在本文中,我们研究了具有内置社区结构的合成随机图模型的属性和性能。这样的模型对于评估和调整自然界无监督的社区检测算法很重要。我们提出了ABCDE,这是ABCD的多线程实现(社区检测的人工基准)图生成器。我们讨论了该算法的实现详细信息,并将其与ABCD模型的先前可用顺序版本以及标准和广泛使用的LFR(Lancichinetti-Fortunato-Radicchi)发电机进行了比较。我们表明,ABCDE的速度比NetworkIT中提供的LFR的并行实现要快十倍,并且比例比缩放更好。此外,该算法不仅更快,而且ABCD生成的随机图具有与原始LFR算法生成的属性相似的属性,而LFR的并行网络实现LFR会产生具有明显不同特征的图形。
translated by 谷歌翻译
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。
translated by 谷歌翻译
图形嵌入是将网络的节点转换为一组向量。良好的嵌入应捕获底层图形拓扑和结构,节点到节点关系以及图形,其子图和节点的其他相关信息。如果实现了这些目标,则嵌入是网络的有意义,可以理解的,通常是压缩的。不幸的是,选择最好的嵌入是一个具有挑战性的任务,并且通常需要域名专家。在本文中,我们扩展了评估作者最近引入的图形嵌入的框架。现在,该框架为每个嵌入的嵌入分配两个分数,本地和全局,测量评估嵌入的嵌入的质量,以便分别需要良好地表示网络的全局属性。如果需要,最好的嵌入可以以无监督的方式选择,或者框架可以识别一些值得进一步调查的少数嵌入。该框架灵活,可扩展,可以处理无向/定向,加权/未加权图。
translated by 谷歌翻译
图形嵌入是图形节点到一组向量的转换。良好的嵌入应捕获图形拓扑,节点与节点的关系以及有关图,其子图和节点的其他相关信息。如果实现了这些目标,则嵌入是网络中有意义的,可理解的,可理解的压缩表示形式,可用于其他机器学习工具,例如节点分类,社区检测或链接预测。主要的挑战是,需要确保嵌入很好地描述图形的属性。结果,选择最佳嵌入是一项具有挑战性的任务,并且通常需要领域专家。在本文中,我们在现实世界网络和人为生成的网络上进行了一系列广泛的实验,并使用选定的图嵌入算法进行了一系列的实验。根据这些实验,我们制定了两个一般结论。首先,如果需要在运行实验之前选择一种嵌入算法,则Node2Vec是最佳选择,因为它在我们的测试中表现最好。话虽如此,在所有测试中都没有单一的赢家,此外,大多数嵌入算法都具有应该调整并随机分配的超参数。因此,如果可能的话,我们对从业者的主要建议是生成几个问题的嵌入,然后使用一个通用框架,该框架为无监督的图形嵌入比较提供了工具。该框架(最近在文献中引入并在GitHub存储库中很容易获得)将分歧分数分配给嵌入,以帮助区分好的分数和不良的分数。
translated by 谷歌翻译
In this paper, we propose a new short-term load forecasting (STLF) model based on contextually enhanced hybrid and hierarchical architecture combining exponential smoothing (ES) and a recurrent neural network (RNN). The model is composed of two simultaneously trained tracks: the context track and the main track. The context track introduces additional information to the main track. It is extracted from representative series and dynamically modulated to adjust to the individual series forecasted by the main track. The RNN architecture consists of multiple recurrent layers stacked with hierarchical dilations and equipped with recently proposed attentive dilated recurrent cells. These cells enable the model to capture short-term, long-term and seasonal dependencies across time series as well as to weight dynamically the input information. The model produces both point forecasts and predictive intervals. The experimental part of the work performed on 35 forecasting problems shows that the proposed model outperforms in terms of accuracy its predecessor as well as standard statistical models and state-of-the-art machine learning models.
translated by 谷歌翻译
Tools of Topological Data Analysis provide stable summaries encapsulating the shape of the considered data. Persistent homology, the most standard and well studied data summary, suffers a number of limitations; its computations are hard to distribute, it is hard to generalize to multifiltrations and is computationally prohibitive for big data-sets. In this paper we study the concept of Euler Characteristics Curves, for one parameter filtrations and Euler Characteristic Profiles, for multi-parameter filtrations. While being a weaker invariant in one dimension, we show that Euler Characteristic based approaches do not possess some handicaps of persistent homology; we show efficient algorithms to compute them in a distributed way, their generalization to multifiltrations and practical applicability for big data problems. In addition we show that the Euler Curves and Profiles enjoys certain type of stability which makes them robust tool in data analysis. Lastly, to show their practical applicability, multiple use-cases are considered.
translated by 谷歌翻译
Hierarchical decomposition of control is unavoidable in large dynamical systems. In reinforcement learning (RL), it is usually solved with subgoals defined at higher policy levels and achieved at lower policy levels. Reaching these goals can take a substantial amount of time, during which it is not verified whether they are still worth pursuing. However, due to the randomness of the environment, these goals may become obsolete. In this paper, we address this gap in the state-of-the-art approaches and propose a method in which the validity of higher-level actions (thus lower-level goals) is constantly verified at the higher level. If the actions, i.e. lower level goals, become inadequate, they are replaced by more appropriate ones. This way we combine the advantages of hierarchical RL, which is fast training, and flat RL, which is immediate reactivity. We study our approach experimentally on seven benchmark environments.
translated by 谷歌翻译
我们提出了三种新型的修剪技术,以提高推理意识到的可区分神经结构搜索(DNAS)的成本和结果。首先,我们介绍了DNA的随机双路构建块,它可以通过内存和计算复杂性在内部隐藏尺寸上进行搜索。其次,我们在搜索过程中提出了一种在超级网的随机层中修剪块的算法。第三,我们描述了一种在搜索过程中修剪不必要的随机层的新技术。由搜索产生的优化模型称为Prunet,并在Imagenet Top-1图像分类精度的推理潜伏期中为NVIDIA V100建立了新的最先进的Pareto边界。将Prunet作为骨架还优于COCO对象检测任务的GPUNET和EFIDENENET,相对于平均平均精度(MAP)。
translated by 谷歌翻译
积极和未标记的学习是一个重要的问题,在许多应用中自然出现。几乎所有现有方法的显着局限性在于假设倾向得分函数是恒定的(疤痕假设),这在许多实际情况下都是不现实的。避免这种假设,我们将参数方法考虑到后验概率和倾向得分功能的关节估计问题。我们表明,在轻度假设下,当两个函数具有相同的参数形式(例如,具有不同参数的逻辑)时,相应的参数是可识别的。在此激励的情况下,我们提出了两种估计方法:关节最大似然法和第二种方法基于两种Fisher一致表达式的交替实现。我们的实验结果表明,所提出的方法比基于预期最大化方案的现有方法可比性或更好。
translated by 谷歌翻译
有效的强化学习需要适当的平衡探索和剥削,由动作分布的分散定义。但是,这种平衡取决于任务,学习过程的当前阶段以及当前的环境状态。指定动作分布分散的现有方法需要依赖问题的超参数。在本文中,我们建议使用以下原则自动指定动作分布分布:该分布应具有足够的分散,以评估未来的政策。为此,应调整色散以确保重播缓冲区中的动作和产生它们的分布模式的足够高的概率(密度),但是这种分散不应更高。这样,可以根据缓冲区中的动作有效评估策略,但是当此策略收敛时,动作的探索性随机性会降低。上述原则在挑战性的基准蚂蚁,Halfcheetah,Hopper和Walker2D上进行了验证,并取得了良好的效果。我们的方法使动作标准偏差收敛到与试验和错误优化产生的相似的值。
translated by 谷歌翻译