使用Kellgren-Lawence分级系统在放射线照片中评估放射性骨关节炎的严重程度评估放射科医生的表现,是放射学家的表现。根据Kellgren-Lawence分级系统,开发一种自动化的基于深度学习的算法,该算法使用膝盖X光片的后侧(PA)和侧面(LAT)视图来评估膝关节骨关节炎的严重程度。我们使用了来自多中心骨关节炎研究的2802名患者的9739例检查的数据集(大多数)。该数据集分为2040名患者的训练集,259例患者的验证和503例患者的测试组。一种新型的基于深度学习的方法用于评估膝关节OA分为两个步骤:(1)图像中膝关节的定位,(2)根据KL分级系统进行分类。我们的方法同时使用PA和LAT视图作为模型的输入。将算法生成的分数与整个测试集的最多数据集中提供的等级以及我们机构中5位放射科医生提供的成绩进行了比较。与大多数数据集中提供的评分相比,该模型在整个测试集上获得了71.90%的多级准确性。该组的二次加权KAPPA系数为0.9066。我们机构的所有放射科医生对研究的平均二次加权Kappa为0.748。我们机构的算法和放射科医生之间的平均二次加权Kappa为0.769。所提出的模型表明,KL分类与MSK放射科医生的等效性,但显然可重复性。我们的模型还与我们机构的放射科医生同意与放射科医生相同的程度。该算法可用于提供膝关节炎严重程度的可重复评估。
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膝关节X射线上的膝盖骨关节炎(KOA)的评估是使用总膝关节置换术的中心标准。但是,该评估遭受了不精确的标准,并且读取器间的可变性非常高。对KOA严重性的算法,自动评估可以通过提高其使用的适当性来改善膝盖替代程序的总体结果。我们提出了一种基于深度学习的新型五步算法,以自动从X光片后验(PA)视图对KOA进行评级:(1)图像预处理(2)使用Yolo V3-tiny模型,图像在图像中定位膝关节, (3)使用基于卷积神经网络的分类器对骨关节炎的严重程度进行初步评估,(4)关节分割和关节空间狭窄(JSN)的计算(JSN)和(5),JSN和最初的结合评估确定最终的凯尔格伦法律(KL)得分。此外,通过显示用于进行评估的分割面具,我们的算法与典型的“黑匣子”深度学习分类器相比表现出更高的透明度。我们使用我们机构的两个公共数据集和一个数据集进行了全面的评估,并表明我们的算法达到了最先进的性能。此外,我们还从机构中的多个放射科医生那里收集了评分,并表明我们的算法在放射科医生级别进行。该软件已在https://github.com/maciejmazurowowski/osteoarthitis-classification上公开提供。
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There are multiple scales of abstraction from which we can describe the same image, depending on whether we are focusing on fine-grained details or a more global attribute of the image. In brain mapping, learning to automatically parse images to build representations of both small-scale features (e.g., the presence of cells or blood vessels) and global properties of an image (e.g., which brain region the image comes from) is a crucial and open challenge. However, most existing datasets and benchmarks for neuroanatomy consider only a single downstream task at a time. To bridge this gap, we introduce a new dataset, annotations, and multiple downstream tasks that provide diverse ways to readout information about brain structure and architecture from the same image. Our multi-task neuroimaging benchmark (MTNeuro) is built on volumetric, micrometer-resolution X-ray microtomography images spanning a large thalamocortical section of mouse brain, encompassing multiple cortical and subcortical regions. We generated a number of different prediction challenges and evaluated several supervised and self-supervised models for brain-region prediction and pixel-level semantic segmentation of microstructures. Our experiments not only highlight the rich heterogeneity of this dataset, but also provide insights into how self-supervised approaches can be used to learn representations that capture multiple attributes of a single image and perform well on a variety of downstream tasks. Datasets, code, and pre-trained baseline models are provided at: https://mtneuro.github.io/ .
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We investigate how humans perform the task of dubbing video content from one language into another, leveraging a novel corpus of 319.57 hours of video from 54 professionally produced titles. This is the first such large-scale study we are aware of. The results challenge a number of assumptions commonly made in both qualitative literature on human dubbing and machine-learning literature on automatic dubbing, arguing for the importance of vocal naturalness and translation quality over commonly emphasized isometric (character length) and lip-sync constraints, and for a more qualified view of the importance of isochronic (timing) constraints. We also find substantial influence of the source-side audio on human dubs through channels other than the words of the translation, pointing to the need for research on ways to preserve speech characteristics, as well as semantic transfer such as emphasis/emotion, in automatic dubbing systems.
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This work presents a detailed linguistic analysis into why larger Transformer-based pre-trained language models with more parameters and lower perplexity nonetheless yield surprisal estimates that are less predictive of human reading times. First, regression analyses show a strictly monotonic, positive log-linear relationship between perplexity and fit to reading times for the more recently released five GPT-Neo variants and eight OPT variants on two separate datasets, replicating earlier results limited to just GPT-2 (Oh et al., 2022). Subsequently, analysis of residual errors reveals a systematic deviation of the larger variants, such as underpredicting reading times of named entities and making compensatory overpredictions for reading times of function words such as modals and conjunctions. These results suggest that the propensity of larger Transformer-based models to 'memorize' sequences during training makes their surprisal estimates diverge from humanlike expectations, which warrants caution in using pre-trained language models to study human language processing.
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Contrastive learning has been successfully used for retrieval of semantically aligned sentences, but it often requires large batch sizes or careful engineering to work well. In this paper, we instead propose a generative model for learning multilingual text embeddings which can be used to retrieve or score sentence pairs. Our model operates on parallel data in $N$ languages and, through an approximation we introduce, efficiently encourages source separation in this multilingual setting, separating semantic information that is shared between translations from stylistic or language-specific variation. We show careful large-scale comparisons between contrastive and generation-based approaches for learning multilingual text embeddings, a comparison that has not been done to the best of our knowledge despite the popularity of these approaches. We evaluate this method on a suite of tasks including semantic similarity, bitext mining, and cross-lingual question retrieval -- the last of which we introduce in this paper. Overall, our Variational Multilingual Source-Separation Transformer (VMSST) model outperforms both a strong contrastive and generative baseline on these tasks.
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A central challenge of building more powerful Graph Neural Networks (GNNs) is the oversmoothing phenomenon, where increasing the network depth leads to homogeneous node representations and thus worse classification performance. While previous works have only demonstrated that oversmoothing is inevitable when the number of graph convolutions tends to infinity, in this paper, we precisely characterize the mechanism behind the phenomenon via a non-asymptotic analysis. Specifically, we distinguish between two different effects when applying graph convolutions -- an undesirable mixing effect that homogenizes node representations in different classes, and a desirable denoising effect that homogenizes node representations in the same class. By quantifying these two effects on random graphs sampled from the Contextual Stochastic Block Model (CSBM), we show that oversmoothing happens once the mixing effect starts to dominate the denoising effect, and the number of layers required for this transition is $O(\log N/\log (\log N))$ for sufficiently dense graphs with $N$ nodes. We also extend our analysis to study the effects of Personalized PageRank (PPR) on oversmoothing. Our results suggest that while PPR mitigates oversmoothing at deeper layers, PPR-based architectures still achieve their best performance at a shallow depth and are outperformed by the graph convolution approach on certain graphs. Finally, we support our theoretical results with numerical experiments, which further suggest that the oversmoothing phenomenon observed in practice may be exacerbated by the difficulty of optimizing deep GNN models.
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Dialect differences caused by regional, social, and economic barriers cause performance discrepancies for many groups of users of language technology. Fair, inclusive, and equitable language technology must critically be dialect invariant, meaning that performance remains constant over dialectal shifts. Current English systems often fall significantly short of this ideal since they are designed and tested on a single dialect: Standard American English. We introduce Multi-VALUE -- a suite of resources for evaluating and achieving English dialect invariance. We build a controllable rule-based translation system spanning 50 English dialects and a total of 189 unique linguistic features. Our translation maps Standard American English text to synthetic form of each dialect, which uses an upper-bound on the natural density of features in that dialect. First, we use this system to build stress tests for question answering, machine translation, and semantic parsing tasks. Stress tests reveal significant performance disparities for leading models on non-standard dialects. Second, we use this system as a data augmentation technique to improve the dialect robustness of existing systems. Finally, we partner with native speakers of Chicano and Indian English to release new gold-standard variants of the popular CoQA task.
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We present a novel corpus for French dialect identification comprising 413,522 French text samples collected from public news websites in Belgium, Canada, France and Switzerland. To ensure an accurate estimation of the dialect identification performance of models, we designed the corpus to eliminate potential biases related to topic, writing style, and publication source. More precisely, the training, validation and test splits are collected from different news websites, while searching for different keywords (topics). This leads to a French cross-domain (FreCDo) dialect identification task. We conduct experiments with four competitive baselines, a fine-tuned CamemBERT model, an XGBoost based on fine-tuned CamemBERT features, a Support Vector Machines (SVM) classifier based on fine-tuned CamemBERT features, and an SVM based on word n-grams. Aside from presenting quantitative results, we also make an analysis of the most discriminative features learned by CamemBERT. Our corpus is available at https://github.com/MihaelaGaman/FreCDo.
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Natural language inference has trended toward studying contexts beyond the sentence level. An important application area is law: past cases often do not foretell how they apply to new situations and implications must be inferred. This paper introduces LawngNLI, constructed from U.S. legal opinions with automatic labels with high human-validated accuracy. Premises are long and multigranular. Experiments show two use cases. First, LawngNLI can benchmark for in-domain generalization from short to long contexts. It has remained unclear if large-scale long-premise NLI datasets actually need to be constructed: near-top performance on long premises could be achievable by fine-tuning using short premises. Without multigranularity, benchmarks cannot distinguish lack of fine-tuning on long premises versus domain shift between short and long datasets. In contrast, our long and short premises share the same examples and domain. Models fine-tuned using several past NLI datasets and/or our short premises fall short of top performance on our long premises. So for at least certain domains (such as ours), large-scale long-premise datasets are needed. Second, LawngNLI can benchmark for implication-based retrieval. Queries are entailed or contradicted by target documents, allowing users to move between arguments and evidence. Leading retrieval models perform reasonably zero shot on a LawngNLI-derived retrieval task. We compare different systems for re-ranking, including lexical overlap and cross-encoders fine-tuned using a modified LawngNLI or past NLI datasets. LawngNLI can train and test systems for implication-based case retrieval and argumentation.
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