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arXiv 2210.04993cs.CVcs.AIcs.LG
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基于演化类本体的持续学习

Continual Learning with Evolving Class Ontologies

CMU(卡内基梅隆大学);UIUC(伊利诺伊大学厄巴纳-香槟分校);Argo AI;Texas A&M University(得克萨斯农工大学)

Zhiqiu Lin, Deepak Pathak, Yu-Xiong Wang, Deva Ramanan, Shu Kong

摘要:

终身学习者必须认识到随着时间的推移而演变的概念词汇。一个常见但未充分探索的场景是使用不断改进/扩展旧类的类标签进行学习。例如,人类在狗繁殖之前就学会了识别${\tt dog}$。在实际环境中,数据集$\textit{versioning}$经常引入对本体的细化,例如,随着自主操作扩展到新的城市,自主车辆基准将先前的${\tt vehicle}$类细化为${\tt school-bus}$。本文形式化了一个研究$\textit{Learning with Evolving Class Ontology}$(LECO)问题的协议。LECO需要在不同的时间段(TP)中学习分类器;每个TP引入新的“精细”标签本体,其细化旧的“粗略”标签本体(例如,改进先前${\tt dog}$的狗品种)。LECO探索了诸如是否注释新数据或重新标记旧数据、如何利用粗糙标签以及是否微调先前TP的模型或从头开始训练等问题。为了回答这些问题,我们利用相关问题的见解,如类增量学习。我们通过图像分类(CIFAR和iNaturalist)和语义分割(Mapillary)的镜头在LECO协议下验证它们。我们的实验得出了令人惊讶的结论;虽然目前的现状是用新的本体(如COCO到LVIS或Mapillary1.2到2.0)重新标记现有的数据集,但LECO证明了一个更好的策略是用新的本体注释$\textit{new}$数据。然而,这会产生一个新旧标签不一致的聚合数据集,使学习变得复杂。为了应对这一挑战,我们采用了半监督和部分标签学习的方法。这样的策略可以令人惊讶地接近最优,接近一个“预言机”,它在用最新本体详尽标记的聚合数据集上学习。

英文摘要:

Lifelong learners must recognize concept vocabularies that evolve over time. A common yet underexplored scenario is learning with class labels that continually refine/expand old classes. For example, humans learn to recognize ${\tt dog}$ before dog breeds. In practical settings, dataset $\textit{versioning}$ often introduces refinement to ontologies, such as autonomous vehicle benchmarks that refine a previous ${\tt vehicle}$ class into ${\tt school-bus}$ as autonomous operations expand to new cities. This paper formalizes a protocol for studying the problem of $\textit{Learning with Evolving Class Ontology}$ (LECO). LECO requires learning classifiers in distinct time periods (TPs); each TP introduces a new ontology of "fine" labels that refines old ontologies of "coarse" labels (e.g., dog breeds that refine the previous ${\tt dog}$). LECO explores such questions as whether to annotate new data or relabel the old, how to leverage coarse labels, and whether to finetune the previous TP's model or train from scratch. To answer these questions, we leverage insights from related problems such as class-incremental learning. We validate them under the LECO protocol through the lens of image classification (CIFAR and iNaturalist) and semantic segmentation (Mapillary). Our experiments lead to surprising conclusions; while the current status quo is to relabel existing datasets with new ontologies (such as COCO-to-LVIS or Mapillary1.2-to-2.0), LECO demonstrates that a far better strategy is to annotate $\textit{new}$ data with the new ontology. However, this produces an aggregate dataset with inconsistent old-vs-new labels, complicating learning. To address this challenge, we adopt methods from semi-supervised and partial-label learning. Such strategies can surprisingly be made near-optimal, approaching an "oracle" that learns on the aggregate dataset exhaustively labeled with the newest ontology.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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