Existing knowledge graph (KG) embedding models have primarily focused on static KGs. However, real-world KGs do not remain static, but rather evolve and grow in tandem with the development of KG applications. Consequently, new facts and previously unseen entities and relations continually emerge, necessitating an embedding model that can quickly learn and transfer new knowledge through growth. Motivated by this, we delve into an expanding field of KG embedding in this paper, i.e., lifelong KG embedding. We consider knowledge transfer and retention of the learning on growing snapshots of a KG without having to learn embeddings from scratch. The proposed model includes a masked KG autoencoder for embedding learning and update, with an embedding transfer strategy to inject the learned knowledge into the new entity and relation embeddings, and an embedding regularization method to avoid catastrophic forgetting. To investigate the impacts of different aspects of KG growth, we construct four datasets to evaluate the performance of lifelong KG embedding. Experimental results show that the proposed model outperforms the state-of-the-art inductive and lifelong embedding baselines.
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Transcranial temporal interference stimulation (tTIS) has been reported to be effective in stimulating deep brain structures in experimental studies. However, a computational framework for optimizing the tTIS strategy and simulating the impact of tTIS on the brain is still lacking, as previous methods rely on predefined parameters and hardly adapt to additional constraints. Here, we propose a general framework, namely multi-objective optimization via evolutionary algorithm (MOVEA), to solve the nonconvex optimization problem for various stimulation techniques, including tTIS and transcranial alternating current stimulation (tACS). By optimizing the electrode montage in a two-stage structure, MOVEA can be compatible with additional constraints (e.g., the number of electrodes, additional avoidance regions), and MOVEA can accelerate to obtain the Pareto fronts. These Pareto fronts consist of a set of optimal solutions under different requirements, suggesting a trade-off relationship between conflicting objectives, such as intensity and focality. Based on MOVEA, we make comprehensive comparisons between tACS and tTIS in terms of intensity, focality and maneuverability for targets of different depths. Our results show that although the tTIS can only obtain a relatively low maximum achievable electric field strength, for example, the maximum intensity of motor area under tTIS is 0.42V /m, while 0.51V /m under tACS, it helps improve the focality by reducing 60% activated volume outside the target. We further perform ANOVA on the stimulation results of eight subjects with tACS and tTIS. Despite the individual differences in head models, our results suggest that tACS has a greater intensity and tTIS has a higher focality. These findings provide guidance on the choice between tACS and tTIS and indicate a great potential in tTIS-based personalized neuromodulation. Code will be released soon.
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当系统中有某些未知术语和隐藏的物理机制时,基于第一原理的复杂物理系统的管理方程可能会非常具有挑战性。在这项工作中,我们采用深度学习体系结构来学习基于从完全动力学模型中获取的数据的等离子体系统的流体部分微分方程(PDE)。证明了学到的多臂流体PDE可以融合诸如Landau阻尼等动力学效应。基于学习的流体闭合,数据驱动的多音阶流体建模可以很好地再现从完全动力学模型中得出的所有物理量。Landau阻尼的计算阻尼率与完全动力学的模拟和线性理论一致。用于复杂物理系统的PDE的数据驱动的流体建模可以应用于改善流体闭合并降低全球系统多规模建模的计算成本。
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多年来,旨在从已知事实中推断出新结论的知识图(KGS)的推理主要集中在静态KG上。现实生活中知识的不断增长提出了使能够扩大KGS的归纳推理能力的必要性。现有的归纳工作假设新实体都在批处理中一次出现,这过度简化了新实体不断出现的实际情况。这项研究探讨了一个更现实,更具挑战性的环境,新实体分为多批次。我们提出了一个基于步行的归纳推理模型来解决新环境。具体而言,具有自适应关系聚合的图形卷积网络旨在使用其邻近关系编码和更新实体。为了捕捉不同的邻居的重要性,我们在聚合过程中采用了一种查询反馈注意机制。此外,为了减轻新实体的稀疏链接问题,我们提出了一种链接增强策略,以将可信赖的事实添加到KGS中。我们构建了三个新数据集,用于模拟此多批次出现方案。实验结果表明,我们所提出的模型优于基于最先进的基于嵌入的,基于步行的基于步行和基于规则的模型。
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问答(QA)系统越来越多地部署在支持现实世界决策的应用程序中。但是,最新的模型依赖于深层神经网络,这些网络很难被人类解释。固有的可解释模型或事后解释性方法可以帮助用户理解模型如何达到其预测,并在成功的情况下增加对系统的信任。此外,研究人员可以利用这些见解来开发更准确和偏见的新方法。在本文中,我们介绍了Square V2(Square的新版本),以根据图形和基于图形的说明等方法进行比较模型提供解释性基础架构。尽管显着图对于检查每个输入令牌对模型预测的重要性很有用,但来自外部知识图的基于图的解释使用户能够验证模型预测背后的推理。此外,我们提供了多种对抗性攻击,以比较质量检查模型的鲁棒性。通过这些解释性方法和对抗性攻击,我们旨在简化对可信赖的质量检查模型的研究。 Square可在https://square.ukp-lab.de上找到。
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实体对齐是知识图(kg)集成中的基本且至关重要的技术。多年来,对实体一致性的研究一直存在于KG是静态的假设,该假设忽略了现实世界KG的生长本质。随着KG的成长,先前的一致性结果面临需要重新审视的,而新实体对齐等待被发现。在本文中,我们建议并深入研究现实但未开发的设置,称为持续实体对齐。为了避免在新实体和三元组来时对整个KGS进行整个模型,我们为此任务提供了一种持续的对齐方法。它基于实体邻接,重建实体的表示,使其能够使用其现有邻居快速而有归纳的新实体生成嵌入。它选择并重播部分预先对准的实体对,仅训练一部分KG,同时提取可信赖的知识对准知识增强。由于不可避免地要包含与以前的作品不同的不可匹配的实体,因此所提出的方法采用双向最近的邻居匹配来找到新的实体对齐并更新旧的对齐。此外,我们还通过模拟多语言dbpedia的增长来构建新数据集。广泛的实验表明,我们的持续比对方法比基于再培训或归纳学习的基准更有效。
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与外部知识的接地对话系统是提高响应质量的一种有希望的方法。大多数现有的作品采用知识图(KGS)作为外部资源,关注对话的最后一句话中实体的贡献,以了解上下文理解和响应。然而,在多转变环境中隐含的知识与公斤关系之间的过渡规律之间的相关性是不足的。为此,我们提出了一个关系过渡意识知识的对话生成模型(RT-KGD)。具体而言,受到人类对话潜在逻辑的启发,我们的模型将对话级别的关系过渡规律与转向级实体语义信息相结合。以这种方式,知识之间的相互作用被认为是产生丰富的线索,以预测适当的知识并产生相干响应。自动评估和手动评估的实验结果表明,我们的模型表现优于最先进的基准。
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密集的检索方法可以克服词汇差距并导致显着改善的搜索结果。但是,它们需要大量的培训数据,这些数据不适用于大多数域。如前面的工作所示(Thakur等,2021b),密集检索的性能在域移位下严重降低。这限制了密集检索方法的使用,只有几个具有大型训练数据集的域。在本文中,我们提出了一种新颖的无监督域适配方法生成伪标签(GPL),其将查询发生器与来自跨编码器的伪标记相结合。在六种代表性域专用数据集中,我们发现所提出的GPL可以优于箱子外的最先进的密集检索方法,最高可达8.9点NDCG @ 10。 GPL需要来自目标域的少(未标记)数据,并且在其培训中比以前的方法更强大。我们进一步调查了六种最近训练方法在检索任务的域改编方案中的作用,其中只有三种可能会产生改善的结果。最好的方法,Tsdae(Wang等,2021)可以与GPL结合,在六个任务中产生了1.0点NDCG @ 10的另一个平均改善。
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Audio-visual approaches involving visual inputs have laid the foundation for recent progress in speech separation. However, the optimization of the concurrent usage of auditory and visual inputs is still an active research area. Inspired by the cortico-thalamo-cortical circuit, in which the sensory processing mechanisms of different modalities modulate one another via the non-lemniscal sensory thalamus, we propose a novel cortico-thalamo-cortical neural network (CTCNet) for audio-visual speech separation (AVSS). First, the CTCNet learns hierarchical auditory and visual representations in a bottom-up manner in separate auditory and visual subnetworks, mimicking the functions of the auditory and visual cortical areas. Then, inspired by the large number of connections between cortical regions and the thalamus, the model fuses the auditory and visual information in a thalamic subnetwork through top-down connections. Finally, the model transmits this fused information back to the auditory and visual subnetworks, and the above process is repeated several times. The results of experiments on three speech separation benchmark datasets show that CTCNet remarkably outperforms existing AVSS methods with considerablely fewer parameters. These results suggest that mimicking the anatomical connectome of the mammalian brain has great potential for advancing the development of deep neural networks. Project repo is https://github.com/JusperLee/CTCNet.
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深度神经网络和其他现代机器学习模型的培训通常包括解决高维且受大规模数据约束的非凸优化问题。在这里,基于动量的随机优化算法在近年来变得尤其流行。随机性来自数据亚采样,从而降低了计算成本。此外,动量和随机性都应该有助于算法克服当地的最小化器,并希望在全球范围内融合。从理论上讲,这种随机性和动量的结合被糟糕地理解。在这项工作中,我们建议并分析具有动量的随机梯度下降的连续时间模型。该模型是一个分段确定的马尔可夫过程,它通过阻尼不足的动态系统和通过动力学系统的随机切换来代表粒子运动。在我们的分析中,我们研究了长期限制,子采样到无填充采样极限以及动量到非摩托车的限制。我们对随着时间的推移降低动量的情况特别感兴趣:直觉上,动量有助于在算法的初始阶段克服局部最小值,但禁止后来快速收敛到全球最小化器。在凸度的假设下,当降低随时间的动量时,我们显示了动力学系统与全局最小化器的收敛性,并让子采样率转移到无穷大。然后,我们提出了一个稳定的,合成的离散方案,以从我们的连续时间动力学系统中构造算法。在数值实验中,我们研究了我们在凸面和非凸测试问题中的离散方案。此外,我们训练卷积神经网络解决CIFAR-10图像分类问题。在这里,与动量相比,我们的算法与随机梯度下降相比达到了竞争性结果。
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