从语言学习者到残疾人,文本可读性评估对不同目标人士有广泛的应用。网络上文本内容生产的快速速度使得如果没有机器学习和自然语言处理技术的好处,就无法测量文本复杂性。尽管各种研究涉及近年来英语文本的可读性评估,但仍有改进其他语言的模型的空间。在本文中,我们提出了一种基于转移学习的德语文本评估文本复杂性评估的新模型。我们的结果表明,该模型比从输入文本中提取的语言特征优于更多经典的解决方案。最佳模型是基于BERT预训练的语言模型,达到了均方根误差(RMSE)为0.483。
translated by 谷歌翻译
最近,由于受监督人员重新识别(REID)的表现不佳,域名概括(DG)人REID引起了很多关注,旨在学习一个不敏感的模型,并可以抵抗域的影响偏见。在本文中,我们首先通过实验验证样式因素是域偏差的重要组成部分。基于这个结论,我们提出了一种样式变量且无关紧要的学习方法(SVIL)方法,以消除样式因素对模型的影响。具体来说,我们在SVIL中设计了样式的抖动模块(SJM)。 SJM模块可以丰富特定源域的样式多样性,并减少各种源域的样式差异。这导致该模型重点关注与身份相关的信息,并对样式变化不敏感。此外,我们将SJM模块与元学习算法有机结合,从而最大程度地提高了好处并进一步提高模型的概括能力。请注意,我们的SJM模块是插件和推理,无需成本。广泛的实验证实了我们的SVIL的有效性,而我们的方法的表现优于DG-REID基准测试的最先进方法。
translated by 谷歌翻译
基于自然语言(NL)的车辆检索旨在搜索给定文本描述的特定车辆。不同于基于图像的车辆检索,基于NL的车辆检索不仅需要考虑车辆外观,还需要考虑周围环境和时间关系。在本文中,我们提出了一个具有空间关系建模(SSM)方法的对称网络,用于基于NL的车辆检索。具体而言,我们设计了一个对称网络,以学习文本描述和车辆图像之间的统一跨模式表示,其中保留了车辆外观细节和车辆轨迹全球信息。此外,为了更好地利用位置信息,我们提出了一种空间关系建模方法,以考虑周围环境和相互关系的考虑。定性和定量实验验证了所提出的方法的有效性。我们在第六届AI城市挑战赛的测试集上获得了43.92%的MRR准确性,该挑战是基于自然语言的车辆检索轨道,在公共排行榜上所有有​​效的提交中排名第一。该代码可从https://github.com/hbchen121/aicity2022_track2_ssm获得。
translated by 谷歌翻译
我们研究了从使用套索确定性缺失数据模式控制的相关观察结果中始终如一地恢复回归参数矢量的稀疏模式的问题。我们考虑通过确定性,不均匀过滤器对观察到的数据集进行审查的情况。通过确定性缺失结构恢复数据集中的稀疏模式可以说,比在统一的随机场景中恢复更具挑战性。在本文中,我们通过利用审查过滤器的拓扑特性,提出了一种有效的算法来插入价值的算法。然后,我们提供了新的理论结果,以使用拟议的插补策略来精确恢复稀疏模式。我们的分析表明,在某些统计和拓扑条件下,可以在多项式时间和对数样品复杂性中恢复隐藏的稀疏模式。
translated by 谷歌翻译
We propose the framework of dual convexified convolutional neural networks (DCCNNs). In this framework, we first introduce a primal learning problem motivated by convexified convolutional neural networks (CCNNs), and then construct the dual convex training program through careful analysis of the Karush-Kuhn-Tucker (KKT) conditions and Fenchel conjugates. Our approach reduces the computational overhead of constructing a large kernel matrix and more importantly, eliminates the ambiguity of factorizing the matrix. Due to the low-rank structure in CCNNs and the related subdifferential of nuclear norms, there is no closed-form expression to recover the primal solution from the dual solution. To overcome this, we propose a highly novel weight recovery algorithm, which takes the dual solution and the kernel information as the input, and recovers the linear weight and the output of convolutional layer, instead of weight parameter. Furthermore, our recovery algorithm exploits the low-rank structure and imposes a small number of filters indirectly, which reduces the parameter size. As a result, DCCNNs inherit all the statistical benefits of CCNNs, while enjoying a more formal and efficient workflow.
translated by 谷歌翻译
A recent study has shown a phenomenon called neural collapse in that the within-class means of features and the classifier weight vectors converge to the vertices of a simplex equiangular tight frame at the terminal phase of training for classification. In this paper, we explore the corresponding structures of the last-layer feature centers and classifiers in semantic segmentation. Based on our empirical and theoretical analysis, we point out that semantic segmentation naturally brings contextual correlation and imbalanced distribution among classes, which breaks the equiangular and maximally separated structure of neural collapse for both feature centers and classifiers. However, such a symmetric structure is beneficial to discrimination for the minor classes. To preserve these advantages, we introduce a regularizer on feature centers to encourage the network to learn features closer to the appealing structure in imbalanced semantic segmentation. Experimental results show that our method can bring significant improvements on both 2D and 3D semantic segmentation benchmarks. Moreover, our method ranks 1st and sets a new record (+6.8% mIoU) on the ScanNet200 test leaderboard. Code will be available at https://github.com/dvlab-research/Imbalanced-Learning.
translated by 谷歌翻译
Weakly-supervised object localization aims to indicate the category as well as the scope of an object in an image given only the image-level labels. Most of the existing works are based on Class Activation Mapping (CAM) and endeavor to enlarge the discriminative area inside the activation map to perceive the whole object, yet ignore the co-occurrence confounder of the object and context (e.g., fish and water), which makes the model inspection hard to distinguish object boundaries. Besides, the use of CAM also brings a dilemma problem that the classification and localization always suffer from a performance gap and can not reach their highest accuracy simultaneously. In this paper, we propose a casual knowledge distillation method, dubbed KD-CI-CAM, to address these two under-explored issues in one go. More specifically, we tackle the co-occurrence context confounder problem via causal intervention (CI), which explores the causalities among image features, contexts, and categories to eliminate the biased object-context entanglement in the class activation maps. Based on the de-biased object feature, we additionally propose a multi-teacher causal distillation framework to balance the absorption of classification knowledge and localization knowledge during model training. Extensive experiments on several benchmarks demonstrate the effectiveness of KD-CI-CAM in learning clear object boundaries from confounding contexts and addressing the dilemma problem between classification and localization performance.
translated by 谷歌翻译
Witnessing the impressive achievements of pre-training techniques on large-scale data in the field of computer vision and natural language processing, we wonder whether this idea could be adapted in a grab-and-go spirit, and mitigate the sample inefficiency problem for visuomotor driving. Given the highly dynamic and variant nature of the input, the visuomotor driving task inherently lacks view and translation invariance, and the visual input contains massive irrelevant information for decision making, resulting in predominant pre-training approaches from general vision less suitable for the autonomous driving task. To this end, we propose PPGeo (Policy Pre-training via Geometric modeling), an intuitive and straightforward fully self-supervised framework curated for the policy pretraining in visuomotor driving. We aim at learning policy representations as a powerful abstraction by modeling 3D geometric scenes on large-scale unlabeled and uncalibrated YouTube driving videos. The proposed PPGeo is performed in two stages to support effective self-supervised training. In the first stage, the geometric modeling framework generates pose and depth predictions simultaneously, with two consecutive frames as input. In the second stage, the visual encoder learns driving policy representation by predicting the future ego-motion and optimizing with the photometric error based on current visual observation only. As such, the pre-trained visual encoder is equipped with rich driving policy related representations and thereby competent for multiple visuomotor driving tasks. Extensive experiments covering a wide span of challenging scenarios have demonstrated the superiority of our proposed approach, where improvements range from 2% to even over 100% with very limited data. Code and models will be available at https://github.com/OpenDriveLab/PPGeo.
translated by 谷歌翻译
In this work, we focus on instance-level open vocabulary segmentation, intending to expand a segmenter for instance-wise novel categories without mask annotations. We investigate a simple yet effective framework with the help of image captions, focusing on exploiting thousands of object nouns in captions to discover instances of novel classes. Rather than adopting pretrained caption models or using massive caption datasets with complex pipelines, we propose an end-to-end solution from two aspects: caption grounding and caption generation. In particular, we devise a joint Caption Grounding and Generation (CGG) framework based on a Mask Transformer baseline. The framework has a novel grounding loss that performs explicit and implicit multi-modal feature alignments. We further design a lightweight caption generation head to allow for additional caption supervision. We find that grounding and generation complement each other, significantly enhancing the segmentation performance for novel categories. We conduct extensive experiments on the COCO dataset with two settings: Open Vocabulary Instance Segmentation (OVIS) and Open Set Panoptic Segmentation (OSPS). The results demonstrate the superiority of our CGG framework over previous OVIS methods, achieving a large improvement of 6.8% mAP on novel classes without extra caption data. Our method also achieves over 15% PQ improvements for novel classes on the OSPS benchmark under various settings.
translated by 谷歌翻译
Nearest-Neighbor (NN) classification has been proven as a simple and effective approach for few-shot learning. The query data can be classified efficiently by finding the nearest support class based on features extracted by pretrained deep models. However, NN-based methods are sensitive to the data distribution and may produce false prediction if the samples in the support set happen to lie around the distribution boundary of different classes. To solve this issue, we present P3DC-Shot, an improved nearest-neighbor based few-shot classification method empowered by prior-driven data calibration. Inspired by the distribution calibration technique which utilizes the distribution or statistics of the base classes to calibrate the data for few-shot tasks, we propose a novel discrete data calibration operation which is more suitable for NN-based few-shot classification. Specifically, we treat the prototypes representing each base class as priors and calibrate each support data based on its similarity to different base prototypes. Then, we perform NN classification using these discretely calibrated support data. Results from extensive experiments on various datasets show our efficient non-learning based method can outperform or at least comparable to SOTA methods which need additional learning steps.
translated by 谷歌翻译