动态模型是我们理解和预测自然系统行为的能力。无论是从第一原理推导还是从观察数据开发的动力模型,它们都基于我们选择状态变量。状态变量的选择是由便利性和直觉驱动的,在数据​​驱动的情况下,观察到的变量通常被选择为状态变量。这些变量的维度(以及动态模型)可以任意大,从而掩盖了系统的基本行为。实际上,这些变量通常是高度冗余的,并且该系统是由一组潜在的内在变量集驱动的。在这项研究中,我们将流形的数学理论与神经网络的代表能力相结合,以开发一种方法,该方法直接从时间序列数据中学习了系统的内在状态变量,还可以学习其动力学的预测模型。我们方法的区别在于,它有能力将数据减少到其居住的非线性流形的固有维度。从流形理论中的图表和地图集的概念可以实现这种能力,从而使歧管由缝制在一起的贴片的集合表示,这是获得内在维度的必要表示。我们在几个具有低维行为的高维系统上证明了这种方法。最终的框架提供了开发最低维度的动态模型的能力,从而捕获了系统的本质。
translated by 谷歌翻译
Artificial Intelligence (AI) has become commonplace to solve routine everyday tasks. Because of the exponential growth in medical imaging data volume and complexity, the workload on radiologists is steadily increasing. We project that the gap between the number of imaging exams and the number of expert radiologist readers required to cover this increase will continue to expand, consequently introducing a demand for AI-based tools that improve the efficiency with which radiologists can comfortably interpret these exams. AI has been shown to improve efficiency in medical-image generation, processing, and interpretation, and a variety of such AI models have been developed across research labs worldwide. However, very few of these, if any, find their way into routine clinical use, a discrepancy that reflects the divide between AI research and successful AI translation. To address the barrier to clinical deployment, we have formed MONAI Consortium, an open-source community which is building standards for AI deployment in healthcare institutions, and developing tools and infrastructure to facilitate their implementation. This report represents several years of weekly discussions and hands-on problem solving experience by groups of industry experts and clinicians in the MONAI Consortium. We identify barriers between AI-model development in research labs and subsequent clinical deployment and propose solutions. Our report provides guidance on processes which take an imaging AI model from development to clinical implementation in a healthcare institution. We discuss various AI integration points in a clinical Radiology workflow. We also present a taxonomy of Radiology AI use-cases. Through this report, we intend to educate the stakeholders in healthcare and AI (AI researchers, radiologists, imaging informaticists, and regulators) about cross-disciplinary challenges and possible solutions.
translated by 谷歌翻译
The reward hypothesis posits that, "all of what we mean by goals and purposes can be well thought of as maximization of the expected value of the cumulative sum of a received scalar signal (reward)." We aim to fully settle this hypothesis. This will not conclude with a simple affirmation or refutation, but rather specify completely the implicit requirements on goals and purposes under which the hypothesis holds.
translated by 谷歌翻译
We present NusaCrowd, a collaborative initiative to collect and unite existing resources for Indonesian languages, including opening access to previously non-public resources. Through this initiative, we have has brought together 137 datasets and 117 standardized data loaders. The quality of the datasets has been assessed manually and automatically, and their effectiveness has been demonstrated in multiple experiments. NusaCrowd's data collection enables the creation of the first zero-shot benchmarks for natural language understanding and generation in Indonesian and its local languages. Furthermore, NusaCrowd brings the creation of the first multilingual automatic speech recognition benchmark in Indonesian and its local languages. Our work is intended to help advance natural language processing research in under-represented languages.
translated by 谷歌翻译
Dry Eye Disease (DED) is one of the most common ocular diseases: over five percent of US adults suffer from DED. Tear film instability is a known factor for DED, and is thought to be regulated in large part by the thin lipid layer that covers and stabilizes the tear film. In order to aid eye related disease diagnosis, this work proposes a novel paradigm in using computer vision techniques to numerically analyze the tear film lipid layer (TFLL) spread. Eleven videos of the tear film lipid layer spread are collected with a micro-interferometer and a subset are annotated. A tracking algorithm relying on various pillar computer vision techniques is developed. Our method can be found at https://easytear-dev.github.io/.
translated by 谷歌翻译
Estimating the probability of failure for complex real-world systems using high-fidelity computational models is often prohibitively expensive, especially when the probability is small. Exploiting low-fidelity models can make this process more feasible, but merging information from multiple low-fidelity and high-fidelity models poses several challenges. This paper presents a robust multi-fidelity surrogate modeling strategy in which the multi-fidelity surrogate is assembled using an active learning strategy using an on-the-fly model adequacy assessment set within a subset simulation framework for efficient reliability analysis. The multi-fidelity surrogate is assembled by first applying a Gaussian process correction to each low-fidelity model and assigning a model probability based on the model's local predictive accuracy and cost. Three strategies are proposed to fuse these individual surrogates into an overall surrogate model based on model averaging and deterministic/stochastic model selection. The strategies also dictate which model evaluations are necessary. No assumptions are made about the relationships between low-fidelity models, while the high-fidelity model is assumed to be the most accurate and most computationally expensive model. Through two analytical and two numerical case studies, including a case study evaluating the failure probability of Tristructural isotropic-coated (TRISO) nuclear fuels, the algorithm is shown to be highly accurate while drastically reducing the number of high-fidelity model calls (and hence computational cost).
translated by 谷歌翻译
OutlierDetection.jl is an open-source ecosystem for outlier detection in Julia. It provides a range of high-performance outlier detection algorithms implemented directly in Julia. In contrast to previous packages, our ecosystem enables the development highly-scalable outlier detection algorithms using a high-level programming language. Additionally, it provides a standardized, yet flexible, interface for future outlier detection algorithms and allows for model composition unseen in previous packages. Best practices such as unit testing, continuous integration, and code coverage reporting are enforced across the ecosystem. The most recent version of OutlierDetection.jl is available at https://github.com/OutlierDetectionJL/OutlierDetection.jl.
translated by 谷歌翻译
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.
translated by 谷歌翻译
尽管No-U-Turn采样器(螺母)是执行贝叶斯推断的广泛采用方法,但它需要许多后梯度,在实践中计算可能很昂贵。最近,人们对基于物理的动力学(或哈密顿)系统和哈密顿神经网络(HNNS)的机器学习引起了重大兴趣。但是,这些类型的体系结构尚未应用于有效地解决贝叶斯推论问题。我们建议使用HNN有效地进行贝叶斯推断,而无需大量的后梯度。我们向HNNS(L-HNN)引入潜在变量输出,以提高表达性和减少的集成误差。我们将L-HNN集成在坚果中,并进一步提出一种在线错误监控方案,以防止L-HNNS可能几乎没有培训数据的区域中采样堕落。考虑到几种复杂的高维后密度,并将其性能与螺母进行比较,我们证明了在线错误监测中的L-HNN。
translated by 谷歌翻译
元学习是机器学习的一个分支,旨在将相关任务分布的数据合成以有效地解决新的数据。在过程控制中,许多系统具有相似且充分理解的动力学,这表明可以通过元学习创建可推广的控制器是可行的。在这项工作中,我们制定了一种元加强学习(META-RL)控制策略,该策略利用已知的离线信息进行培训,例如模型结构。对模型参数的分布而不是单个模型,对元RL代理进行了训练,从而使代理能够自动适应过程动力学的变化,同时保持性能。一个关键的设计元素是能够在培训期间离线利用基于模型的信息,同时保持与新环境交互的无模型策略结构。我们以前的工作已经证明了如何将这种方法应用于调整比例综合控制器以控制一阶过程的与工业相关的问题。在这项工作中,我们简要地重新引入了我们的方法,并证明了如何将其扩展到比例综合衍生的控制器和二阶系统。
translated by 谷歌翻译