我们研究了如何在只有几个类别(几次拍摄设置)给出的一些样本时识别来自Unseen类别(开放式分类)的样本的问题。学习良好抽象的挑战是一个非常少数样本的课程使得从看不见的类别中检测样本非常困难;因此,开放式识别在少量拍摄设置中受到最小的关注。大多数开放式少量拍摄分类方法正规化SoftMax得分以表明开放类样本的均匀概率,但我们认为这种方法通常是不准确的,特别是在细粒度。相反,我们提出了一种新颖的示例性重建的元学习策略,用于共同检测开放类样本,以及通过基于度量的分类对来自观众的样本进行分类。充当类的代表的示例可以在训练数据集中提供或在特征域中估计。我们的框架,名为重建示例的基于少量拍摄的少量开放式分类器(Refofs),在各种数据集上测试,实验结果明确突出了我们作为新技术的方法。
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Search and Rescue (SAR) missions in remote environments often employ autonomous multi-robot systems that learn, plan, and execute a combination of local single-robot control actions, group primitives, and global mission-oriented coordination and collaboration. Often, SAR coordination strategies are manually designed by human experts who can remotely control the multi-robot system and enable semi-autonomous operations. However, in remote environments where connectivity is limited and human intervention is often not possible, decentralized collaboration strategies are needed for fully-autonomous operations. Nevertheless, decentralized coordination may be ineffective in adversarial environments due to sensor noise, actuation faults, or manipulation of inter-agent communication data. In this paper, we propose an algorithmic approach based on adversarial multi-agent reinforcement learning (MARL) that allows robots to efficiently coordinate their strategies in the presence of adversarial inter-agent communications. In our setup, the objective of the multi-robot team is to discover targets strategically in an obstacle-strewn geographical area by minimizing the average time needed to find the targets. It is assumed that the robots have no prior knowledge of the target locations, and they can interact with only a subset of neighboring robots at any time. Based on the centralized training with decentralized execution (CTDE) paradigm in MARL, we utilize a hierarchical meta-learning framework to learn dynamic team-coordination modalities and discover emergent team behavior under complex cooperative-competitive scenarios. The effectiveness of our approach is demonstrated on a collection of prototype grid-world environments with different specifications of benign and adversarial agents, target locations, and agent rewards.
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This paper presents a novel federated reinforcement learning (Fed-RL) methodology to enhance the cyber resiliency of networked microgrids. We formulate a resilient reinforcement learning (RL) training setup which (a) generates episodic trajectories injecting adversarial actions at primary control reference signals of the grid forming (GFM) inverters and (b) trains the RL agents (or controllers) to alleviate the impact of the injected adversaries. To circumvent data-sharing issues and concerns for proprietary privacy in multi-party-owned networked grids, we bring in the aspects of federated machine learning and propose a novel Fed-RL algorithm to train the RL agents. To this end, the conventional horizontal Fed-RL approaches using decoupled independent environments fail to capture the coupled dynamics in a networked microgrid, which leads us to propose a multi-agent vertically federated variation of actor-critic algorithms, namely federated soft actor-critic (FedSAC) algorithm. We created a customized simulation setup encapsulating microgrid dynamics in the GridLAB-D/HELICS co-simulation platform compatible with the OpenAI Gym interface for training RL agents. Finally, the proposed methodology is validated with numerical examples of modified IEEE 123-bus benchmark test systems consisting of three coupled microgrids.
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Existing Temporal Action Detection (TAD) methods typically take a pre-processing step in converting an input varying-length video into a fixed-length snippet representation sequence, before temporal boundary estimation and action classification. This pre-processing step would temporally downsample the video, reducing the inference resolution and hampering the detection performance in the original temporal resolution. In essence, this is due to a temporal quantization error introduced during the resolution downsampling and recovery. This could negatively impact the TAD performance, but is largely ignored by existing methods. To address this problem, in this work we introduce a novel model-agnostic post-processing method without model redesign and retraining. Specifically, we model the start and end points of action instances with a Gaussian distribution for enabling temporal boundary inference at a sub-snippet level. We further introduce an efficient Taylor-expansion based approximation, dubbed as Gaussian Approximated Post-processing (GAP). Extensive experiments demonstrate that our GAP can consistently improve a wide variety of pre-trained off-the-shelf TAD models on the challenging ActivityNet (+0.2% -0.7% in average mAP) and THUMOS (+0.2% -0.5% in average mAP) benchmarks. Such performance gains are already significant and highly comparable to those achieved by novel model designs. Also, GAP can be integrated with model training for further performance gain. Importantly, GAP enables lower temporal resolutions for more efficient inference, facilitating low-resource applications. The code will be available in https://github.com/sauradip/GAP
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Few-shot (FS) and zero-shot (ZS) learning are two different approaches for scaling temporal action detection (TAD) to new classes. The former adapts a pretrained vision model to a new task represented by as few as a single video per class, whilst the latter requires no training examples by exploiting a semantic description of the new class. In this work, we introduce a new multi-modality few-shot (MMFS) TAD problem, which can be considered as a marriage of FS-TAD and ZS-TAD by leveraging few-shot support videos and new class names jointly. To tackle this problem, we further introduce a novel MUlti-modality PromPt mETa-learning (MUPPET) method. This is enabled by efficiently bridging pretrained vision and language models whilst maximally reusing already learned capacity. Concretely, we construct multi-modal prompts by mapping support videos into the textual token space of a vision-language model using a meta-learned adapter-equipped visual semantics tokenizer. To tackle large intra-class variation, we further design a query feature regulation scheme. Extensive experiments on ActivityNetv1.3 and THUMOS14 demonstrate that our MUPPET outperforms state-of-the-art alternative methods, often by a large margin. We also show that our MUPPET can be easily extended to tackle the few-shot object detection problem and again achieves the state-of-the-art performance on MS-COCO dataset. The code will be available in https://github.com/sauradip/MUPPET
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网络值时间序列是目前的网络数据的常见形式。然而,研究由网络价值随机过程产生的网络序列的总体行为相对较少。现有的大多数研究都集中在简单的设置上,其中网络在整个时间内是独立的(或有条件独立的),并且所有边缘在每个时间步骤均同步更新。在本文中,我们研究了聚集的邻接矩阵的浓度特性以及与懒惰网络值随机过程产生的网络序列相关的相应拉普拉斯矩阵,其中边缘异步不断地更新,并且每个边缘都遵循其懒惰的随机过程,以更新独立于其更新其他边缘。我们证明了这些集中度的有用性,从而证明了标准估计器在社区估计和变更点估计问题中的一致性。我们还进行了一项仿真研究,以证明懒惰参数的影响,该参数控制时间相关的程度,对社区和变化点估计的准确性。
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大规模弱监督的产品检索是实际上有用但在计算上具有挑战性的问题。本文介绍了在第九届CVPR 2022的第九次透明视觉分类研讨会(FGVC9)举行的eBay视觉搜索挑战赛(Eproduct)的新颖解决方案。这项竞赛提出了两个挑战:(a)电子商务是一个非常好的挑战。 - 包含的领域,包括许多具有细微视觉差异的产品; (b)缺少用于模型训练的目标实例级标签,只有粗糙的类别标签和产品标签可用。为了克服这些障碍,我们通过一系列专用设计制定了强大的解决方案:(a)我们从产品头衔中挖掘了数千个伪属性,而不是直接使用文本培训数据,并将其用作多标签分类的基础真相。 (b)我们将几个强大的骨架与高级培训配方结合在一起,以进行更判别的表示。 (c)我们进一步介绍了许多后处理技术,包括美白,重新排列和模型集合以进行检索。通过达到71.53%的3月,我们的解决方案“涉及国王”在排行榜上获得了第二个职位。
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当动作集具有良好的曲率时,我们在任何线性匪徒算法产生的设计矩阵的特征矩阵上介绍了一个非呈现的下限。具体而言,我们表明,每当算法的预期累积后悔为$ o(\ sqrt {n})$时,预期设计矩阵的最低特征值将随着$ \ omega(\ sqrt {n})$的增长而生长为$ n $是学习范围,动作空间在最佳臂周围具有恒定的Hessian。这表明,这种作用空间在离散(即分离良好的)动作空间中迫使多项式下限而不是对数下限,如\ cite {lattimore2017end}所示。此外,虽然先前的结果仅在渐近方案(如$ n \ to \ infty $)中保留,但我们对这些``本地富裕的''动作空间的结果随时都在。此外,在温和的技术假设下,我们以高概率获得了对最小本本特征值的相似下限。我们将结果应用于两个实用的方案 - \ emph {model selection}和\ emph {clustering}在线性匪徒中。对于模型选择,我们表明了一个基于时期的线性匪徒算法适应了真实模型的复杂性,以时代数量的速率指数,借助我们的新频谱结合。对于聚类,我们考虑了一个多代理框架,我们通过利用光谱结果,该框架来证明该框架,该框架,该框架,该框架通过光谱结果,该频谱结果,该框架的结果,该频谱结果,该框架的结果,该频谱结果该框架,该框架的结果不需要强制探索 - 代理商可以运行线性匪徒算法并立即估算其基本参数,从而产生低遗憾。
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现有的时间动作检测(TAD)方法依赖于大型培训数据,包括细分级注释,仅限于在推理期间单独识别先前看到的课程。为每类兴趣收集和注释一个大型培训集是昂贵的,因此无法计算。零射TAD(ZS-TAD)通过启用预训练的模型来识别任何看不见的动作类别来解决这一障碍。同时,ZS-TAD的调查大大降低,ZS-Tad也更具挑战性。受零摄像图像分类的成功的启发,我们旨在解决更复杂的TAD任务。一种直观的方法是将现成的建议探测器与剪辑样式分类集成。但是,由于顺序定位(例如,提案生成)和分类设计,它很容易进行定位误差传播。为了克服这个问题,在本文中,我们通过视觉提示(陈旧)提出了一种新型的零射击时间动作检测模型。这种新颖的设计通过破坏介于两者之间的错误传播途径来有效地消除了定位和分类之间的依赖性。我们进一步介绍了分类和定位之间的相互作用机制,以改善优化。对标准ZS-TAD视频基准测试的广泛实验表明,我们的陈旧的表现明显优于最先进的替代方案。此外,我们的模型还与最近的强大竞争对手相比,在受到监督的TAD上还能产生卓越的成果。 Stale的Pytorch实现可从https://github.com/sauradip/stale获得。
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现有的时间动作检测(TAD)方法依赖于带有细分级注释的大量培训数据。因此,收集和注释这样的训练集非常昂贵且不可计入。半监督的TAD(SS-TAD)通过利用规模自由的未标记视频来减轻此问题。但是,SS-Tad也比有监督的TAD更具挑战性的问题,因此研究得多。先前的SS-TAD方法直接结合了现有的基于建议的TAD方法和SSL方法。由于它们的顺序定位(例如,提案生成)和分类设计,它们很容易出现误差传播。为了克服这一局限性,在这项工作中,我们提出了一种基于无建议的时间掩模(点)的新型半监督时间动作检测模型,并具有平行的定位(掩码生成)和分类体系结构。这种新颖的设计通过切断介于两者之间的错误传播途径来有效地消除了定位和分类之间的依赖性。我们进一步介绍了用于预测细化的分类和本地化之间的交互机制,以及用于自我监督模型预训练的新借口任务。对两个标准基准测试的广泛实验表明,我们的现场表现要优于最先进的替代方案,通常是很大的边距。 pytorch实施现场可在https://github.com/sauradip/spot上获得
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