犯罪预测问题的现有方法在表达细节时不成功,因为它们将概率值分配给大区域。本文介绍了一种具有图形卷积网络(GCN)和多变量高斯分布的新架构,以执行适用于任何时空数据的高分辨率预测。通过利用GCN的灵活结构并提供细分算法,我们以高分辨率在高分辨率下解决稀疏问题。我们用图形卷积门控经常性单位(Graph-concgru)构建我们的模型,以学习空间,时间和分类关系。在图形的每个节点中,我们学习来自GCN的提取特征的多变量概率分布。我们对现实生活和合成数据集进行实验,我们的模型获得了最佳验证和基线模型中的最佳测试分数,具有显着改进。我们表明我们的模型不仅是生成的,而且是精确的。
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对于电网操作,具有精细时间和空间分辨率的太阳能发电准确预测对于电网的操作至关重要。然而,与数值天气预报(NWP)结合机器学习的最先进方法具有粗略分辨率。在本文中,我们采用曲线图信号处理透视和型号的多网站光伏(PV)生产时间序列作为图表上的信号,以捕获它们的时空依赖性并实现更高的空间和时间分辨率预测。我们提出了两种新颖的图形神经网络模型,用于确定性多站点PV预测,被称为图形 - 卷积的长期内存(GCLSTM)和图形 - 卷积变压器(GCTRAFO)模型。这些方法仅依赖于生产数据并利用PV系统提供密集的虚拟气象站网络的直觉。所提出的方法是在整整一年的两组数据集中评估:1)来自304个真实光伏系统的生产数据,以及2)模拟生产1000个PV系统,包括瑞士分布。该拟议的模型优于最先进的多站点预测方法,用于预测前方6小时的预测视野。此外,所提出的模型以NWP优于最先进的单站点方法,如前方的视野上的输入。
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接触犯罪和暴力会损害个人的生活质量和社区的经济增长。鉴于机器学习的迅速发展,需要探索自动解决方案以防止犯罪。随着细粒度的城市和公共服务数据的可用性越来越多,最近融合了这种跨域信息以促进犯罪预测的激增。通过捕获有关社会结构,环境和犯罪趋势的信息,现有的机器学习预测模型从不同观点探索了动态犯罪模式。但是,这些方法主要将这种多源知识转换为隐性和潜在表示(例如,学区的嵌入),这仍然是研究显式因素对幕后犯罪发生的影响的影响仍然是一个挑战。在本文中,我们提出了一个时空的元数据指导性犯罪预测(STMEC)框架,以捕获犯罪行为的动态模式,并明确地表征了环境和社会因素如何相互互动以产生预测。广泛的实验表明,与其他先进的时空模型相比,STMEC的优越性,尤其是在预测重罪(例如使用危险武器的抢劫和袭击)时。
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Modeling multivariate time series has long been a subject that has attracted researchers from a diverse range of fields including economics, finance, and traffic. A basic assumption behind multivariate time series forecasting is that its variables depend on one another but, upon looking closely, it's fair to say that existing methods fail to fully exploit latent spatial dependencies between pairs of variables. In recent years, meanwhile, graph neural networks (GNNs) have shown high capability in handling relational dependencies. GNNs require well-defined graph structures for information propagation which means they cannot be applied directly for multivariate time series where the dependencies are not known in advance. In this paper, we propose a general graph neural network framework designed specifically for multivariate time series data. Our approach automatically extracts the uni-directed relations among variables through a graph learning module, into which external knowledge like variable attributes can be easily integrated. A novel mix-hop propagation layer and a dilated inception layer are further proposed to capture the spatial and temporal dependencies within the time series. The graph learning, graph convolution, and temporal convolution modules are jointly learned in an end-to-end framework. Experimental results show that our proposed model outperforms the state-of-the-art baseline methods on 3 of 4 benchmark datasets and achieves on-par performance with other approaches on two traffic datasets which provide extra structural information. CCS CONCEPTS• Computing methodologies → Neural networks; Artificial intelligence.
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建模传染病传播的时空性质可以提供有用的直觉,以了解疾病传播的时变方面,并且在人们的行动模式中观察到的潜在的复杂空间依赖性。此外,可以利用县级多相关时间序列信息,以便在单个时间序列进行预测。添加到这一挑战是实时数据常常偏离单向高斯分布假设,并且可以显示一些复杂的混合模式。由此激励,我们开发了一种基于深度学习的时间序列模型,用于自动回归混合密度动态扩散网络(ARM3DNet)的概率预测,其认为人们的移动性和疾病在动态定向图上传播。实现高斯混合模型层以考虑从多个相关时间序列学习的实时数据的多模式性质。我们展示了我们的模型,当由于动态协变量特征和混合成分的最佳组合培训时,可以超越传统的统计和深度学习模式,以预测美国县级的Covid-19死亡和案例的数量。
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近年来,图形神经网络(GNN)与复发性神经网络(RNN)的变体相结合,在时空预测任务中达到了最先进的性能。对于流量预测,GNN模型使用道路网络的图形结构来解释链接和节点之间的空间相关性。最近的解决方案要么基于复杂的图形操作或避免预定义的图。本文提出了一种新的序列结构,以使用具有稀疏体系结构的GNN-RNN细胞在多个抽象的抽象上提取时空相关性,以减少训练时间与更复杂的设计相比。通过多个编码器编码相同的输入序列,并随着编码层的增量增加,使网络能够通过多级抽象来学习一般和详细的信息。我们进一步介绍了来自加拿大蒙特利尔的街道细分市场流量数据的新基准数据集。与高速公路不同,城市路段是循环的,其特征是复杂的空间依赖性。与基线方法相比,一小时预测的实验结果和我们的MSLTD街道级段数据集对我们的模型提高了7%以上,同时将计算资源要求提高了一半以上竞争方法。
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Deep learning has revolutionized many machine learning tasks in recent years, ranging from image classification and video processing to speech recognition and natural language understanding. The data in these tasks are typically represented in the Euclidean space. However, there is an increasing number of applications where data are generated from non-Euclidean domains and are represented as graphs with complex relationships and interdependency between objects. The complexity of graph data has imposed significant challenges on existing machine learning algorithms. Recently, many studies on extending deep learning approaches for graph data have emerged. In this survey, we provide a comprehensive overview of graph neural networks (GNNs) in data mining and machine learning fields. We propose a new taxonomy to divide the state-of-the-art graph neural networks into four categories, namely recurrent graph neural networks, convolutional graph neural networks, graph autoencoders, and spatial-temporal graph neural networks. We further discuss the applications of graph neural networks across various domains and summarize the open source codes, benchmark data sets, and model evaluation of graph neural networks. Finally, we propose potential research directions in this rapidly growing field.
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准确性和可解释性是犯罪预测模型的两个基本属性。由于犯罪可能对人类生命,经济和安全的不利影响,我们需要一个可以尽可能准确地预测未来犯罪的模型,以便可以采取早期步骤来避免犯罪。另一方面,可解释的模型揭示了模型预测背后的原因,确保其透明度并允许我们相应地规划预防犯罪步骤。开发模型的关键挑战是捕获特定犯罪类别的非线性空间依赖和时间模式,同时保持模型的底层结构可解释。在本文中,我们开发AIST,一种用于犯罪预测的注意力的可解释的时空时间网络。基于过去的犯罪发生,外部特征(例如,流量流量和兴趣点(POI)信息)和犯罪趋势,AICT模拟了犯罪类别的动态时空相关性。广泛的实验在使用真实数据集的准确性和解释性方面表现出我们模型的优越性。
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人口级社会事件,如民事骚乱和犯罪,往往对我们的日常生活产生重大影响。预测此类事件对于决策和资源分配非常重要。由于缺乏关于事件发生的真实原因和潜在机制的知识,事件预测传统上具有挑战性。近年来,由于两个主要原因,研究事件预测研究取得了重大进展:(1)机器学习和深度学习算法的开发和(2)社交媒体,新闻来源,博客,经济等公共数据的可访问性指标和其他元数据源。软件/硬件技术中的数据的爆炸性增长导致了社会事件研究中的深度学习技巧的应用。本文致力于提供社会事件预测的深层学习技术的系统和全面概述。我们专注于两个社会事件的域名:\ Texit {Civil unrest}和\ texit {犯罪}。我们首先介绍事件预测问题如何作为机器学习预测任务制定。然后,我们总结了这些问题的数据资源,传统方法和最近的深度学习模型的发展。最后,我们讨论了社会事件预测中的挑战,并提出了一些有希望的未来研究方向。
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Reliable forecasting of traffic flow requires efficient modeling of traffic data. Different correlations and influences arise in a dynamic traffic network, making modeling a complicated task. Existing literature has proposed many different methods to capture the complex underlying spatial-temporal relations of traffic networks. However, methods still struggle to capture different local and global dependencies of long-range nature. Also, as more and more sophisticated methods are being proposed, models are increasingly becoming memory-heavy and, thus, unsuitable for low-powered devices. In this paper, we focus on solving these problems by proposing a novel deep learning framework - STLGRU. Specifically, our proposed STLGRU can effectively capture both local and global spatial-temporal relations of a traffic network using memory-augmented attention and gating mechanism. Instead of employing separate temporal and spatial components, we show that our memory module and gated unit can learn the spatial-temporal dependencies successfully, allowing for reduced memory usage with fewer parameters. We extensively experiment on several real-world traffic prediction datasets to show that our model performs better than existing methods while the memory footprint remains lower. Code is available at \url{https://github.com/Kishor-Bhaumik/STLGRU}.
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Spatiotemporal forecasting has various applications in neuroscience, climate and transportation domain. Traffic forecasting is one canonical example of such learning task. The task is challenging due to (1) complex spatial dependency on road networks, (2) non-linear temporal dynamics with changing road conditions and (3) inherent difficulty of long-term forecasting. To address these challenges, we propose to model the traffic flow as a diffusion process on a directed graph and introduce Diffusion Convolutional Recurrent Neural Network (DCRNN), a deep learning framework for traffic forecasting that incorporates both spatial and temporal dependency in the traffic flow. Specifically, DCRNN captures the spatial dependency using bidirectional random walks on the graph, and the temporal dependency using the encoder-decoder architecture with scheduled sampling. We evaluate the framework on two real-world large scale road network traffic datasets and observe consistent improvement of 12% -15% over state-of-the-art baselines.
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最近的研究侧重于制定流量预测作为一种时空图形建模问题。它们通常在每个时间步骤构造静态空间图,然后将每个节点连接在相邻时间步骤之间以构造时空图形。在这样的图形中,不同时间步骤的不同节点之间的相关性未明确地反映,这可以限制图形神经网络的学习能力。同时,这些模型在不同时间步骤中使用相同的邻接矩阵时,忽略节点之间的动态时空相关性。为了克服这些限制,我们提出了一种时空关节图卷积网络(StJGCN),用于交通预测在公路网络上的几个时间上限。具体地,我们在任何两个时间步长之间构造预定的和自适应时空关节图(STJG),这代表了全面和动态的时空相关性。我们进一步设计了STJG上的扩张因果时空关节图卷积层,以捕获与多个范围不同的视角的时空依赖关系。提出了一种多范围注意机制来聚合不同范围的信息。四个公共交通数据集的实验表明,STJGCN是计算的高效和优于11个最先进的基线方法。
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多变量时间序列(MTS)预测在许多智能应用中引起了很多关注。它不是一个琐碎的任务,因为我们需要考虑一个可变的依赖关系和可变间依赖关系。但是,现有的作品是针对特定场景设计的,需要很多域知识和专家努力,这难以在不同的场景之间传输。在本文中,我们提出了一种尺度意识的神经结构,用于MTS预测(SNAS4MTF)的搜索框架。多尺度分解模块将原始时间序列转换为多尺度子系列,可以保留多尺度的时间模式。自适应图形学习模块在没有任何先前知识的情况下,在不同的时间尺度下递送不同的变量间依赖关系。对于MTS预测,搜索空间旨在在每次尺度上捕获可变的可变依赖性和可变间依赖关系。在端到端框架中共同学习多尺度分解,自适应图学习和神经架构搜索模块。两个现实世界数据集的大量实验表明,与最先进的方法相比,SNAS4MTF实现了有希望的性能。
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我们研究了具有动态,可能的周期性的流量的预测问题和区域之间的关节空间依赖关系。鉴于从时隙0到T-1的城市中区的聚合流入和流出流量,我们预测了任何区域的时间t的流量。该地区的现有技术通常以脱钩的方式考虑空间和时间依赖性,或者在具有大量超参数曲调的训练中是相当的计算密集。我们提出了ST-TIS,一种新颖,轻巧和准确的空间变压器,具有信息融合和区域采样进行交通预测。 ST-TIS将规范变压器与信息融合和区域采样延伸。信息融合模块捕获区域之间的复杂空间依赖关系。该区域采样模块是提高效率和预测精度,将计算复杂性切割为依赖性学习从$ O(n ^ 2)$到$ O(n \ sqrt {n})$,其中n是区域的数量。比最先进的模型的参数较少,我们模型的离线培训在调整和计算方面明显更快(培训时间和网络参数减少高达90±90 \%)。尽管存在这种培训效率,但大量实验表明,ST-TIS在网上预测中大幅度更准确,而不是最先进的方法(平均改善高达11 \%$ 11 \%$ ON MAPE上的$ 14 \%$ 14 \%$ 14 \%$ ON MAPE) 。
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本文旨在统一非欧几里得空间中的空间依赖性和时间依赖性,同时捕获流量数据的内部空间依赖性。对于具有拓扑结构的时空属性实体,时空是连续的和统一的,而每个节点的当前状态都受到每个邻居的变异时期的邻居的过去状态的影响。大多数用于流量预测研究的空间依赖性和时间相关性的空间神经网络在处理中分别损害了时空完整性,而忽略了邻居节点的时间依赖期可以延迟和动态的事实。为了建模这种实际条件,我们提出了一种新型的空间 - 周期性图神经网络,将空间和时间视为不可分割的整体,以挖掘时空图,同时通过消息传播机制利用每个节点的发展时空依赖性。进行消融和参数研究的实验已经验证了拟议的遍及术的有效性,并且可以从https://github.com/nnzhan/traversenet中找到详细的实现。
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Time series anomaly detection has applications in a wide range of research fields and applications, including manufacturing and healthcare. The presence of anomalies can indicate novel or unexpected events, such as production faults, system defects, or heart fluttering, and is therefore of particular interest. The large size and complex patterns of time series have led researchers to develop specialised deep learning models for detecting anomalous patterns. This survey focuses on providing structured and comprehensive state-of-the-art time series anomaly detection models through the use of deep learning. It providing a taxonomy based on the factors that divide anomaly detection models into different categories. Aside from describing the basic anomaly detection technique for each category, the advantages and limitations are also discussed. Furthermore, this study includes examples of deep anomaly detection in time series across various application domains in recent years. It finally summarises open issues in research and challenges faced while adopting deep anomaly detection models.
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流量预测是智能交通系统中时空学习任务的规范示例。现有方法在图形卷积神经操作员中使用预定的矩阵捕获空间依赖性。但是,显式的图形结构损失了节点之间关系的一些隐藏表示形式。此外,传统的图形卷积神经操作员无法在图上汇总远程节点。为了克服这些限制,我们提出了一个新型的网络,空间 - 周期性自适应图卷积,并通过注意力网络(Staan)进行交通预测。首先,我们采用自适应依赖性矩阵,而不是在GCN处理过程中使用预定义的矩阵来推断节点之间的相互依存关系。其次,我们集成了基于图形注意力网络的PW注意,该图形是为全局依赖性设计的,而GCN作为空间块。更重要的是,在我们的时间块中采用了堆叠的散布的1D卷积,具有长期预测的效率,用于捕获不同的时间序列。我们在两个现实世界数据集上评估了我们的Staan,并且实验验证了我们的模型优于最先进的基线。
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Graph classification is an important area in both modern research and industry. Multiple applications, especially in chemistry and novel drug discovery, encourage rapid development of machine learning models in this area. To keep up with the pace of new research, proper experimental design, fair evaluation, and independent benchmarks are essential. Design of strong baselines is an indispensable element of such works. In this thesis, we explore multiple approaches to graph classification. We focus on Graph Neural Networks (GNNs), which emerged as a de facto standard deep learning technique for graph representation learning. Classical approaches, such as graph descriptors and molecular fingerprints, are also addressed. We design fair evaluation experimental protocol and choose proper datasets collection. This allows us to perform numerous experiments and rigorously analyze modern approaches. We arrive to many conclusions, which shed new light on performance and quality of novel algorithms. We investigate application of Jumping Knowledge GNN architecture to graph classification, which proves to be an efficient tool for improving base graph neural network architectures. Multiple improvements to baseline models are also proposed and experimentally verified, which constitutes an important contribution to the field of fair model comparison.
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基于预测方法的深度学习已成为时间序列预测或预测的许多应用中的首选方法,通常通常优于其他方法。因此,在过去的几年中,这些方法现在在大规模的工业预测应用中无处不在,并且一直在预测竞赛(例如M4和M5)中排名最佳。这种实践上的成功进一步提高了学术兴趣,以理解和改善深厚的预测方法。在本文中,我们提供了该领域的介绍和概述:我们为深入预测的重要构建块提出了一定深度的深入预测;随后,我们使用这些构建块,调查了最近的深度预测文献的广度。
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Deep learning approaches for spatio-temporal prediction problems such as crowd-flow prediction assumes data to be of fixed and regular shaped tensor and face challenges of handling irregular, sparse data tensor. This poses limitations in use-case scenarios such as predicting visit counts of individuals' for a given spatial area at a particular temporal resolution using raster/image format representation of the geographical region, since the movement patterns of an individual can be largely restricted and localized to a certain part of the raster. Additionally, current deep-learning approaches for solving such problem doesn't account for the geographical awareness of a region while modelling the spatio-temporal movement patterns of an individual. To address these limitations, there is a need to develop a novel strategy and modeling approach that can handle both sparse, irregular data while incorporating geo-awareness in the model. In this paper, we make use of quadtree as the data structure for representing the image and introduce a novel geo-aware enabled deep learning layer, GA-ConvLSTM that performs the convolution operation based on a novel geo-aware module based on quadtree data structure for incorporating spatial dependencies while maintaining the recurrent mechanism for accounting for temporal dependencies. We present this approach in the context of the problem of predicting spatial behaviors of an individual (e.g., frequent visits to specific locations) through deep-learning based predictive model, GADST-Predict. Experimental results on two GPS based trace data shows that the proposed method is effective in handling frequency visits over different use-cases with considerable high accuracy.
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