无任务持续学习(CL)旨在学习非平稳数据流,而无需明确的任务定义,不要忘记以前的知识。广泛采用的内存重播方法可能会逐渐对长数据流有效,因为该模型可能会记住存储的示例并过度拟合内存缓冲区。其次,现有方法忽略了内存数据分布的高不确定性,因为内存数据分布与所有先前数据示例的分布之间存在很大差距。为了解决这些问题,我们首次提出了一个原则的内存演进框架,以使内存缓冲区逐渐难以通过分布强大的优化(DRO)来动态发展内存数据分布。然后,我们得出了一个方法家族,以通过Wasserstein梯度流(WGF)在连续概率中进化内存缓冲区数据。所提出的DRO是W.R.T最糟糕的记忆数据分布,因此保证了模型性能,并且比现有基于内存重新播放的方法更加可靠的功能。对现有基准测试的广泛实验证明了拟议方法减轻遗忘的有效性。作为拟议框架的副产品,与现有的无任务CL方法相比,我们的方法对对抗性示例更强大。
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我们探索无任务持续学习(CL),其中培训模型以避免在没有明确的任务边界或身份的情况下造成灾难性的遗忘。在无任务CL上的许多努力中,一个值得注意的方法是基于内存的,存储和重放训练示例的子集。然而,由于CL模型不断更新,所以存储的示例的效用可以随时间缩短。这里,我们提出基于梯度的存储器编辑(GMED),该框架是通过梯度更新在连续输入空间中编辑存储的示例的框架,以便为重放创建更多的“具有挑战性”示例。 GMED编辑的例子仍然类似于其未编辑的形式,但可以在即将到来的模型更新中产生增加的损失,从而使未来的重播在克服灾难性遗忘方面更有效。通过施工,GMED可以与其他基于内存的CL算法一起无缝应用,以进一步改进。实验验证了GMED的有效性,以及我们最好的方法显着优于基线和以前的五个数据集中的最先进。可以在https://github.com/ink-usc/gmed找到代码。
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持续学习(CL)旨在开发单一模型适应越来越多的任务的技术,从而潜在地利用跨任务的学习以资源有效的方式。 CL系统的主要挑战是灾难性的遗忘,在学习新任务时忘记了早期的任务。为了解决此问题,基于重播的CL方法在遇到遇到任务中选择的小缓冲区中维护和重复培训。我们提出梯度Coreset重放(GCR),一种新颖的重播缓冲区选择和使用仔细设计的优化标准的更新策略。具体而言,我们选择并维护一个“Coreset”,其与迄今为止关于当前模型参数的所有数据的梯度紧密近似,并讨论其有效应用于持续学习设置所需的关键策略。在学习的离线持续学习环境中,我们在最先进的最先进的最先进的持续学习环境中表现出显着的收益(2%-4%)。我们的调查结果还有效地转移到在线/流媒体CL设置,从而显示现有方法的5%。最后,我们展示了持续学习的监督对比损失的价值,当与我们的子集选择策略相结合时,累计增益高达5%。
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在线持续学习(OCL)旨在通过单个通过数据从非平稳数据流进行逐步训练神经网络。基于彩排的方法试图用少量的内存近似观察到的输入分布,并以后重新审视它们以避免忘记。尽管具有强烈的经验表现,但排练方法仍然遭受了过去数据损失景观和记忆样本的差异。本文重新讨论了在线设置中的排练动态。我们从偏见和动态的经验风险最小化的角度从固有的内存过度拟合风险中提供了理论见解,并检查重复排练的优点和限制。受我们的分析的启发,一个简单而直观的基线,重复的增强彩排(RAR)旨在解决在线彩排的拟合不足的困境。令人惊讶的是,在四个相当不同的OCL基准测试中,这种简单的基线表现优于香草排练9%-17%,并且显着改善了基于最新的彩排方法miR,ASER和SCR。我们还证明,RAR成功地实现了过去数据的损失格局和其学习轨迹中的高损失山脊厌恶的准确近似。进行了广泛的消融研究,以研究重复和增强彩排和增强学习(RL)之间的相互作用(RL),以动态调整RAR的超参数以平衡在线稳定性 - 塑性权衡折衷。
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当许多松散相关的未标记数据可用并且稀缺标记的数据时,机器智能的范式从纯粹的监督学习转变为更实用的情况。大多数现有算法都假定基础任务分布是固定的。在这里,我们考虑了随着时间的推移,该任务分布中的一个更现实和具有挑战性的环境会不断发展。我们将这个问题称为半监督的元学习,并具有不断发展的任务分布,缩写为集合。在这种更现实的环境中出现了两个关键挑战:(i)在存在大量未标记的分发(OOD)数据的情况下,如何使用未标记的数据; (ii)如何防止由于任务分配转移而导致先前学习的任务分布的灾难性遗忘。我们提出了一种强大的知识和知识保留的半监督元学习方法(秩序),以应对这两个主要挑战。具体而言,我们的订单引入了一种新型的共同信息正则化,以使用未标记的OOD数据鲁棒化模型,并采用最佳的运输正规化来记住以前在特征空间中学习的知识。此外,我们在一个非常具有挑战性的数据集上测试我们的方法:大规模非平稳的半监督任务分布的集合,该任务分布由(至少)72K任务组成。通过广泛的实验,我们证明了拟议的订单减轻了忘记不断发展的任务分布,并且对OOD数据比相关的强基础更强大。
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Despite significant advances, the performance of state-of-the-art continual learning approaches hinges on the unrealistic scenario of fully labeled data. In this paper, we tackle this challenge and propose an approach for continual semi-supervised learning -- a setting where not all the data samples are labeled. An underlying issue in this scenario is the model forgetting representations of unlabeled data and overfitting the labeled ones. We leverage the power of nearest-neighbor classifiers to non-linearly partition the feature space and learn a strong representation for the current task, as well as distill relevant information from previous tasks. We perform a thorough experimental evaluation and show that our method outperforms all the existing approaches by large margins, setting a strong state of the art on the continual semi-supervised learning paradigm. For example, on CIFAR100 we surpass several others even when using at least 30 times less supervision (0.8% vs. 25% of annotations).
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持续学习旨在快速,不断地从一系列任务中学习当前的任务。与其他类型的方法相比,基于经验重播的方法表现出了极大的优势来克服灾难性的遗忘。该方法的一个常见局限性是上一个任务和当前任务之间的数据不平衡,这将进一步加剧遗忘。此外,如何在这种情况下有效解决稳定性困境也是一个紧迫的问题。在本文中,我们通过提出一个通过多尺度知识蒸馏和数据扩展(MMKDDA)提出一个名为Meta学习更新的新框架来克服这些挑战。具体而言,我们应用多尺度知识蒸馏来掌握不同特征级别的远程和短期空间关系的演变,以减轻数据不平衡问题。此外,我们的方法在在线持续训练程序中混合了来自情节记忆和当前任务的样品,从而减轻了由于概率分布的变化而减轻了侧面影响。此外,我们通过元学习更新来优化我们的模型,该更新诉诸于前面所看到的任务数量,这有助于保持稳定性和可塑性之间的更好平衡。最后,我们对四个基准数据集的实验评估显示了提出的MMKDDA框架对其他流行基线的有效性,并且还进行了消融研究,以进一步分析每个组件在我们的框架中的作用。
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持续学习(CL)依次学习像人类这样的新任务,其目标是实现更好的稳定性(S,记住过去的任务)和可塑性(P,适应新任务)。由于过去的培训数据不可用,因此探索培训示例中S和P的影响差异很有价值,这可能会改善对更好的SP的学习模式。受影响函数的启发(如果),我们首先研究了示例通过添加扰动来示例体重和计算影响推导的影响。为了避免在神经网络中Hessian逆的存储和计算负担,我们提出了一种简单而有效的METASP算法,以模拟IF计算中的两个关键步骤,并获得S-和P-Aware示例的影响。此外,我们建议通过解决双目标优化问题来融合两种示例影响,并获得对SP Pareto最优性的融合影响。融合影响可用于控制模型的更新并优化排练的存储。经验结果表明,我们的算法在任务和类别基准CL数据集上都显着优于最先进的方法。
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A continual learning agent learns online with a non-stationary and never-ending stream of data. The key to such learning process is to overcome the catastrophic forgetting of previously seen data, which is a well known problem of neural networks. To prevent forgetting, a replay buffer is usually employed to store the previous data for the purpose of rehearsal. Previous works often depend on task boundary and i.i.d. assumptions to properly select samples for the replay buffer. In this work, we formulate sample selection as a constraint reduction problem based on the constrained optimization view of continual learning. The goal is to select a fixed subset of constraints that best approximate the feasible region defined by the original constraints. We show that it is equivalent to maximizing the diversity of samples in the replay buffer with parameters gradient as the feature. We further develop a greedy alternative that is cheap and efficient. The advantage of the proposed method is demonstrated by comparing to other alternatives under the continual learning setting. Further comparisons are made against state of the art methods that rely on task boundaries which show comparable or even better results for our method.
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Online Class Incremental learning (CIL) is a challenging setting in Continual Learning (CL), wherein data of new tasks arrive in incoming streams and online learning models need to handle incoming data streams without revisiting previous ones. Existing works used a single centroid adapted with incoming data streams to characterize a class. This approach possibly exposes limitations when the incoming data stream of a class is naturally multimodal. To address this issue, in this work, we first propose an online mixture model learning approach based on nice properties of the mature optimal transport theory (OT-MM). Specifically, the centroids and covariance matrices of the mixture model are adapted incrementally according to incoming data streams. The advantages are two-fold: (i) we can characterize more accurately complex data streams and (ii) by using centroids for each class produced by OT-MM, we can estimate the similarity of an unseen example to each class more reasonably when doing inference. Moreover, to combat the catastrophic forgetting in the CIL scenario, we further propose Dynamic Preservation. Particularly, after performing the dynamic preservation technique across data streams, the latent representations of the classes in the old and new tasks become more condensed themselves and more separate from each other. Together with a contraction feature extractor, this technique facilitates the model in mitigating the catastrophic forgetting. The experimental results on real-world datasets show that our proposed method can significantly outperform the current state-of-the-art baselines.
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最近,持续学习(CL)引起了巨大的兴趣,因为它使深度学习模型能够获取新知识,而无需忘记以前学习的信息。但是,大多数现有作品都需要了解任务身份和边界,这在实际情况下是不现实的。在本文中,我们在CL中解决了一个更具挑战性和更现实的环境,即无任务的持续学习(TFCL),其中模型在没有明确任务信息的非平稳数据流上培训。为了解决TFCL,我们引入了一个进化的混合模型,其网络体系结构动态扩展以适应数据分布移动。我们通过评估使用Hilbert Schmidt独立标准(HSIC)评估存储在每个混合模型组件中的知识与当前存储器缓冲区的知识之间的概率距离来实现此扩展机制。我们进一步介绍了两种简单的辍学机制,以选择性地删除存储的示例,以避免记忆超载,同时保留内存多样性。经验结果表明,所提出的方法可实现出色的性能。
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持续学习(CL)旨在制定模仿人类能力顺序学习新任务的能力,同时能够保留从过去经验获得的知识。在本文中,我们介绍了内存约束在线连续学习(MC-OCL)的新问题,这对存储器开销对可能算法可以用于避免灾难性遗忘的记忆开销。最多,如果不是全部,之前的CL方法违反了这些约束,我们向MC-OCL提出了一种算法解决方案:批量蒸馏(BLD),基于正则化的CL方法,有效地平衡了稳定性和可塑性,以便学习数据流,同时保留通过蒸馏解决旧任务的能力。我们在三个公开的基准测试中进行了广泛的实验评估,经验证明我们的方法成功地解决了MC-OCL问题,并实现了需要更高内存开销的先前蒸馏方法的可比准确性。
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古典机器学习者仅设计用于解决一项任务,而无需采用新的新兴任务或课程,而这种能力在现实世界中更实用和人类。为了解决这种缺点,阐述了持续的机器学习者,以表彰使用域和班级的任务流,不同的任务之间的转变。在本文中,我们提出了一种基于一个基于对比的连续学习方法,其能够处理多个持续学习场景。具体地,我们通过特征传播和对比表示学习来对准当前和先前的表示空间来弥合不同任务之间的域移位。为了进一步减轻特征表示的类别的班次,利用了监督的对比损失以使与不同类别的相同类的示例嵌入。广泛的实验结果表明,与一组尖端连续学习方法相比,六个连续学习基准中提出的方法的出色性能。
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Lack of performance when it comes to continual learning over non-stationary distributions of data remains a major challenge in scaling neural network learning to more human realistic settings. In this work we propose a new conceptualization of the continual learning problem in terms of a temporally symmetric trade-off between transfer and interference that can be optimized by enforcing gradient alignment across examples. We then propose a new algorithm, Meta-Experience Replay (MER), that directly exploits this view by combining experience replay with optimization based meta-learning. This method learns parameters that make interference based on future gradients less likely and transfer based on future gradients more likely. 1 We conduct experiments across continual lifelong supervised learning benchmarks and non-stationary reinforcement learning environments demonstrating that our approach consistently outperforms recently proposed baselines for continual learning. Our experiments show that the gap between the performance of MER and baseline algorithms grows both as the environment gets more non-stationary and as the fraction of the total experiences stored gets smaller.
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Continual Learning (CL) is a field dedicated to devise algorithms able to achieve lifelong learning. Overcoming the knowledge disruption of previously acquired concepts, a drawback affecting deep learning models and that goes by the name of catastrophic forgetting, is a hard challenge. Currently, deep learning methods can attain impressive results when the data modeled does not undergo a considerable distributional shift in subsequent learning sessions, but whenever we expose such systems to this incremental setting, performance drop very quickly. Overcoming this limitation is fundamental as it would allow us to build truly intelligent systems showing stability and plasticity. Secondly, it would allow us to overcome the onerous limitation of retraining these architectures from scratch with the new updated data. In this thesis, we tackle the problem from multiple directions. In a first study, we show that in rehearsal-based techniques (systems that use memory buffer), the quantity of data stored in the rehearsal buffer is a more important factor over the quality of the data. Secondly, we propose one of the early works of incremental learning on ViTs architectures, comparing functional, weight and attention regularization approaches and propose effective novel a novel asymmetric loss. At the end we conclude with a study on pretraining and how it affects the performance in Continual Learning, raising some questions about the effective progression of the field. We then conclude with some future directions and closing remarks.
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We motivate Energy-Based Models (EBMs) as a promising model class for continual learning problems. Instead of tackling continual learning via the use of external memory, growing models, or regularization, EBMs change the underlying training objective to cause less interference with previously learned information. Our proposed version of EBMs for continual learning is simple, efficient, and outperforms baseline methods by a large margin on several benchmarks. Moreover, our proposed contrastive divergence-based training objective can be combined with other continual learning methods, resulting in substantial boosts in their performance. We further show that EBMs are adaptable to a more general continual learning setting where the data distribution changes without the notion of explicitly delineated tasks. These observations point towards EBMs as a useful building block for future continual learning methods.
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Continual Learning is considered a key step toward next-generation Artificial Intelligence. Among various methods, replay-based approaches that maintain and replay a small episodic memory of previous samples are one of the most successful strategies against catastrophic forgetting. However, since forgetting is inevitable given bounded memory and unbounded tasks, how to forget is a problem continual learning must address. Therefore, beyond simply avoiding catastrophic forgetting, an under-explored issue is how to reasonably forget while ensuring the merits of human memory, including 1. storage efficiency, 2. generalizability, and 3. some interpretability. To achieve these simultaneously, our paper proposes a new saliency-augmented memory completion framework for continual learning, inspired by recent discoveries in memory completion separation in cognitive neuroscience. Specifically, we innovatively propose to store the part of the image most important to the tasks in episodic memory by saliency map extraction and memory encoding. When learning new tasks, previous data from memory are inpainted by an adaptive data generation module, which is inspired by how humans complete episodic memory. The module's parameters are shared across all tasks and it can be jointly trained with a continual learning classifier as bilevel optimization. Extensive experiments on several continual learning and image classification benchmarks demonstrate the proposed method's effectiveness and efficiency.
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持续学习研究的主要重点领域是通过设计新算法对分布变化更强大的新算法来减轻神经网络中的“灾难性遗忘”问题。尽管持续学习文献的最新进展令人鼓舞,但我们对神经网络的特性有助于灾难性遗忘的理解仍然有限。为了解决这个问题,我们不关注持续的学习算法,而是在这项工作中专注于模型本身,并研究神经网络体系结构对灾难性遗忘的“宽度”的影响,并表明宽度在遗忘遗产方面具有出人意料的显着影响。为了解释这种效果,我们从各个角度研究网络的学习动力学,例如梯度正交性,稀疏性和懒惰的培训制度。我们提供了与不同架构和持续学习基准之间的经验结果一致的潜在解释。
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恶意软件(恶意软件)分类为持续学习(CL)制度提供了独特的挑战,这是由于每天收到的新样本的数量以及恶意软件的发展以利用新漏洞。在典型的一天中,防病毒供应商将获得数十万个独特的软件,包括恶意和良性,并且在恶意软件分类器的一生中,有超过十亿个样品很容易积累。鉴于问题的规模,使用持续学习技术的顺序培训可以在减少培训和存储开销方面提供可观的好处。但是,迄今为止,还没有对CL应用于恶意软件分类任务的探索。在本文中,我们研究了11种应用于三个恶意软件任务的CL技术,涵盖了常见的增量学习方案,包括任务,类和域增量学习(IL)。具体而言,使用两个现实的大规模恶意软件数据集,我们评估了CL方法在二进制恶意软件分类(domain-il)和多类恶意软件家庭分类(Task-IL和类IL)任务上的性能。令我们惊讶的是,在几乎所有情况下,持续的学习方法显着不足以使训练数据的幼稚关节重播 - 在某些情况下,将精度降低了70个百分点以上。与关节重播相比,有选择性重播20%的存储数据的一种简单方法可以实现更好的性能,占训练时间的50%。最后,我们讨论了CL技术表现出乎意料差的潜在原因,希望它激发进一步研究在恶意软件分类域中更有效的技术。
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Continual Learning (CL) is an emerging machine learning paradigm that aims to learn from a continuous stream of tasks without forgetting knowledge learned from the previous tasks. To avoid performance decrease caused by forgetting, prior studies exploit episodic memory (EM), which stores a subset of the past observed samples while learning from new non-i.i.d. data. Despite the promising results, since CL is often assumed to execute on mobile or IoT devices, the EM size is bounded by the small hardware memory capacity and makes it infeasible to meet the accuracy requirements for real-world applications. Specifically, all prior CL methods discard samples overflowed from the EM and can never retrieve them back for subsequent training steps, incurring loss of information that would exacerbate catastrophic forgetting. We explore a novel hierarchical EM management strategy to address the forgetting issue. In particular, in mobile and IoT devices, real-time data can be stored not just in high-speed RAMs but in internal storage devices as well, which offer significantly larger capacity than the RAMs. Based on this insight, we propose to exploit the abundant storage to preserve past experiences and alleviate the forgetting by allowing CL to efficiently migrate samples between memory and storage without being interfered by the slow access speed of the storage. We call it Carousel Memory (CarM). As CarM is complementary to existing CL methods, we conduct extensive evaluations of our method with seven popular CL methods and show that CarM significantly improves the accuracy of the methods across different settings by large margins in final average accuracy (up to 28.4%) while retaining the same training efficiency.
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