In the last years, the number of IoT devices deployed has suffered an undoubted explosion, reaching the scale of billions. However, some new cybersecurity issues have appeared together with this development. Some of these issues are the deployment of unauthorized devices, malicious code modification, malware deployment, or vulnerability exploitation. This fact has motivated the requirement for new device identification mechanisms based on behavior monitoring. Besides, these solutions have recently leveraged Machine and Deep Learning techniques due to the advances in this field and the increase in processing capabilities. In contrast, attackers do not stay stalled and have developed adversarial attacks focused on context modification and ML/DL evaluation evasion applied to IoT device identification solutions. This work explores the performance of hardware behavior-based individual device identification, how it is affected by possible context- and ML/DL-focused attacks, and how its resilience can be improved using defense techniques. In this sense, it proposes an LSTM-CNN architecture based on hardware performance behavior for individual device identification. Then, previous techniques have been compared with the proposed architecture using a hardware performance dataset collected from 45 Raspberry Pi devices running identical software. The LSTM-CNN improves previous solutions achieving a +0.96 average F1-Score and 0.8 minimum TPR for all devices. Afterward, context- and ML/DL-focused adversarial attacks were applied against the previous model to test its robustness. A temperature-based context attack was not able to disrupt the identification. However, some ML/DL state-of-the-art evasion attacks were successful. Finally, adversarial training and model distillation defense techniques are selected to improve the model resilience to evasion attacks, without degrading its performance.
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Cybercriminals are moving towards zero-day attacks affecting resource-constrained devices such as single-board computers (SBC). Assuming that perfect security is unrealistic, Moving Target Defense (MTD) is a promising approach to mitigate attacks by dynamically altering target attack surfaces. Still, selecting suitable MTD techniques for zero-day attacks is an open challenge. Reinforcement Learning (RL) could be an effective approach to optimize the MTD selection through trial and error, but the literature fails when i) evaluating the performance of RL and MTD solutions in real-world scenarios, ii) studying whether behavioral fingerprinting is suitable for representing SBC's states, and iii) calculating the consumption of resources in SBC. To improve these limitations, the work at hand proposes an online RL-based framework to learn the correct MTD mechanisms mitigating heterogeneous zero-day attacks in SBC. The framework considers behavioral fingerprinting to represent SBCs' states and RL to learn MTD techniques that mitigate each malicious state. It has been deployed on a real IoT crowdsensing scenario with a Raspberry Pi acting as a spectrum sensor. More in detail, the Raspberry Pi has been infected with different samples of command and control malware, rootkits, and ransomware to later select between four existing MTD techniques. A set of experiments demonstrated the suitability of the framework to learn proper MTD techniques mitigating all attacks (except a harmfulness rootkit) while consuming <1 MB of storage and utilizing <55% CPU and <80% RAM.
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嗜睡是驾驶员和交通事故主要原因之一的主要关注点。认知神经科学和计算机科学的进步已通过使用脑部计算机界面(BCIS)和机器学习(ML)来检测驾驶员的嗜睡。然而,几个挑战仍然开放,应该面对。首先,文献中缺少使用一组ML算法的多种ML算法对嗜睡检测性能的全面评估。最后,需要研究适合受试者组的可扩展ML模型的检测性能,并将其与文献中提出的单个模型进行比较。为了改善这些局限性,这项工作提出了一个智能框架,该框架采用了BCIS和基于脑电图(EEG)的功能,以检测驾驶场景中的嗜睡。 SEED-VIG数据集用于喂食不同的ML回归器和三类分类器,然后评估,分析和比较单个受试者和组的表现最佳模型。有关单个模型的更多详细信息,随机森林(RF)获得了78%的F1分数,改善了通过文献中使用的模型(例如支持向量机(SVM))获得的58%。关于可扩展模型,RF达到了79%的F1得分,证明了这些方法的有效性。所学的经验教训可以总结如下:i)不仅SVM,而且文献中未充分探索的其他模型与嗜睡检测有关,ii)ii)适用于受试者组的可伸缩方法也有效地检测嗜睡,即使新受试者也是如此评估模型培训中未包括的。
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交通事故是年轻人死亡的主要原因,这一问题今天占了大量受害者。已经提出了几种技术来预防事故,是脑部计算机界面(BCIS)最有前途的技术之一。在这种情况下,BCI被用来检测情绪状态,集中问题或压力很大的情况,这可能在道路上起着基本作用,因为它们与驾驶员的决定直接相关。但是,在驾驶场景中,没有广泛的文献应用BCI来检测受试者的情绪。在这种情况下,需要解决一些挑战,例如(i)执行驾驶任务对情绪检测的影响以及(ii)在驾驶场景中哪些情绪更可检测到的情绪。为了改善这些挑战,这项工作提出了一个框架,该框架着重于使用机器学习和深度学习算法的脑电图检测情绪。此外,已经设计了两个场景的用例。第一种情况是聆听声音作为要执行的主要任务,而在第二种情况下,聆听声音成为次要任务,这是使用驱动模拟器的主要任务。这样,它旨在证明BCI在这种驾驶方案中是否有用。结果改善了文献中现有的结果,可在发现两种情绪(非刺激性和愤怒)中达到99%的准确性,三种情绪(非刺激性,愤怒和中立)的93%,四种情绪(非刺激)(非 - 刺激,愤怒,中立和喜悦)。
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近年来经历的计算设备部署爆炸,由诸如互联网(物联网)和5G的技术(IOT)和5G等技术的激励,导致了全局情景,随着网络安全的风险和威胁的增加。其中,设备欺骗和模糊的网络攻击因其影响而脱颖而出,并且通常需要推出的低复杂性。为了解决这个问题,已经出现了几种解决方案,以根据行为指纹和机器/深度学习(ML / DL)技术的组合来识别设备模型和类型。但是,这些解决方案不适合数据隐私和保护的方案,因为它们需要数据集中处理以进行处理。在这种情况下,尚未完全探索较新的方法,例如联合学习(FL),特别是当恶意客户端存在于场景设置时。目前的工作分析并比较了使用基于执行时间的事件的v一体的集中式DL模型的设备模型识别性能。对于实验目的,已经收集并公布了属于四种不同模型的55个覆盆子PI的执行时间特征的数据集。使用此数据集,所提出的解决方案在两个设置,集中式和联合中实现了0.9999的精度,在保留数据隐私时显示没有性能下降。后来,使用几种聚集机制作为对策,评估标签翻转攻击在联邦模型训练期间的影响。 ZENO和协调明智的中值聚合表现出最佳性能,尽管当他们的性能大大降低时,当完全恶意客户(所有培训样本中毒)增长超过50%时大大降临。
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This work presents a set of neural network (NN) models specifically designed for accurate and efficient fluid dynamics forecasting. In this work, we show how neural networks training can be improved by reducing data complexity through a modal decomposition technique called higher order dynamic mode decomposition (HODMD), which identifies the main structures inside flow dynamics and reconstructs the original flow using only these main structures. This reconstruction has the same number of samples and spatial dimension as the original flow, but with a less complex dynamics and preserving its main features. We also show the low computational cost required by the proposed NN models, both in their training and inference phases. The core idea of this work is to test the limits of applicability of deep learning models to data forecasting in complex fluid dynamics problems. Generalization capabilities of the models are demonstrated by using the same neural network architectures to forecast the future dynamics of four different multi-phase flows. Data sets used to train and test these deep learning models come from Direct Numerical Simulations (DNS) of these flows.
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Social insects such as ants communicate via pheromones which allows them to coordinate their activity and solve complex tasks as a swarm, e.g. foraging for food. This behaviour was shaped through evolutionary processes. In computational models, self-coordination in swarms has been implemented using probabilistic or action rules to shape the decision of each agent and the collective behaviour. However, manual tuned decision rules may limit the behaviour of the swarm. In this work we investigate the emergence of self-coordination and communication in evolved swarms without defining any rule. We evolve a swarm of agents representing an ant colony. We use a genetic algorithm to optimize a spiking neural network (SNN) which serves as an artificial brain to control the behaviour of each agent. The goal of the colony is to find optimal ways to forage for food in the shortest amount of time. In the evolutionary phase, the ants are able to learn to collaborate by depositing pheromone near food piles and near the nest to guide its cohorts. The pheromone usage is not encoded into the network; instead, this behaviour is established through the optimization procedure. We observe that pheromone-based communication enables the ants to perform better in comparison to colonies where communication did not emerge. We assess the foraging performance by comparing the SNN based model to a rule based system. Our results show that the SNN based model can complete the foraging task more efficiently in a shorter time. Our approach illustrates that even in the absence of pre-defined rules, self coordination via pheromone emerges as a result of the network optimization. This work serves as a proof of concept for the possibility of creating complex applications utilizing SNNs as underlying architectures for multi-agent interactions where communication and self-coordination is desired.
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Recent advances in self-supervised visual representation learning have paved the way for unsupervised methods tackling tasks such as object discovery and instance segmentation. However, discovering objects in an image with no supervision is a very hard task; what are the desired objects, when to separate them into parts, how many are there, and of what classes? The answers to these questions depend on the tasks and datasets of evaluation. In this work, we take a different approach and propose to look for the background instead. This way, the salient objects emerge as a by-product without any strong assumption on what an object should be. We propose FOUND, a simple model made of a single $conv1\times1$ initialized with coarse background masks extracted from self-supervised patch-based representations. After fast training and refining these seed masks, the model reaches state-of-the-art results on unsupervised saliency detection and object discovery benchmarks. Moreover, we show that our approach yields good results in the unsupervised semantic segmentation retrieval task. The code to reproduce our results is available at https://github.com/valeoai/FOUND.
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A generalized understanding of protein dynamics is an unsolved scientific problem, the solution of which is critical to the interpretation of the structure-function relationships that govern essential biological processes. Here, we approach this problem by constructing coarse-grained molecular potentials based on artificial neural networks and grounded in statistical mechanics. For training, we build a unique dataset of unbiased all-atom molecular dynamics simulations of approximately 9 ms for twelve different proteins with multiple secondary structure arrangements. The coarse-grained models are capable of accelerating the dynamics by more than three orders of magnitude while preserving the thermodynamics of the systems. Coarse-grained simulations identify relevant structural states in the ensemble with comparable energetics to the all-atom systems. Furthermore, we show that a single coarse-grained potential can integrate all twelve proteins and can capture experimental structural features of mutated proteins. These results indicate that machine learning coarse-grained potentials could provide a feasible approach to simulate and understand protein dynamics.
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Domain adaptation has been vastly investigated in computer vision but still requires access to target images at train time, which might be intractable in some conditions, especially for long-tail samples. In this paper, we propose the task of `Prompt-driven Zero-shot Domain Adaptation', where we adapt a model trained on a source domain using only a general textual description of the target domain, i.e., a prompt. First, we leverage a pretrained contrastive vision-language model (CLIP) to optimize affine transformations of source features, bringing them closer to target text embeddings, while preserving their content and semantics. Second, we show that augmented features can be used to perform zero-shot domain adaptation for semantic segmentation. Experiments demonstrate that our method significantly outperforms CLIP-based style transfer baselines on several datasets for the downstream task at hand. Our prompt-driven approach even outperforms one-shot unsupervised domain adaptation on some datasets, and gives comparable results on others. The code is available at https://github.com/astra-vision/PODA.
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