Artificial Intelligence (AI) is having a tremendous impact across most areas of science. Applications of AI in healthcare have the potential to improve our ability to detect, diagnose, prognose, and intervene on human disease. For AI models to be used clinically, they need to be made safe, reproducible and robust, and the underlying software framework must be aware of the particularities (e.g. geometry, physiology, physics) of medical data being processed. This work introduces MONAI, a freely available, community-supported, and consortium-led PyTorch-based framework for deep learning in healthcare. MONAI extends PyTorch to support medical data, with a particular focus on imaging, and provide purpose-specific AI model architectures, transformations and utilities that streamline the development and deployment of medical AI models. MONAI follows best practices for software-development, providing an easy-to-use, robust, well-documented, and well-tested software framework. MONAI preserves the simple, additive, and compositional approach of its underlying PyTorch libraries. MONAI is being used by and receiving contributions from research, clinical and industrial teams from around the world, who are pursuing applications spanning nearly every aspect of healthcare.

Federated learning (FL) enables the building of robust and generalizable AI models by leveraging diverse datasets from multiple collaborators without centralizing the data. We created NVIDIA FLARE as an open-source software development kit (SDK) to make it easier for data scientists to use FL in their research and real-world applications. The SDK includes solutions for state-of-the-art FL algorithms and federated machine learning approaches, which facilitate building workflows for distributed learning across enterprises and enable platform developers to create a secure, privacy-preserving offering for multiparty collaboration utilizing homomorphic encryption or differential privacy. The SDK is a lightweight, flexible, and scalable Python package, and allows researchers to bring their data science workflows implemented in any training libraries (PyTorch, TensorFlow, XGBoost, or even NumPy) and apply them in real-world FL settings. This paper introduces the key design principles of FLARE and illustrates some use cases (e.g., COVID analysis) with customizable FL workflows that implement different privacy-preserving algorithms. Code is available at https://github.com/NVIDIA/NVFlare.

在构建医学成像数据集以进行深度学习方面，要注释下一步是一个具有挑战性的问题。解决这个问题的有前途的方法之一是主动学习（AL）。但是，关于哪些AL算法和采集功能最有用的数据集，AL一直很难破解。同样，当要开始的数据零标记时，问题会加剧，首先要标记哪个卷。这就是AL中的冷启动问题。我们针对3D图像分割提出了两种新型策略。首先，我们通过提出代理任务，然后利用从代理任务产生的不确定性来解决冷门问题，以对要注释的未标记数据进行排名。其次，我们为每个主动迭代制作了一个两阶段的学习框架，其中未标记的数据在第二阶段也被用作半监督的微调策略。我们展示了我们对来自医学分割十项全能的两个著名大型公共数据集的方法的希望。结果表明，数据和半监督框架的初始选择都显示出几种AL策略的显着改善。

已经提出了分裂学习（SL）以分散的方式训练深度学习模型。对于具有垂直数据分配的分散医疗保健应用，SL可以有益，因为它允许具有互补功能或图像的机构为一组共享的患者共同开发更强大且可推广的模型。在这项工作中，我们提出了“ split-u-net”，并成功地将SL应用于协作生物医学图像分割。但是，SL需要交换中间激活图和梯度，以允许跨不同特征空间的训练模型，这可能会泄漏数据并提高隐私问题。因此，我们还量化了用于生物医学图像分割的常见SL情况下的数据泄漏量，并通过应用适当的防御策略提供了抵消此类泄漏的方法。

联合学习（FL）是一种分布式机器学习技术，可以在避免明确的数据共享的同时进行协作模型培训。 FL算法的固有保护属性使其对医疗领域特别有吸引力。但是，如果有异质的客户数据分布，则标准FL方法是不稳定的，需要密集的超参数调整以实现最佳性能。常规的超参数优化算法在现实世界中的FL应用中是不切实际的，因为它们涉及大量的培训试验，而计算预算有限，这些试验通常是不起作用的。在这项工作中，我们提出了一种有效的增强学习（RL）的联合次数超参数优化算法，称为自动FEDRL，其中在线RL代理可以根据当前的培训进度动态调整每个客户的超参数。进行了广泛的实验以研究不同的搜索策略和RL代理。该方法的有效性在CIFAR-10数据集的异质数据分配以及两个现实世界中的医学图像分割数据集上进行了验证，用于胸部CT中的COVID-19变病变分段，腹部CT中的胰腺细分。

医学成像的病变分割是临床研究中的一个重要课题。研究人员提出了各种检测和分段算法来解决这项任务。最近，基于深度学习的方法显着提高了传统方法的性能。然而，大多数最先进的深度学习方法需要手动设计多个网络组件和培训策略。在本文中，我们提出了一种新的自动化机器学习算法T-Automl，不仅搜索最佳神经结构，而且还可以同时找到超参数和数据增强策略的最佳组合。该方法采用现代变压器模型，引入了适应搜索空间嵌入的动态长度，并且可以显着提高搜索能力。我们在几个大型公共病变分割数据集上验证T-Automl并实现最先进的性能。

The number of international benchmarking competitions is steadily increasing in various fields of machine learning (ML) research and practice. So far, however, little is known about the common practice as well as bottlenecks faced by the community in tackling the research questions posed. To shed light on the status quo of algorithm development in the specific field of biomedical imaging analysis, we designed an international survey that was issued to all participants of challenges conducted in conjunction with the IEEE ISBI 2021 and MICCAI 2021 conferences (80 competitions in total). The survey covered participants' expertise and working environments, their chosen strategies, as well as algorithm characteristics. A median of 72% challenge participants took part in the survey. According to our results, knowledge exchange was the primary incentive (70%) for participation, while the reception of prize money played only a minor role (16%). While a median of 80 working hours was spent on method development, a large portion of participants stated that they did not have enough time for method development (32%). 25% perceived the infrastructure to be a bottleneck. Overall, 94% of all solutions were deep learning-based. Of these, 84% were based on standard architectures. 43% of the respondents reported that the data samples (e.g., images) were too large to be processed at once. This was most commonly addressed by patch-based training (69%), downsampling (37%), and solving 3D analysis tasks as a series of 2D tasks. K-fold cross-validation on the training set was performed by only 37% of the participants and only 50% of the participants performed ensembling based on multiple identical models (61%) or heterogeneous models (39%). 48% of the respondents applied postprocessing steps.

End-to-End speech-to-speech translation (S2ST) is generally evaluated with text-based metrics. This means that generated speech has to be automatically transcribed, making the evaluation dependent on the availability and quality of automatic speech recognition (ASR) systems. In this paper, we propose a text-free evaluation metric for end-to-end S2ST, named BLASER, to avoid the dependency on ASR systems. BLASER leverages a multilingual multimodal encoder to directly encode the speech segments for source input, translation output and reference into a shared embedding space and computes a score of the translation quality that can be used as a proxy to human evaluation. To evaluate our approach, we construct training and evaluation sets from more than 40k human annotations covering seven language directions. The best results of BLASER are achieved by training with supervision from human rating scores. We show that when evaluated at the sentence level, BLASER correlates significantly better with human judgment compared to ASR-dependent metrics including ASR-SENTBLEU in all translation directions and ASR-COMET in five of them. Our analysis shows combining speech and text as inputs to BLASER does not increase the correlation with human scores, but best correlations are achieved when using speech, which motivates the goal of our research. Moreover, we show that using ASR for references is detrimental for text-based metrics.

在全球范围内消除语言障碍的目标的驱动下，机器翻译已巩固自己是当今人工智能研究的关键重点。但是，这样的努力围绕着一小部分语言结合在一起，留下了绝大多数低资源的语言。在确保安全，高质量的结果的同时，在牢记道德考虑的同时，打破200个语言障碍需要什么？没有留下的语言，我们首先通过与母语人士的探索性访谈来解决对低资源语言翻译支持的必要性来应对这一挑战。然后，我们创建了旨在缩小低资源和高资源语言之间的性能差距的数据集和模型。更具体地说，我们开发了一种有条件的计算模型，基于专家的稀疏混合物，该模型经过针对针对低资源语言量身定制的新颖有效的数据挖掘技术培训的。我们提出了多次建筑和培训改进，以抵消数千个任务的培训。至关重要的是，我们使用人类翻译的基准，Flores-200评估了40,000多种不同的翻译方向的性能，并将人类评估与新型毒性基准相结合，涵盖Flores-200的所有语言，以评估翻译安全性。我们的模型相对于先前的最新技术，实现了44％BLEU的改善，为实现通用翻译系统奠定了重要的基础。最后，我们开源此工作中描述的所有贡献，可在https://github.com/facebookresearch/fairseq/tree/nllb上访问。

语言模型既展示了定量的改进，又展示了新的定性功能，随着规模的增加。尽管它们具有潜在的变革性影响，但这些新能力的特征却很差。为了为未来的研究提供信息，为破坏性的新模型能力做准备，并改善社会有害的效果，至关重要的是，我们必须了解目前和近乎未来的能力和语言模型的局限性。为了应对这一挑战，我们介绍了超越模仿游戏基准（Big Bench）。 Big Bench目前由204个任务组成，由132家机构的442位作者贡献。任务主题是多样的，从语言学，儿童发展，数学，常识性推理，生物学，物理学，社会偏见，软件开发等等。 Big-Bench专注于被认为超出当前语言模型的功能的任务。我们评估了OpenAI的GPT型号，Google内部密集变压器体系结构和大型基础上的开关稀疏变压器的行为，跨越了数百万到数十亿个参数。此外，一个人类专家评估者团队执行了所有任务，以提供强大的基准。研究结果包括：模型性能和校准都随规模改善，但绝对的术语（以及与评估者的性能相比）；在模型类中的性能非常相似，尽管带有稀疏性。逐渐和预测的任务通常涉及大量知识或记忆成分，而在临界规模上表现出“突破性”行为的任务通常涉及多个步骤或组成部分或脆性指标；社交偏见通常会随着含糊不清的环境而随着规模而增加，但这可以通过提示来改善。