个性化Pagerank(PPR)是无监督学习图表(例如节点排名,标签和图形嵌入)的基本工具。但是,尽管数据隐私是最近的最重要问题之一,但现有的PPR算法并非旨在保护用户隐私。 PPR对输入图边缘高度敏感:仅一个边缘的差异可能会导致PPR矢量发生很大变化,并可能泄漏私人用户数据。在这项工作中,我们提出了一种输出近似PPR的算法,并证明对输入边缘的敏感性有界限。此外,我们证明,当输入图具有较大的程度时,我们的算法与非私有算法相似。我们敏感性的PPR直接暗示了用于几种图形学习工具的私有算法,例如差异私有(DP)PPR排名,DP节点分类和DP节点嵌入。为了补充我们的理论分析,我们还经验验证了算法的实际性能。
translated by 谷歌翻译
TensorFlow GNN(TF-GNN)是张量曲线的图形神经网络的可扩展库。它是从自下而上设计的,以支持当今信息生态系统中发生的丰富的异质图数据。Google的许多生产模型都使用TF-GNN,最近已作为开源项目发布。在本文中,我们描述了TF-GNN数据模型,其KERAS建模API以及相关功能,例如图形采样,分布式训练和加速器支持。
translated by 谷歌翻译
尽管图形神经网络(GNNS)领域的进步,但目前仅使用少量数据集来评估新模型。这种持续依赖少数数据集提供了对模型之间的性能差异的最小见解,对于可能具有与用作学术基准的数据集有很大不同的工业从业人员而言,尤其具有挑战性。在Google在GNN基础架构和开源软件方面的工作过程中,我们试图开发改进的基准,这些基准可健壮,可调,可扩展且可推广。在这项工作中,我们介绍了GraphWorld,这是一种新的方法和系统,用于对任何可疑的GNN任务进行任意大量的合成图种群进行基准测试GNN模型。 GraphWorld允许用户有效地生成具有数百万个统计上不同数据集的世界。它可访问,可扩展且易于使用。 GraphWorld可以在没有专门硬件的情况下在一台计算机上运行,​​也可以轻松地扩展到在任意群集或云框架上运行。使用GraphWorld,用户对Graph Generator参数具有细粒度的控制,并且可以使用内置的超参数调整基准测试任意GNN模型。我们从GraphWorld实验中介绍了有关数以百亿个基准数据集中数以万计的GNN模型的性能特征的见解。我们进一步表明,GraphWorld有效地探索了标准基准测试的基准数据集空间区域,从而揭示了在历史上无法获得的模型之间的比较。使用GraphWorld,我们还能够研究图形属性与任务性能指标之间的关系,这对于经典的现实基准集合而言,这几乎是不可能的。
translated by 谷歌翻译
图形神经网络(GNN)已在许多图分析任务(例如节点分类和链接预测)上实现了最新结果。然而,事实证明,图形群集等图形上的重要无监督问题对GNN的进步具有更大的抵抗力。图群集的总体目标与GNN中的节点合并相同 - 这是否意味着GNN池方法在聚类图上做得很好?令人惊讶的是,答案是没有的 - 当前的GNN合并方法通常无法恢复群集结构,而在简单的基线(例如应用于学习的表示形式上的K-均值)良好工作的情况下。我们通过仔细设计一组实验来进一步研究,以研究图形结构和属性数据中的不同信噪比情景。为了解决这些方法在聚类中的性能不佳,我们引入了深层模块化网络(DMON),这是一种受群集质量模块化量度启发的无监督池方法,并显示了它如何解决现实世界图的挑战性聚类结构的恢复。同样,在现实世界中,我们表明DMON产生的高质量簇与地面真相标签密切相关,从而实现了最先进的结果,比不同指标的其他合并方法提高了40%以上。
translated by 谷歌翻译
Charisma is considered as one's ability to attract and potentially also influence others. Clearly, there can be considerable interest from an artificial intelligence's (AI) perspective to provide it with such skill. Beyond, a plethora of use cases opens up for computational measurement of human charisma, such as for tutoring humans in the acquisition of charisma, mediating human-to-human conversation, or identifying charismatic individuals in big social data. A number of models exist that base charisma on various dimensions, often following the idea that charisma is given if someone could and would help others. Examples include influence (could help) and affability (would help) in scientific studies or power (could help), presence, and warmth (both would help) as a popular concept. Modelling high levels in these dimensions for humanoid robots or virtual agents, seems accomplishable. Beyond, also automatic measurement appears quite feasible with the recent advances in the related fields of Affective Computing and Social Signal Processing. Here, we, thereforem present a blueprint for building machines that can appear charismatic, but also analyse the charisma of others. To this end, we first provide the psychological perspective including different models of charisma and behavioural cues of it. We then switch to conversational charisma in spoken language as an exemplary modality that is essential for human-human and human-computer conversations. The computational perspective then deals with the recognition and generation of charismatic behaviour by AI. This includes an overview of the state of play in the field and the aforementioned blueprint. We then name exemplary use cases of computational charismatic skills before switching to ethical aspects and concluding this overview and perspective on building charisma-enabled AI.
translated by 谷歌翻译
Network Intrusion and Detection Systems (NIDS) are essential for malicious traffic and cyberattack detection in modern networks. Artificial intelligence-based NIDS are powerful tools that can learn complex data correlations for accurate attack prediction. Graph Neural Networks (GNNs) provide an opportunity to analyze network topology along with flow features which makes them particularly suitable for NIDS applications. However, successful application of such tool requires large amounts of carefully collected and labeled data for training and testing. In this paper we inspect different versions of ToN-IoT dataset and point out inconsistencies in some versions. We filter the full version of ToN-IoT and present a new version labeled ToN-IoT-R. To ensure generalization we propose a new standardized and compact set of flow features which are derived solely from NetFlowv5-compatible data. We separate numeric data and flags into different categories and propose a new dataset-agnostic normalization approach for numeric features. This allows us to preserve meaning of flow flags and we propose to conduct targeted analysis based on, for instance, network protocols. For flow classification we use E-GraphSage algorithm with modified node initialization technique that allows us to add node degree to node features. We achieve high classification accuracy on ToN-IoT-R and compare it with previously published results for ToN-IoT, NF-ToN-IoT, and NF-ToN-IoT-v2. We highlight the importance of careful data collection and labeling and appropriate data preprocessing choice and conclude that the proposed set of features is more applicable for real NIDS due to being less demanding to traffic monitoring equipment while preserving high flow classification accuracy.
translated by 谷歌翻译
Heuristic search algorithms, e.g. A*, are the commonly used tools for pathfinding on grids, i.e. graphs of regular structure that are widely employed to represent environments in robotics, video games etc. Instance-independent heuristics for grid graphs, e.g. Manhattan distance, do not take the obstacles into account and, thus, the search led by such heuristics performs poorly in the obstacle-rich environments. To this end, we suggest learning the instance-dependent heuristic proxies that are supposed to notably increase the efficiency of the search. The first heuristic proxy we suggest to learn is the correction factor, i.e. the ratio between the instance independent cost-to-go estimate and the perfect one (computed offline at the training phase). Unlike learning the absolute values of the cost-to-go heuristic function, which was known before, when learning the correction factor the knowledge of the instance-independent heuristic is utilized. The second heuristic proxy is the path probability, which indicates how likely the grid cell is lying on the shortest path. This heuristic can be utilized in the Focal Search framework as the secondary heuristic, allowing us to preserve the guarantees on the bounded sub-optimality of the solution. We learn both suggested heuristics in a supervised fashion with the state-of-the-art neural networks containing attention blocks (transformers). We conduct a thorough empirical evaluation on a comprehensive dataset of planning tasks, showing that the suggested techniques i) reduce the computational effort of the A* up to a factor of $4$x while producing the solutions, which costs exceed the costs of the optimal solutions by less than $0.3$% on average; ii) outperform the competitors, which include the conventional techniques from the heuristic search, i.e. weighted A*, as well as the state-of-the-art learnable planners.
translated by 谷歌翻译
Self-supervised learning (SSL) aims to produce useful feature representations without access to any human-labeled data annotations. Due to the success of recent SSL methods based on contrastive learning, such as SimCLR, this problem has gained popularity. Most current contrastive learning approaches append a parametrized projection head to the end of some backbone network to optimize the InfoNCE objective and then discard the learned projection head after training. This raises a fundamental question: Why is a learnable projection head required if we are to discard it after training? In this work, we first perform a systematic study on the behavior of SSL training focusing on the role of the projection head layers. By formulating the projection head as a parametric component for the InfoNCE objective rather than a part of the network, we present an alternative optimization scheme for training contrastive learning based SSL frameworks. Our experimental study on multiple image classification datasets demonstrates the effectiveness of the proposed approach over alternatives in the SSL literature.
translated by 谷歌翻译
The evolution of wireless communications into 6G and beyond is expected to rely on new machine learning (ML)-based capabilities. These can enable proactive decisions and actions from wireless-network components to sustain quality-of-service (QoS) and user experience. Moreover, new use cases in the area of vehicular and industrial communications will emerge. Specifically in the area of vehicle communication, vehicle-to-everything (V2X) schemes will benefit strongly from such advances. With this in mind, we have conducted a detailed measurement campaign with the purpose of enabling a plethora of diverse ML-based studies. The resulting datasets offer GPS-located wireless measurements across diverse urban environments for both cellular (with two different operators) and sidelink radio access technologies, thus enabling a variety of different studies towards V2X. The datasets are labeled and sampled with a high time resolution. Furthermore, we make the data publicly available with all the necessary information to support the on-boarding of new researchers. We provide an initial analysis of the data showing some of the challenges that ML needs to overcome and the features that ML can leverage, as well as some hints at potential research studies.
translated by 谷歌翻译
Segmentation of lidar data is a task that provides rich, point-wise information about the environment of robots or autonomous vehicles. Currently best performing neural networks for lidar segmentation are fine-tuned to specific datasets. Switching the lidar sensor without retraining on a big set of annotated data from the new sensor creates a domain shift, which causes the network performance to drop drastically. In this work we propose a new method for lidar domain adaption, in which we use annotated panoptic lidar datasets and recreate the recorded scenes in the structure of a different lidar sensor. We narrow the domain gap to the target data by recreating panoptic data from one domain in another and mixing the generated data with parts of (pseudo) labeled target domain data. Our method improves the nuScenes to SemanticKITTI unsupervised domain adaptation performance by 15.2 mean Intersection over Union points (mIoU) and by 48.3 mIoU in our semi-supervised approach. We demonstrate a similar improvement for the SemanticKITTI to nuScenes domain adaptation by 21.8 mIoU and 51.5 mIoU, respectively. We compare our method with two state of the art approaches for semantic lidar segmentation domain adaptation with a significant improvement for unsupervised and semi-supervised domain adaptation. Furthermore we successfully apply our proposed method to two entirely unlabeled datasets of two state of the art lidar sensors Velodyne Alpha Prime and InnovizTwo, and train well performing semantic segmentation networks for both.
translated by 谷歌翻译