在更广泛的地球科学中对人工智能模型的常见需求是表示和编码各种类型的空间数据，例如点（例如，兴趣点），折线（例如，轨迹），多边形（例如，行政区域），图（例如，运输网络）或栅格（例如，遥感图像），隐藏的嵌入空间中，使得它们可以容易地结合到深度学习模型中。一个基本步骤是将单个点位置编码为嵌入空间，使得该嵌入对下游机器学习模型（例如支持向量机和神经网络）进行学习友好。我们调用此过程位置编码。但是，对位置编码的概念，其潜在应用以及需要解决的关键挑战缺乏系统审查。本文旨在填补这一差距。我们首先提供了一个正式的编码定义，并讨论了从机器学习角度从机械研究编码的必要性。接下来，我们提供关于当前地点景观研究的全面调查和讨论。我们根据其输入和编码方法将位置编码模型分类为不同类别，并基于它们是参数，多尺度，距离保存和方向意识的方式进行比较。我们证明现有的位置编码模型可以在共享配方框架下统一。我们还讨论了不同类型的空间数据的位置编码的应用。最后，我们指出了在未来需要解决的研究中的几个挑战。

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.

Point cloud learning has lately attracted increasing attention due to its wide applications in many areas, such as computer vision, autonomous driving, and robotics. As a dominating technique in AI, deep learning has been successfully used to solve various 2D vision problems. However, deep learning on point clouds is still in its infancy due to the unique challenges faced by the processing of point clouds with deep neural networks. Recently, deep learning on point clouds has become even thriving, with numerous methods being proposed to address different problems in this area. To stimulate future research, this paper presents a comprehensive review of recent progress in deep learning methods for point clouds. It covers three major tasks, including 3D shape classification, 3D object detection and tracking, and 3D point cloud segmentation. It also presents comparative results on several publicly available datasets, together with insightful observations and inspiring future research directions.

Pre-publication draft of a book to be published byMorgan & Claypool publishers. Unedited version released with permission. All relevant copyrights held by the author and publisher extend to this pre-publication draft.

Deep learning has been shown to be successful in a number of domains, ranging from acoustics, images, to natural language processing. However, applying deep learning to the ubiquitous graph data is non-trivial because of the unique characteristics of graphs. Recently, substantial research efforts have been devoted to applying deep learning methods to graphs, resulting in beneficial advances in graph analysis techniques. In this survey, we comprehensively review the different types of deep learning methods on graphs. We divide the existing methods into five categories based on their model architectures and training strategies: graph recurrent neural networks, graph convolutional networks, graph autoencoders, graph reinforcement learning, and graph adversarial methods. We then provide a comprehensive overview of these methods in a systematic manner mainly by following their development history. We also analyze the differences and compositions of different methods. Finally, we briefly outline the applications in which they have been used and discuss potential future research directions.

Point cloud completion is a generation and estimation issue derived from the partial point clouds, which plays a vital role in the applications in 3D computer vision. The progress of deep learning (DL) has impressively improved the capability and robustness of point cloud completion. However, the quality of completed point clouds is still needed to be further enhanced to meet the practical utilization. Therefore, this work aims to conduct a comprehensive survey on various methods, including point-based, convolution-based, graph-based, and generative model-based approaches, etc. And this survey summarizes the comparisons among these methods to provoke further research insights. Besides, this review sums up the commonly used datasets and illustrates the applications of point cloud completion. Eventually, we also discussed possible research trends in this promptly expanding field.

人类自然有效地在复杂的场景中找到突出区域。通过这种观察的动机，引入了计算机视觉中的注意力机制，目的是模仿人类视觉系统的这一方面。这种注意机制可以基于输入图像的特征被视为动态权重调整过程。注意机制在许多视觉任务中取得了巨大的成功，包括图像分类，对象检测，语义分割，视频理解，图像生成，3D视觉，多模态任务和自我监督的学习。在本调查中，我们对计算机愿景中的各种关注机制进行了全面的审查，并根据渠道注意，空间关注，暂时关注和分支注意力进行分类。相关的存储库https：//github.com/menghaoguo/awesome-vision-tions致力于收集相关的工作。我们还建议了未来的注意机制研究方向。

图表是一个宇宙数据结构，广泛用于组织现实世界中的数据。像交通网络，社交和学术网络这样的各种实际网络网络可以由图表代表。近年来，目睹了在网络中代表顶点的快速发展，进入低维矢量空间，称为网络表示学习。表示学习可以促进图形数据上的新算法的设计。在本调查中，我们对网络代表学习的当前文献进行了全面审查。现有算法可以分为三组：浅埋模型，异构网络嵌入模型，图形神经网络的模型。我们为每个类别审查最先进的算法，并讨论这些算法之间的基本差异。调查的一个优点是，我们系统地研究了不同类别的算法底层的理论基础，这提供了深入的见解，以更好地了解网络表示学习领域的发展。

图表神经网络（GNNS）最近在人工智能（AI）领域的普及，这是由于它们作为输入数据相对非结构化数据类型的独特能力。尽管GNN架构的一些元素在概念上类似于传统神经网络（以及神经网络变体）的操作中，但是其他元件代表了传统深度学习技术的偏离。本教程通过整理和呈现有关GNN最常见和性能变种的动机，概念，数学和应用的细节，将GNN的权力和新颖性暴露给AI从业者。重要的是，我们简明扼要地向实际示例提出了本教程，从而为GNN的主题提供了实用和可访问的教程。

在过去十年中，图形内核引起了很多关注，并在结构化数据上发展成为一种快速发展的学习分支。在过去的20年中，该领域发生的相当大的研究活动导致开发数十个图形内核，每个图形内核都对焦于图形的特定结构性质。图形内核已成功地成功地在广泛的域中，从社交网络到生物信息学。本调查的目标是提供图形内核的文献的统一视图。特别是，我们概述了各种图形内核。此外，我们对公共数据集的几个内核进行了实验评估，并提供了比较研究。最后，我们讨论图形内核的关键应用，并概述了一些仍有待解决的挑战。

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。

Machine learning on graphs is an important and ubiquitous task with applications ranging from drug design to friendship recommendation in social networks. The primary challenge in this domain is finding a way to represent, or encode, graph structure so that it can be easily exploited by machine learning models. Traditionally, machine learning approaches relied on user-defined heuristics to extract features encoding structural information about a graph (e.g., degree statistics or kernel functions). However, recent years have seen a surge in approaches that automatically learn to encode graph structure into low-dimensional embeddings, using techniques based on deep learning and nonlinear dimensionality reduction. Here we provide a conceptual review of key advancements in this area of representation learning on graphs, including matrix factorization-based methods, random-walk based algorithms, and graph neural networks. We review methods to embed individual nodes as well as approaches to embed entire (sub)graphs. In doing so, we develop a unified framework to describe these recent approaches, and we highlight a number of important applications and directions for future work.

Point clouds are characterized by irregularity and unstructuredness, which pose challenges in efficient data exploitation and discriminative feature extraction. In this paper, we present an unsupervised deep neural architecture called Flattening-Net to represent irregular 3D point clouds of arbitrary geometry and topology as a completely regular 2D point geometry image (PGI) structure, in which coordinates of spatial points are captured in colors of image pixels. \mr{Intuitively, Flattening-Net implicitly approximates a locally smooth 3D-to-2D surface flattening process while effectively preserving neighborhood consistency.} \mr{As a generic representation modality, PGI inherently encodes the intrinsic property of the underlying manifold structure and facilitates surface-style point feature aggregation.} To demonstrate its potential, we construct a unified learning framework directly operating on PGIs to achieve \mr{diverse types of high-level and low-level} downstream applications driven by specific task networks, including classification, segmentation, reconstruction, and upsampling. Extensive experiments demonstrate that our methods perform favorably against the current state-of-the-art competitors. We will make the code and data publicly available at https://github.com/keeganhk/Flattening-Net.

变压器一直是自然语言处理（NLP）和计算机视觉（CV）革命的核心。 NLP和CV的显着成功启发了探索变压器在点云处理中的使用。但是，变压器如何应对点云的不规则性和无序性质？变压器对于不同的3D表示（例如，基于点或体素）的合适性如何？各种3D处理任务的变压器有多大的能力？截至目前，仍然没有对这些问题的研究进行系统的调查。我们第一次为3D点云分析提供了越来越受欢迎的变压器的全面概述。我们首先介绍变压器体系结构的理论，并在2D/3D字段中审查其应用程序。然后，我们提出三种不同的分类法（即实现 - 数据表示和基于任务），它们可以从多个角度对当前的基于变压器的方法进行分类。此外，我们介绍了研究3D中自我注意机制的变异和改进的结果。为了证明变压器在点云分析中的优势，我们提供了基于各种变压器的分类，分割和对象检测方法的全面比较。最后，我们建议三个潜在的研究方向，为3D变压器的开发提供福利参考。

即使机器学习算法已经在数据科学中发挥了重要作用，但许多当前方法对输入数据提出了不现实的假设。由于不兼容的数据格式，或数据集中的异质，分层或完全缺少的数据片段，因此很难应用此类方法。作为解决方案，我们提出了一个用于样本表示，模型定义和培训的多功能，统一的框架，称为“ Hmill”。我们深入审查框架构建和扩展的机器学习的多个范围范式。从理论上讲，为HMILL的关键组件的设计合理，我们将通用近似定理的扩展显示到框架中实现的模型所实现的所有功能的集合。本文还包含有关我们实施中技术和绩效改进的详细讨论，该讨论将在MIT许可下发布供下载。该框架的主要资产是其灵活性，它可以通过相同的工具对不同的现实世界数据源进行建模。除了单独观察到每个对象的一组属性的标准设置外，我们解释了如何在框架中实现表示整个对象系统的图表中的消息推断。为了支持我们的主张，我们使用框架解决了网络安全域的三个不同问题。第一种用例涉及来自原始网络观察结果的IoT设备识别。在第二个问题中，我们研究了如何使用以有向图表示的操作系统的快照可以对恶意二进制文件进行分类。最后提供的示例是通过网络中实体之间建模域黑名单扩展的任务。在所有三个问题中，基于建议的框架的解决方案可实现与专业方法相当的性能。

点设置分类旨在建立一个表示学习模型，该模型区分点设置数据的空间和分类配置。此问题是在许多应用领域，如免疫学和微生物生态学的社会重要性。由于不同类别的点之间的相互作用并不总是平等，因此这个问题是具有挑战性的;结果，表示学习模型必须选择性地学习最相关的多分类关系。相关工程有限（1）学习不同多分类关系的重要性，特别是对于高阶相互作用，（2）并不完全利用超出只测量相对距离或应用前馈的点的空间分布神经网络坐标。为了克服这些限制，我们利用动态图形卷积神经网络（DGCNN）架构来设计新的多类别DGCNN（MC-DGCNN），为多分类点设置分类提供位置表示和点对注意层。 MC-DGCNN具有识别每个点对的分类重要性，并将其扩展到N-Way空间关系，同时仍然保留DGCNN（例如，差异性）的所有属性和益处。实验结果表明，该拟议的架构是在计算上有效的，显着优于现实世界数据集上的当前深度学习架构。

生物医学网络是与疾病网络的蛋白质相互作用的普遍描述符，从蛋白质相互作用，一直到医疗保健系统和科学知识。随着代表学习提供强大的预测和洞察的显着成功，我们目睹了表现形式学习技术的快速扩展，进入了这些网络的建模，分析和学习。在这篇综述中，我们提出了一个观察到生物学和医学中的网络长期原则 - 而在机器学习研究中经常出口 - 可以为代表学习提供概念基础，解释其当前的成功和限制，并告知未来进步。我们综合了一系列算法方法，即在其核心利用图形拓扑到将网络嵌入到紧凑的向量空间中，并捕获表示陈述学习证明有用的方式的广度。深远的影响包括鉴定复杂性状的变异性，单细胞的异心行为及其对健康的影响，协助患者的诊断和治疗以及制定安全有效的药物。

近年来，基于Weisfeiler-Leman算法的算法和神经架构，是一个众所周知的Graph同构问题的启发式问题，它成为具有图形和关系数据的机器学习的强大工具。在这里，我们全面概述了机器学习设置中的算法的使用，专注于监督的制度。我们讨论了理论背景，展示了如何将其用于监督的图形和节点表示学习，讨论最近的扩展，并概述算法的连接（置换 - ）方面的神经结构。此外，我们概述了当前的应用和未来方向，以刺激进一步的研究。

The success of machine learning algorithms generally depends on data representation, and we hypothesize that this is because different representations can entangle and hide more or less the different explanatory factors of variation behind the data. Although specific domain knowledge can be used to help design representations, learning with generic priors can also be used, and the quest for AI is motivating the design of more powerful representation-learning algorithms implementing such priors. This paper reviews recent work in the area of unsupervised feature learning and deep learning, covering advances in probabilistic models, auto-encoders, manifold learning, and deep networks. This motivates longer-term unanswered questions about the appropriate objectives for learning good representations, for computing representations (i.e., inference), and the geometrical connections between representation learning, density estimation and manifold learning.