A major open problem on the road to artificial intelligence is the development of incrementally learning systems that learn about more and more concepts over time from a stream of data. In this work, we introduce a new training strategy, iCaRL, that allows learning in such a classincremental way: only the training data for a small number of classes has to be present at the same time and new classes can be added progressively.iCaRL learns strong classifiers and a data representation simultaneously. This distinguishes it from earlier works that were fundamentally limited to fixed data representations and therefore incompatible with deep learning architectures. We show by experiments on CIFAR-100 and ImageNet ILSVRC 2012 data that iCaRL can learn many classes incrementally over a long period of time where other strategies quickly fail.

Although deep learning approaches have stood out in recent years due to their state-of-the-art results, they continue to suffer from catastrophic forgetting, a dramatic decrease in overall performance when training with new classes added incrementally. This is due to current neural network architectures requiring the entire dataset, consisting of all the samples from the old as well as the new classes, to update the model-a requirement that becomes easily unsustainable as the number of classes grows. We address this issue with our approach to learn deep neural networks incrementally, using new data and only a small exemplar set corresponding to samples from the old classes. This is based on a loss composed of a distillation measure to retain the knowledge acquired from the old classes, and a cross-entropy loss to learn the new classes. Our incremental training is achieved while keeping the entire framework end-to-end, i.e., learning the data representation and the classifier jointly, unlike recent methods with no such guarantees. We evaluate our method extensively on the CIFAR-100 and Im-ageNet (ILSVRC 2012) image classification datasets, and show state-of-the-art performance.

Many modern computer vision algorithms suffer from two major bottlenecks: scarcity of data and learning new tasks incrementally. While training the model with new batches of data the model looses it's ability to classify the previous data judiciously which is termed as catastrophic forgetting. Conventional methods have tried to mitigate catastrophic forgetting of the previously learned data while the training at the current session has been compromised. The state-of-the-art generative replay based approaches use complicated structures such as generative adversarial network (GAN) to deal with catastrophic forgetting. Additionally, training a GAN with few samples may lead to instability. In this work, we present a novel method to deal with these two major hurdles. Our method identifies a better embedding space with an improved contrasting loss to make classification more robust. Moreover, our approach is able to retain previously acquired knowledge in the embedding space even when trained with new classes. We update previous session class prototypes while training in such a way that it is able to represent the true class mean. This is of prime importance as our classification rule is based on the nearest class mean classification strategy. We have demonstrated our results by showing that the embedding space remains intact after training the model with new classes. We showed that our method preformed better than the existing state-of-the-art algorithms in terms of accuracy across different sessions.

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.

Conventionally, deep neural networks are trained offline, relying on a large dataset prepared in advance. This paradigm is often challenged in real-world applications, e.g. online services that involve continuous streams of incoming data. Recently, incremental learning receives increasing attention, and is considered as a promising solution to the practical challenges mentioned above. However, it has been observed that incremental learning is subject to a fundamental difficulty -catastrophic forgetting, namely adapting a model to new data often results in severe performance degradation on previous tasks or classes. Our study reveals that the imbalance between previous and new data is a crucial cause to this problem. In this work, we develop a new framework for incrementally learning a unified classifier, i.e. a classifier that treats both old and new classes uniformly. Specifically, we incorporate three components, cosine normalization, less-forget constraint, and inter-class separation, to mitigate the adverse effects of the imbalance. Experiments show that the proposed method can effectively rebalance the training process, thus obtaining superior performance compared to the existing methods. On CIFAR-100 and ImageNet, our method can reduce the classification errors by more than 6% and 13% respectively, under the incremental setting of 10 phases.

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.

The dynamic expansion architecture is becoming popular in class incremental learning, mainly due to its advantages in alleviating catastrophic forgetting. However, task confusion is not well assessed within this framework, e.g., the discrepancy between classes of different tasks is not well learned (i.e., inter-task confusion, ITC), and certain priority is still given to the latest class batch (i.e., old-new confusion, ONC). We empirically validate the side effects of the two types of confusion. Meanwhile, a novel solution called Task Correlated Incremental Learning (TCIL) is proposed to encourage discriminative and fair feature utilization across tasks. TCIL performs a multi-level knowledge distillation to propagate knowledge learned from old tasks to the new one. It establishes information flow paths at both feature and logit levels, enabling the learning to be aware of old classes. Besides, attention mechanism and classifier re-scoring are applied to generate more fair classification scores. We conduct extensive experiments on CIFAR100 and ImageNet100 datasets. The results demonstrate that TCIL consistently achieves state-of-the-art accuracy. It mitigates both ITC and ONC, while showing advantages in battle with catastrophic forgetting even no rehearsal memory is reserved.

域分类是自然语言理解（NLU）中的基本任务，通常需要快速住宿到新的新兴域。即使新模型可访问，此约束使其无法培育所有先前的域。大多数现有的持续学习方法患有低精度和性能波动，特别是当旧数据和新数据的分布显着不同时。事实上，关键的真实问题不是没有旧数据的，而是效率效率恢复模型与整个旧数据集。是否有可能利用一些旧数据来产生高精度并保持稳定的性能，同时在不引入额外的普通公共表？在本文中，我们提出了一个可在各种环境下稳定地产生高性能的文本数据的一个封路数据不断学习模型。具体地，我们利用Fisher信息选择可以“记录”原始模型的关键信息的示例。此外，提出了一种称为动态重量整合的新颖方案，以在恢复过程中启用自由的自由学习。广泛的实验表明基线患有波动的性能，因此在实践中无用。相反，我们建议的CCFI显着且始终如一地优于平均精度高达20％的最佳最新方法，CCFI的每个组件有效地贡献了整体性能。

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。

Lifelong learning has attracted much attention, but existing works still struggle to fight catastrophic forgetting and accumulate knowledge over long stretches of incremental learning. In this work, we propose PODNet, a model inspired by representation learning. By carefully balancing the compromise between remembering the old classes and learning new ones, PODNet fights catastrophic forgetting, even over very long runs of small incremental tasks -a setting so far unexplored by current works. PODNet innovates on existing art with an efficient spatialbased distillation-loss applied throughout the model and a representation comprising multiple proxy vectors for each class. We validate those innovations thoroughly, comparing PODNet with three state-of-the-art models on three datasets: CIFAR100, ImageNet100, and ImageNet1000. Our results showcase a significant advantage of PODNet over existing art, with accuracy gains of 12.10, 6.51, and 2.85 percentage points, respectively. 5

Modern machine learning suffers from catastrophic forgetting when learning new classes incrementally. The performance dramatically degrades due to the missing data of old classes. Incremental learning methods have been proposed to retain the knowledge acquired from the old classes, by using knowledge distilling and keeping a few exemplars from the old classes. However, these methods struggle to scale up to a large number of classes. We believe this is because of the combination of two factors: (a) the data imbalance between the old and new classes, and (b) the increasing number of visually similar classes. Distinguishing between an increasing number of visually similar classes is particularly challenging, when the training data is unbalanced. We propose a simple and effective method to address this data imbalance issue. We found that the last fully connected layer has a strong bias towards the new classes, and this bias can be corrected by a linear model. With two bias parameters, our method performs remarkably well on two large datasets: ImageNet (1000 classes) and MS-Celeb-1M (10000 classes), outperforming the state-of-the-art algorithms by 11.1% and 13.2% respectively.

在本文中，我们提出了一种学习内部特征表示模型的新方法，该模型是\ Textit {兼容}与先前学识的。兼容功能可用于直接比较旧和新的学习功能，允许它们随时间互换使用。这消除了在顺序升级表示模型时，可以对视觉搜索系统提取用于在画廊集中的所有先前看到的图像的新功能。在非常大的画廊集和/或实时系统（即面部识别系统，社交网络，终身系统，终身系统，机器人和监测系统）的情况下，提取新功能通常是非常昂贵或不可行的。我们的方法是通过实质性（核心）称为兼容表示，通过鼓励自身定义到学习的表示模型来实现兼容性，而无需依赖以前学习的模型。实用性允许功能在随时间偏移下不改变的统计属性，以便当前学习的功能与旧版本相互操作。我们评估了种植大规模训练数据集中的单一和连续的多模型升级，我们表明我们的方法通过大幅度实现了实现兼容特征来提高现有技术。特别是，通过从Casia-Webface培训和在野外（LFW）中的标记面上评估的培训数据升级十次，我们获得了49 \％的测量倍数达到兼容的平均次数，这是544 \％对先前最先进的相对改善。

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/。

很少有类别的课堂学习（FSCIL）旨在使用一些示例逐步微调模型（在基础课上培训），而不忘记先前的培训。最近的工作主要解决了2D图像。但是，由于相机技术的发展，3D点云数据比以往任何时候都更可用，这需要考虑3D数据的FSCIL。本文介绍了3D域中的FSCIL。除了灾难性忘记过去的知识和过度贴合数据的众所周知的问题外，3D FSCIL还可以带来更新的挑战。例如，基类可能在现实情况下包含许多合成实例。相比之下，新型类​​别只有少数几个实际扫描的样本（来自RGBD传感器）以增量步骤获得。由于数据从合成到真实的变化，FSCIL会承受其他挑战，以后的增量步骤降低了性能。我们尝试使用微莎普（正交基矢量）来解决此问题，并使用预定义的一组规则来描述任何3D对象。它支持逐步训练，几乎没有示例将合成与真实数据变化最小化。我们使用流行的合成数据集（ModelNet和Shapenet）和3D实范围的数据集（ScanoBjectNN和CO3D）为3D FSCIL提供新的测试协议。通过比较最先进的方法，我们确定了3D域中方法的有效性。

在不忘记以前的任务的情况下不断获得新知识的能力仍然是计算机视觉系统的具有挑战性问题。标准的持续学习基准专注于在离线设置中从静态IID图像学习。在这里，我们研究了一个更具挑战性和现实的在线持续学习问题，称为在线流学习。像人类一样，一些AI代理必须从连续的不重复数据流逐步学习。我们提出了一种新颖的模型，假设驱动的增强存储器网络（HAMN），其有效地使用“假设”的增强内存矩阵来巩固先前的知识，并重播重建的图像特征以避免灾难性的遗忘。与像素级和生成的重播方法相比，Hamn的优点是两倍。首先，基于假设的知识合并避免了图像像素空间中的冗余信息，并使内存使用更有效。其次，增强记忆中的假设可以重新用于学习新任务，提高泛化和转移学习能力。鉴于视频流缺乏在线增量类学习数据集，我们介绍并调整两个额外的视频数据集，Toybox和Ilab，用于在线流学习。我们还在Core50和在线CIFAR100数据集上评估我们的方法。我们的方法显着优于所有最先进的方法，同时提供更有效的内存使用情况。所有源代码和数据都在https://github.com/kreimanlab/augmem公开使用

Graph learning is a popular approach for performing machine learning on graph-structured data. It has revolutionized the machine learning ability to model graph data to address downstream tasks. Its application is wide due to the availability of graph data ranging from all types of networks to information systems. Most graph learning methods assume that the graph is static and its complete structure is known during training. This limits their applicability since they cannot be applied to problems where the underlying graph grows over time and/or new tasks emerge incrementally. Such applications require a lifelong learning approach that can learn the graph continuously and accommodate new information whilst retaining previously learned knowledge. Lifelong learning methods that enable continuous learning in regular domains like images and text cannot be directly applied to continuously evolving graph data, due to its irregular structure. As a result, graph lifelong learning is gaining attention from the research community. This survey paper provides a comprehensive overview of recent advancements in graph lifelong learning, including the categorization of existing methods, and the discussions of potential applications and open research problems.

Neural networks are prone to catastrophic forgetting when trained incrementally on different tasks. Popular incremental learning methods mitigate such forgetting by retaining a subset of previously seen samples and replaying them during the training on subsequent tasks. However, this is not always possible, e.g., due to data protection regulations. In such restricted scenarios, one can employ generative models to replay either artificial images or hidden features to a classifier. In this work, we propose Genifer (GENeratIve FEature-driven image Replay), where a generative model is trained to replay images that must induce the same hidden features as real samples when they are passed through the classifier. Our technique therefore incorporates the benefits of both image and feature replay, i.e.: (1) unlike conventional image replay, our generative model explicitly learns the distribution of features that are relevant for classification; (2) in contrast to feature replay, our entire classifier remains trainable; and (3) we can leverage image-space augmentations, which increase distillation performance while also mitigating overfitting during the training of the generative model. We show that Genifer substantially outperforms the previous state of the art for various settings on the CIFAR-100 and CUB-200 datasets.

深入学习在物体识别任务中取得了显着的成功，通过像想象成像的大规模数据集的可用性。然而，在没有重放旧数据的情况下逐步学习时，深度学习系统遭受灾难性的遗忘。对于真实世界的应用，机器人还需要逐步学习新对象。此外，由于机器人提供有限的人类援助，他们必须只能从几个例子中学习。但是，非常少量的对象识别数据集和基准测试以测试机器人视觉的增量学习能力。此外，没有专门为几个例子提供用于增量对象学习的数据集或基准。为了填补这个差距，我们呈现了一个新的DataSet称为F-Siol-310（几次增量对象学习），该数据集专门捕获用于测试机器人视觉的少量增量对象学习能力。我们还提供了在F-SIOL-310上的8个增量学习算法的基准和评估，以备将来的比较。我们的结果表明，机器人视觉的几次射击增量对象学习问题远未解决。

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.

课堂学习学习需要可塑性和稳定性，以便在保留过去的知识的同时从新数据中学习。由于灾难性的遗忘，当没有内存缓冲区可用时，在这两个属性之间找到妥协尤其具有挑战性。主流方法需要存储两个深层模型，因为它们使用微调与以前的增量状态的知识蒸馏一起整合了新类。我们提出了一种具有相似数量参数但分布不同的方法，以便在可塑性和稳定性之间找到更好的平衡。遵循已经通过基于转移的增量方法部署的方法，我们在初始状态后冻结了功能提取器。最古老的增量状态的类对这种冷冻提取器进行训练，以确保稳定性。使用部分微调模型预测最近的类别以引入可塑性。我们提出的可塑性层可以纳入任何用于无内存增量学习的基于转移的方法，并将其应用于两种此类方法。评估是通过三个大型数据集进行的。结果表明，与现有方法相比，所有测试的配置中均获得了性能提高。