We present a method for providing statistical guarantees on runtime safety and goal reachability for integrated planning and control of a class of systems with unknown nonlinear stochastic underactuated dynamics. Specifically, given a dynamics dataset, our method jointly learns a mean dynamics model, a spatially-varying disturbance bound that captures the effect of noise and model mismatch, and a feedback controller based on contraction theory that stabilizes the learned dynamics. We propose a sampling-based planner that uses the mean dynamics model and simultaneously bounds the closed-loop tracking error via a learned disturbance bound. We employ techniques from Extreme Value Theory (EVT) to estimate, to a specified level of confidence, several constants which characterize the learned components and govern the size of the tracking error bound. This ensures plans are guaranteed to be safely tracked at runtime. We validate that our guarantees translate to empirical safety in simulation on a 10D quadrotor, and in the real world on a physical CrazyFlie quadrotor and Clearpath Jackal robot, whereas baselines that ignore the model error and stochasticity are unsafe.

我们为一类不确定的控制型非线性系统提供了一种运动计划算法，该系统可以在使用高维传感器测量值（例如RGB-D图像）和反馈控制循环中的学习感知模块时确保运行时安全性和目标达到性能。首先，给定状态和观察数据集，我们训练一个感知系统，该系统试图从观察结果中倒入状态的一部分，并估计感知错误上的上限，该误差有效，在数据附近有可信赖的域中具有很高的概率。接下来，我们使用收缩理论来设计稳定的状态反馈控制器和收敛的动态观察者，该观察者使用学习的感知系统来更新其状态估计。当该控制器在动力学和不正确状态估计中遇到错误时，我们会在轨迹跟踪误差上得出一个绑定。最后，我们将此绑定到基于采样的运动计划器中，引导它返回可以使用传感器数据在运行时安全跟踪的轨迹。我们展示了我们在4D汽车上模拟的方法，6D平面四极管以及使用RGB（-D）传感器测量的17D操纵任务，这表明我们的方法安全可靠地将系统转向了目标，而无法考虑的基线，这些基线无法考虑。受信任的域或状态估计错误可能不安全。

我们提出了一种从本地最佳示范中学习被代表为高斯过程（GPS）的学习限制的方法。我们的方法使用Karush-Kuhn-Tucker（KKT）最优状态来确定在该规约紧密的演示中的位置，以及这些状态的约束梯度的缩放。然后，我们训练约束的GP表示，这是一致的，并概括了这些信息。我们进一步表明，GP不确定性可以在Kinodynamic RRT内使用以计划概率 - 安全的轨迹，并且我们可以利用计划者内的GP结构来恰好实现指定的安全概率。我们展示了我们的方法可以学习复杂的非线性约束，在5D非整理车，12D四轮机器和3连杆平面臂上演示，所有这些都是在需要最小的限制信息。我们的结果表明学习的GP约束是准确的，优于先前的约束学习方法，需要更高的先验知识。

Large language models (LLMs) have demonstrated impressive capabilities in natural language understanding and generation, but the quality bar for medical and clinical applications is high. Today, attempts to assess models' clinical knowledge typically rely on automated evaluations on limited benchmarks. There is no standard to evaluate model predictions and reasoning across a breadth of tasks. To address this, we present MultiMedQA, a benchmark combining six existing open question answering datasets spanning professional medical exams, research, and consumer queries; and HealthSearchQA, a new free-response dataset of medical questions searched online. We propose a framework for human evaluation of model answers along multiple axes including factuality, precision, possible harm, and bias. In addition, we evaluate PaLM (a 540-billion parameter LLM) and its instruction-tuned variant, Flan-PaLM, on MultiMedQA. Using a combination of prompting strategies, Flan-PaLM achieves state-of-the-art accuracy on every MultiMedQA multiple-choice dataset (MedQA, MedMCQA, PubMedQA, MMLU clinical topics), including 67.6% accuracy on MedQA (US Medical License Exam questions), surpassing prior state-of-the-art by over 17%. However, human evaluation reveals key gaps in Flan-PaLM responses. To resolve this we introduce instruction prompt tuning, a parameter-efficient approach for aligning LLMs to new domains using a few exemplars. The resulting model, Med-PaLM, performs encouragingly, but remains inferior to clinicians. We show that comprehension, recall of knowledge, and medical reasoning improve with model scale and instruction prompt tuning, suggesting the potential utility of LLMs in medicine. Our human evaluations reveal important limitations of today's models, reinforcing the importance of both evaluation frameworks and method development in creating safe, helpful LLM models for clinical applications.

Diffusion models are state-of-the-art deep learning empowered generative models that are trained based on the principle of learning forward and reverse diffusion processes via progressive noise-addition and denoising. To gain a better understanding of the limitations and potential risks, this paper presents the first study on the robustness of diffusion models against backdoor attacks. Specifically, we propose BadDiffusion, a novel attack framework that engineers compromised diffusion processes during model training for backdoor implantation. At the inference stage, the backdoored diffusion model will behave just like an untampered generator for regular data inputs, while falsely generating some targeted outcome designed by the bad actor upon receiving the implanted trigger signal. Such a critical risk can be dreadful for downstream tasks and applications built upon the problematic model. Our extensive experiments on various backdoor attack settings show that BadDiffusion can consistently lead to compromised diffusion models with high utility and target specificity. Even worse, BadDiffusion can be made cost-effective by simply finetuning a clean pre-trained diffusion model to implant backdoors. We also explore some possible countermeasures for risk mitigation. Our results call attention to potential risks and possible misuse of diffusion models.

Point-of-Care Ultrasound (POCUS) refers to clinician-performed and interpreted ultrasonography at the patient's bedside. Interpreting these images requires a high level of expertise, which may not be available during emergencies. In this paper, we support POCUS by developing classifiers that can aid medical professionals by diagnosing whether or not a patient has pneumothorax. We decomposed the task into multiple steps, using YOLOv4 to extract relevant regions of the video and a 3D sparse coding model to represent video features. Given the difficulty in acquiring positive training videos, we trained a small-data classifier with a maximum of 15 positive and 32 negative examples. To counteract this limitation, we leveraged subject matter expert (SME) knowledge to limit the hypothesis space, thus reducing the cost of data collection. We present results using two lung ultrasound datasets and demonstrate that our model is capable of achieving performance on par with SMEs in pneumothorax identification. We then developed an iOS application that runs our full system in less than 4 seconds on an iPad Pro, and less than 8 seconds on an iPhone 13 Pro, labeling key regions in the lung sonogram to provide interpretable diagnoses.

复杂的多目标任务需要在多个相互连接的级别（例如联盟形成，调度和运动计划）上协调异质机器人。动态变化（例如传感器和执行器故障，通信损失和意外延迟）加剧了这一挑战。我们将动态迭代任务分配图搜索（D-ITAGS）介绍到\ textit {同时}地址在涉及异构团队的动态设置中，地址为联盟组建，调度和运动计划。 D-Itag通过两个关键特征实现弹性：i）交错执行，ii）有针对性的维修。 \ textIt {交错执行}可以在每一层进行有效搜索解决方案，同时避免与其他层不兼容。 \ textIt {目标修复}识别并修复了现有解决方案的一部分，该解决方案在保存其余部分的同时受到给定破坏的影响。除了算法贡献外，我们还提供理论上的见解，以了解这些设置中时间和资源最优性之间固有的权衡，并在计划次级临时性上得出有意义的界限。我们的实验表明，在动态设置中，i）d-itag的速度明显比从头开始的重新计算要快得多，而溶液质量几乎没有损失，ii）理论次优界在实践中始终保持。

分散的多基金会计划一直是机器人技术研究的重要领域。该领域中有趣且有影响力的应用是在未结构化的道路环境中分散的车辆协调。例如，在十字路口中，在没有中央协调员的情况下，在相交路径的多个车辆上解除多种车辆是有用的。我们从常识中学到的是，要使车辆浏览这种未建筑的环境，驾驶员必须理解并符合附近驾驶员观察到的隐式“社会礼节”。为了研究这种隐式驾驶协议，我们收集了伯克利DeepDrive无人机数据集。该数据集包含1）一组航空视频记录未结构化驾驶，2）图像和注释的集合来训练车辆检测模型，3）一个用于说明典型用法的开发脚本套件。我们认为，该数据集是研究人类驱动因素和次要兴趣的分散多种计划的主要兴趣，用于遥感环境中的计算机视觉。

我们解决了使四足机器人能够使用强化学习在现实世界中执行精确的射击技巧的问题。开发算法使腿部机器人能够向给定的目标射击足球，这是一个具有挑战性的问题，它将机器人运动控制和计划结合到一项任务中。为了解决这个问题，我们需要考虑控制动态腿部机器人期间的动态限制和运动稳定性。此外，我们需要考虑运动计划，以在地面上射击难以模拟的可变形球，并不确定摩擦到所需的位置。在本文中，我们提出了一个层次结构框架，该框架利用深厚的强化学习来训练（a）强大的运动控制政策，可以跟踪任意动议，以及（b）一项计划政策，以决定所需的踢球运动将足球射击到目标。我们将提议的框架部署在A1四足动物机器人上，使其能够将球准确地射击到现实世界中的随机目标。

逆文本归一化（ITN）用于将自动语音识别（ASR）系统的口语输出转换为书面形式。传统手工制作的ITN规则可以复杂地转录和维护。同时，神经建模方法需要与ASR系统相同或相似的域（内域数据）中的质量大规模口语写作示例。这两种方法都需要昂贵且复杂的注释。在本文中，我们提出了一种数据增强技术，该技术可有效地从室外文本数据中产生丰富的口语写入数字对，并以最少的人类注释。我们从经验上证明，使用我们的数据增强技术训练的ITN模型始终超过ITN模型，该模型仅使用14.44％的总体准确性，仅在所有数字表面（例如红衣主教，货币和分数）上使用内域数据进行训练。