In this work, we introduce a hypergraph representation learning framework called Hypergraph Neural Networks (HNN) that jointly learns hyperedge embeddings along with a set of hyperedge-dependent embeddings for each node in the hypergraph. HNN derives multiple embeddings per node in the hypergraph where each embedding for a node is dependent on a specific hyperedge of that node. Notably, HNN is accurate, data-efficient, flexible with many interchangeable components, and useful for a wide range of hypergraph learning tasks. We evaluate the effectiveness of the HNN framework for hyperedge prediction and hypergraph node classification. We find that HNN achieves an overall mean gain of 7.72% and 11.37% across all baseline models and graphs for hyperedge prediction and hypergraph node classification, respectively.

Graph Neural Networks (GNNs) have become increasingly important in recent years due to their state-of-the-art performance on many important downstream applications. Existing GNNs have mostly focused on learning a single node representation, despite that a node often exhibits polysemous behavior in different contexts. In this work, we develop a persona-based graph neural network framework called PersonaSAGE that learns multiple persona-based embeddings for each node in the graph. Such disentangled representations are more interpretable and useful than a single embedding. Furthermore, PersonaSAGE learns the appropriate set of persona embeddings for each node in the graph, and every node can have a different number of assigned persona embeddings. The framework is flexible enough and the general design helps in the wide applicability of the learned embeddings to suit the domain. We utilize publicly available benchmark datasets to evaluate our approach and against a variety of baselines. The experiments demonstrate the effectiveness of PersonaSAGE for a variety of important tasks including link prediction where we achieve an average gain of 15% while remaining competitive for node classification. Finally, we also demonstrate the utility of PersonaSAGE with a case study for personalized recommendation of different entity types in a data management platform.

Learning fair graph representations for downstream applications is becoming increasingly important, but existing work has mostly focused on improving fairness at the global level by either modifying the graph structure or objective function without taking into account the local neighborhood of a node. In this work, we formally introduce the notion of neighborhood fairness and develop a computational framework for learning such locally fair embeddings. We argue that the notion of neighborhood fairness is more appropriate since GNN-based models operate at the local neighborhood level of a node. Our neighborhood fairness framework has two main components that are flexible for learning fair graph representations from arbitrary data: the first aims to construct fair neighborhoods for any arbitrary node in a graph and the second enables adaption of these fair neighborhoods to better capture certain application or data-dependent constraints, such as allowing neighborhoods to be more biased towards certain attributes or neighbors in the graph.Furthermore, while link prediction has been extensively studied, we are the first to investigate the graph representation learning task of fair link classification. We demonstrate the effectiveness of the proposed neighborhood fairness framework for a variety of graph machine learning tasks including fair link prediction, link classification, and learning fair graph embeddings. Notably, our approach achieves not only better fairness but also increases the accuracy in the majority of cases across a wide variety of graphs, problem settings, and metrics.

As multimodal learning finds applications in a wide variety of high-stakes societal tasks, investigating their robustness becomes important. Existing work has focused on understanding the robustness of vision-and-language models to imperceptible variations on benchmark tasks. In this work, we investigate the robustness of multimodal classifiers to cross-modal dilutions - a plausible variation. We develop a model that, given a multimodal (image + text) input, generates additional dilution text that (a) maintains relevance and topical coherence with the image and existing text, and (b) when added to the original text, leads to misclassification of the multimodal input. Via experiments on Crisis Humanitarianism and Sentiment Detection tasks, we find that the performance of task-specific fusion-based multimodal classifiers drops by 23.3% and 22.5%, respectively, in the presence of dilutions generated by our model. Metric-based comparisons with several baselines and human evaluations indicate that our dilutions show higher relevance and topical coherence, while simultaneously being more effective at demonstrating the brittleness of the multimodal classifiers. Our work aims to highlight and encourage further research on the robustness of deep multimodal models to realistic variations, especially in human-facing societal applications. The code and other resources are available at https://claws-lab.github.io/multimodal-robustness/.

基于会话的建议系统在会话中捕获用户的短期兴趣。会话上下文（即，会话中用户在会话中的高级兴趣或意图）在大多数数据集中都没有明确给出，并且隐式推断会话上下文作为项目级属性的汇总是粗略的。在本文中，我们提出了ISCON，该ISCON隐含地将会议上下文化。ISCON首先通过创建会话信息图，学习图嵌入和聚类来为会话生成隐式上下文，以将会话分配给上下文。然后，ISCON训练会话上下文预测器，并使用预测上下文的嵌入来增强下一项目的预测准确性。四个数据集的实验表明，ISCON比最新模型具有优越的下一项目预测准确性。REDDIT数据集中的ISCON的案例研究证实，分配的会话上下文是独特而有意义的。

给定图形学习任务，例如链接预测，在新的图数据集上，我们如何自动选择最佳方法及其超参数（集体称为模型）？图形学习的模型选择在很大程度上是临时的。一种典型的方法是将流行方法应用于新数据集，但这通常是次优的。另一方面，系统比较新图上的模型迅速变得太成本过高，甚至不切实际。在这项工作中，我们为自动图机学习开发了第一种称为AutoGML的元学习方法，该方法利用了基准图数据集中大量现有方法的先前性能，并携带此先前的经验以自动选择有效的有效用于新图的模型，无需任何模型培训或评估。为了捕获来自不同领域的图形之间的相似性，我们引入了量化图形结构特征的专业元图特征。然后，我们设计了一个代表模型和图形之间关系的元图，并开发了在元图上运行的图形元学习器，该图估计了每个模型与不同图的相关性。通过广泛的实验，我们表明，使用AutoGML选择新图的方法显着优于始终应用流行方法以及几个现有的元学习者，同时在测试时非常快。

网络科学和技术的快速发展取决于可共享的数据集。当前，没有用于报告和共享网络数据集的标准实践。一些网络数据集提供商仅共享链接，而另一些网络数据集提供商提供了一些上下文或基本统计信息。结果，关键信息可能无意间删除，网络数据集消费者可能会误解或忽略关键方面。使用网络数据集不适当地导致严重的后果（例如，歧视），尤其是当将网络上的机器学习模型部署在高维护域中时。挑战出现，因为网络通常在不同的领域（例如网络科学，物理等）上使用并具有复杂的结构。为了促进网络数据集提供商和消费者之间的通信，我们提出了网络报告。网络报告是一个结构化的描述，总结和上下文化网络数据集。网络报告从先前的工作中扩展了数据集报告（例如，数据集的数据表）的想法，其中包含非i.i.d的网络特定说明。自然，人口统计信息，网络特征等。我们希望网络报告鼓励不同领域的网络研发透明度和问责制。

给定实体及其在Web数据中的交互，可能在不同的时间发生，我们如何找到实体社区并跟踪其演变？在本文中，我们从图形群集的角度处理这项重要任务。最近，通过深层聚类方法，已经实现了各个领域的最新聚类性能。特别是，深图聚类（DGC）方法通过学习节点表示和群集分配在关节优化框架中成功扩展到图形结构的数据。尽管建模选择有所不同（例如，编码器架构），但现有的DGC方法主要基于自动编码器，并使用相同的群集目标和相对较小的适应性。同样，尽管许多现实世界图都是动态的，但以前的DGC方法仅被视为静态图。在这项工作中，我们开发了CGC，这是一个新颖的端到端图形聚类框架，其与现有方法的根本不同。 CGC在对比度图学习框架中学习节点嵌入和群集分配，在多级别方案中仔细选择了正面和负样本，以反映层次结构的社区结构和网络同质。此外，我们将CGC扩展到时间不断发展的数据，其中时间图以增量学习方式执行，并具有检测更改点的能力。对现实世界图的广泛评估表明，所提出的CGC始终优于现有方法。

学习时空事件的动态是一个根本的问题。神经点过程提高了与深神经网络的点过程模型的表现。但是，大多数现有方法只考虑没有空间建模的时间动态。我们提出了深蓝点过程（DeepStpp），这是一款整合时空点流程的深层动力学模型。我们的方法灵活，高效，可以在空间和时间准确地预测不规则采样的事件。我们方法的关键构造是非参数时空强度函数，由潜在过程管理。强度函数享有密度的闭合形式集成。潜在进程捕获事件序列的不确定性。我们使用摊销变分推理来推断使用深网络的潜在进程。使用合成数据集，我们验证我们的模型可以准确地学习真实的强度函数。在真实世界的基准数据集上，我们的模型展示了最先进的基线的卓越性能。

在本文中，我们介绍了对非对称确定点处理（NDPP）的在线和流媒体地图推断和学习问题，其中数据点以任意顺序到达，并且算法被约束以使用单次通过数据以及子线性存储器。在线设置有额外要求在任何时间点维护有效的解决方案。为了解决这些新问题，我们提出了具有理论担保的算法，在几个真实的数据集中评估它们，并显示它们对最先进的离线算法提供了可比的性能，该算法将整个数据存储在内存中并采取多次传递超过它。