现有的基于匹配的方法通过从像素级内存中检索支持功能执行视频对象细分(VOS),而某些像素可能会遭受内存中缺乏对应关系(即看不见),这不可避免地限制了他们的细分性能。在本文中,我们提出了一个两流网络(TSN)。我们的TSN包含(i)带有常规像素级内存的像素流,以根据其像素级内存检索分割可见像素。 (ii)一个看不见的像素的实例流,其中对实例的整体理解是在动态分割头上以基于目标实例的特征进行条件的。 (iii)一个像素划分模块生成路由图,将两个流的输出嵌入在一起融合在一起。紧凑的实例流有效地提高了看不见的像素的分割精度,同时将两个流与自适应路由图融合在一起,导致整体性能提升。通过广泛的实验,我们证明了我们提出的TSN的有效性,并且还报告了2018年YouTube-VOS的最先进性能为86.1%,在Davis-2017验证案例中为87.5%。
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促性腺营养蛋白释放激素受体(GNRH1R)是治疗子宫疾病的有前途的治疗靶标。迄今为止,在临床研究中可以使用几个GNRH1R拮抗剂,而不满足多个财产约束。为了填补这一空白,我们旨在开发一个基于学习的框架,以促进有效,有效地发现具有理想特性的新的口服小型分子药物靶向GNRH1R。在目前的工作中,首先通过充分利用已知活性化合物和靶蛋白的结构的信息,首先提出了配体和结构组合模型,即LS-Molgen,首先提出了分子生成的方法,该信息通过其出色的性能证明了这一点。比分别基于配体或结构方法。然后,进行了A中的计算机筛选,包括活性预测,ADMET评估,分子对接和FEP计算,其中约30,000个生成的新型分子被缩小到8,以进行实验合成和验证。体外和体内实验表明,其中三个表现出有效的抑制活性(化合物5 IC50 = 0.856 nm,化合物6 IC50 = 0.901 nm,化合物7 IC50 = 2.54 nm对GNRH1R,并且化合物5在基本PK属性中表现良好例如半衰期,口服生物利用度和PPB等。我们认为,提议的配体和结构组合结合的分子生成模型和整个计算机辅助工作流程可能会扩展到从头开始的类似任务或铅优化的类似任务。
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Proteins are fundamental biological entities that play a key role in life activities. The amino acid sequences of proteins can be folded into stable 3D structures in the real physicochemical world, forming a special kind of sequence-structure data. With the development of Artificial Intelligence (AI) techniques, Protein Representation Learning (PRL) has recently emerged as a promising research topic for extracting informative knowledge from massive protein sequences or structures. To pave the way for AI researchers with little bioinformatics background, we present a timely and comprehensive review of PRL formulations and existing PRL methods from the perspective of model architectures, pretext tasks, and downstream applications. We first briefly introduce the motivations for protein representation learning and formulate it in a general and unified framework. Next, we divide existing PRL methods into three main categories: sequence-based, structure-based, and sequence-structure co-modeling. Finally, we discuss some technical challenges and potential directions for improving protein representation learning. The latest advances in PRL methods are summarized in a GitHub repository https://github.com/LirongWu/awesome-protein-representation-learning.
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Solving partial differential equations is difficult. Recently proposed neural resolution-invariant models, despite their effectiveness and efficiency, usually require equispaced spatial points of data. However, sampling in spatial domain is sometimes inevitably non-equispaced in real-world systems, limiting their applicability. In this paper, we propose a Non-equispaced Fourier PDE Solver (\textsc{NFS}) with adaptive interpolation on resampled equispaced points and a variant of Fourier Neural Operators as its components. Experimental results on complex PDEs demonstrate its advantages in accuracy and efficiency. Compared with the spatially-equispaced benchmark methods, it achieves superior performance with $42.85\%$ improvements on MAE, and is able to handle non-equispaced data with a tiny loss of accuracy. Besides, to our best knowledge, \textsc{NFS} is the first ML-based method with mesh invariant inference ability to successfully model turbulent flows in non-equispaced scenarios, with a minor deviation of the error on unseen spatial points.
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Recent years have witnessed great success in handling graph-related tasks with Graph Neural Networks (GNNs). Despite their great academic success, Multi-Layer Perceptrons (MLPs) remain the primary workhorse for practical industrial applications. One reason for this academic-industrial gap is the neighborhood-fetching latency incurred by data dependency in GNNs, which make it hard to deploy for latency-sensitive applications that require fast inference. Conversely, without involving any feature aggregation, MLPs have no data dependency and infer much faster than GNNs, but their performance is less competitive. Motivated by these complementary strengths and weaknesses, we propose a Graph Self-Distillation on Neighborhood (GSDN) framework to reduce the gap between GNNs and MLPs. Specifically, the GSDN framework is based purely on MLPs, where structural information is only implicitly used as prior to guide knowledge self-distillation between the neighborhood and the target, substituting the explicit neighborhood information propagation as in GNNs. As a result, GSDN enjoys the benefits of graph topology-awareness in training but has no data dependency in inference. Extensive experiments have shown that the performance of vanilla MLPs can be greatly improved with self-distillation, e.g., GSDN improves over stand-alone MLPs by 15.54\% on average and outperforms the state-of-the-art GNNs on six datasets. Regarding inference speed, GSDN infers 75X-89X faster than existing GNNs and 16X-25X faster than other inference acceleration methods.
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图边缘扰动致力于通过修改图形结构来损害图神经网络的预测。以前的灰色框攻击者采用替代模型的梯度来定位脆弱的边缘以扰动图形结构。但是,图形结构上的梯度存在不可靠性,这是先前工作很少研究的。在本文中,我们讨论并分析了由结构梯度的不可靠性引起的错误。这些误差是由于图形结构的离散性以及图形结构上元梯度的不可靠性引起的粗糙梯度使用。为了解决这些问题,我们提出了一种新的攻击模型,该模型采用减少结构梯度内部错误的方法。我们提出Edge离散抽样以选择与分层候选选择相关的边缘扰动,以确保计算效率。此外,提出了语义不变性和动量梯度集合,以解决语义增强图上的梯度波动以及替代模型的不稳定性。实验是在未靶向的灰色盒中毒场景中进行的,并证明了我们方法的性能的改善。
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时间点过程(TPP)通常用于模拟具有出现时间戳的异步事件序列,并由以历史影响为条件的概率模型揭示。尽管以前的许多作品通过最大程度地提高了TPP模型的“合适性”,但它们的预测性能不令人满意,这意味着模型产生的时间戳与真实的观察相距甚远。最近,诸如DENOTO扩散和得分匹配模型之类的深层生成模型通过证明其生成高质量样本的能力,在图像生成任务方面取得了巨大进展。但是,在事件发生在TPP的情况下,尚无完整而统一的作品来探索和研究生成模型的潜力。在这项工作中,我们尝试通过设计一个unified \ textbf {g} \ textbf {n} eural \ textbf {t} emporal \ emporal \ textbf {p} oint \ textbf {p} rocess {p} rocess(\ textsc {\ textsc { GNTPP})模型探索其可行性和有效性,并进一步改善模型的预测性能。此外,在衡量历史影响方面,我们修改了细心的模型,这些模型总结了历史事件的影响,并以适应性的重新加权术语来考虑事件的类型关系和时间间隔。已经进行了广泛的实验,以说明\ textsc {gntpp}的预测能力的提高,并用一系列生成概率解码器,并从修订后的注意力中获得了绩效增长。据我们所知,这是第一批适应生成模型在完整的统一框架中并在TPP背景下研究其有效性的作品。我们的代码库包括第5.1.1节中给出的所有方法。5.1.1在\ url {https://github.com/bird-tao/gntpp}中打开。我们希望代码框架可以促进神经TPP的未来研究。
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渗透是气候,物理,材料科学,流行病学,金融等重要主题。用机器学习方法预测渗透阈值仍然具有挑战性。在本文中,我们构建了一个强大的图形卷积神经网络,以监督和无监督的方式研究渗透。从监督的学习角度,图形卷积神经网络同时并正确训练不同晶格类型的数据,例如正方形和三角形晶格。对于无监督的视角,将图形卷积神经网络和混乱方法结合在一起,可以通过“ W”形性能获得渗透阈值。这项工作的发现打开了建立一个更通用的框架的可能性,该框架可以探究与渗透相关的现象。
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设计私人投票规则是值得信赖的民主的重要问题。在本文中,根据差异隐私的框架,我们根据知名的Condorcet方法提出了三类随机投票规则:Laplacian Condorcet方法($ cm^{lap} _ \ lambda $),指数condorcet方法($ cmcmential condorcet方法^{exp} _ \ lambda $)和随机响应condorcet方法($ cm^{rr} _ \ lambda $),其中$ \ lambda $代表噪声级别。通过准确估计随机性引入的错误,我们表明$ cm^{exp} _ \ lambda $是大多数情况下最准确的机制。我们证明,我们的所有规则都满足绝对单调性,Lexi参与,概率帕累托效率,近似概率孔孔标准和近似SD-StrategyProofness。此外,$ cm^{rr} _ \ lambda $满足(非适当的)概率condorcet标准,而$ cm^{lap} _ \ lambda $和$ cm^{exp} _ \ \ lambda _ 。最后,我们将差异隐私视为投票公理,并讨论其与其他公理的关系。
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我们可以将袖珍配体的相互作用知识注入预训练的模型并共同学习其化学空间吗?近年来,预处理的分子和蛋白质引起了很大的关注,而这些方法中的大多数都集中在学习一个化学空间,并且缺乏注射生物学知识。我们提出一个共同监督预告片(COSP)的框架,以同时学习3D口袋和配体表示。我们使用封闭式的几何消息传递层来对3D口袋和配体进行建模,其中每个节点的化学特征,几何位置和方向都被考虑。为了学习生物学有意义的嵌入,我们通过对比度损失将袖珍配体相互作用知识注入预处理模型。考虑到分子的特异性,我们进一步提出了化学相似性增强的负抽样策略,以提高对比度学习绩效。通过广泛的实验,我们得出的结论是,COSP可以在口袋匹配,分子属性预测和虚拟筛选中获得竞争成果。
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