Traffic forecasting is an important application of spatiotemporal series prediction. Among different methods, graph neural networks have achieved so far the most promising results, learning relations between graph nodes then becomes a crucial task. However, improvement space is very limited when these relations are learned in a node-to-node manner. The challenge stems from (1) obscure temporal dependencies between different stations, (2) difficulties in defining variables beyond the node level, and (3) no ready-made method to validate the learned relations. To confront these challenges, we define legitimate traffic causal variables to discover the causal relation inside the traffic network, which is carefully checked with statistic tools and case analysis. We then present a novel model named Graph Spatial-Temporal Network Based on Causal Insight (GT-CausIn), where prior learned causal information is integrated with graph diffusion layers and temporal convolutional network (TCN) layers. Experiments are carried out on two real-world traffic datasets: PEMS-BAY and METR-LA, which show that GT-CausIn significantly outperforms the state-of-the-art models on mid-term and long-term prediction.
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如今,基础模型已成为人工智能中的基本基础设施之一,铺平了通往通用情报的方式。但是,现实提出了两个紧急挑战:现有的基础模型由英语社区主导;用户通常会获得有限的资源,因此不能总是使用基础模型。为了支持中文社区的发展,我们介绍了一个名为Fengshenbang的开源项目,该项目由认知计算与自然语言研究中心(CCNL)领导。我们的项目具有全面的功能,包括大型预培训模型,用户友好的API,基准,数据集等。我们将所有这些都包装在三个子项目中:风水次模型,风水框架和狂热基准。 Fengshenbang的开源路线图旨在重新评估中国预培训的大型大型模型的开源社区,促使整个中国大型模型社区的发展。我们还希望构建一个以用户为中心的开源生态系统,以允许个人访问所需的模型以匹配其计算资源。此外,我们邀请公司,大学和研究机构与我们合作建立大型开源模型的生态系统。我们希望这个项目将成为中国认知情报的基础。
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给定标签噪声的数据(即数据不正确),深神经网络将逐渐记住标签噪声和损害模型性能。为了减轻此问题,提出了课程学习,以通过在有意义的(例如,易于硬)序列中订购培训样本来提高模型性能和概括。先前的工作将错误的样本作为通用的硬性样本,而无需区分硬样品(即正确数据中的硬样品)和不正确的样本。确实,模型应该从硬样本中学习,以促进概括而不是过度拟合错误。在本文中,我们通过在现有的任务损失之外附加新颖的损失函数Indimloss来解决此问题。它的主要影响是在训练的早期阶段自动,稳定地估计简易样品和困难样本(包括硬和不正确的样品)的重要性,以改善模型性能。然后,在以下阶段中,歧视专门用于区分硬性和不正确样本以改善模型的概括。这种培训策略可以以自我监督的方式动态制定,从而有效地模仿课程学习的主要原则。关于图像分类,图像回归,文本序列回归和事件关系推理的实验证明了我们方法的多功能性和有效性,尤其是在存在多样化的噪声水平的情况下。
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自然语言理解(NLU)模型倾向于依靠虚假的相关性(即数据集偏见)来在分布数据集上实现高性能,但在分布外部的数据集中的性能差。大多数现有的偏见方法通常都以偏见的特征(即引起这种虚假相关性的表面特征)来识别和削弱这些样品。但是,下降加权这些样品阻碍了从这些样品的无偏见部分学习的模型。为了应对这一挑战,在本文中,我们建议从特征空间的角度以细粒度的方式消除虚假的相关性。具体而言,我们引入了随机傅立叶特征和加权重采样,以将功能之间的依赖关系解释以减轻虚假相关性。在获得非相关的功能后,我们进一步设计了一种基于相互信息的方法来净化它们,这迫使模型学习与任务更相关的功能。对两个经过良好研究的NLU任务进行的广泛实验表明,我们的方法优于其他比较方法。
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最近,通过深度学习框架提取动态系统的数据驱动法则在各个领域都引起了很多关注。此外,越来越多的研究工作倾向于将确定性动力学系统转移到随机动力学系统上,尤其是由非高斯乘法噪声驱动的系统。但是,对于高斯病例,许多基于原木样式的算法不能直接扩展到非高斯场景,这些场景可能存在很高的错误和低收敛问题。在这项工作中,我们克服了其中的一些挑战,并确定由$ \ alpha $稳定的l \'evy噪声驱动的随机动力系统,仅来自随机的成对数据。我们的创新包括:(1)设计一种深度学习方法,以学习l \'evy诱发的噪声的漂移和扩散系数,并在所有值中使用$ \ alpha $,(2)学习复杂的乘法噪声,而无需限制小噪声强度,(( 3)在一般输入数据假设下,即随机系统识别的端到端完整框架,即$ \ alpha $稳定的随机变量。最后,数值实验和与非本地KRAMERS-MOYAL公式与力矩生成功能的比较证实了我们方法的有效性。
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随着现代深层学习技术的快速发展,动态系统和神经网络的研究越来越多地利用了很多不同的方式。由于在现实世界观察中经常出现不确定性,因此SDES(随机微分方程)来发挥重要作用。更具体地,在本文中,我们使用配备神经网络的SDE集合来预测具有大跳跃性能和高概率分布偏移的嘈杂时间序列的长期趋势。我们的贡献是,首先,我们使用相位空间重建方法来提取时间序列数据的内在尺寸,以确定我们预测模型的输入结构。其次,我们探索由$ \ alpha $ -stable l \'evy motion驱动的SDE来模拟时间序列数据,通过神经网络近似来解决问题。第三,我们构建了达到多时间步长预测的注意机制。最后,我们通过将其应用于股票营销时间序列预测并显示结果优于几个基线深度学习模型来说明我们的方法。
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Pretraining is a dominant paradigm in computer vision. Generally, supervised ImageNet pretraining is commonly used to initialize the backbones of person re-identification (Re-ID) models. However, recent works show a surprising result that CNN-based pretraining on ImageNet has limited impacts on Re-ID system due to the large domain gap between ImageNet and person Re-ID data. To seek an alternative to traditional pretraining, here we investigate semantic-based pretraining as another method to utilize additional textual data against ImageNet pretraining. Specifically, we manually construct a diversified FineGPR-C caption dataset for the first time on person Re-ID events. Based on it, a pure semantic-based pretraining approach named VTBR is proposed to adopt dense captions to learn visual representations with fewer images. We train convolutional neural networks from scratch on the captions of FineGPR-C dataset, and then transfer them to downstream Re-ID tasks. Comprehensive experiments conducted on benchmark datasets show that our VTBR can achieve competitive performance compared with ImageNet pretraining - despite using up to 1.4x fewer images, revealing its potential in Re-ID pretraining.
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In this paper, we study the problem of knowledge-intensive text-to-SQL, in which domain knowledge is necessary to parse expert questions into SQL queries over domain-specific tables. We formalize this scenario by building a new Chinese benchmark KnowSQL consisting of domain-specific questions covering various domains. We then address this problem by presenting formulaic knowledge, rather than by annotating additional data examples. More concretely, we construct a formulaic knowledge bank as a domain knowledge base and propose a framework (ReGrouP) to leverage this formulaic knowledge during parsing. Experiments using ReGrouP demonstrate a significant 28.2% improvement overall on KnowSQL.
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Weakly-supervised object localization aims to indicate the category as well as the scope of an object in an image given only the image-level labels. Most of the existing works are based on Class Activation Mapping (CAM) and endeavor to enlarge the discriminative area inside the activation map to perceive the whole object, yet ignore the co-occurrence confounder of the object and context (e.g., fish and water), which makes the model inspection hard to distinguish object boundaries. Besides, the use of CAM also brings a dilemma problem that the classification and localization always suffer from a performance gap and can not reach their highest accuracy simultaneously. In this paper, we propose a casual knowledge distillation method, dubbed KD-CI-CAM, to address these two under-explored issues in one go. More specifically, we tackle the co-occurrence context confounder problem via causal intervention (CI), which explores the causalities among image features, contexts, and categories to eliminate the biased object-context entanglement in the class activation maps. Based on the de-biased object feature, we additionally propose a multi-teacher causal distillation framework to balance the absorption of classification knowledge and localization knowledge during model training. Extensive experiments on several benchmarks demonstrate the effectiveness of KD-CI-CAM in learning clear object boundaries from confounding contexts and addressing the dilemma problem between classification and localization performance.
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Dynamic treatment regimes assign personalized treatments to patients sequentially over time based on their baseline information and time-varying covariates. In mobile health applications, these covariates are typically collected at different frequencies over a long time horizon. In this paper, we propose a deep spectral Q-learning algorithm, which integrates principal component analysis (PCA) with deep Q-learning to handle the mixed frequency data. In theory, we prove that the mean return under the estimated optimal policy converges to that under the optimal one and establish its rate of convergence. The usefulness of our proposal is further illustrated via simulations and an application to a diabetes dataset.
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