我们提出了一个模型预测控制(MPC),以避免自治药物和动态障碍之间的碰撞。避免碰撞的限制是通过在代表代理和障碍物的凸组之间执行正距离的,并使用Lagrange二重性进行了谨慎地对其进行重新校正。这种方法即使对于多面体来说也可以平稳避免碰撞限制,否则需要混合组合或非平滑限制。我们考虑了不确定障碍位置的三种广泛使用的描述:1)具有多重支持的任意分布,2)高斯分布和3)任意分布,并以已知的前两个矩。对于每种情况,我们都会获得避免碰撞限制的确定性重新制定。拟议的MPC公式优化了反馈政策,以减少满足碰撞避免限制的保守主义。使用卡拉中交通交叉点的模拟对所提出的方法进行了验证。
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我们提出了Adios,这是一个用于自我监督学习的遮罩图像模型(MIM)框架,同时使用对抗性目标学习掩盖功能和图像编码器。对图像编码器进行了训练,以最大程度地减少原始图像的表示形式与蒙版图像的表示之间的距离。相反,掩蔽函数旨在最大化此距离。阿迪奥斯(Adios)始终改进有关各种任务和数据集的最先进的自我监督学习(SSL)方法 - 包括Imagenet100和STL10上的分类,CIFAR10/100上的转移学习,Flowers102和Inaturalist,以及鲁棒性在背景挑战中进行了评估(Xiao等,2021) - 同时产生语义意义的面具。与MAE,BEIT和IBOT等现代MIM模型不同,Adios不依赖视觉变压器的图像斑点令牌构造,并且可以用卷积的骨架来实现。我们进一步证明,与对流行MIM模型中使用的掩盖方案相比,阿迪奥斯学到的面具在改善SSL方法的表示方面更有效。
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AI正在经历范式转变,随着模型的兴起(例如Bert,Dall-E,GPT-3),这些模型经过大规模的数据训练,并且可以适应广泛的下游任务。我们称这些模型基础模型来强调其至关重要但不完整的特征。该报告提供了基础模型的机会和风险的详尽说明,包括其功能(例如语言,愿景,机器人技术,推理,人类互动)和技术原则(例如,模型架构,培训程序,数据,系统,安全,安全性,评估,理论)对其应用(例如法律,医疗保健,教育)和社会影响(例如不平等,滥用,经济和环境影响,法律和道德考虑)。尽管基础模型基于标准的深度学习和转移学习,但它们的规模导致了新的新兴能力,以及它们在许多任务中的有效性都激发了同质化。同质化提供了强大的杠杆作用,但要求谨慎,因为基础模型的缺陷均由下游的所有适应模型继承。尽管即将广泛地部署基础模型,但我们目前对它们的工作方式,失败以及由于其新兴属性的影响而缺乏清晰的了解。为了解决这些问题,我们认为基础模型的许多批判性研究都需要与他们的基本社会技术性质相称。
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元强化学习(RL)方法可以使用比标准RL少的数据级的元培训策略,但元培训本身既昂贵又耗时。如果我们可以在离线数据上进行元训练,那么我们可以重复使用相同的静态数据集,该数据集将一次标记为不同任务的奖励,以在元测试时间适应各种新任务的元训练策略。尽管此功能将使Meta-RL成为现实使用的实用工具,但离线META-RL提出了除在线META-RL或标准离线RL设置之外的其他挑战。 Meta-RL学习了一种探索策略,该策略收集了用于适应的数据,并元培训策略迅速适应了新任务的数据。由于该策略是在固定的离线数据集上进行了元训练的,因此当适应学识渊博的勘探策略收集的数据时,它可能表现得不可预测,这与离线数据有系统地不同,从而导致分布变化。我们提出了一种混合脱机元元素算法,该算法使用带有奖励的脱机数据来进行自适应策略,然后收集其他无监督的在线数据,而无需任何奖励标签来桥接这一分配变化。通过不需要在线收集的奖励标签,此数据可以便宜得多。我们将我们的方法比较了在模拟机器人的运动和操纵任务上进行离线元rl的先前工作,并发现使用其他无监督的在线数据收集可以显着提高元训练政策的自适应能力,从而匹配完全在线的表现。在一系列具有挑战性的域上,需要对新任务进行概括。
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Multimodal VAEs seek to model the joint distribution over heterogeneous data (e.g.\ vision, language), whilst also capturing a shared representation across such modalities. Prior work has typically combined information from the modalities by reconciling idiosyncratic representations directly in the recognition model through explicit products, mixtures, or other such factorisations. Here we introduce a novel alternative, the MEME, that avoids such explicit combinations by repurposing semi-supervised VAEs to combine information between modalities implicitly through mutual supervision. This formulation naturally allows learning from partially-observed data where some modalities can be entirely missing -- something that most existing approaches either cannot handle, or do so to a limited extent. We demonstrate that MEME outperforms baselines on standard metrics across both partial and complete observation schemes on the MNIST-SVHN (image-image) and CUB (image-text) datasets. We also contrast the quality of the representations learnt by mutual supervision against standard approaches and observe interesting trends in its ability to capture relatedness between data.
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对头部磁共振成像(MRI)检查的需求不断增长,以及全球放射科医生的短缺,导致在全球报告头部MRI扫描所花费的时间增加。对于许多神经系统疾病,这种延迟会导致发病率和死亡率增加。一种自动分解工具可以通过在成像时识别异常并确定这些扫描的报告优先级来减少异常检查的报告时间。在这项工作中,我们提出了一个卷积神经网络,用于检测$ \ text {t} _2 $加权的头部MRI扫描中临床上相关的异常。使用经过验证的神经放射学报告分类器,我们从两家英国两家大型医院进行了43,754张标记的数据集,以进行模型培训,并在800张测试集上证明了准确的分类(AUC下的区域(AUC)= 0.943),由800张扫描集进行了标签。神经放射学家团队。重要的是,当仅在一家医院接受扫描培训时,模型从另一家医院进行了扫描($ \ delta $ auc $ \ leq $ 0.02)。一项模拟研究表明,我们的模型将使异常检查的平均报告时间从28天到14天,并从两家医院的9天到5天,这表明在临床分类环境中使用了可行性。
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We present a principled approach to incorporating labels in VAEs that captures the rich characteristic information associated with those labels. While prior work has typically conflated these by learning latent variables that directly correspond to label values, we argue this is contrary to the intended effect of supervision in VAEs-capturing rich label characteristics with the latents. For example, we may want to capture the characteristics of a face that make it look young, rather than just the age of the person. To this end, we develop the CCVAE, a novel VAE model and concomitant variational objective which captures label characteristics explicitly in the latent space, eschewing direct correspondences between label values and latents. Through judicious structuring of mappings between such characteristic latents and labels, we show that the CCVAE can effectively learn meaningful representations of the characteristics of interest across a variety of supervision schemes. In particular, we show that the CCVAE allows for more effective and more general interventions to be performed, such as smooth traversals within the characteristics for a given label, diverse conditional generation, and transferring characteristics across datapoints.
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Making histopathology image classifiers robust to a wide range of real-world variability is a challenging task. Here, we describe a candidate deep learning solution for the Mitosis Domain Generalization Challenge 2022 (MIDOG) to address the problem of generalization for mitosis detection in images of hematoxylin-eosin-stained histology slides under high variability (scanner, tissue type and species variability). Our approach consists in training a rotation-invariant deep learning model using aggressive data augmentation with a training set enriched with hard negative examples and automatically selected negative examples from the unlabeled part of the challenge dataset. To optimize the performance of our models, we investigated a hard negative mining regime search procedure that lead us to train our best model using a subset of image patches representing 19.6% of our training partition of the challenge dataset. Our candidate model ensemble achieved a F1-score of .697 on the final test set after automated evaluation on the challenge platform, achieving the third best overall score in the MIDOG 2022 Challenge.
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Reading comprehension of legal text can be a particularly challenging task due to the length and complexity of legal clauses and a shortage of expert-annotated datasets. To address this challenge, we introduce the Merger Agreement Understanding Dataset (MAUD), an expert-annotated reading comprehension dataset based on the American Bar Association's 2021 Public Target Deal Points Study, with over 39,000 examples and over 47,000 total annotations. Our fine-tuned Transformer baselines show promising results, with models performing well above random on most questions. However, on a large subset of questions, there is still room for significant improvement. As the only expert-annotated merger agreement dataset, MAUD is valuable as a benchmark for both the legal profession and the NLP community.
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Deep learning techniques with neural networks have been used effectively in computational fluid dynamics (CFD) to obtain solutions to nonlinear differential equations. This paper presents a physics-informed neural network (PINN) approach to solve the Blasius function. This method eliminates the process of changing the non-linear differential equation to an initial value problem. Also, it tackles the convergence issue arising in the conventional series solution. It is seen that this method produces results that are at par with the numerical and conventional methods. The solution is extended to the negative axis to show that PINNs capture the singularity of the function at $\eta=-5.69$
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