Neural architectures can be naturally viewed as computational graphs. Motivated by this perspective, we, in this paper, study neural architecture search (NAS) through the lens of learning random graph models. In contrast to existing NAS methods which largely focus on searching for a single best architecture, i.e, point estimation, we propose GraphPNAS a deep graph generative model that learns a distribution of well-performing architectures. Relying on graph neural networks (GNNs), our GraphPNAS can better capture topologies of good neural architectures and relations between operators therein. Moreover, our graph generator leads to a learnable probabilistic search method that is more flexible and efficient than the commonly used RNN generator and random search methods. Finally, we learn our generator via an efficient reinforcement learning formulation for NAS. To assess the effectiveness of our GraphPNAS, we conduct extensive experiments on three search spaces, including the challenging RandWire on TinyImageNet, ENAS on CIFAR10, and NAS-Bench-101/201. The complexity of RandWire is significantly larger than other search spaces in the literature. We show that our proposed graph generator consistently outperforms RNN-based one and achieves better or comparable performances than state-of-the-art NAS methods.
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射血分数(EF)是心脏功能的关键指标,可以鉴定患有心脏失败等心脏功能障碍的患者。通过手动追踪左心室并估算其在某些帧上的体积,可以从被称为超声心动图(ECHO)的心脏超声视频估计。由于手动过程和视频质量的变化,这些估计表现出很高的观察者间变异性。这种不准确的来源和对快速评估的需求需要可靠且可解释的机器学习技术。在这项工作中,我们介绍了基于图神经网络(GNN)的模型Echognn,以从Echo视频中估算EF。我们的模型首先从一个或多个Echo Cine系列的框架中输入潜在的回声图。然后,它估计了该图的节点和边缘的权重,表明各个框架的重要性有助于EF估计。 GNN回归器使用此加权图来预测EF。我们在定性和定量上表明,学到的图形权重通过识别临界帧进行EF估计提供了解释性,可用于确定何时需要人类干预。在Echonet-Dynamic公共EF数据集上,ECHOGNN实现了与最新状态相当的EF预测性能,并提供了解释性,鉴于此任务中固有的高观察者可变异性至关重要。
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我们介绍了一种方法,例如针对3D点云的提案生成。现有技术通常直接在单个进料前进的步骤中回归建议,从而导致估计不准确。我们表明,这是一个关键的瓶颈,并提出了一种基于迭代双边滤波的方法。遵循双边滤波的精神,我们考虑了每个点的深度嵌入以及它们在3D空间中的位置。我们通过合成实验表明,在为给定的兴趣点生成实例建议时,我们的方法会带来巨大的改进。我们进一步验证了我们在挑战性扫描基准测试中的方法,从而在自上而下的方法的子类别中实现了最佳实例分割性能。
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基于深度学习的模型占主导地位的生产推荐系统的当前景观。此外,近年来目睹了模型规模的指数增长 - 从谷歌的2016年模型,最新的Facebook的型号有10亿个参数,具有12万亿参数。型号容量的每次跳跃都有显着的质量增强,这使我们相信100万亿参数的时代即将来临。然而,即使在工业规模数据中心内,这些模型的培训也在挑战。这种困难是从训练计算的惊人的异质性继承 - 模型的嵌入层可以包括总模型尺寸的99.99%,这是极其内存密集的;虽然其余的神经网络越来越多地计算密集型。为支持培训此类巨大模式,迫切需要有效的分布式培训系统。在本文中,我们通过仔细共同设计优化算法和分布式系统架构来解决这一挑战。具体而言,为了确保培训效率和训练精度,我们设计一种新型混合训练算法,其中嵌入层和密集的神经网络由不同的同步机制处理;然后,我们构建一个名为Persia的系统(短暂的并行推荐培训系统,其中包含混合加速),以支持这种混合培训算法。理论上的示范和实证研究均达到100万亿参数,以证明了波斯的系统设计和实施。我们将Pensia公开使用(在https://github.com/persiamml/persia),以便任何人都能够以100万亿参数的规模轻松培训推荐模型。
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软致动器在符合性和形态方面表现出具有很大的优势,用于操纵细腻物体和在密闭空间中的检查。对于可以提供扭转运动的软致动器有一个未满足的需要。放大工作空间并增加自由度。为此目标,我们呈现由硅胶制成的折纸启发的软充气执行器(OSPas)。原型可以输出多于一个旋转的旋转(高达435 {\ DEG}),比以前的同行更大。我们描述了设计和制作方法,构建了运动学模型和仿真模型,并分析和优化参数。最后,我们通过整合到能够同时抓住和提升脆弱或扁平物体的夹具,这是一种能够与扭转致动器的直角拾取和放置物品的多功能机器人,以及柔软的蛇通过扭转致动器的扭转能够改变姿态和方向的机器人。
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We propose a motion forecasting model that exploits a novel structured map representation as well as actor-map interactions. Instead of encoding vectorized maps as raster images, we construct a lane graph from raw map data to explicitly preserve the map structure. To capture the complex topology and long range dependencies of the lane graph, we propose LaneGCN which extends graph convolutions with multiple adjacency matrices and along-lane dilation. To capture the complex interactions between actors and maps, we exploit a fusion network consisting of four types of interactions, actor-to-lane, lane-to-lane, laneto-actor and actor-to-actor. Powered by LaneGCN and actor-map interactions, our model is able to predict accurate and realistic multi-modal trajectories. Our approach significantly outperforms the state-of-the-art on the large scale Argoverse motion forecasting benchmark.
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In this paper, we propose a unified panoptic segmentation network (UPSNet) for tackling the newly proposed panoptic segmentation task. On top of a single backbone residual network, we first design a deformable convolution based semantic segmentation head and a Mask R-CNN style instance segmentation head which solve these two subtasks simultaneously. More importantly, we introduce a parameter-free panoptic head which solves the panoptic segmentation via pixel-wise classification. It first leverages the logits from the previous two heads and then innovatively expands the representation for enabling prediction of an extra unknown class which helps better resolve the conflicts between semantic and instance segmentation. Additionally, it handles the challenge caused by the varying number of instances and permits back propagation to the bottom modules in an end-to-end manner. Extensive experimental results on Cityscapes, COCO and our internal dataset demonstrate that our UPSNet achieves stateof-the-art performance with much faster inference. Code has been made available at: https://github.com/ uber-research/UPSNet. * Equal contribution.† This work was done when Hengshuang Zhao was an intern at Uber ATG.
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Interview has been regarded as one of the most crucial step for recruitment. To fully prepare for the interview with the recruiters, job seekers usually practice with mock interviews between each other. However, such a mock interview with peers is generally far away from the real interview experience: the mock interviewers are not guaranteed to be professional and are not likely to behave like a real interviewer. Due to the rapid growth of online recruitment in recent years, recruiters tend to have online interviews, which makes it possible to collect real interview data from real interviewers. In this paper, we propose a novel application named EZInterviewer, which aims to learn from the online interview data and provides mock interview services to the job seekers. The task is challenging in two ways: (1) the interview data are now available but still of low-resource; (2) to generate meaningful and relevant interview dialogs requires thorough understanding of both resumes and job descriptions. To address the low-resource challenge, EZInterviewer is trained on a very small set of interview dialogs. The key idea is to reduce the number of parameters that rely on interview dialogs by disentangling the knowledge selector and dialog generator so that most parameters can be trained with ungrounded dialogs as well as the resume data that are not low-resource. Evaluation results on a real-world job interview dialog dataset indicate that we achieve promising results to generate mock interviews. With the help of EZInterviewer, we hope to make mock interview practice become easier for job seekers.
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General nonlinear sieve learnings are classes of nonlinear sieves that can approximate nonlinear functions of high dimensional variables much more flexibly than various linear sieves (or series). This paper considers general nonlinear sieve quasi-likelihood ratio (GN-QLR) based inference on expectation functionals of time series data, where the functionals of interest are based on some nonparametric function that satisfy conditional moment restrictions and are learned using multilayer neural networks. While the asymptotic normality of the estimated functionals depends on some unknown Riesz representer of the functional space, we show that the optimally weighted GN-QLR statistic is asymptotically Chi-square distributed, regardless whether the expectation functional is regular (root-$n$ estimable) or not. This holds when the data are weakly dependent beta-mixing condition. We apply our method to the off-policy evaluation in reinforcement learning, by formulating the Bellman equation into the conditional moment restriction framework, so that we can make inference about the state-specific value functional using the proposed GN-QLR method with time series data. In addition, estimating the averaged partial means and averaged partial derivatives of nonparametric instrumental variables and quantile IV models are also presented as leading examples. Finally, a Monte Carlo study shows the finite sample performance of the procedure
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This paper presents a safety-critical locomotion control framework for quadrupedal robots. Our goal is to enable quadrupedal robots to safely navigate in cluttered environments. To tackle this, we introduce exponential Discrete Control Barrier Functions (exponential DCBFs) with duality-based obstacle avoidance constraints into a Nonlinear Model Predictive Control (NMPC) with Whole-Body Control (WBC) framework for quadrupedal locomotion control. This enables us to use polytopes to describe the shapes of the robot and obstacles for collision avoidance while doing locomotion control of quadrupedal robots. Compared to most prior work, especially using CBFs, that utilize spherical and conservative approximation for obstacle avoidance, this work demonstrates a quadrupedal robot autonomously and safely navigating through very tight spaces in the real world. (Our open-source code is available at github.com/HybridRobotics/quadruped_nmpc_dcbf_duality, and the video is available at youtu.be/p1gSQjwXm1Q.)
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