流数据分类的重要问题之一是概念漂移的发生,包括分类任务的概率特征的变化。这种现象不稳定了分类模型的性能,并严重降低了其质量。需要抵消这种现象的适当策略来使分类器适应变化的概率特征。实现此类解决方案的一个重要问题是访问数据标签。它通常是昂贵的,从而最大限度地减少与该过程相关的费用,提出了基于半监督学习的学习策略,例如,采用主动学习方法,该方法指示哪些传入对象是有价值的,以便标记为提高分类器的性能。本文提出了一种基于基于分类器集合学习的非静止数据流的基于块的方法,以及考虑可以成功应用于任何数据流分类算法的有限预算的主动学习策略。已经通过使用真实和生成的数据流进行了计算机实验来评估所提出的方法。结果证实了最先进的方法的高质量。
translated by 谷歌翻译
The celebrated FedAvg algorithm of McMahan et al. (2017) is based on three components: client sampling (CS), data sampling (DS) and local training (LT). While the first two are reasonably well understood, the third component, whose role is to reduce the number of communication rounds needed to train the model, resisted all attempts at a satisfactory theoretical explanation. Malinovsky et al. (2022) identified four distinct generations of LT methods based on the quality of the provided theoretical communication complexity guarantees. Despite a lot of progress in this area, none of the existing works were able to show that it is theoretically better to employ multiple local gradient-type steps (i.e., to engage in LT) than to rely on a single local gradient-type step only in the important heterogeneous data regime. In a recent breakthrough embodied in their ProxSkip method and its theoretical analysis, Mishchenko et al. (2022) showed that LT indeed leads to provable communication acceleration for arbitrarily heterogeneous data, thus jump-starting the $5^{\rm th}$ generation of LT methods. However, while these latest generation LT methods are compatible with DS, none of them support CS. We resolve this open problem in the affirmative. In order to do so, we had to base our algorithmic development on new algorithmic and theoretical foundations.
translated by 谷歌翻译
Deep spiking neural networks (SNNs) offer the promise of low-power artificial intelligence. However, training deep SNNs from scratch or converting deep artificial neural networks to SNNs without loss of performance has been a challenge. Here we propose an exact mapping from a network with Rectified Linear Units (ReLUs) to an SNN that fires exactly one spike per neuron. For our constructive proof, we assume that an arbitrary multi-layer ReLU network with or without convolutional layers, batch normalization and max pooling layers was trained to high performance on some training set. Furthermore, we assume that we have access to a representative example of input data used during training and to the exact parameters (weights and biases) of the trained ReLU network. The mapping from deep ReLU networks to SNNs causes zero percent drop in accuracy on CIFAR10, CIFAR100 and the ImageNet-like data sets Places365 and PASS. More generally our work shows that an arbitrary deep ReLU network can be replaced by an energy-efficient single-spike neural network without any loss of performance.
translated by 谷歌翻译
We leverage probabilistic models of neural representations to investigate how residual networks fit classes. To this end, we estimate class-conditional density models for representations learned by deep ResNets. We then use these models to characterize distributions of representations across learned classes. Surprisingly, we find that classes in the investigated models are not fitted in an uniform way. On the contrary: we uncover two groups of classes that are fitted with markedly different distributions of representations. These distinct modes of class-fitting are evident only in the deeper layers of the investigated models, indicating that they are not related to low-level image features. We show that the uncovered structure in neural representations correlate with memorization of training examples and adversarial robustness. Finally, we compare class-conditional distributions of neural representations between memorized and typical examples. This allows us to uncover where in the network structure class labels arise for memorized and standard inputs.
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
视觉奇数任务被认为是对人类的普遍独立的分析智能测试。人工智能的进步导致了重要的突破,但是与人类在此类分析智能任务上竞争仍然具有挑战性,并且通常诉诸于非生物学上的架构。我们提出了一个具有生物学现实的系统,该系统从合成眼动运动中接收输入 - 扫视,并与结合新皮质神经元动力学的神经元一起处理它们。我们介绍了一个程序生成的视觉奇数数据集,以训练扩展常规关系网络和我们建议的系统的体系结构。两种方法都超过了人类的准确性,我们发现两者都具有相同的基本推理基本机制。最后,我们表明,具有生物学启发的网络可实现卓越的准确性,学习速度更快,所需的参数比常规网络更少。
translated by 谷歌翻译
持续学习系统将知识从先前看到的任务转移以最大程度地提高新任务的能力是该领域的重大挑战,从而限制了持续学习解决方案对现实情况的适用性。因此,本研究旨在扩大我们在不断加强学习的特定情况下对转移及其驱动力的理解。我们采用SAC作为基础RL算法和持续的世界作为连续控制任务的套件。我们系统地研究SAC(演员和评论家,勘探和数据)的不同组成部分如何影响转移功效,并提供有关各种建模选项的建议。在最近的连续世界基准中评估了最佳的选择,即称为clonex-sac。 Clonex-SAC获得了87%的最终成功率,而Packnet的80%是基准中的最佳方法。此外,根据连续世界提供的指标,转移从0.18增至0.54。
translated by 谷歌翻译
素描和项目是一个框架,它统一了许多已知的迭代方法来求解线性系统及其变体,并进一步扩展了非线性优化问题。它包括流行的方法,例如随机kaczmarz,坐标下降,凸优化的牛顿方法的变体等。在本文中,我们通过新的紧密频谱边界为预期的草图投影矩阵获得了素描和项目的收敛速率的敏锐保证。我们的估计值揭示了素描和项目的收敛率与另一个众所周知但看似无关的算法家族的近似误差之间的联系,这些算法使用草图加速了流行的矩阵因子化,例如QR和SVD。这种连接使我们更接近准确量化草图和项目求解器的性能如何取决于其草图大小。我们的分析不仅涵盖了高斯和次高斯的素描矩阵,还涵盖了一个有效的稀疏素描方法,称为较少的嵌入方法。我们的实验备份了理论,并证明即使极稀疏的草图在实践中也显示出相同的收敛属性。
translated by 谷歌翻译
在针对自闭症谱系障碍患者的机器人辅助治疗中,如果必须手动控制机器人,则在治疗过程中的治疗师工作量会增加。为了允许治疗师专注于与人的互动,机器人应该更加自主,即它应该能够解释该人的状态并根据其行为不断适应其行为。在本文中,我们开发了一个个性化的机器人行为模型,该模型可以在活动期间的机器人决策过程中使用。该行为模型是在从真实交互数据中学到的用户模型的帮助下训练的。我们将Q学习用于此任务,因此结果表明该策略需要大约10,000次迭代才能收敛。因此,我们调查了改善收敛速度的政策转移;我们表明这是一个可行的解决方案,但是不适当的初始政策可以导致最终的最终回报。
translated by 谷歌翻译
我们提出了一种利用分布人工神经网络的概率电价预测(EPF)的新方法。EPF的新型网络结构基于包含概率层的正则分布多层感知器(DMLP)。使用TensorFlow概率框架,神经网络的输出被定义为一个分布,是正常或可能偏斜且重尾的Johnson的SU(JSU)。在预测研究中,将该方法与最新基准进行了比较。该研究包括预测,涉及德国市场的日常电价。结果显示了对电价建模时较高时刻的重要性的证据。
translated by 谷歌翻译