Deep latent variable models have achieved significant empirical successes in model-based reinforcement learning (RL) due to their expressiveness in modeling complex transition dynamics. On the other hand, it remains unclear theoretically and empirically how latent variable models may facilitate learning, planning, and exploration to improve the sample efficiency of RL. In this paper, we provide a representation view of the latent variable models for state-action value functions, which allows both tractable variational learning algorithm and effective implementation of the optimism/pessimism principle in the face of uncertainty for exploration. In particular, we propose a computationally efficient planning algorithm with UCB exploration by incorporating kernel embeddings of latent variable models. Theoretically, we establish the sample complexity of the proposed approach in the online and offline settings. Empirically, we demonstrate superior performance over current state-of-the-art algorithms across various benchmarks.
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Recently, webly supervised learning (WSL) has been studied to leverage numerous and accessible data from the Internet. Most existing methods focus on learning noise-robust models from web images while neglecting the performance drop caused by the differences between web domain and real-world domain. However, only by tackling the performance gap above can we fully exploit the practical value of web datasets. To this end, we propose a Few-shot guided Prototypical (FoPro) representation learning method, which only needs a few labeled examples from reality and can significantly improve the performance in the real-world domain. Specifically, we initialize each class center with few-shot real-world data as the ``realistic" prototype. Then, the intra-class distance between web instances and ``realistic" prototypes is narrowed by contrastive learning. Finally, we measure image-prototype distance with a learnable metric. Prototypes are polished by adjacent high-quality web images and involved in removing distant out-of-distribution samples. In experiments, FoPro is trained on web datasets with a few real-world examples guided and evaluated on real-world datasets. Our method achieves the state-of-the-art performance on three fine-grained datasets and two large-scale datasets. Compared with existing WSL methods under the same few-shot settings, FoPro still excels in real-world generalization. Code is available at https://github.com/yuleiqin/fopro.
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Learning fine-grained interplay between vision and language allows to a more accurate understanding for VisionLanguage tasks. However, it remains challenging to extract key image regions according to the texts for semantic alignments. Most existing works are either limited by textagnostic and redundant regions obtained with the frozen detectors, or failing to scale further due to its heavy reliance on scarce grounding (gold) data to pre-train detectors. To solve these problems, we propose Self-Locator Aided Network (SLAN) for cross-modal understanding tasks without any extra gold data. SLAN consists of a region filter and a region adaptor to localize regions of interest conditioned on different texts. By aggregating cross-modal information, the region filter selects key regions and the region adaptor updates their coordinates with text guidance. With detailed region-word alignments, SLAN can be easily generalized to many downstream tasks. It achieves fairly competitive results on five cross-modal understanding tasks (e.g., 85.7% and 69.2% on COCO image-to-text and text-to-image retrieval, surpassing previous SOTA methods). SLAN also demonstrates strong zero-shot and fine-tuned transferability to two localization tasks.
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由于字体之类的文本属性是文档格式和页面样式的核心设计元素,因此自动属性识别有利于全面的实用应用。现有方法在区分不同属性方面已经产生令人满意的性能,但是它们仍然在区分类似属性的情况下只有微妙的差异。此外,在现实世界中出现意外和明显的成像扭曲的现实情况下,他们的性能严重下降。在本文中,我们旨在通过提出炸玉米饼来解决这些问题,炸玉米饼是针对最常见文档场景量身定制的文本属性识别的对比框架。具体而言,炸玉米饼利用对比学习来消除由模糊和开放式属性引起的歧义陷阱。为了实现这一目标,我们从三个角度设计了学习范式:1)生成属性视图,2)提取微妙但至关重要的细节,以及3)利用有价值的视图对学习,以充分解锁预训练潜力。广泛的实验表明,Taco超过了受监督的对应物,并在多个属性识别任务上取得了最新的进步。将提供炸玉米饼的在线服务。
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表示学习通常通过管理维度的诅咒在加强学习中起关键作用。代表性的算法类别利用了随机过渡动力学的光谱分解,以构建在理想化环境中具有强大理论特性的表示。但是,当前的光谱方法的适用性有限,因为它们是用于仅国家的聚合并源自策略依赖性过渡内核的,而无需考虑勘探问题。为了解决这些问题,我们提出了一种替代光谱方法,光谱分解表示(SPEDER),该方法从动力学中提取了国家行动抽象而不诱导虚假依赖数据收集策略,同时还可以平衡探索访问权分析交易 - 在学习过程中关闭。理论分析确定了在线和离线设置中所提出的算法的样本效率。此外,一项实验研究表明,在几个基准测试中,比当前的最新算法表现出色。
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图像和语言建模对于视觉前训练(VLP)至关重要,该培训旨在从大规模配对的图像文本数据中学习多模式表示。但是,我们观察到,大多数现有的VLP方法着重于建模图像和文本特征之间的相互作用,同时忽略图像和文本之间的信息差异,从而遭受焦点偏见。为了解决这个问题,我们提出了一个视觉语言掩盖自动编码器框架(VLMAE)。VLMAE采用视觉生成学习,促进该模型获得细粒度和公正的特征。与以前的作品不同,Vlmae注意图像中几乎所有关键的补丁,提供了更全面的理解。广泛的实验表明,VLMAE在各种视觉语言下游任务中取得更好的性能,包括视觉问答,即使有20%的预训练速度,图像文本检索和视觉接地也是如此。
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基于文本的人检索旨在根据文本描述找到查询人员。关键是学习视觉文本模式之间的常见潜在空间映射。为了实现这一目标,现有的作品采用细分来获得明确的跨模式对齐方式或利用注意力来探索显着对准。这些方法有两个缺点:1)标记交叉模式比对很耗时。 2)注意方法可以探索显着的跨模式对齐,但可能会忽略一些微妙而有价值的对。为了缓解这些问题,我们为基于文本的人检索引入了一个隐式视觉文本(IVT)框架。与以前的模型不同,IVT利用单个网络来学习两种模式的表示形式,这有助于视觉文本相互作用。为了探索细粒的对准,我们进一步提出了两个隐式语义比对范式:多级比对(MLA)和双向掩码建模(BMM)。 MLA模块在句子,短语和单词级别上探索了更精细的匹配,而BMM模块旨在挖掘视觉和文本模态之间的\ textbf {更多}语义对齐。进行了广泛的实验,以评估公共数据集中提出的IVT,即Cuhk-Pedes,RSTPREID和ICFG-PEDES。即使没有明确的身体部位对准,我们的方法仍然可以达到最先进的表现。代码可在以下网址获得:https://github.com/tencentyouturesearch/personretrieval-ivt。
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从单眼图像中恢复纹理的3D网格是高度挑战的,尤其是对于缺乏3D地面真理的野外物体。在这项工作中,我们提出了网络文化,这是一个新的框架,可通过利用3D GAN预先训练的3D纹理网格合成的3D GAN的生成性先验。重建是通过在3D GAN中搜索最类似于目标网格的潜在空间来实现重建。由于预先训练的GAN以网状几何形状和纹理封装了丰富的3D语义,因此在GAN歧管内进行搜索,因此自然地使重建的真实性和忠诚度正常。重要的是,这种正则化直接应用于3D空间,从而提供了在2D空间中未观察到的网格零件的关键指导。标准基准测试的实验表明,我们的框架获得了忠实的3D重建,并在观察到的部分和未观察到的部分中都具有一致的几何形状和纹理。此外,它可以很好地推广到不太常见的网格中,例如可变形物体的扩展表达。代码在https://github.com/junzhezhang/mesh-inversion上发布
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通常通过利用低级别表示来解决马尔可夫决策过程(MDP)中维度的诅咒。这激发了有关线性MDP的最新理论研究。但是,大多数方法在不切实际的假设下对分解的归一化或在实践中引入未解决的计算挑战。相反,我们考虑了线性MDP的替代定义,该定义自动确保正常化,同时允许通过对比度估计进行有效的表示。该框架还承认了置信度调整的索引算法,从而使面对不确定性的乐观或悲观主义,使得有效而有原则的方法。据我们所知,这为线性MDP提供了第一种实用的表示学习方法,该方法既可以实现强大的理论保证和经验绩效。从理论上讲,我们证明所提出的算法在在线和离线设置中均有效。从经验上讲,我们在几个基准测试中表现出优于现有基于模型的现有模型和无模型算法的卓越性能。
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文档信息提取(DIE)由于其在现实世界中的各种高级应用而引起了越来越多的关注。尽管最近的文献已经取得了竞争成果,但在处理具有嘈杂的OCR结果或突变布局的复杂文档时,这些方法通常会失败。本文提出了用于现实世界情景的生成多模式网络(GMN),以解决这些问题,这是一种强大的多模式生成方法,没有预定义的标签类别。借助精心设计的空间编码器和模态感知的蒙版模块,GMN可以处理复杂的文档,这些文档很难序列化为顺序。此外,GMN可以容忍OCR结果中的错误,并且不需要字符级注释,这是至关重要的,因为对众多文档的细粒注释很费力,甚至需要具有专门域知识的注释者。广泛的实验表明,GMN在几个公共模具数据集上实现了新的最新性能,并超过了其他方法,尤其是在现实的场景中。
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