Information spread on networks can be efficiently modeled by considering three features: documents' content, time of publication relative to other publications, and position of the spreader in the network. Most previous works model up to two of those jointly, or rely on heavily parametric approaches. Building on recent Dirichlet-Point processes literature, we introduce the Houston (Hidden Online User-Topic Network) model, that jointly considers all those features in a non-parametric unsupervised framework. It infers dynamic topic-dependent underlying diffusion networks in a continuous-time setting along with said topics. It is unsupervised; it considers an unlabeled stream of triplets shaped as \textit{(time of publication, information's content, spreading entity)} as input data. Online inference is conducted using a sequential Monte-Carlo algorithm that scales linearly with the size of the dataset. Our approach yields consequent improvements over existing baselines on both cluster recovery and subnetworks inference tasks.

The publication time of a document carries a relevant information about its semantic content. The Dirichlet-Hawkes process has been proposed to jointly model textual information and publication dynamics. This approach has been used with success in several recent works, and extended to tackle specific challenging problems --typically for short texts or entangled publication dynamics. However, the prior in its current form does not allow for complex publication dynamics. In particular, inferred topics are independent from each other --a publication about finance is assumed to have no influence on publications about politics, for instance. In this work, we develop the Multivariate Powered Dirichlet-Hawkes Process (MPDHP), that alleviates this assumption. Publications about various topics can now influence each other. We detail and overcome the technical challenges that arise from considering interacting topics. We conduct a systematic evaluation of MPDHP on a range of synthetic datasets to define its application domain and limitations. Finally, we develop a use case of the MPDHP on Reddit data. At the end of this article, the interested reader will know how and when to use MPDHP, and when not to.

大多数信息传播模型在线依赖于以下假设：信息彼此独立传播。但是，一些作品指出了研究相互作用在现实世界过程中的作用的必要性，并强调了这样做的可能困难：相互作用稀疏和简短。作为答案，最近的进步开发了模型来说明潜在出版物动态的相互作用。在本文中，我们建议扩展和应用一个这样的模型，以确定Reddit的新闻头条之间的互动是否在其基本出版机制中起重要作用。在对2019年的100,000个新闻标题进行了深入的案例研究之后，我们检索了有关互动的最新结论，并得出结论，它们在该数据集中扮演了较小的角色。

使用Twitter进行事件检测的小调查。这项工作首先定义了问题陈述，然后总结并整理了解决问题的不同研究工作。

Neyman-Scott processes (NSPs) are point process models that generate clusters of points in time or space. They are natural models for a wide range of phenomena, ranging from neural spike trains to document streams. The clustering property is achieved via a doubly stochastic formulation: first, a set of latent events is drawn from a Poisson process; then, each latent event generates a set of observed data points according to another Poisson process. This construction is similar to Bayesian nonparametric mixture models like the Dirichlet process mixture model (DPMM) in that the number of latent events (i.e. clusters) is a random variable, but the point process formulation makes the NSP especially well suited to modeling spatiotemporal data. While many specialized algorithms have been developed for DPMMs, comparatively fewer works have focused on inference in NSPs. Here, we present novel connections between NSPs and DPMMs, with the key link being a third class of Bayesian mixture models called mixture of finite mixture models (MFMMs). Leveraging this connection, we adapt the standard collapsed Gibbs sampling algorithm for DPMMs to enable scalable Bayesian inference on NSP models. We demonstrate the potential of Neyman-Scott processes on a variety of applications including sequence detection in neural spike trains and event detection in document streams.

分析短文（例如社交媒体帖子）由于其固有的简洁而非常困难。除了对此类帖子的主题进行分类之外，一个常见的下游任务是将这些文档的作者分组以进行后续分析。我们提出了一个新颖的模型，该模型通过对同一文档中的单词之间的强大依赖进行建模以及用户级主题分布来扩展潜在的Dirichlet分配。我们还同时群集用户，消除了对事后集群估计的需求，并通过将嘈杂的用户级主题分布缩小到典型值来改善主题估计。我们的方法的性能和比传统方法的性能（或更好），我们在美国参议员的推文数据集中证明了它的有用性，恢复了反映党派意识形态的有意义的主题和群集。我们还通过表征参议员群体讨论并提供不确定性量化的主题的遗产，从而在这些政治家中开发了一种新的回声室衡量标准。

尽管社交媒体中的Echo Chambers受到了相当大的审查，但仍缺少用于检测和分析的一般模型。在这项工作中，我们旨在通过提出一个概率的生成模型来填补这一空白，该模型通过一系列具有一定程度的回声室行为来解释社交媒体足迹（即社交网络结构和信息传播）。并以极性。具体而言，回声室被建模为可渗透到具有相似意识形态极性的信息的社区，并且对相反的倾向信息不渗透：这允许将回声室与缺乏明确意识形态保持一致的社区区分。为了了解模型参数，我们提出了对广义期望最大化算法的可扩展的随机适应，该算法优化了观察社会联系和信息传播的关节可能性。合成数据的实验表明，我们的算法能够及其具有回声室行为和意见极性的程度正确地重建地面真相社区。关于两极分化社会和政治辩论的现实数据的实验，例如英国脱欧公投或COVID-19疫苗运动，证实了我们提议在检测回声室方面的有效性。最后，我们展示了我们的模型如何提高辅助预测任务的准确性，例如立场检测和未来传播的预测。

去年，在推荐系统中使用随机块建模（SBM）的兴趣恢复了。这些模型被视为能够处理标记数据的张量分解技术的灵活替代方法。最近提议通过将较大的上下文作为输入数据并在上下文相关元素之间添加二阶交互来解决通过SBM解决离散建议问题的最新作品。在这项工作中，我们表明这些模型都是单个全局框架的特殊情况：序列化的交互混合成员随机块模型（SIMSBM）。它允许建模任意较大的上下文以及任意高级的交互作用。我们证明了SIMSBM概括了一些最近基于SBM的基线。此外，我们证明我们的配方允许在六个现实世界数据集上增加预测能力。

本次调查绘制了用于分析社交媒体数据的生成方法的研究状态的广泛的全景照片（Sota）。它填补了空白，因为现有的调查文章在其范围内或被约会。我们包括两个重要方面，目前正在挖掘和建模社交媒体的重要性：动态和网络。社会动态对于了解影响影响或疾病的传播，友谊的形成，友谊的形成等，另一方面，可以捕获各种复杂关系，提供额外的洞察力和识别否则将不会被注意的重要模式。

We describe latent Dirichlet allocation (LDA), a generative probabilistic model for collections of discrete data such as text corpora. LDA is a three-level hierarchical Bayesian model, in which each item of a collection is modeled as a finite mixture over an underlying set of topics. Each topic is, in turn, modeled as an infinite mixture over an underlying set of topic probabilities. In the context of text modeling, the topic probabilities provide an explicit representation of a document. We present efficient approximate inference techniques based on variational methods and an EM algorithm for empirical Bayes parameter estimation. We report results in document modeling, text classification, and collaborative filtering, comparing to a mixture of unigrams model and the probabilistic LSI model.

网络欺骗是作为对攻击者和数据盗贼保卫网络和系统的有希望的方法。然而，尽管部署相对便宜，但由于丰富的互动欺骗技术在很大程度上被手动的事实，规模的现实内容的产生是非常昂贵的。随着最近的机器学习改进，我们现在有机会为创建逼真和诱惑模拟内容带来规模和自动化。在这项工作中，我们提出了一个框架，以便在规模上自动化电子邮件和即时消息风格组通信。组织内的这种消息传递平台包含私人通信和文档附件内的许多有价值的信息，使其成为对手的诱惑目标。我们解决了模拟此类系统的两个关键方面：与参与者进行沟通的何时何地和生成局部多方文本以填充模拟对话线程。我们将LognormMix-Net时间点流程作为一种方法，建立在Shchur等人的强度建模方法上。〜\ Cite {Shchur2019Ints}为单播和多铸造通信创建生成模型。我们展示了使用微调，预先训练的语言模型来生成令人信服的多方对话线程。通过将LognormMix-Net TPP（要生成通信时间戳，发件人和收件人）使用语言模型来模拟实时电子邮件服务器，该语言模型生成多方电子邮件线程的内容。我们对基于现实主义的数量的基于现实的属性评估生成的内容，这鼓励模型学会生成将引起对手的注意力来实现欺骗结果。

We develop stochastic variational inference, a scalable algorithm for approximating posterior distributions. We develop this technique for a large class of probabilistic models and we demonstrate it with two probabilistic topic models, latent Dirichlet allocation and the hierarchical Dirichlet process topic model. Using stochastic variational inference, we analyze several large collections of documents: 300K articles from Nature, 1.8M articles from The New York Times, and 3.8M articles from Wikipedia. Stochastic inference can easily handle data sets of this size and outperforms traditional variational inference, which can only handle a smaller subset. (We also show that the Bayesian nonparametric topic model outperforms its parametric counterpart.) Stochastic variational inference lets us apply complex Bayesian models to massive data sets.

这项工作引入了一种新颖的多变量时间点过程，部分均值行为泊松（PMBP）过程，可以利用以将多变量霍克斯过程适合部分间隔删除的数据，该数据包括在尺寸和间隔子集上的事件时间戳的混合中组成的数据。 - 委员会互补尺寸的事件计数。首先，我们通过其条件强度定义PMBP过程，并导出子临界性的规律性条件。我们展示了鹰过程和MBP过程（Rizoiu等人）是PMBP过程的特殊情况。其次，我们提供了能够计算PMBP过程的条件强度和采样事件历史的数字方案。第三，我们通过使用合成和现实世界数据集来证明PMBP过程的适用性：我们测试PMBP过程的能力，以恢复多变量霍克参数给出鹰过程的样本事件历史。接下来，我们在YouTube流行预测任务上评估PMBP过程，并表明它优于当前最先进的鹰强度过程（Rizoiu等人。（2017b））。最后，在Covid19的策划数据集上，关于国家样本的Covid19每日案例计数和Covid19相关的新闻文章，我们展示了PMBP拟合参数上的聚类使各国的分类能够分类案件和新闻的国家级互动报告。

Many dynamical systems exhibit latent states with intrinsic orderings such as "ally", "neutral" and "enemy" relationships in international relations. Such latent states are evidenced through entities' cooperative versus conflictual interactions which are similarly ordered. Models of such systems often involve state-to-action emission and state-to-state transition matrices. It is common practice to assume that the rows of these stochastic matrices are independently sampled from a Dirichlet distribution. However, this assumption discards ordinal information and treats states and actions falsely as order-invariant categoricals, which hinders interpretation and evaluation. To address this problem, we propose the Ordered Matrix Dirichlet (OMD): rows are sampled conditionally dependent such that probability mass is shifted to the right of the matrix as we move down rows. This results in a well-ordered mapping between latent states and observed action types. We evaluate the OMD in two settings: a Hidden Markov Model and a novel Bayesian Dynamic Poisson Tucker Model tailored to political event data. Models built on the OMD recover interpretable latent states and show superior forecasting performance in few-shot settings. We detail the wide applicability of the OMD to other domains where models with Dirichlet-sampled matrices are popular (e.g. topic modeling) and publish user-friendly code.

我们为在不平衡的短文本数据集中发现稀缺主题提供了一个简单而通用的解决方案，即基于共同发生的网络模型CWIBTD，可以同时解决短文本主题的稀疏和不平衡的问题并减轻效果的效果。偶尔成对的单词出现，使模型更多地集中在发现稀缺主题上。与以前的方法不同，CWIBTD使用共发生的单词网络对每个单词的主题分布进行建模，从而改善了数据空间的语义密度，并确保其在识别稀有主题方面的敏感性，通过改善计算节点活动的方式和正常方式。在某种程度上，稀缺的话题和大主题。此外，使用与LDA相同的Gibbs采样使CWIBTD易于扩展到Viri-OUS应用程序方案。在不夸张的短文本数据集中进行的广泛实验验证证实了CWIBTD在发现稀有主题时的优越性。我们的模型可用于早期，准确地发现社交平台上新兴主题或意外事件。

使用机器学习算法从未标记的文本中提取知识可能很复杂。文档分类和信息检索是两个应用程序，可以从无监督的学习（例如文本聚类和主题建模）中受益，包括探索性数据分析。但是，无监督的学习范式提出了可重复性问题。初始化可能会导致可变性，具体取决于机器学习算法。此外，关于群集几何形状，扭曲可能会产生误导。在原因中，异常值和异常的存在可能是决定因素。尽管初始化和异常问题与文本群集和主题建模相关，但作者并未找到对它们的深入分析。这项调查提供了这些亚地区的系统文献综述（2011-2022），并提出了共同的术语，因为类似的程序具有不同的术语。作者描述了研究机会，趋势和开放问题。附录总结了与审查的作品直接或间接相关的文本矢量化，分解和聚类算法的理论背景。

Analyzing the behavior of complex interdependent networks requires complete information about the network topology and the interdependent links across networks. For many applications such as critical infrastructure systems, understanding network interdependencies is crucial to anticipate cascading failures and plan for disruptions. However, data on the topology of individual networks are often publicly unavailable due to privacy and security concerns. Additionally, interdependent links are often only revealed in the aftermath of a disruption as a result of cascading failures. We propose a scalable nonparametric Bayesian approach to reconstruct the topology of interdependent infrastructure networks from observations of cascading failures. Metropolis-Hastings algorithm coupled with the infrastructure-dependent proposal are employed to increase the efficiency of sampling possible graphs. Results of reconstructing a synthetic system of interdependent infrastructure networks demonstrate that the proposed approach outperforms existing methods in both accuracy and computational time. We further apply this approach to reconstruct the topology of one synthetic and two real-world systems of interdependent infrastructure networks, including gas-power-water networks in Shelby County, TN, USA, and an interdependent system of power-water networks in Italy, to demonstrate the general applicability of the approach.

霍克斯过程是一类特殊的时间点过程，表现出自然的因果关系，因为过去事件的发生可能会增加未来事件的可能性。在多维时间过程的维度之间发现潜在影响网络在学科中至关重要，在这些学科中，高频数据将模拟，例如在财务数据或地震数据中。本文处理了多维鹰派过程中学习Granger-Causal网络的问题。我们将此问题提出为模型选择任务，其中我们遵循最小描述长度（MDL）原理。此外，我们建议使用蒙特卡洛方法提出一种用于基于MDL的推理的一般算法，并将其用于因果发现问题。我们将算法与关于合成和现实世界财务数据的最新基线方法进行了比较。合成实验表明，与基线方法相比，与数据尺寸相比，我们方法不可能的图形发现的优势。 G-7债券价格数据的实验结果与专家知识一致。

训练深图神经网络（GNNS）构成了一项具有挑战性的任务，因为GNN的性能可能会遭受隐藏的消息层的数量。文献集中在过度平滑和了解深度GNN的性能恶化的建议上。在本文中，我们提出了一种新的解释，以解决这种恶化的性能现象，即错误的简化，也就是说，通过防止自我浮动和强迫不得加权的边缘来简化图形。我们表明，这种简化可以降低消息通话层的潜力以捕获图的结构信息。鉴于此，我们提出了一个新的框架，Edge增强了图形神经网络（EEGNN）。 EEGNN使用从提出的Dirichlet混合泊松图模型（贝叶斯非参数模型）中提取的结构信息，以改善各种深度消息的GNN的性能。不同数据集的实验表明，与基准相比，我们的方法实现了可观的性能。

在过去的几年中，霍克斯流程的在线学习受到了越来越多的关注，尤其是用于建模演员网络。但是，这些作品通常会模拟事件或参与者的潜在群集之间的丰富相互作用，或者是参与者之间的网络结构。我们建议对参与者网络的潜在结构进行建模，以及在现实世界中的医疗和财务应用环境中进行的丰富互动。合成和现实世界数据的实验结果展示了我们方法的功效。