我们介绍了IST和Unmabel对WMT 2022关于质量估计(QE)的共享任务的共同贡献。我们的团队参与了所有三个子任务:(i)句子和单词级质量预测;(ii)可解释的量化宽松;(iii)关键错误检测。对于所有任务,我们在彗星框架之上构建,将其与OpenKIWI的预测估计架构连接,并为其配备单词级序列标记器和解释提取器。我们的结果表明,在预处理过程中合并参考可以改善下游任务上多种语言对的性能,并且通过句子和单词级别的目标共同培训可以进一步提高。此外,将注意力和梯度信息结合在一起被证明是提取句子级量化量化宽松模型的良好解释的首要策略。总体而言,我们的意见书在几乎所有语言对的所有三个任务中都取得了最佳的结果。
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ICECUBE是一种用于检测1 GEV和1 PEV之间大气和天体中微子的光学传感器的立方公斤阵列,该阵列已部署1.45 km至2.45 km的南极的冰盖表面以下1.45 km至2.45 km。来自ICE探测器的事件的分类和重建在ICeCube数据分析中起着核心作用。重建和分类事件是一个挑战,这是由于探测器的几何形状,不均匀的散射和冰中光的吸收,并且低于100 GEV的光,每个事件产生的信号光子数量相对较少。为了应对这一挑战,可以将ICECUBE事件表示为点云图形,并将图形神经网络(GNN)作为分类和重建方法。 GNN能够将中微子事件与宇宙射线背景区分开,对不同的中微子事件类型进行分类,并重建沉积的能量,方向和相互作用顶点。基于仿真,我们提供了1-100 GEV能量范围的比较与当前ICECUBE分析中使用的当前最新最大似然技术,包括已知系统不确定性的影响。对于中微子事件分类,与当前的IceCube方法相比,GNN以固定的假阳性速率(FPR)提高了信号效率的18%。另外,GNN在固定信号效率下将FPR的降低超过8(低于半百分比)。对于能源,方向和相互作用顶点的重建,与当前最大似然技术相比,分辨率平均提高了13%-20%。当在GPU上运行时,GNN能够以几乎是2.7 kHz的中位数ICECUBE触发速率的速率处理ICECUBE事件,这打开了在在线搜索瞬态事件中使用低能量中微子的可能性。
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当使用基于视觉的方法对被占用和空的空地之间的单个停车位进行分类时,人类专家通常需要注释位置,并标记包含目标停车场中收集的图像的训练集,以微调系统。我们建议研究三种注释类型(多边形,边界框和固定尺寸的正方形),提供停车位的不同数据表示。理由是阐明手工艺注释精度和模型性能之间的最佳权衡。我们还调查了在目标停车场微调预训练型号所需的带注释的停车位数。使用PKLOT数据集使用的实验表明,使用低精度注释(例如固定尺寸的正方形),可以将模型用少于1,000个标记的样品微调到目标停车场。
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巴西最高法院每学期收到数万案件。法院员工花费数千个小时来执行这些案件的初步分析和分类 - 这需要努力从案件管理工作流的后部,更复杂的阶段进行努力。在本文中,我们探讨了来自巴西最高法院的文件多模式分类。我们在6,510起诉讼(339,478页)的新型多模式数据集上训练和评估我们的方法,并用手动注释将每个页面分配给六个类之一。每个诉讼都是页面的有序序列,它们既可以作为图像存储,又是通过光学特征识别提取的相应文本。我们首先训练两个单峰分类器:图像上对Imagenet进行了预先训练的重新编织,并且图像上进行了微调,并且具有多个内核尺寸过滤器的卷积网络在文档文本上从SCRATCH进行了训练。我们将它们用作视觉和文本特征的提取器,然后通过我们提出的融合模块组合。我们的融合模块可以通过使用学习的嵌入来处理缺失的文本或视觉输入,以获取缺少数据。此外,我们尝试使用双向长期记忆(BILSTM)网络和线性链条件随机字段进行实验,以模拟页面的顺序性质。多模式方法的表现都优于文本分类器和视觉分类器,尤其是在利用页面的顺序性质时。
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尽管近期因因果推断领域的进展,迄今为止没有关于从观察数据的收集治疗效应估算的方法。对临床实践的结果是,当缺乏随机试验的结果时,没有指导在真实情景中似乎有效的指导。本文提出了一种务实的方法,以获得从观察性研究的治疗效果的初步但稳健地估算,为前线临床医生提供对其治疗策略的信心程度。我们的研究设计适用于一个公开问题,估算Covid-19密集护理患者的拳击机动的治疗效果。
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In the Earth's magnetosphere, there are fewer than a dozen dedicated probes beyond low-Earth orbit making in-situ observations at any given time. As a result, we poorly understand its global structure and evolution, the mechanisms of its main activity processes, magnetic storms, and substorms. New Artificial Intelligence (AI) methods, including machine learning, data mining, and data assimilation, as well as new AI-enabled missions will need to be developed to meet this Sparse Data challenge.
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Late-life depression (LLD) is a highly prevalent mood disorder occurring in older adults and is frequently accompanied by cognitive impairment (CI). Studies have shown that LLD may increase the risk of Alzheimer's disease (AD). However, the heterogeneity of presentation of geriatric depression suggests that multiple biological mechanisms may underlie it. Current biological research on LLD progression incorporates machine learning that combines neuroimaging data with clinical observations. There are few studies on incident cognitive diagnostic outcomes in LLD based on structural MRI (sMRI). In this paper, we describe the development of a hybrid representation learning (HRL) framework for predicting cognitive diagnosis over 5 years based on T1-weighted sMRI data. Specifically, we first extract prediction-oriented MRI features via a deep neural network, and then integrate them with handcrafted MRI features via a Transformer encoder for cognitive diagnosis prediction. Two tasks are investigated in this work, including (1) identifying cognitively normal subjects with LLD and never-depressed older healthy subjects, and (2) identifying LLD subjects who developed CI (or even AD) and those who stayed cognitively normal over five years. To the best of our knowledge, this is among the first attempts to study the complex heterogeneous progression of LLD based on task-oriented and handcrafted MRI features. We validate the proposed HRL on 294 subjects with T1-weighted MRIs from two clinically harmonized studies. Experimental results suggest that the HRL outperforms several classical machine learning and state-of-the-art deep learning methods in LLD identification and prediction tasks.
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Dataset scaling, also known as normalization, is an essential preprocessing step in a machine learning pipeline. It is aimed at adjusting attributes scales in a way that they all vary within the same range. This transformation is known to improve the performance of classification models, but there are several scaling techniques to choose from, and this choice is not generally done carefully. In this paper, we execute a broad experiment comparing the impact of 5 scaling techniques on the performances of 20 classification algorithms among monolithic and ensemble models, applying them to 82 publicly available datasets with varying imbalance ratios. Results show that the choice of scaling technique matters for classification performance, and the performance difference between the best and the worst scaling technique is relevant and statistically significant in most cases. They also indicate that choosing an inadequate technique can be more detrimental to classification performance than not scaling the data at all. We also show how the performance variation of an ensemble model, considering different scaling techniques, tends to be dictated by that of its base model. Finally, we discuss the relationship between a model's sensitivity to the choice of scaling technique and its performance and provide insights into its applicability on different model deployment scenarios. Full results and source code for the experiments in this paper are available in a GitHub repository.\footnote{https://github.com/amorimlb/scaling\_matters}
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We describe a Physics-Informed Neural Network (PINN) that simulates the flow induced by the astronomical tide in a synthetic port channel, with dimensions based on the Santos - S\~ao Vicente - Bertioga Estuarine System. PINN models aim to combine the knowledge of physical systems and data-driven machine learning models. This is done by training a neural network to minimize the residuals of the governing equations in sample points. In this work, our flow is governed by the Navier-Stokes equations with some approximations. There are two main novelties in this paper. First, we design our model to assume that the flow is periodic in time, which is not feasible in conventional simulation methods. Second, we evaluate the benefit of resampling the function evaluation points during training, which has a near zero computational cost and has been verified to improve the final model, especially for small batch sizes. Finally, we discuss some limitations of the approximations used in the Navier-Stokes equations regarding the modeling of turbulence and how it interacts with PINNs.
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Machine Learning algorithms have been extensively researched throughout the last decade, leading to unprecedented advances in a broad range of applications, such as image classification and reconstruction, object recognition, and text categorization. Nonetheless, most Machine Learning algorithms are trained via derivative-based optimizers, such as the Stochastic Gradient Descent, leading to possible local optimum entrapments and inhibiting them from achieving proper performances. A bio-inspired alternative to traditional optimization techniques, denoted as meta-heuristic, has received significant attention due to its simplicity and ability to avoid local optimums imprisonment. In this work, we propose to use meta-heuristic techniques to fine-tune pre-trained weights, exploring additional regions of the search space, and improving their effectiveness. The experimental evaluation comprises two classification tasks (image and text) and is assessed under four literature datasets. Experimental results show nature-inspired algorithms' capacity in exploring the neighborhood of pre-trained weights, achieving superior results than their counterpart pre-trained architectures. Additionally, a thorough analysis of distinct architectures, such as Multi-Layer Perceptron and Recurrent Neural Networks, attempts to visualize and provide more precise insights into the most critical weights to be fine-tuned in the learning process.
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