Many practical applications, such as recommender systems and learning to rank, involve solving multiple similar tasks. One example is learning of recommendation policies for users with similar movie preferences, where the users may still rank the individual movies slightly differently. Such tasks can be organized in a hierarchy, where similar tasks are related through a shared structure. In this work, we formulate this problem as a contextual off-policy optimization in a hierarchical graphical model from logged bandit feedback. To solve the problem, we propose a hierarchical off-policy optimization algorithm (HierOPO), which estimates the parameters of the hierarchical model and then acts pessimistically with respect to them. We instantiate HierOPO in linear Gaussian models, for which we also provide an efficient implementation and analysis. We prove per-task bounds on the suboptimality of the learned policies, which show a clear improvement over not using the hierarchical model. We also evaluate the policies empirically. Our theoretical and empirical results show a clear advantage of using the hierarchy over solving each task independently.

图形神经网络（GNN）已成为编码图形结构数据的强大工具。由于其广泛的应用程序，越来越需要开发工具来解释GNN如何做出给定的图形结构数据决定。现有的基于学习的GNN解释方法在培训中是特定于任务的，因此遭受了关键的缺点。具体而言，它们无法为使用单个解释器提供多任务预测模型的解释。在GNN以自我监督的方式训练的情况下，他们也无法提供解释，并且在未来的下游任务中使用了结果表示。为了解决这些局限性，我们提出了一个任务不合时宜的GNN解释器（TAGE），该解释器（Tage）独立于下游模型，并在自学人员的情况下接受了训练，而对下游任务不了解。 Tage可以通过看不见的下游任务来解释GNN嵌入模型，并可以有效解释多任务模型。我们的广泛实验表明，通过使用相同的模型来解释多个下游任务的预测，同时实现了与当前最新的GNN解释方法一样好甚至更好的解释质量，可以显着提高解释效率。我们的代码可公开作为DIG库的一部分，网址为https://github.com/divelab/dig/tree/main/main/dig/xgraph/tage/。

图形神经网络（GNNS）在节点分类，回归和推荐任务中取得了最新的最新性能。当可提供高质量和丰富的连接结构时，GNNS工作好。但是，在许多真实世界图中，该要求在节点度具有幂律分布的许多真实世界中，因为许多节点具有较少或嘈杂的连接。这种情况的极端情况是节点可能没有邻居，称为严格的冷启动（SCS）场景。这会强制预测模型依赖于节点的输入特征。与通过蒸馏方法相比，我们提出冷啤酒以解决SCS和嘈杂的邻居设置。我们介绍了功能贡献比（FCR），测量使用电感GNN解决SCS问题的可行性，并选择SCS泛化的最佳体系结构。我们通过实验显示FCR Disentangles图数据集的各种组成部分的贡献，并展示了几个公共基准和专有电子商务数据集上的冷啤酒的优越性。我们方法的源代码可用于：https://github.com/amazon-research/gnn-tail-一致化。

Model compression via quantization and sparsity enhancement has gained an immense interest to enable the deployment of deep neural networks (DNNs) in resource-constrained edge environments. Although these techniques have shown promising results in reducing the energy, latency and memory requirements of the DNNs, their performance in non-ideal real-world settings (such as in the presence of hardware faults) is yet to be completely understood. In this paper, we investigate the impact of bit-flip and stuck-at faults on activation-sparse quantized DNNs (QDNNs). We show that a high level of activation sparsity comes at the cost of larger vulnerability to faults. For instance, activation-sparse QDNNs exhibit up to 17.32% lower accuracy than the standard QDNNs. We also establish that one of the major cause of the degraded accuracy is sharper minima in the loss landscape for activation-sparse QDNNs, which makes them more sensitive to perturbations in the weight values due to faults. Based on this observation, we propose the mitigation of the impact of faults by employing a sharpness-aware quantization (SAQ) training scheme. The activation-sparse and standard QDNNs trained with SAQ have up to 36.71% and 24.76% higher inference accuracy, respectively compared to their conventionally trained equivalents. Moreover, we show that SAQ-trained activation-sparse QDNNs show better accuracy in faulty settings than standard QDNNs trained conventionally. Thus the proposed technique can be instrumental in achieving sparsity-related energy/latency benefits without compromising on fault tolerance.

We present a differentiable formulation of rigid-body contact dynamics for objects and robots represented as compositions of convex primitives. Existing optimization-based approaches simulating contact between convex primitives rely on a bilevel formulation that separates collision detection and contact simulation. These approaches are unreliable in realistic contact simulation scenarios because isolating the collision detection problem introduces contact location non-uniqueness. Our approach combines contact simulation and collision detection into a unified single-level optimization problem. This disambiguates the collision detection problem in a physics-informed manner. Compared to previous differentiable simulation approaches, our formulation features improved simulation robustness and a reduction in computational complexity by more than an order of magnitude. We illustrate the contact and collision differentiability on a robotic manipulation task requiring optimization-through-contact. We provide a numerically efficient implementation of our formulation in the Julia language called Silico.jl.

Edge computing is becoming more and more popular among researchers who seek to take advantage of the edge resources and the minimal time delays, in order to run their robotic applications more efficiently. Recently, many edge architectures have been proposed, each of them having their advantages and disadvantages, depending on each application. In this work, we present two different edge architectures for controlling the trajectory of an Unmanned Aerial Vehicle (UAV). The first architecture is based on docker containers and the second one is based on kubernetes, while the main framework for operating the robot is the Robotic Operating System (ROS). The efficiency of the overall proposed scheme is being evaluated through extended simulations for comparing the two architectures and the overall results obtained.

Path prediction is an essential task for many real-world Cyber-Physical Systems (CPS) applications, from autonomous driving and traffic monitoring/management to pedestrian/worker safety. These real-world CPS applications need a robust, lightweight path prediction that can provide a universal network architecture for multiple subjects (e.g., pedestrians and vehicles) from different perspectives. However, most existing algorithms are tailor-made for a unique subject with a specific camera perspective and scenario. This article presents Pishgu, a universal lightweight network architecture, as a robust and holistic solution for path prediction. Pishgu's architecture can adapt to multiple path prediction domains with different subjects (vehicles, pedestrians), perspectives (bird's-eye, high-angle), and scenes (sidewalk, highway). Our proposed architecture captures the inter-dependencies within the subjects in each frame by taking advantage of Graph Isomorphism Networks and the attention module. We separately train and evaluate the efficacy of our architecture on three different CPS domains across multiple perspectives (vehicle bird's-eye view, pedestrian bird's-eye view, and human high-angle view). Pishgu outperforms state-of-the-art solutions in the vehicle bird's-eye view domain by 42% and 61% and pedestrian high-angle view domain by 23% and 22% in terms of ADE and FDE, respectively. Additionally, we analyze the domain-specific details for various datasets to understand their effect on path prediction and model interpretation. Finally, we report the latency and throughput for all three domains on multiple embedded platforms showcasing the robustness and adaptability of Pishgu for real-world integration into CPS applications.

尽管进行了数十年的研究，但现有的导航系统在野外部署时仍然面临现实世界中的挑战，例如在混乱的家庭环境或人类占领的公共场所中。为了解决这个问题，我们提出了一类新的隐式控制政策，将模仿学习的好处与模型预测控制（MPC）的系统约束的强大处理结合在一起。我们的方法称为Performer-MPC，使用了通过表演者提供的视觉上下文嵌入的学习成本函数（一种低级隐式意见变压器）。我们共同训练成本函数并构建依靠它的控制器，有效地端到端解决相应的双层优化问题。我们表明，由此产生的策略通过利用一些在不同挑战的现实世界情景中利用一些专家演示来提高标准MPC绩效。与标准的MPC政策相比，表演者MPC在混乱的环境中实现了40％的目标，而在人类浏览时，社交指标的目标> 65％。

Airbnb is a two-sided marketplace, bringing together hosts who own listings for rent, with prospective guests from around the globe. Applying neural network-based learning to rank techniques has led to significant improvements in matching guests with hosts. These improvements in ranking were driven by a core strategy: order the listings by their estimated booking probabilities, then iterate on techniques to make these booking probability estimates more and more accurate. Embedded implicitly in this strategy was an assumption that the booking probability of a listing could be determined independently of other listings in search results. In this paper we discuss how this assumption, pervasive throughout the commonly-used learning to rank frameworks, is false. We provide a theoretical foundation correcting this assumption, followed by efficient neural network architectures based on the theory. Explicitly accounting for possible similarities between listings, and reducing them to diversify the search results generated strong positive impact. We discuss these metric wins as part of the online A/B tests of the theory. Our method provides a practical way to diversify search results for large-scale production ranking systems.

边缘计算是一项有前途的技术，可以在需要瞬时数据处理的技术领域提供新功能。机器和深度学习等领域的研究人员对其应用程序进行了广泛的边缘和云计算，这主要是由于他们提供的大量计算和存储资源。目前，机器人技术也正在寻求利用这些功能，并且随着5G网络的开发，可以克服该领域的一些现有限制。在这种情况下，重要的是要知道如何利用新兴的边缘体系结构，当今存在哪些类型的边缘体系结构和平台，以及哪些可以并且应该基于每个机器人应用程序使用。一般而言，边缘平台可以以不同的方式实现和使用，尤其是因为有几个提供商提供或多或少提供的一组服务以及一些基本差异。因此，本研究针对那些从事下一代机器人系统开发的人解决了这些讨论，并将有助于理解每个边缘计算体系结构的优势和缺点，以便明智地选择适合每个应用程序的功能。