连续的时间加强学习提供了一种吸引人的形式主义,用于描述控制问题,其中时间的流逝并不自然地分为离散的增量。在这里,我们考虑了预测在连续时间随机环境中相互作用的代理商获得的回报分布的问题。准确的回报预测已被证明可用于确定对风险敏感的控制,学习状态表示,多基因协调等的最佳策略。我们首先要建立汉密尔顿 - 雅各布人(HJB)方程的分布模拟,以扩散和更广泛的feller-dynkin过程。然后,我们将此方程式专注于返回分布近似于$ n $均匀加权粒子的设置,这是分销算法中常见的设计选择。我们的派生突出显示了由于统计扩散率而引起的其他术语,这是由于在连续时间设置中正确处理分布而产生的。基于此,我们提出了一种可访问算法,用于基于JKO方案近似求解分布HJB,该方案可以在在线控制算法中实现。我们证明了这种算法在合成控制问题中的有效性。
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Recently, many causal estimators for Conditional Average Treatment Effect (CATE) and instrumental variable (IV) problems have been published and open sourced, allowing to estimate granular impact of both randomized treatments (such as A/B tests) and of user choices on the outcomes of interest. However, the practical application of such models has ben hampered by the lack of a valid way to score the performance of such models out of sample, in order to select the best one for a given application. We address that gap by proposing novel scoring approaches for both the CATE case and an important subset of instrumental variable problems, namely those where the instrumental variable is customer acces to a product feature, and the treatment is the customer's choice to use that feature. Being able to score model performance out of sample allows us to apply hyperparameter optimization methods to causal model selection and tuning. We implement that in an open source package that relies on DoWhy and EconML libraries for implementation of causal inference models (and also includes a Transformed Outcome model implementation), and on FLAML for hyperparameter optimization and for component models used in the causal models. We demonstrate on synthetic data that optimizing the proposed scores is a reliable method for choosing the model and its hyperparameter values, whose estimates are close to the true impact, in the randomized CATE and IV cases. Further, we provide examles of applying these methods to real customer data from Wise.
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我们介绍了泰德(Tidee),这是一种体现的代理,它根据学识渊博的常识对象和房间安排先验来整理一个无序场景。泰德(Tidee)探索家庭环境,检测到其自然位置的对象,渗透到它们的合理对象上下文,在当前场景中定位此类上下文,并重新定位对象。常识先验在三个模块中编码:i)检测到现象对象的视觉声音检测器,ii)对象和空间关系的关联神经图记忆,提出了对象重新定位的合理语义插座和表面,以及iii)引导代理商探索的可视搜索网络,以有效地将利益定位在当前场景中以重新定位对象。我们测试了在AI2THOR模拟环境中整理混乱的场景的潮汐。 Tidee直接从像素和原始深度输入中执行任务,而没有事先观察到同一房间,仅依靠从单独的一组培训房屋中学到的先验。人类对由此产生的房间进行重组的评估表明,泰德(Tidee)的表现优于该模型的消融版本,这些版本不使用一个或多个常识性先验。在相关的房间重新安排基准测试中,该基准使代理可以在重新排列前查看目标状态,我们的模型的简化版本大大胜过了最佳的方法,可以通过大幅度的差距。代码和数据可在项目网站上获得:https://tidee-agent.github.io/。
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为不依赖LiDAR的自动驾驶汽车建造3D感知系统是一个关键的研究问题,因为与摄像机和其他传感器相比,LiDar系统的费用很高。当前方法使用从车辆周围的摄像机收集的多视图RGB数据,并从透视图像到2D接地平面的神经“升力”特征,从而产生“鸟类的眼光”(BEV)的特征代表车辆周围的3D空间。最近的研究重点是将功能从图像提升到BEV平面的方式。相反,我们提出了一个简单的基线模型,其中“提升”步骤简单地平均所有投影图像位置的特征,并发现它的表现优于BEV车辆分割中当前最新的。我们的消融表明,批处理大小,数据增强和输入分辨率在性能中起着很大的作用。此外,我们重新考虑了雷达输入的效用,雷达输入的实用性以前被最近的作品忽略或没有忽略。借助简单的RGB-radar融合模块,我们获得了相当大的性能提升,从而接近了启用激光雷达系统的精度。
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通常将视频中的跟踪像素作为光流估计问题进行研究,其中每个像素都用位移向量描述,该位移向量将其定位在下一帧中。即使可以免费获得更广泛的时间上下文,但要考虑到这一点的事先努力仅在2框方法上产生了少量收益。在本文中,我们重新访问Sand and Teller的“粒子视频”方法,并将像素跟踪作为远程运动估计问题,其中每个像素都用轨迹描述,该轨迹将其定位在以后的多个帧中。我们使用该组件重新构建了这种经典方法,这些组件可以驱动流量和对象跟踪中最新的最新方法,例如密集的成本图,迭代优化和学习的外观更新。我们使用从现有的光流数据中挖掘出的远程Amodal点轨迹来训练我们的模型,并通过多帧的遮挡合成增强,这些轨迹会增强。我们在轨迹估计基准和关键点标签传播任务中测试我们的方法,并与最新的光流和功能跟踪方法进行比较。
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来自科幻小说的普通愿景是机器人将有一天居住在我们的物理空间中,感知世界,才能协助我们的物理劳动力,并通过自然语言与我们沟通。在这里,我们研究如何使用虚拟环境的简化设计如何与人类自然交互的人工代理。我们表明,与自我监督学习的模拟世界中的人类交互的模仿学习足以产生我们称之为MIA的多模式互动剂,这成功与非对抗人类互动75%的时间。我们进一步确定了提高性能的架构和算法技术,例如分层动作选择。完全,我们的结果表明,模仿多模态,实时人类行为可以提供具有丰富的行为的富含性的令人生意的和令人惊讶的有效手段,然后可以为特定目的进行微调,从而铺设基础用于培训互动机器人或数字助理的能力。可以在https://youtu.be/zfgrif7my找到MIA的行为的视频
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In this work we aim to solve a large collection of tasks using a single reinforcement learning agent with a single set of parameters. A key challenge is to handle the increased amount of data and extended training time. We have developed a new distributed agent IMPALA (Importance Weighted Actor-Learner Architecture) that not only uses resources more efficiently in singlemachine training but also scales to thousands of machines without sacrificing data efficiency or resource utilisation. We achieve stable learning at high throughput by combining decoupled acting and learning with a novel off-policy correction method called V-trace. We demonstrate the effectiveness of IMPALA for multi-task reinforcement learning on DMLab-30 (a set of 30 tasks from the DeepMind Lab environment (Beattie et al., 2016)) and Atari-57 (all available Atari games in Arcade Learning Environment (Bellemare et al., 2013a)). Our results show that IMPALA is able to achieve better performance than previous agents with less data, and crucially exhibits positive transfer between tasks as a result of its multi-task approach. The source code is publicly available at github.com/deepmind/scalable agent.
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We propose a conceptually simple and lightweight framework for deep reinforcement learning that uses asynchronous gradient descent for optimization of deep neural network controllers. We present asynchronous variants of four standard reinforcement learning algorithms and show that parallel actor-learners have a stabilizing effect on training allowing all four methods to successfully train neural network controllers. The best performing method, an asynchronous variant of actor-critic, surpasses the current state-of-the-art on the Atari domain while training for half the time on a single multi-core CPU instead of a GPU. Furthermore, we show that asynchronous actor-critic succeeds on a wide variety of continuous motor control problems as well as on a new task of navigating random 3D mazes using a visual input.
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