过去,现实世界中社交网络的图表错过了两个重要元素:连接的多重性和表示时间。为此,在本文中,我们为社交网络提供了一个新的动态异质图表示,其中包括图形的每个组件中的时间,即节点和边缘,每种捕获异质性的不同类型。我们通过提出四个与时间有关的查询和深度学习问题来说明这种表示的力量,这些查询和深度学习问题无法轻易在常规的均匀图表中处理。作为概念的证明,我们介绍了新的社交媒体平台(Steemit)的详细表示,我们用它来说明动态查询功能以及使用图形神经网络(GNNS)的预测任务。结果说明了动态异质图表示对社交网络的模型的力量。鉴于这是一个相对研究的领域,我们还说明了在查询优化方面的未来工作以及异质图结构的新动态预测任务的机会。
translated by 谷歌翻译
In this paper, we present a novel control architecture for the online adaptation of bipedal locomotion on inclined obstacles. In particular, we introduce a novel, cost-effective, and versatile foot sensor to detect the proximity of the robot's feet to the ground (bump sensor). By employing this sensor, feedback controllers are implemented to reduce the impact forces during the transition of the swing to stance phase or steeping on inclined unseen obstacles. Compared to conventional sensors based on contact reaction force, this sensor detects the distance to the ground or obstacles before the foot touches the obstacle and therefore provides predictive information to anticipate the obstacles. The controller of the proposed bump sensor interacts with another admittance controller to adjust leg length. The walking experiments show successful locomotion on the unseen inclined obstacle without reducing the locomotion speed with a slope angle of 12. Foot position error causes a hard impact with the ground as a consequence of accumulative error caused by links and connections' deflection (which is manufactured by university tools). The proposed framework drastically reduces the feet' impact with the ground.
translated by 谷歌翻译
6D object pose estimation problem has been extensively studied in the field of Computer Vision and Robotics. It has wide range of applications such as robot manipulation, augmented reality, and 3D scene understanding. With the advent of Deep Learning, many breakthroughs have been made; however, approaches continue to struggle when they encounter unseen instances, new categories, or real-world challenges such as cluttered backgrounds and occlusions. In this study, we will explore the available methods based on input modality, problem formulation, and whether it is a category-level or instance-level approach. As a part of our discussion, we will focus on how 6D object pose estimation can be used for understanding 3D scenes.
translated by 谷歌翻译
Recently, there has been a significant amount of interest in satellite telemetry anomaly detection (AD) using neural networks (NN). For AD purposes, the current approaches focus on either forecasting or reconstruction of the time series, and they cannot measure the level of reliability or the probability of correct detection. Although the Bayesian neural network (BNN)-based approaches are well known for time series uncertainty estimation, they are computationally intractable. In this paper, we present a tractable approximation for BNN based on the Monte Carlo (MC) dropout method for capturing the uncertainty in the satellite telemetry time series, without sacrificing accuracy. For time series forecasting, we employ an NN, which consists of several Long Short-Term Memory (LSTM) layers followed by various dense layers. We employ the MC dropout inside each LSTM layer and before the dense layers for uncertainty estimation. With the proposed uncertainty region and by utilizing a post-processing filter, we can effectively capture the anomaly points. Numerical results show that our proposed time series AD approach outperforms the existing methods from both prediction accuracy and AD perspectives.
translated by 谷歌翻译
We focus on causal discovery in the presence of measurement error in linear systems where the mixing matrix, i.e., the matrix indicating the independent exogenous noise terms pertaining to the observed variables, is identified up to permutation and scaling of the columns. We demonstrate a somewhat surprising connection between this problem and causal discovery in the presence of unobserved parentless causes, in the sense that there is a mapping, given by the mixing matrix, between the underlying models to be inferred in these problems. Consequently, any identifiability result based on the mixing matrix for one model translates to an identifiability result for the other model. We characterize to what extent the causal models can be identified under a two-part faithfulness assumption. Under only the first part of the assumption (corresponding to the conventional definition of faithfulness), the structure can be learned up to the causal ordering among an ordered grouping of the variables but not all the edges across the groups can be identified. We further show that if both parts of the faithfulness assumption are imposed, the structure can be learned up to a more refined ordered grouping. As a result of this refinement, for the latent variable model with unobserved parentless causes, the structure can be identified. Based on our theoretical results, we propose causal structure learning methods for both models, and evaluate their performance on synthetic data.
translated by 谷歌翻译
Predicting discrete events in time and space has many scientific applications, such as predicting hazardous earthquakes and outbreaks of infectious diseases. History-dependent spatio-temporal Hawkes processes are often used to mathematically model these point events. However, previous approaches have faced numerous challenges, particularly when attempting to forecast one or multiple future events. In this work, we propose a new neural architecture for multi-event forecasting of spatio-temporal point processes, utilizing transformers, augmented with normalizing flows and probabilistic layers. Our network makes batched predictions of complex history-dependent spatio-temporal distributions of future discrete events, achieving state-of-the-art performance on a variety of benchmark datasets including the South California Earthquakes, Citibike, Covid-19, and Hawkes synthetic pinwheel datasets. More generally, we illustrate how our network can be applied to any dataset of discrete events with associated markers, even when no underlying physics is known.
translated by 谷歌翻译
我们建议在没有观察到的变量的情况下,提出基于订购的方法,用于学习结构方程模型(SEM)的最大祖先图(MAG),直到其Markov等效类(MEC)。文献中的现有基于订购的方法通过学习因果顺序(C-order)恢复图。我们提倡一个名为“可移动顺序”(R-rorder)的新颖订单,因为它们比结构学习的C端口有利。这是因为R-orders是适当定义的优化问题的最小化器,该问题可以准确解决(使用强化学习方法)或大约(使用爬山搜索)。此外,R-orders(与C-orders不同)在MEC中的所有图表中都是不变的,并将C-orders包括为子集。鉴于一组R-orders通常明显大于C-orders集,因此优化问题更容易找到R级而不是C级。我们评估了在现实世界和随机生成的网络上提出的方法的性能和可伸缩性。
translated by 谷歌翻译
因果鉴定是因果推理文献的核心,在该文献中提出了完整的算法来识别感兴趣的因果问题。这些算法的有效性取决于访问正确指定的因果结构的限制性假设。在这项工作中,我们研究了可获得因果结构概率模型的环境。具体而言,因果图中的边缘是分配的概率,例如,可能代表来自领域专家的信念程度。另外,关于边缘的不确定的可能反映了特定统计检验的置信度。在这种情况下自然出现的问题是:给定这样的概率图和感兴趣的特定因果效应,哪些具有最高合理性的子图是什么?我们表明回答这个问题减少了解决NP-HARD组合优化问题,我们称之为边缘ID问题。我们提出有效的算法来近似此问题,并评估我们针对现实世界网络和随机生成图的算法。
translated by 谷歌翻译
捕捉片是由飞机发动机从发射颗粒产生的凝结径,这会扰乱地球的辐射预算。仿真建模用于解释关节尾部的形成和开发。这些模拟在计算密集型上,依赖于高性能计算解决方案,并且关节尾结构的定义不当。我们提出了一个视觉计算系统,以协助定义围栏及其特征,以及计算机生成的飞机发动机仿真参数的分析。我们系统的后端利用了一种缩小构造标准和聚类方法来检测概括的形状和进化,并确定相似的模拟运行。前端系统有助于分析跨多个模拟运行的节尾及其参数。与领域专家的评估表明,这种方法成功地帮助了关注数据调查。
translated by 谷歌翻译
在本文中,我们研究了波斯语的G2P转换的端到端和多模块框架的应用。结果表明,我们提出的多模型G2P系统在准确性和速度方面优于我们的端到端系统。该系统由发音词典作为我们的查找表组成,以及使用GRU和Transformer架构创建的波斯语中的同符,OOV和EZAFE的单独模型。该系统是序列级别而不是单词级别,它使其能够有效地捕获单词(跨字信息)之间的不成文关系,而无需进行任何预处理,而无需进行任何预歧歧义和EZAFE识别。经过评估后,我们的系统达到了94.48%的单词级准确性,表现优于先前的波斯语G2P系统。
translated by 谷歌翻译