Time Series Classification (TSC) is an important and challenging problem in data mining. With the increase of time series data availability, hundreds of TSC algorithms have been proposed. Among these methods, only a few have considered Deep Neural Networks (DNNs) to perform this task. This is surprising as deep learning has seen very successful applications in the last years. DNNs have indeed revolutionized the field of computer vision especially with the advent of novel deeper architectures such as Residual and Convolutional Neural Networks. Apart from images, sequential data such as text and audio can also be processed with DNNs to reach state-of-the-art performance for document classification and speech recognition. In this article, we study the current state-ofthe-art performance of deep learning algorithms for TSC by presenting an empirical study of the most recent DNN architectures for TSC. We give an overview of the most successful deep learning applications in various time series domains under a unified taxonomy of DNNs for TSC. We also provide an open source deep learning framework to the TSC community where we implemented each of the compared approaches and evaluated them on a univariate TSC benchmark (the UCR/UEA archive) and 12 multivariate time series datasets. By training 8,730 deep learning models on 97 time series datasets, we propose the most exhaustive study of DNNs for TSC to date.

Multi-lingual language models (LM), such as mBERT, XLM-R, mT5, mBART, have been remarkably successful in enabling natural language tasks in low-resource languages through cross-lingual transfer from high-resource ones. In this work, we try to better understand how such models, specifically mT5, transfer *any* linguistic and semantic knowledge across languages, even though no explicit cross-lingual signals are provided during pre-training. Rather, only unannotated texts from each language are presented to the model separately and independently of one another, and the model appears to implicitly learn cross-lingual connections. This raises several questions that motivate our study, such as: Are the cross-lingual connections between every language pair equally strong? What properties of source and target language impact the strength of cross-lingual transfer? Can we quantify the impact of those properties on the cross-lingual transfer? In our investigation, we analyze a pre-trained mT5 to discover the attributes of cross-lingual connections learned by the model. Through a statistical interpretation framework over 90 language pairs across three tasks, we show that transfer performance can be modeled by a few linguistic and data-derived features. These observations enable us to interpret cross-lingual understanding of the mT5 model. Through these observations, one can favorably choose the best source language for a task, and can anticipate its training data demands. A key finding of this work is that similarity of syntax, morphology and phonology are good predictors of cross-lingual transfer, significantly more than just the lexical similarity of languages. For a given language, we are able to predict zero-shot performance, that increases on a logarithmic scale with the number of few-shot target language data points.

Model extraction is a major threat for embedded deep neural network models that leverages an extended attack surface. Indeed, by physically accessing a device, an adversary may exploit side-channel leakages to extract critical information of a model (i.e., its architecture or internal parameters). Different adversarial objectives are possible including a fidelity-based scenario where the architecture and parameters are precisely extracted (model cloning). We focus this work on software implementation of deep neural networks embedded in a high-end 32-bit microcontroller (Cortex-M7) and expose several challenges related to fidelity-based parameters extraction through side-channel analysis, from the basic multiplication operation to the feed-forward connection through the layers. To precisely extract the value of parameters represented in the single-precision floating point IEEE-754 standard, we propose an iterative process that is evaluated with both simulations and traces from a Cortex-M7 target. To our knowledge, this work is the first to target such an high-end 32-bit platform. Importantly, we raise and discuss the remaining challenges for the complete extraction of a deep neural network model, more particularly the critical case of biases.

This paper focuses on the uncertainty estimation of white matter lesions (WML) segmentation in magnetic resonance imaging (MRI). On one side, voxel-scale segmentation errors cause the erroneous delineation of the lesions; on the other side, lesion-scale detection errors lead to wrong lesion counts. Both of these factors are clinically relevant for the assessment of multiple sclerosis patients. This work aims to compare the ability of different voxel- and lesion- scale uncertainty measures to capture errors related to segmentation and lesion detection respectively. Our main contributions are (i) proposing new measures of lesion-scale uncertainty that do not utilise voxel-scale uncertainties; (ii) extending an error retention curves analysis framework for evaluation of lesion-scale uncertainty measures. Our results obtained on the multi-center testing set of 58 patients demonstrate that the proposed lesion-scale measures achieves the best performance among the analysed measures. All code implementations are provided at https://github.com/NataliiaMolch/MS_WML_uncs

深度神经网络模型大量部署在各种硬件平台上。这导致出现新的攻击向量，这些攻击向量大大扩展了标准攻击表面，这是由对抗机器学习社区广泛研究的。旨在通过瞄准存储在内存中的参数（权重）的第一个旨在极大地降低模型性能的攻击之一是位翼攻击（BFA）。在这项工作中，我们指出了与BFA相关的一些评估挑战。首先，标准威胁模型中缺乏对手的预算是有问题的，尤其是在处理身体攻击时。此外，由于BFA提出了关键的可变性，因此我们讨论了某些培训参数的影响以及模型体系结构的重要性。这项工作是第一个介绍BFA对与卷积神经网络相比呈现不同行为的完全连接体系结构的影响的作品。这些结果突出了定义鲁棒和合理评估方法的重要性，以正确评估基于参数的攻击的危险，并衡量国防提供的实际鲁棒性水平。

卵巢癌是最致命的妇科恶性肿瘤。该疾病在早期阶段最常是无症状的，其诊断依赖于经阴道超声图像的专家评估。超声是表征附加质量的一线成像方式，它需要大量的专业知识，其分析是主观的和劳动的，因此易于误差。因此，在临床实践中需要进行自动化的过程，以促进和标准化扫描评估。使用监督的学习，我们证明了附加质量的分割是可能的，但是，患病率和标签不平衡限制了代表性不足的类别的性能。为了减轻这种情况，我们应用了一种新颖的病理学数据合成器。我们通过使用Poisson图像编辑将较少常见的质量整合到其他样品中，从而创建及其相应的地面真实分割的合成医学图像。我们的方法在所有班级中都取得了最佳性能，包括与NNU-NET基线方法相比，提高了多达8％。

DeepMind的游戏理论与多代理团队研究多学科学习的几个方面，从计算近似值到游戏理论中的基本概念，再到在富裕的空间环境中模拟社会困境，并在困难的团队协调任务中培训3-D类人动物。我们小组的一个签名目的是使用DeepMind在DeepMind中提供的资源和专业知识，以深入强化学习来探索复杂环境中的多代理系统，并使用这些基准来提高我们的理解。在这里，我们总结了我们团队的最新工作，并提出了一种分类法，我们认为这重点介绍了多代理研究中许多重要的开放挑战。

当今许多大型系统的设计，从交通路由环境到智能电网，都依赖游戏理论平衡概念。但是，随着$ n $玩家游戏的大小通常会随着$ n $而成倍增长，标准游戏理论分析实际上是不可行的。最近的方法通过考虑平均场游戏，匿名$ n $玩家游戏的近似值，在这种限制中，玩家的数量是无限的，而人口的状态分布，而不是每个单独的球员的状态，是兴趣。然而，迄今为止研究最多的平均场平衡的平均场nash平衡的实际可计算性通常取决于有益的非一般结构特性，例如单调性或收缩性能，这是已知的算法收敛所必需的。在这项工作中，我们通过开发均值相关和与粗相关的平衡的概念来研究平均场比赛的替代途径。我们证明，可以使用三种经典算法在\ emph {ash All Games}中有效地学习它们，而无需对游戏结构进行任何其他假设。此外，我们在文献中已经建立了对应关系，从而获得了平均场 - $ n $玩家过渡的最佳范围，并经验证明了这些算法在简单游戏中的收敛性。

考虑到来源提供准确的信息（可信度）的可能性，加权多数投票（WMV）是集体决策制定的众所周知的最佳决策规则。但是，实际上，可信度不是对决策者的已知数量 - 他们必须依靠称为信托的估计。计算信任的（机器学习）算法在具有系统上不高估或低估可信度的属性时称为无偏见。为了正式分析决策过程的不确定性，我们介绍和分析了这种无偏信任值的两个重要特性：正确性的稳定性和最优性的稳定性。正确性的稳定性意味着决策者认为自己所获得的决策准确性等于实际准确性。我们证明了正确性的稳定性。最优性的稳定性意味着基于信任做出的决策与基于可信赖性的情况一样好。最佳稳定性不达到。我们分析了两者之间的差异及其界限。我们还概述了对信任和可信度变化的敏感决策正确性的敏感性。

我们介绍了DeepNash，这是一种能够学习从头开始播放不完美的信息游戏策略的自主代理，直到人类的专家级别。 Stratego是人工智能（AI）尚未掌握的少数标志性棋盘游戏之一。这个受欢迎的游戏具有$ 10^{535} $节点的巨大游戏树，即，$ 10^{175} $倍的$倍于GO。它具有在不完美的信息下需要决策的其他复杂性，类似于德克萨斯州Hold'em扑克，该扑克的游戏树较小（以$ 10^{164} $节点为单位）。 Stratego中的决策是在许多离散的动作上做出的，而动作与结果之间没有明显的联系。情节很长，在球员获胜之前经常有数百次动作，而Stratego中的情况则不能像扑克中那样轻松地分解成管理大小的子问题。由于这些原因，Stratego几十年来一直是AI领域的巨大挑战，现有的AI方法几乎没有达到业余比赛水平。 Deepnash使用游戏理论，无模型的深钢筋学习方法，而无需搜索，该方法学会通过自我播放来掌握Stratego。 DeepNash的关键组成部分的正则化NASH Dynamics（R-NAD）算法通过直接修改基础多项式学习动力学来收敛到近似NASH平衡，而不是围绕它“循环”。 Deepnash在Stratego中击败了现有的最先进的AI方法，并在Gravon Games平台上获得了年度（2022年）和历史前3名，并与人类专家竞争。