模型提取攻击已经再次兴趣了解来自查询的神经网络的经典问题。在这项工作中,我们给出了学习任意一个隐藏层神经网络激活的第一个多项式时间算法,提供了对网络的黑盒访问。正式,我们表明,如果$ F $是一个具有Relu激活的任意一个隐藏的层神经网络,则存在一个具有Query复杂性和运行时间的算法,这些复杂性和运行时间在所有参数中输出网络$ f'$实现低平方丢失相对达到高斯措施的$ F $。虽然安全文献中的许多作品已经提出和经验证明了某些算法的有效性,但是,即使对于最坏情况的网络,我们也是最完全多项式时间对效率保证的影响(特别是我们的算法在整个算法中取得成功)环境)。
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A Digital Twin (DT) is a simulation of a physical system that provides information to make decisions that add economic, social or commercial value. The behaviour of a physical system changes over time, a DT must therefore be continually updated with data from the physical systems to reflect its changing behaviour. For resource-constrained systems, updating a DT is non-trivial because of challenges such as on-board learning and the off-board data transfer. This paper presents a framework for updating data-driven DTs of resource-constrained systems geared towards system health monitoring. The proposed solution consists of: (1) an on-board system running a light-weight DT allowing the prioritisation and parsimonious transfer of data generated by the physical system; and (2) off-board robust updating of the DT and detection of anomalous behaviours. Two case studies are considered using a production gas turbine engine system to demonstrate the digital representation accuracy for real-world, time-varying physical systems.
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Recent advances in upper limb prostheses have led to significant improvements in the number of movements provided by the robotic limb. However, the method for controlling multiple degrees of freedom via user-generated signals remains challenging. To address this issue, various machine learning controllers have been developed to better predict movement intent. As these controllers become more intelligent and take on more autonomy in the system, the traditional approach of representing the human-machine interface as a human controlling a tool becomes limiting. One possible approach to improve the understanding of these interfaces is to model them as collaborative, multi-agent systems through the lens of joint action. The field of joint action has been commonly applied to two human partners who are trying to work jointly together to achieve a task, such as singing or moving a table together, by effecting coordinated change in their shared environment. In this work, we compare different prosthesis controllers (proportional electromyography with sequential switching, pattern recognition, and adaptive switching) in terms of how they present the hallmarks of joint action. The results of the comparison lead to a new perspective for understanding how existing myoelectric systems relate to each other, along with recommendations for how to improve these systems by increasing the collaborative communication between each partner.
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With the rise in high resolution remote sensing technologies there has been an explosion in the amount of data available for forest monitoring, and an accompanying growth in artificial intelligence applications to automatically derive forest properties of interest from these datasets. Many studies use their own data at small spatio-temporal scales, and demonstrate an application of an existing or adapted data science method for a particular task. This approach often involves intensive and time-consuming data collection and processing, but generates results restricted to specific ecosystems and sensor types. There is a lack of widespread acknowledgement of how the types and structures of data used affects performance and accuracy of analysis algorithms. To accelerate progress in the field more efficiently, benchmarking datasets upon which methods can be tested and compared are sorely needed. Here, we discuss how lack of standardisation impacts confidence in estimation of key forest properties, and how considerations of data collection need to be accounted for in assessing method performance. We present pragmatic requirements and considerations for the creation of rigorous, useful benchmarking datasets for forest monitoring applications, and discuss how tools from modern data science can improve use of existing data. We list a set of example large-scale datasets that could contribute to benchmarking, and present a vision for how community-driven, representative benchmarking initiatives could benefit the field.
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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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对使用因果机器学习模型做出的决策的现实测试是成功应用的基本先决条件。我们专注于评估和改善上下文治疗作业决策:这些是适用于例如客户,每个都有自己的上下文信息,以最大程度地获得奖励。在本文中,我们介绍了一个模型不足的框架,用于收集数据,以通过贝叶斯实验设计评估和改善上下文决策。具体而言,我们的方法用于对过去治疗作业的遗憾的数据有效评估。与A/B测试之类的方法不同,我们的方法避免了分配已知是高度优势的治疗方法,同时进行一些探索以收集相关信息。我们通过引入一个基于信息的设计目标来实现这一目标,我们优化了端到端。我们的方法适用于离散和连续治疗。在几项仿真研究中,将我们的信息理论方法与基准者进行比较,这表明了我们提出的方法的出色表现。
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域对抗训练无处不在地实现不变表示,并广泛用于各种域适应任务。近来,融合到平滑最佳的方法已显示出对分类等监督学习任务的改进的概括。在这项工作中,我们分析了增强配方对域对抗训练的影响,其目的是任务损失(例如分类,回归等)和对抗性术语的组合。我们发现,相对于(W.R.T.)任务损失融合了平滑的最小值,可以稳定对抗性训练,从而在目标域上获得更好的性能。与任务损失相反,我们的分析表明,融合到平滑的最小W.R.T.对抗损失导致目标结构域的次级概括。基于分析,我们介绍了平滑的域对抗训练(SDAT)程序,该程序有效地增强了现有域对抗方法的性能,以进行分类和对象检测任务。我们的分析还提供了对社区中亚当(Adam)对域名对抗训练的广泛使用的洞察力。
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语言模型既展示了定量的改进,又展示了新的定性功能,随着规模的增加。尽管它们具有潜在的变革性影响,但这些新能力的特征却很差。为了为未来的研究提供信息,为破坏性的新模型能力做准备,并改善社会有害的效果,至关重要的是,我们必须了解目前和近乎未来的能力和语言模型的局限性。为了应对这一挑战,我们介绍了超越模仿游戏基准(Big Bench)。 Big Bench目前由204个任务组成,由132家机构的442位作者贡献。任务主题是多样的,从语言学,儿童发展,数学,常识性推理,生物学,物理学,社会偏见,软件开发等等。 Big-Bench专注于被认为超出当前语言模型的功能的任务。我们评估了OpenAI的GPT型号,Google内部密集变压器体系结构和大型基础上的开关稀疏变压器的行为,跨越了数百万到数十亿个参数。此外,一个人类专家评估者团队执行了所有任务,以提供强大的基准。研究结果包括:模型性能和校准都随规模改善,但绝对的术语(以及与评估者的性能相比);在模型类中的性能非常相似,尽管带有稀疏性。逐渐和预测的任务通常涉及大量知识或记忆成分,而在临界规模上表现出“突破性”行为的任务通常涉及多个步骤或组成部分或脆性指标;社交偏见通常会随着含糊不清的环境而随着规模而增加,但这可以通过提示来改善。
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我们提出了Adios,这是一个用于自我监督学习的遮罩图像模型(MIM)框架,同时使用对抗性目标学习掩盖功能和图像编码器。对图像编码器进行了训练,以最大程度地减少原始图像的表示形式与蒙版图像的表示之间的距离。相反,掩蔽函数旨在最大化此距离。阿迪奥斯(Adios)始终改进有关各种任务和数据集的最先进的自我监督学习(SSL)方法 - 包括Imagenet100和STL10上的分类,CIFAR10/100上的转移学习,Flowers102和Inaturalist,以及鲁棒性在背景挑战中进行了评估(Xiao等,2021) - 同时产生语义意义的面具。与MAE,BEIT和IBOT等现代MIM模型不同,Adios不依赖视觉变压器的图像斑点令牌构造,并且可以用卷积的骨架来实现。我们进一步证明,与对流行MIM模型中使用的掩盖方案相比,阿迪奥斯学到的面具在改善SSL方法的表示方面更有效。
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在本文中,我们为Pavlovian信号传达的多方面的研究 - 一个过程中学到的一个过程,一个代理商通过另一个代理商通知决策的时间扩展预测。信令紧密连接到时间和时间。在生成和接收信号的服务中,已知人类和其他动物代表时间,确定自过去事件以来的时间,预测到未来刺激的时间,并且都识别和生成展开时间的模式。我们调查通过引入部分可观察到的决策域来对学习代理之间的影响和信令在我们称之为霜冻空心的情况下如何影响学习代理之间的影响和信令。在该域中,预测学习代理和加强学习代理被耦合到两部分决策系统,该系统可以在避免时间条件危险时获取稀疏奖励。我们评估了两个域变型:机器代理在七态线性步行中交互,以及虚拟现实环境中的人机交互。我们的结果展示了帕夫洛维亚信号传导的学习速度,对药剂 - 代理协调具有不同时间表示(并且不)的影响,以及颞次锯齿对药剂和人毒剂相互作用的影响方式不同。作为主要贡献,我们将Pavlovian信号传导为固定信号范例与两个代理之间完全自适应通信学习之间的天然桥梁。我们进一步展示了如何从固定的信令过程计算地构建该自适应信令处理,其特征在于,通过快速的连续预测学习和对接收信号的性质的最小限制。因此,我们的结果表明了加固学习代理之间的沟通学习的可行建设者的途径。
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