新颖的检测方法识别不代表模型训练集的样本,从而标记误导性预测并在部署时间带来更大的灵活性和透明度。但是,该领域的研究仅考虑了离线环境中的新颖性检测。最近,在计算机视觉社区中,应用程序越来越多,应用程序需要更灵活的框架 - 持续学习 - 在该框架中,代表新域,新类或新任务的新数据在不同的时间点可用。在这种情况下,新颖性检测变得越来越重要,有趣且具有挑战性。这项工作确定了这两个问题之间的关键联系,并研究了持续学习环境下的新颖性检测问题。我们制定了持续的新颖性检测问题,并提出了基准,在该基准中,我们比较了不同持续学习设置下的几种新颖性检测方法。我们表明,持续学习会影响新颖性检测算法的行为,而新颖性检测可以确定持续学习者的行为的见解。我们进一步提出了基准并讨论可能的研究方向。我们认为,这两个问题的耦合是将视觉模型付诸实践的有前途的方向。
translated by 谷歌翻译
本文研究持续学习(CL)的逐步学习(CIL)。已经提出了许多方法来处理CIL中的灾难性遗忘(CF)。大多数方法都会为单个头网络中所有任务的所有类别构建单个分类器。为了防止CF,一种流行的方法是记住以前任务中的少数样本,并在培训新任务时重播它们。但是,这种方法仍然患有严重的CF,因为在内存中仅使用有限的保存样本数量来更新或调整了先前任务的参数。本文提出了一种完全不同的方法,该方法使用变压器网络为每个任务(称为多头模型)构建一个单独的分类器(头部),称为更多。与其在内存中使用保存的样本在现有方法中更新以前的任务/类的网络,不如利用保存的样本来构建特定任务分类器(添加新的分类头),而无需更新用于先前任务/类的网络。新任务的模型经过培训,可以学习任务的类别,并且还可以检测到不是从相同数据分布(即,均分布(OOD))的样本。这使测试实例属于的任务的分类器能够为正确的类产生高分,而其他任务的分类器可以产生低分,因为测试实例不是来自这些分类器的数据分布。实验结果表明,更多的表现优于最先进的基线,并且自然能够在持续学习环境中进行OOD检测。
translated by 谷歌翻译
人类智慧的主食是以不断的方式获取知识的能力。在Stark对比度下,深网络忘记灾难性,而且为此原因,类增量连续学习促进方法的子字段逐步学习一系列任务,将顺序获得的知识混合成综合预测。这项工作旨在评估和克服我们以前提案黑暗体验重播(Der)的陷阱,这是一种简单有效的方法,将排练和知识蒸馏结合在一起。灵感来自于我们的思想不断重写过去的回忆和对未来的期望,我们赋予了我的能力,即我的能力来修改其重播记忆,以欢迎有关过去数据II的新信息II)为学习尚未公开的课程铺平了道路。我们表明,这些策略的应用导致了显着的改进;实际上,得到的方法 - 被称为扩展-DAR(X-DER) - 优于标准基准(如CiFar-100和MiniimAgeNet)的技术状态,并且这里引入了一个新颖的。为了更好地了解,我们进一步提供了广泛的消融研究,以证实并扩展了我们以前研究的结果(例如,在持续学习设置中知识蒸馏和漂流最小值的价值)。
translated by 谷歌翻译
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.
translated by 谷歌翻译
Artificial neural networks thrive in solving the classification problem for a particular rigid task, acquiring knowledge through generalized learning behaviour from a distinct training phase. The resulting network resembles a static entity of knowledge, with endeavours to extend this knowledge without targeting the original task resulting in a catastrophic forgetting. Continual learning shifts this paradigm towards networks that can continually accumulate knowledge over different tasks without the need to retrain from scratch. We focus on task incremental classification, where tasks arrive sequentially and are delineated by clear boundaries. Our main contributions concern (1) a taxonomy and extensive overview of the state-of-the-art; (2) a novel framework to continually determine the stability-plasticity trade-off of the continual learner; (3) a comprehensive experimental comparison of 11 state-of-the-art continual learning methods and 4 baselines. We empirically scrutinize method strengths and weaknesses on three benchmarks, considering Tiny Imagenet and large-scale unbalanced iNaturalist and a sequence of recognition datasets. We study the influence of model capacity, weight decay and dropout regularization, and the order in which the tasks are presented, and qualitatively compare methods in terms of required memory, computation time and storage.
translated by 谷歌翻译
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.
translated by 谷歌翻译
Online continual learning (OCL) aims to enable model learning from a non-stationary data stream to continuously acquire new knowledge as well as retain the learnt one, under the constraints of having limited system size and computational cost, in which the main challenge comes from the "catastrophic forgetting" issue -- the inability to well remember the learnt knowledge while learning the new ones. With the specific focus on the class-incremental OCL scenario, i.e. OCL for classification, the recent advance incorporates the contrastive learning technique for learning more generalised feature representation to achieve the state-of-the-art performance but is still unable to fully resolve the catastrophic forgetting. In this paper, we follow the strategy of adopting contrastive learning but further introduce the semantically distinct augmentation technique, in which it leverages strong augmentation to generate more data samples, and we show that considering these samples semantically different from their original classes (thus being related to the out-of-distribution samples) in the contrastive learning mechanism contributes to alleviate forgetting and facilitate model stability. Moreover, in addition to contrastive learning, the typical classification mechanism and objective (i.e. softmax classifier and cross-entropy loss) are included in our model design for faster convergence and utilising the label information, but particularly equipped with a sampling strategy to tackle the tendency of favouring the new classes (i.e. model bias towards the recently learnt classes). Upon conducting extensive experiments on CIFAR-10, CIFAR-100, and Mini-Imagenet datasets, our proposed method is shown to achieve superior performance against various baselines.
translated by 谷歌翻译
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。
translated by 谷歌翻译
现代ML方法在培训数据是IID,大规模和良好标记的时候Excel。在不太理想的条件下学习仍然是一个开放的挑战。在不利条件下,几次射击,持续的,转移和代表学习的子场在学习中取得了很大的进步;通过方法和见解,每个都提供了独特的优势。这些方法解决了不同的挑战,例如依次到达的数据或稀缺的训练示例,然而,在部署之前,ML系统将面临困难的条件。因此,需要可以处理实际设置中许多学习挑战的一般ML系统。为了促进一般ML方法目标的研究,我们介绍了一个新的统一评估框架 - 流体(灵活的顺序数据)。流体集成了几次拍摄,持续的,转移和表示学习的目标,同时能够比较和整合这些子场的技术。在流体中,学习者面临数据流,并且必须在选择如何更新自身时进行顺序预测,快速调整到新颖的类别,并处理更改的数据分布;虽然会计计算总额。我们对广泛的方法进行实验,这些方法阐述了新的洞察当前解决方案的优缺点并表明解决了新的研究问题。作为更一般方法的起点,我们展示了两种新的基线,其在流体上优于其他评估的方法。项目页面:https://raivn.cs.washington.edu/projects/fluid/。
translated by 谷歌翻译
尽管深度神经网络(DNNS)在封闭世界的学习方案中取得了令人印象深刻的分类性能,但它们通常无法概括地在动态的开放世界环境中看不见的类别,在这种环境中,概念数量无界的数量。相反,人类和动物学习者具有通过识别和适应新颖观察结果来逐步更新知识的能力。特别是,人类通过独家(唯一)基本特征集来表征概念,这些特征既用于识别已知类别和识别新颖性。受到自然学习者的启发,我们引入了稀疏的高级独特,低水平共享的特征表示(Shels),同时鼓励学习独家的高级功能和必不可少的,共享的低级功能。高级功能的排他性使DNN能够自动检测到分布(OOD)数据,而通过稀疏的低级功能可以有效利用容量,可以容纳新知识。最终的方法使用OOD检测来执行班级持续学习,而没有已知的类边界。我们表明,使用木材进行新颖性检测导致对各种基准数据集的最新OOD检测方法的统计显着改善。此外,我们证明了木木模型在课堂学习环境中减轻灾难性的遗忘,从而实现了一个组合的新颖性检测和住宿框架,该框架支持在开放世界中学习
translated by 谷歌翻译
持续学习旨在使单个模型能够学习一系列任务,而不会造成灾难性的遗忘。表现最好的方法通常需要排练缓冲区来存储过去的原始示例以进行经验重播,但是,由于隐私和内存约束,这会限制其实际价值。在这项工作中,我们提出了一个简单而有效的框架,即DualPrompt,该框架学习了一组称为提示的参数,以正确指示预先训练的模型,以依次学习到达的任务,而不会缓冲过去的示例。 DualPrompt提出了一种新颖的方法,可以将互补提示附加到预训练的主链上,然后将目标提出为学习任务不变和特定于任务的“指令”。通过广泛的实验验证,双启示始终在具有挑战性的课堂开发环境下始终设置最先进的表现。尤其是,双启示的表现优于最近的高级持续学习方法,其缓冲尺寸相对较大。我们还引入了一个更具挑战性的基准Split Imagenet-R,以帮助概括无连续的持续学习研究。源代码可在https://github.com/google-research/l2p上找到。
translated by 谷歌翻译
持续学习(CL)调查如何在无需遗忘的情况下培训在任务流上的深网络。文献中提出的CL设置假设每个传入示例都与地面真实注释配对。然而,这与许多真实应用的冲突这项工作探讨了持续的半监督学习(CSSL):这里只有一小部分标记的输入示例显示给学习者。我们评估当前CL方法(例如:EWC,LWF,Icarl,ER,GDumb,Der)在这部小说和具有挑战性的情况下,过度装箱纠缠忘记。随后,我们设计了一种新的CSSL方法,用于在学习时利用度量学习和一致性正则化来利用未标记的示例。我们展示我们的提案对监督越来越令人惊讶的是,我们的提案呈现出更高的恢复能力,甚至更令人惊讶地,仅依赖于25%的监督,以满足全面监督培训的优于营业型SOTA方法。
translated by 谷歌翻译
持续学习背后的主流范例一直在使模型参数调整到非静止数据分布,灾难性遗忘是中央挑战。典型方法在测试时间依赖排练缓冲区或已知的任务标识,以检索学到的知识和地址遗忘,而这项工作呈现了一个新的范例,用于持续学习,旨在训练更加简洁的内存系统而不在测试时间访问任务标识。我们的方法学会动态提示(L2P)预先训练的模型,以在不同的任务转换下顺序地学习任务。在我们提出的框架中,提示是小型可学习参数,这些参数在内存空间中保持。目标是优化提示,以指示模型预测并明确地管理任务不变和任务特定知识,同时保持模型可塑性。我们在流行的图像分类基准下进行全面的实验,具有不同挑战的持续学习环境,其中L2P始终如一地优于现有最先进的方法。令人惊讶的是,即使没有排练缓冲区,L2P即使没有排练缓冲,L2P也能实现竞争力的结果,并直接适用于具有挑战性的任务不可行的持续学习。源代码在https://github.com/google-Research/l2p中获得。
translated by 谷歌翻译
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.
translated by 谷歌翻译
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).
translated by 谷歌翻译
这项工作调查了持续学习(CL)与转移学习(TL)之间的纠缠。特别是,我们阐明了网络预训练的广泛应用,强调它本身受到灾难性遗忘的影响。不幸的是,这个问题导致在以后任务期间知识转移的解释不足。在此基础上,我们提出了转移而不忘记(TWF),这是在固定的经过预定的兄弟姐妹网络上建立的混合方法,该方法不断传播源域中固有的知识,通过层次损失项。我们的实验表明,TWF在各种设置上稳步优于其他CL方法,在各种数据集和不同的缓冲尺寸上,平均每种类型的精度增长了4.81%。
translated by 谷歌翻译
人类的持续学习(CL)能力与稳定性与可塑性困境密切相关,描述了人类如何实现持续的学习能力和保存的学习信息。自发育以来,CL的概念始终存在于人工智能(AI)中。本文提出了对CL的全面审查。与之前的评论不同,主要关注CL中的灾难性遗忘现象,本文根据稳定性与可塑性机制的宏观视角来调查CL。类似于生物对应物,“智能”AI代理商应该是I)记住以前学到的信息(信息回流); ii)不断推断新信息(信息浏览:); iii)转移有用的信息(信息转移),以实现高级CL。根据分类学,评估度量,算法,应用以及一些打开问题。我们的主要贡献涉及I)从人工综合情报层面重新检查CL; ii)在CL主题提供详细和广泛的概述; iii)提出一些关于CL潜在发展的新颖思路。
translated by 谷歌翻译
Continual Learning, also known as Lifelong or Incremental Learning, has recently gained renewed interest among the Artificial Intelligence research community. Recent research efforts have quickly led to the design of novel algorithms able to reduce the impact of the catastrophic forgetting phenomenon in deep neural networks. Due to this surge of interest in the field, many competitions have been held in recent years, as they are an excellent opportunity to stimulate research in promising directions. This paper summarizes the ideas, design choices, rules, and results of the challenge held at the 3rd Continual Learning in Computer Vision (CLVision) Workshop at CVPR 2022. The focus of this competition is the complex continual object detection task, which is still underexplored in literature compared to classification tasks. The challenge is based on the challenge version of the novel EgoObjects dataset, a large-scale egocentric object dataset explicitly designed to benchmark continual learning algorithms for egocentric category-/instance-level object understanding, which covers more than 1k unique main objects and 250+ categories in around 100k video frames.
translated by 谷歌翻译
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。
translated by 谷歌翻译
Continual learning (CL) learns a sequence of tasks incrementally. There are two popular CL settings, class incremental learning (CIL) and task incremental learning (TIL). A major challenge of CL is catastrophic forgetting (CF). While a number of techniques are already available to effectively overcome CF for TIL, CIL remains to be highly challenging. So far, little theoretical study has been done to provide a principled guidance on how to solve the CIL problem. This paper performs such a study. It first shows that probabilistically, the CIL problem can be decomposed into two sub-problems: Within-task Prediction (WP) and Task-id Prediction (TP). It further proves that TP is correlated with out-of-distribution (OOD) detection, which connects CIL and OOD detection. The key conclusion of this study is that regardless of whether WP and TP or OOD detection are defined explicitly or implicitly by a CIL algorithm, good WP and good TP or OOD detection are necessary and sufficient for good CIL performances. Additionally, TIL is simply WP. Based on the theoretical result, new CIL methods are also designed, which outperform strong baselines in both CIL and TIL settings by a large margin.
translated by 谷歌翻译