数字推荐系统（例如Spotify和Netflix）不仅会影响消费者的行为，还会影响生产者的激励措施：生产商试图提供系统推荐的内容。但是将产生什么内容？在本文中，我们研究了内容推荐系统中的供应方均衡。我们将用户和内容建模为$ d $维矢量，并推荐与每个用户具有最高点产品的内容。我们模型的主要特征是生产者的决策空间高维，用户群是异质的。这引起了平衡的新定性现象：首先是流派的形成，生产者专门竞争用户的亚集。使用二元参数，我们得出了这种专业化的必要条件。其次，我们表明生产商可以在平衡下实现正利润，这在完美的竞争中通常是不可能的。我们得出了足够的条件，并证明它与内容的专业化密切相关。在这两种结果中，用户的几何形状与生产者成本的结构之间的相互作用都会影响供应方均衡的结构。从概念上讲，我们的工作是研究推荐系统如何塑造生产者之间供应方竞争的起点。

这项研究提出了依赖电压突触可塑性（VDSP），这是一种新型的脑启发的无监督的本地学习规则，用于在线实施HEBB对神经形态硬件的可塑性机制。拟议的VDSP学习规则仅更新了突触后神经元的尖峰的突触电导，这使得相对于标准峰值依赖性可塑性（STDP）的更新数量减少了两倍。此更新取决于突触前神经元的膜电位，该神经元很容易作为神经元实现的一部分，因此不需要额外的存储器来存储。此外，该更新还对突触重量进行了正规化，并防止重复刺激时的重量爆炸或消失。进行严格的数学分析以在VDSP和STDP之间达到等效性。为了验证VDSP的系统级性能，我们训练一个单层尖峰神经网络（SNN），以识别手写数字。我们报告85.01 $ \ pm $ 0.76％（平均$ \ pm $ s.d。）对于MNIST数据集中的100个输出神经元网络的精度。在缩放网络大小时，性能会提高（400个输出神经元的89.93 $ \ pm $ 0.41％，500个神经元为90.56 $ \ pm $ 0.27），这验证了大规模计算机视觉任务的拟议学习规则的适用性。有趣的是，学习规则比STDP更好地适应输入信号的频率，并且不需要对超参数进行手动调整。

在机器学习中，我们传统上评估单个模型的性能，平均在测试输入集合中进行平均。在这项工作中，我们提出了一种新方法：在$ \ textit {单个输入点} $上评估时，我们测量了模型集合的性能。具体来说，我们研究了一个点的$ \ textit {profile {profile} $：模型在测试分布上的平均性能与他们在该点上的角度表现之间的关系。我们发现配置文件可以在分布和分发的模型和数据的结构中产生新的见解。例如，我们从经验上表明，实际数据分布由具有质量不同的点组成。一方面，有“兼容”点，在角度和平均性能之间具有很强的相关性。另一方面，有些点具有弱甚至$ \ textit {nogate} $相关性：提高整体模型精度实际上$ \ textit {hurts} $性能的情况。我们证明，这些实验观察与先前工作中提出的几种简化学习模型的预测不一致。作为一个应用程序，我们使用配置文件来构造一个数据集，我们称为CIFAR-10-NENG：CINIC-10的子集，因此对于标准模型，CIFAR-10-NENG上的准确性为$ \ textit {negalissiper {negalissiperational {negalishatied} CIFAR-10测试。这首先说明了一个完全逆转“准确性”的OOD数据集（Miller，Taori，Raghunathan，Sagawa，Koh，Koh，Shankar，Liang，Carmon和Schmidt 2021）

尽管深度学习使图像介绍方面取得了巨大的飞跃，但当前的方法通常无法综合现实的高频细节。在本文中，我们建议将超分辨率应用于粗糙的重建输出，以高分辨率进行精炼，然后将输出降低到原始分辨率。通过将高分辨率图像引入改进网络，我们的框架能够重建更多的细节，这些细节通常由于光谱偏置而被平滑 - 神经网络倾向于比高频更好地重建低频。为了协助培训大型高度孔洞的改进网络，我们提出了一种渐进的学习技术，其中缺失区域的大小随着培训的进行而增加。我们的缩放，完善和缩放策略，结合了高分辨率的监督和渐进学习，构成了一种框架 - 不合时宜的方法，用于增强高频细节，可应用于任何基于CNN的涂层方法。我们提供定性和定量评估以及消融分析，以显示我们方法的有效性。这种看似简单但功能强大的方法优于最先进的介绍方法。我们的代码可在https://github.com/google/zoom-to-inpaint中找到

Learning policies from fixed offline datasets is a key challenge to scale up reinforcement learning (RL) algorithms towards practical applications. This is often because off-policy RL algorithms suffer from distributional shift, due to mismatch between dataset and the target policy, leading to high variance and over-estimation of value functions. In this work, we propose variance regularization for offline RL algorithms, using stationary distribution corrections. We show that by using Fenchel duality, we can avoid double sampling issues for computing the gradient of the variance regularizer. The proposed algorithm for offline variance regularization (OVAR) can be used to augment any existing offline policy optimization algorithms. We show that the regularizer leads to a lower bound to the offline policy optimization objective, which can help avoid over-estimation errors, and explains the benefits of our approach across a range of continuous control domains when compared to existing state-of-the-art algorithms.

In the process of materials discovery, chemists currently need to perform many laborious, time-consuming, and often dangerous lab experiments. To accelerate this process, we propose a framework for robots to assist chemists by performing lab experiments autonomously. The solution allows a general-purpose robot to perform diverse chemistry experiments and efficiently make use of available lab tools. Our system can load high-level descriptions of chemistry experiments, perceive a dynamic workspace, and autonomously plan the required actions and motions to perform the given chemistry experiments with common tools found in the existing lab environment. Our architecture uses a modified PDDLStream solver for integrated task and constrained motion planning, which generates plans and motions that are guaranteed to be safe by preventing collisions and spillage. We present a modular framework that can scale to many different experiments, actions, and lab tools. In this work, we demonstrate the utility of our framework on three pouring skills and two foundational chemical experiments for materials synthesis: solubility and recrystallization. More experiments and updated evaluations can be found at https://ac-rad.github.io/arc-icra2023.

This paper proposes an easy-to-compute upper bound for the overlap index between two probability distributions without requiring any knowledge of the distribution models. The computation of our bound is time-efficient and memory-efficient and only requires finite samples. The proposed bound shows its value in one-class classification and domain shift analysis. Specifically, in one-class classification, we build a novel one-class classifier by converting the bound into a confidence score function. Unlike most one-class classifiers, the training process is not needed for our classifier. Additionally, the experimental results show that our classifier \textcolor{\colorname}{can be accurate with} only a small number of in-class samples and outperforms many state-of-the-art methods on various datasets in different one-class classification scenarios. In domain shift analysis, we propose a theorem based on our bound. The theorem is useful in detecting the existence of domain shift and inferring data information. The detection and inference processes are both computation-efficient and memory-efficient. Our work shows significant promise toward broadening the applications of overlap-based metrics.

We study algorithms for detecting and including glass objects in an optimization-based Simultaneous Localization and Mapping (SLAM) algorithm in this work. When LiDAR data is the primary exteroceptive sensory input, glass objects are not correctly registered. This occurs as the incident light primarily passes through the glass objects or reflects away from the source, resulting in inaccurate range measurements for glass surfaces. Consequently, the localization and mapping performance is impacted, thereby rendering navigation in such environments unreliable. Optimization-based SLAM solutions, which are also referred to as Graph SLAM, are widely regarded as state of the art. In this paper, we utilize a simple and computationally inexpensive glass detection scheme for detecting glass objects and present the methodology to incorporate the identified objects into the occupancy grid maintained by such an algorithm (Google Cartographer). We develop both local (submap level) and global algorithms for achieving the objective mentioned above and compare the maps produced by our method with those produced by an existing algorithm that utilizes particle filter based SLAM.

By transferring knowledge from large, diverse, task-agnostic datasets, modern machine learning models can solve specific downstream tasks either zero-shot or with small task-specific datasets to a high level of performance. While this capability has been demonstrated in other fields such as computer vision, natural language processing or speech recognition, it remains to be shown in robotics, where the generalization capabilities of the models are particularly critical due to the difficulty of collecting real-world robotic data. We argue that one of the keys to the success of such general robotic models lies with open-ended task-agnostic training, combined with high-capacity architectures that can absorb all of the diverse, robotic data. In this paper, we present a model class, dubbed Robotics Transformer, that exhibits promising scalable model properties. We verify our conclusions in a study of different model classes and their ability to generalize as a function of the data size, model size, and data diversity based on a large-scale data collection on real robots performing real-world tasks. The project's website and videos can be found at robotics-transformer.github.io

We propose a framework in which multiple entities collaborate to build a machine learning model while preserving privacy of their data. The approach utilizes feature embeddings from shared/per-entity feature extractors transforming data into a feature space for cooperation between entities. We propose two specific methods and compare them with a baseline method. In Shared Feature Extractor (SFE) Learning, the entities use a shared feature extractor to compute feature embeddings of samples. In Locally Trained Feature Extractor (LTFE) Learning, each entity uses a separate feature extractor and models are trained using concatenated features from all entities. As a baseline, in Cooperatively Trained Feature Extractor (CTFE) Learning, the entities train models by sharing raw data. Secure multi-party algorithms are utilized to train models without revealing data or features in plain text. We investigate the trade-offs among SFE, LTFE, and CTFE in regard to performance, privacy leakage (using an off-the-shelf membership inference attack), and computational cost. LTFE provides the most privacy, followed by SFE, and then CTFE. Computational cost is lowest for SFE and the relative speed of CTFE and LTFE depends on network architecture. CTFE and LTFE provide the best accuracy. We use MNIST, a synthetic dataset, and a credit card fraud detection dataset for evaluations.