completely. Inspired by SemBERT, we use semantic role labels from the SRL task to add semantics to pre-trained language models such as mBERT, XLM-R, PhoBERT. This experiment was conducted to compare the influence of semantics on the classification of answerability for the Vietnamese machine reading comprehension. Additionally, we hope this experiment will enhance the encoder for the Retro-Reader model's Sketchy Reading Module. The improved Retro-Reader model's encoder with semantics was first applied to the Vietnamese Machine Reading Comprehension task and obtained positive results.
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Diabetic Retinopathy (DR) is a leading cause of vision loss in the world, and early DR detection is necessary to prevent vision loss and support an appropriate treatment. In this work, we leverage interactive machine learning and introduce a joint learning framework, termed DRG-Net, to effectively learn both disease grading and multi-lesion segmentation. Our DRG-Net consists of two modules: (i) DRG-AI-System to classify DR Grading, localize lesion areas, and provide visual explanations; (ii) DRG-Expert-Interaction to receive feedback from user-expert and improve the DRG-AI-System. To deal with sparse data, we utilize transfer learning mechanisms to extract invariant feature representations by using Wasserstein distance and adversarial learning-based entropy minimization. Besides, we propose a novel attention strategy at both low- and high-level features to automatically select the most significant lesion information and provide explainable properties. In terms of human interaction, we further develop DRG-Net as a tool that enables expert users to correct the system's predictions, which may then be used to update the system as a whole. Moreover, thanks to the attention mechanism and loss functions constraint between lesion features and classification features, our approach can be robust given a certain level of noise in the feedback of users. We have benchmarked DRG-Net on the two largest DR datasets, i.e., IDRID and FGADR, and compared it to various state-of-the-art deep learning networks. In addition to outperforming other SOTA approaches, DRG-Net is effectively updated using user feedback, even in a weakly-supervised manner.
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