State-of-the-art brain tumor segmentation is based on deep learning models applied to multi-modal MRIs. Currently, these models are trained on images after a preprocessing stage that involves registration, interpolation, brain extraction (BE, also known as skull-stripping) and manual correction by an expert. However, for clinical practice, this last step is tedious and time-consuming and, therefore, not always feasible, resulting in skull-stripping faults that can negatively impact the tumor segmentation quality. Still, the extent of this impact has never been measured for any of the many different BE methods available. In this work, we propose an automatic brain tumor segmentation pipeline and evaluate its performance with multiple BE methods. Our experiments show that the choice of a BE method can compromise up to 15.7% of the tumor segmentation performance. Moreover, we propose training and testing tumor segmentation models on non-skull-stripped images, effectively discarding the BE step from the pipeline. Our results show that this approach leads to a competitive performance at a fraction of the time. We conclude that, in contrast to the current paradigm, training tumor segmentation models on non-skull-stripped images can be the best option when high performance in clinical practice is desired.
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Text classification is a natural language processing (NLP) task relevant to many commercial applications, like e-commerce and customer service. Naturally, classifying such excerpts accurately often represents a challenge, due to intrinsic language aspects, like irony and nuance. To accomplish this task, one must provide a robust numerical representation for documents, a process known as embedding. Embedding represents a key NLP field nowadays, having faced a significant advance in the last decade, especially after the introduction of the word-to-vector concept and the popularization of Deep Learning models for solving NLP tasks, including Convolutional Neural Networks (CNNs), Recurrent Neural Networks (RNNs), and Transformer-based Language Models (TLMs). Despite the impressive achievements in this field, the literature coverage regarding generating embeddings for Brazilian Portuguese texts is scarce, especially when considering commercial user reviews. Therefore, this work aims to provide a comprehensive experimental study of embedding approaches targeting a binary sentiment classification of user reviews in Brazilian Portuguese. This study includes from classical (Bag-of-Words) to state-of-the-art (Transformer-based) NLP models. The methods are evaluated with five open-source databases with pre-defined data partitions made available in an open digital repository to encourage reproducibility. The Fine-tuned TLMs achieved the best results for all cases, being followed by the Feature-based TLM, LSTM, and CNN, with alternate ranks, depending on the database under analysis.
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预测住宅功率使用对于辅助智能电网来管理和保护能量以确保有效使用的必不可少。客户级别的准确能量预测将直接反映电网系统的效率,但由于许多影响因素,例如气象和占用模式,预测建筑能源使用是复杂的任务。在成瘾中,鉴于多传感器环境的出现以及能量消费者和智能电网之间的两种方式通信,在能量互联网(IOE)中,高维时间序列越来越多地出现。因此,能够计算高维时间序列的方法在智能建筑和IOE应用中具有很大的价值。模糊时间序列(FTS)模型作为数据驱动的非参数模型的易于实现和高精度。不幸的是,如果所有功能用于训练模型,现有的FTS模型可能是不可行的。我们通过将原始高维数据投入低维嵌入空间并在该低维表示中使用多变量FTS方法来提出一种用于处理高维时间序列的新方法。组合这些技术使得能够更好地表示多变量时间序列的复杂内容和更准确的预测。
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一种有效的横向传输方法是在一种语言中微调在监督数据集上的双语或多语言模型,并以零拍方式在另一种语言上进行评估。在培训时间或推理时间翻译例子也是可行的替代方案。然而,存在与文献中很少有关的这些方法相关的成本。在这项工作中,我们在其有效性(例如,准确性),开发和部署成本方面分析交叉语言方法,以及推理时间的延迟。我们的三个任务的实验表明最好的交叉方法是高度任务依赖性的。最后,通过结合零射和翻译方法,我们在这项工作中使用的三个数据集中实现了最先进的。基于这些结果,我们对目标语言手动标记的培训数据有所了解。代码和翻译的数据集可在https://github.com/unicamp-dl/cross-lingsual-analysis上获得
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A generalized understanding of protein dynamics is an unsolved scientific problem, the solution of which is critical to the interpretation of the structure-function relationships that govern essential biological processes. Here, we approach this problem by constructing coarse-grained molecular potentials based on artificial neural networks and grounded in statistical mechanics. For training, we build a unique dataset of unbiased all-atom molecular dynamics simulations of approximately 9 ms for twelve different proteins with multiple secondary structure arrangements. The coarse-grained models are capable of accelerating the dynamics by more than three orders of magnitude while preserving the thermodynamics of the systems. Coarse-grained simulations identify relevant structural states in the ensemble with comparable energetics to the all-atom systems. Furthermore, we show that a single coarse-grained potential can integrate all twelve proteins and can capture experimental structural features of mutated proteins. These results indicate that machine learning coarse-grained potentials could provide a feasible approach to simulate and understand protein dynamics.
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在多语言甚至单语言中鉴定的模型的零拍跨语言能力刺激了许多假设,以解释这一有趣的经验结果。但是,由于预处理的成本,大多数研究都使用公共模型的公共模型,其预处理方法(例如代币化,语料库规模和计算预算的选择)可能会大不相同。当研究人员对自己的模型预识时,他们通常会在预算有限的情况下这样做,并且与SOTA模型相比,最终的模型的表现可能明显不足。这些实验差异导致有关这些模型跨语性能力的性质的各种不一致的结论。为了帮助对该主题进行进一步研究,我们发布了10个单语字节级模型,并在相同的配置下进行了严格审慎的概述,并具有大型计算预算(相当于V100的420天)和Corpora,比原始BERT大4倍。由于它们不含令牌,因此消除了看不见的令牌嵌入的问题,从而使研究人员可以在具有不同脚本的语言中尝试更广泛的跨语言实验。此外,我们释放了在不自然语言文本上预测的两个模型,这些模型可用于理智检查实验。关于质量检查和NLI任务的实验表明,我们的单语模型实现了多语言的竞争性能,因此可以加强我们对语言模型中跨语性可传递性的理解。
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机器学习潜力是分子模拟的重要工具,但是由于缺乏高质量数据集来训练它们的发展,它们的开发阻碍了它们。我们描述了Spice数据集,这是一种新的量子化学数据集,用于训练与模拟与蛋白质相互作用的药物样的小分子相关的潜在。它包含超过110万个小分子,二聚体,二肽和溶剂化氨基酸的构象。它包括15个元素,带电和未充电的分子以及广泛的共价和非共价相互作用。它提供了在{\ omega} b97m-d3(bj)/def2-tzVPPD理论水平以及其他有用的数量(例如多极矩和键阶)上计算出的力和能量。我们在其上训练一组机器学习潜力,并证明它们可以在化学空间的广泛区域中实现化学精度。它可以作为创建可转移的,准备使用潜在功能用于分子模拟的宝贵资源。
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纳米四轮驱动器是小的,敏捷且廉价的平台,非常适合在狭窄,混乱的环境中部署。由于其有效载荷有限,这些车辆在处理能力方面受到了高度限制,从而使基于常规视觉的方法具有安全性和自主导航不兼容。最近的机器学习发展有望在低潜伏期处高性能感知,而专用的边缘计算硬件有可能增强这些有限设备的处理能力。在这项工作中,我们提出了Nanoflownet,这是一个轻巧的卷积神经网络,用于实时密集的光流估计,对边缘计算硬件。我们从最新的语义细分方面汲取灵感来设计该网络。此外,我们使用运动边界地面真实数据指导学习光流的学习,从而改善了性能而不会影响延迟。 MPI-SINTEL数据集的验证结果显示,鉴于其受限的体系结构,该网络的高性能。此外,我们通过将其部署在超低功率GAP8微处理器上,并将其应用于BitCraze Crazyflie,这是34 G纳米四轮摩托车的BitCraze Crazyflie,并将其应用于34 G Nano Quadcopter的BitCraze Crazyflie,从而成功地证明了纳米滚子的功能。
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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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