最近,图形神经网络(GNN)已应用于群集上的调整工作,比手工制作的启发式方法更好地表现了。尽管表现令人印象深刻,但仍然担心这些基于GNN的工作调度程序是否满足用户对其他重要属性的期望,例如防止策略,共享激励和稳定性。在这项工作中,我们考虑对基于GNN的工作调度程序的正式验证。我们解决了几个特定领域的挑战,例如网络,这些挑战比验证图像和NLP分类器时遇到的更深层和规格更丰富。我们开发了拉斯维加斯,这是基于精心设计的算法,将这些调度程序的单步和多步属性验证的第一个通用框架,它们结合了抽象,改进,求解器和证明传输。我们的实验结果表明,与以前的方法相比,维加斯在验证基于GNN的调度程序的重要特性时会达到显着加速。
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添加到输入的最小侵犯扰动已被证明在愚弄深度神经网络方面有效。在本文中,我们介绍了几种创新,使白盒子目标攻击遵循攻击者的目标:欺骗模型将更高的目标类概率分配比任何其他更高的概率,同时停留在距原始距离的指定距离内输入。首先,我们提出了一种新的损失函数,明确地捕获了目标攻击的目标,特别是通过使用所有类的Logits而不是仅仅是一个子集。我们表明,具有这种损失功能的自动PGD比与其他常用损耗功能相比发现更多的对抗示例。其次,我们提出了一种新的攻击方法,它使用进一步发发版本的我们的损失函数捕获错误分类目标和$ l _ {\ infty} $距离限制$ \ epsilon $。这种新的攻击方法在CIFAR10 DataSet上比较成功了1.5--4.2%,而在ImageNet DataSet上比下一个最先进的攻击更成功。我们使用统计测试确认,我们的攻击优于最先进的攻击不同数据集和$ \ epsilon $和不同防御的价值。
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Automatic medical image classification is a very important field where the use of AI has the potential to have a real social impact. However, there are still many challenges that act as obstacles to making practically effective solutions. One of those is the fact that most of the medical imaging datasets have a class imbalance problem. This leads to the fact that existing AI techniques, particularly neural network-based deep-learning methodologies, often perform poorly in such scenarios. Thus this makes this area an interesting and active research focus for researchers. In this study, we propose a novel loss function to train neural network models to mitigate this critical issue in this important field. Through rigorous experiments on three independently collected datasets of three different medical imaging domains, we empirically show that our proposed loss function consistently performs well with an improvement between 2%-10% macro f1 when compared to the baseline models. We hope that our work will precipitate new research toward a more generalized approach to medical image classification.
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The number of international benchmarking competitions is steadily increasing in various fields of machine learning (ML) research and practice. So far, however, little is known about the common practice as well as bottlenecks faced by the community in tackling the research questions posed. To shed light on the status quo of algorithm development in the specific field of biomedical imaging analysis, we designed an international survey that was issued to all participants of challenges conducted in conjunction with the IEEE ISBI 2021 and MICCAI 2021 conferences (80 competitions in total). The survey covered participants' expertise and working environments, their chosen strategies, as well as algorithm characteristics. A median of 72% challenge participants took part in the survey. According to our results, knowledge exchange was the primary incentive (70%) for participation, while the reception of prize money played only a minor role (16%). While a median of 80 working hours was spent on method development, a large portion of participants stated that they did not have enough time for method development (32%). 25% perceived the infrastructure to be a bottleneck. Overall, 94% of all solutions were deep learning-based. Of these, 84% were based on standard architectures. 43% of the respondents reported that the data samples (e.g., images) were too large to be processed at once. This was most commonly addressed by patch-based training (69%), downsampling (37%), and solving 3D analysis tasks as a series of 2D tasks. K-fold cross-validation on the training set was performed by only 37% of the participants and only 50% of the participants performed ensembling based on multiple identical models (61%) or heterogeneous models (39%). 48% of the respondents applied postprocessing steps.
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In classic reinforcement learning algorithms, agents make decisions at discrete and fixed time intervals. The physical duration between one decision and the next becomes a critical hyperparameter. When this duration is too short, the agent needs to make many decisions to achieve its goal, aggravating the problem's difficulty. But when this duration is too long, the agent becomes incapable of controlling the system. Physical systems, however, do not need a constant control frequency. For learning agents, it is desirable to operate with low frequency when possible and high frequency when necessary. We propose a framework called Continuous-Time Continuous-Options (CTCO), where the agent chooses options as sub-policies of variable durations. Such options are time-continuous and can interact with the system at any desired frequency providing a smooth change of actions. The empirical analysis shows that our algorithm is competitive w.r.t. other time-abstraction techniques, such as classic option learning and action repetition, and practically overcomes the difficult choice of the decision frequency.
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Data scarcity is a notable problem, especially in the medical domain, due to patient data laws. Therefore, efficient Pre-Training techniques could help in combating this problem. In this paper, we demonstrate that a model trained on the time direction of functional neuro-imaging data could help in any downstream task, for example, classifying diseases from healthy controls in fMRI data. We train a Deep Neural Network on Independent components derived from fMRI data using the Independent component analysis (ICA) technique. It learns time direction in the ICA-based data. This pre-trained model is further trained to classify brain disorders in different datasets. Through various experiments, we have shown that learning time direction helps a model learn some causal relation in fMRI data that helps in faster convergence, and consequently, the model generalizes well in downstream classification tasks even with fewer data records.
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智能仪表测量值虽然对于准确的需求预测至关重要,但仍面临一些缺点,包括消费者的隐私,数据泄露问题,仅举几例。最近的文献探索了联合学习(FL)作为一种有前途的隐私机器学习替代方案,该替代方案可以协作学习模型,而无需将私人原始数据暴露于短期负载预测中。尽管有着美德,但标准FL仍然容易受到棘手的网络威胁,称为拜占庭式攻击,这是由错误和/或恶意客户进行的。因此,为了提高联邦联邦短期负载预测对拜占庭威胁的鲁棒性,我们开发了一个最先进的基于私人安全的FL框架,以确保单个智能电表的数据的隐私,同时保护FL的安全性模型和架构。我们提出的框架利用了通过符号随机梯度下降(SignsGD)算法的梯度量化的想法,在本地模型培训后,客户仅将梯度的“符号”传输到控制中心。当我们通过涉及一组拜占庭攻击模型的基准神经网络的实验突出显示时,我们提出的方法会非常有效地减轻此类威胁,从而优于常规的FED-SGD模型。
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身份验证系统容易受到模型反演攻击的影响,在这种攻击中,对手能够近似目标机器学习模型的倒数。生物识别模型是这种攻击的主要候选者。这是因为反相生物特征模型允许攻击者产生逼真的生物识别输入,以使生物识别认证系统欺骗。进行成功模型反转攻击的主要限制之一是所需的训练数据量。在这项工作中,我们专注于虹膜和面部生物识别系统,并提出了一种新技术,可大大减少必要的训练数据量。通过利用多个模型的输出,我们能够使用1/10进行模型反演攻击,以艾哈迈德和富勒(IJCB 2020)的训练集大小(IJCB 2020)进行虹膜数据,而Mai等人的训练集大小为1/1000。 (模式分析和机器智能2019)的面部数据。我们将新的攻击技术表示为结构性随机,并损失对齐。我们的攻击是黑框,不需要了解目标神经网络的权重,只需要输出向量的维度和值。为了显示对齐损失的多功能性,我们将攻击框架应用于会员推理的任务(Shokri等,IEEE S&P 2017),对生物识别数据。对于IRIS,针对分类网络的会员推断攻击从52%提高到62%的准确性。
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自从各种任务的自动化开始以来,自动驾驶车辆一直引起人们的兴趣。人类容易疲惫,在道路上的响应时间缓慢,最重要的是,每年约有135万道路交通事故死亡,这已经是一项危险的任务。预计自动驾驶可以减少世界上驾驶事故的数量,这就是为什么这个问题对研究人员感兴趣的原因。目前,自动驾驶汽车在使车辆自动驾驶时使用不同的算法来实现各种子问题。我们将重点关注增强学习算法,更具体地说是Q学习算法和增强拓扑的神经进化(NEAT),即进化算法和人工神经网络的组合,以训练模型代理,以学习如何在给定路径上驱动。本文将重点介绍上述两种算法之间的比较。
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痴呆症是一种神经精神脑障碍,通常会在一个或多个脑细胞停止部分或根本停止工作时发生。在疾病的早期阶段诊断这种疾病是从不良后果中挽救生命并为他们提供更好的医疗保健的至关重要的任务。事实证明,机器学习方法在预测疾病早期痴呆症方面是准确的。痴呆的预测在很大程度上取决于通常从归一化的全脑体积(NWBV)和地图集缩放系数(ASF)收集的收集数据类型,这些数据通常测量并从磁共振成像(MRIS)中进行校正。年龄和性别等其他生物学特征也可以帮助诊断痴呆症。尽管许多研究使用机器学习来预测痴呆症,但我们无法就这些方法的稳定性得出结论,而这些方法在不同的实验条件下更准确。因此,本文研究了有关痴呆预测的机器学习算法的性能的结论稳定性。为此,使用7种机器学习算法和两种功能还原算法,即信息增益(IG)和主成分分析(PCA)进行大量实验。为了检查这些算法的稳定性,IG的特征选择阈值从20%更改为100%,PCA尺寸从2到8。这导致了7x9 + 7x7 = 112实验。在每个实验中,都记录了各种分类评估数据。获得的结果表明,在七种算法中,支持向量机和天真的贝叶斯是最稳定的算法,同时更改选择阈值。同样,发现使用IG似乎比使用PCA预测痴呆症更有效。
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