Domain adaptation aims to transfer the knowledge acquired by models trained on (data-rich) source domains to (low-resource) target domains, for which a popular method is invariant representation learning. While they have been studied extensively for classification and regression problems, how they apply to ranking problems, where the data and metrics have a list structure, is not well understood. Theoretically, we establish a domain adaptation generalization bound for ranking under listwise metrics such as MRR and NDCG. The bound suggests an adaptation method via learning list-level domain-invariant feature representations, whose benefits are empirically demonstrated by unsupervised domain adaptation experiments on real-world ranking tasks, including passage reranking. A key message is that for domain adaptation, the representations should be analyzed at the same level at which the metric is computed, as we show that learning invariant representations at the list level is most effective for adaptation on ranking problems.
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Contrastive Language-Image Pre-trained (CLIP) models have zero-shot ability of classifying an image belonging to "[CLASS]" by using similarity between the image and the prompt sentence "a [CONTEXT] of [CLASS]". Based on exhaustive text cues in "[CONTEXT]", CLIP model is aware of different contexts, e.g. background, style, viewpoint, and exhibits unprecedented robustness against a wide range of distribution shifts. However, recent works find further fine-tuning of CLIP models improves accuracy but sacrifices the robustness on downstream tasks. We conduct an empirical investigation to show fine-tuning will corrupt the context-aware ability of pre-trained CLIP features. To solve this problem, we propose Context-Aware Robust Fine-tuning (CAR-FT). CAR-FT regularizes the model during fine-tuning to capture the context information. Specifically, we use zero-shot prompt weights to get the context distribution contained in the image. By minimizing the Kullback-Leibler Divergence (KLD) between context distributions induced by original/fine-tuned CLIP models, CAR-FT makes the context-aware ability of CLIP inherited into downstream tasks, and achieves both higher In-Distribution (ID) and Out-Of-Distribution (OOD) accuracy. The experimental results show CAR-FT achieves superior robustness on five OOD test datasets of ImageNet, and meanwhile brings accuracy gains on nine downstream tasks. Additionally, CAR-FT surpasses previous Domain Generalization (DG) methods and gets 78.5% averaged accuracy on DomainBed benchmark, building the new state-of-the-art.
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Zero-shot relation triplet extraction (ZeroRTE) aims to extract relation triplets from unstructured texts under the zero-shot setting, where the relation sets at the training and testing stages are disjoint. Previous state-of-the-art method handles this challenging task by leveraging pretrained language models to generate data as additional training samples, which increases the training cost and severely constrains the model performance. To address the above issues, we propose a novel method named PCRED for ZeroRTE with Potential Candidate Relation Selection and Entity Boundary Detection. The remarkable characteristic of PCRED is that it does not rely on additional data and still achieves promising performance. The model adopts a relation-first paradigm, recognizing unseen relations through candidate relation selection. With this approach, the semantics of relations are naturally infused in the context. Entities are extracted based on the context and the semantics of relations subsequently. We evaluate our model on two ZeroRTE datasets. The experiment results show that our method consistently outperforms previous works. Our code will be available at https://anonymous.4open.science/r/PCRED.
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The binding problem is one of the fundamental challenges that prevent the artificial neural network (ANNs) from a compositional understanding of the world like human perception, because disentangled and distributed representations of generative factors can interfere and lead to ambiguity when complex data with multiple objects are presented. In this paper, we propose a brain-inspired hybrid neural network (HNN) that introduces temporal binding theory originated from neuroscience into ANNs by integrating spike timing dynamics (via spiking neural networks, SNNs) with reconstructive attention (by ANNs). Spike timing provides an additional dimension for grouping, while reconstructive feedback coordinates the spikes into temporal coherent states. Through iterative interaction of ANN and SNN, the model continuously binds multiple objects at alternative synchronous firing times in the SNN coding space. The effectiveness of the model is evaluated on synthetic datasets of binary images. By visualization and analysis, we demonstrate that the binding is explainable, soft, flexible, and hierarchical. Notably, the model is trained on single object datasets without explicit supervision on grouping, but successfully binds multiple objects on test datasets, showing its compositional generalization capability. Further results show its binding ability in dynamic situations.
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Despite high global prevalence of hepatic steatosis, no automated diagnostics demonstrated generalizability in detecting steatosis on multiple international datasets. Traditionally, hepatic steatosis detection relies on clinicians selecting the region of interest (ROI) on computed tomography (CT) to measure liver attenuation. ROI selection demands time and expertise, and therefore is not routinely performed in populations. To automate the process, we validated an existing artificial intelligence (AI) system for 3D liver segmentation and used it to purpose a novel method: AI-ROI, which could automatically select the ROI for attenuation measurements. AI segmentation and AI-ROI method were evaluated on 1,014 non-contrast enhanced chest CT images from eight international datasets: LIDC-IDRI, NSCLC-Lung1, RIDER, VESSEL12, RICORD-1A, RICORD-1B, COVID-19-Italy, and COVID-19-China. AI segmentation achieved a mean dice coefficient of 0.957. Attenuations measured by AI-ROI showed no significant differences (p = 0.545) and a reduction of 71% time compared to expert measurements. The area under the curve (AUC) of the steatosis classification of AI-ROI is 0.921 (95% CI: 0.883 - 0.959). If performed as a routine screening method, our AI protocol could potentially allow early non-invasive, non-pharmacological preventative interventions for hepatic steatosis. 1,014 expert-annotated liver segmentations of patients with hepatic steatosis annotations can be downloaded here: https://drive.google.com/drive/folders/1-g_zJeAaZXYXGqL1OeF6pUjr6KB0igJX.
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科学文献是高质量的语料库,支持大量自然语言处理(NLP)研究。但是,现有数据集围绕英语,这限制了中国科学NLP的发展。在这项工作中,我们提出了CSL,这是一个大规模的中国科学文献数据集,其中包含396K论文的标题,摘要,关键字和学术领域。据我们所知,CSL是中文中的第一个科学文档数据集。 CSL可以用作中国语料库。同样,该半结构化数据是一种自然注释,可以构成许多监督的NLP任务。基于CSL,我们提出了一个基准,以评估跨科学领域任务的模型的性能,即摘要,关键字生成和文本分类。我们分析了现有文本到文本模型在评估任务上的行为,并揭示了中国科学NLP任务的挑战,该任务为未来的研究提供了宝贵的参考。数据和代码可在https://github.com/ydli-ai/csl上找到
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最近,随着深度学习的持续发展,指定实体识别任务的表现得到了极大的改进。但是,在某些特定领域(例如生物医学和军事)中数据的隐私和机密性导致数据不足以支持深度神经网络的培训。在本文中,我们提出了一个加密学习框架,以解决数据泄漏的问题以及对某些域中敏感数据的不便披露。我们首次将多个加密算法介绍以在指定实体识别任务中加密培训数据。换句话说,我们使用加密数据训练深神网络。我们在六个中国数据集上进行实验,其中三个是由我们自己构建的。实验结果表明,加密方法可实现令人满意的结果。一些经过加密数据训练的模型的性能甚至超过了未加密方法的性能,该方法验证了引入的加密方法的有效性,并在一定程度上解决了数据泄漏问题。
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近年来,多视图学习迅速发展。尽管许多先前的研究都认为每个实例都出现在所有视图中,但在现实世界应用程序中很常见,从某些视图中丢失实例,从而导致多视图数据不完整。为了解决这个问题,我们提出了一个新型潜在的异质图网络(LHGN),以实现不完整的多视图学习,该学习旨在以灵活的方式尽可能充分地使用多个不完整的视图。通过学习统一的潜在代表,隐含地实现了不同观点之间一致性和互补性之间的权衡。为了探索样本与潜在表示之间的复杂关系,首次提出了邻域约束和视图约束,以构建异质图。最后,为了避免训练和测试阶段之间的任何不一致之处,基于图形学习的分类任务应用了转导学习技术。对现实世界数据集的广泛实验结果证明了我们模型对现有最新方法的有效性。
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使用增强现实(AR)用于导航目的,这表明在手术手术过程中协助医生有益。这些应用通常需要知道外科手术工具和患者的姿势,以提供外科医生在任务执行过程中可以使用的视觉信息。现有的医学级跟踪系统使用放置在手术室内的红外摄像头(OR)来识别感兴趣的对象附加并计算其姿势的复古反射标记。一些市售的AR头式显示器(HMD)使用类似的摄像头进行自定位,手动跟踪和估算对象的深度。这项工作提出了一个使用AR HMD的内置摄像机来准确跟踪复古反射标记的框架,例如在手术过程中使用的标记,而无需集成任何其他组件。该框架还能够同时跟踪多个工具。我们的结果表明,横向翻译的准确度为0.09 +-0.06毫米,可以实现标记的跟踪和检测,纵向翻译的0.42 +-0.32 mm,绕垂直轴旋转的0.80 +-0.39 ver。此外,为了展示所提出的框架的相关性,我们在手术程序的背景下评估了系统的性能。该用例旨在在骨科过程中复制K-Wire插入的场景。为了进行评估,为两名外科医生和一名生物医学研究人员提供了视觉导航,每次都进行了21次注射。该用例的结果提供了与基于AR的导航程序报告的相当精度。
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事实证明,将先验知识纳入预训练的语言模型中对知识驱动的NLP任务有效,例如实体键入和关系提取。当前的培训程序通常通过使用知识掩盖,知识融合和知识更换将外部知识注入模型。但是,输入句子中包含的事实信息尚未完全开采,并且尚未严格检查注射的外部知识。结果,无法完全利用上下文信息,并将引入额外的噪音,或者注入的知识量受到限制。为了解决这些问题,我们提出了MLRIP,该MLRIP修改了Ernie-Baidu提出的知识掩盖策略,并引入了两阶段的实体替代策略。进行全面分析的广泛实验说明了MLRIP在军事知识驱动的NLP任务中基于BERT的模型的优势。
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