为多个机器人制定安全,稳定和高效的避免障碍政策是具有挑战性的。大多数现有研究要么使用集中控制,要么需要与其他机器人进行通信。在本文中,我们提出了一种基于对数地图的新型对数深度强化学习方法,以避免复杂且无通信的多机器人方案。特别是,我们的方法将激光信息转换为对数图。为了提高训练速度和概括性能,我们的政策将在两个专门设计的多机器人方案中进行培训。与其他方法相比,对数图可以更准确地表示障碍,并提高避免障碍的成功率。我们最终在各种模拟和现实情况下评估了我们的方法。结果表明,我们的方法为复杂的多机器人场景和行人场景中的机器人提供了一种更稳定,更有效的导航解决方案。视频可在https://youtu.be/r0esuxe6mze上找到。
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变压器模型最近已成为自然语言处理中的基础模型之一,作为副产品,最近对扩展这些模型具有重大的兴趣和投资。但是,这些大型变压器语言模型的培训和推理成本令人难以置信,因此需要更多的研究来识别更有效的变体。在这项工作中,我们通过用统计语言建模中的文献启发的变压器体系结构提出了一个简单而有效的修改,该架构是通过通过文本序列的离散潜在表示构建的n-grams来增强模型的。我们评估了我们的模型,关于C4数据集的语言建模的N-Strammer以及Superglue数据集的文本分类,并发现它的表现优于诸如变压器和底漆等几个强基线。我们为JAX中的可重复性目的开放源模型。
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为了接近不同的业务目标,在线流量塑造算法旨在改善目标项目的曝光,例如提高新商品的增长。通常,这些算法假设可以通过训练良好的转换速率预测模型访问每个用户项对的实用性。然而,对于真正的电子商务平台,有不可避免的因素阻止我们学习这种准确的模型。为了打破对实用程序的准确输入的沉重依赖,我们提出了一般的在线交通整理协议,用于在线电子商务应用程序。在我们的框架中,我们近似映射奖励得分的函数,这通常是影响排名结果的唯一方法,以对曝光和购买的数量来影响流量整形问题。具体地,我们通过在探索数据点的凸壳上构造的一类转印的线性函数近似上述功能。此外,我们将在线流量整形问题重构为线性编程,其中这些分段线性函数嵌入到目标和约束中。我们的算法可以简单地优化主要空间中的线性编程,并且其解决方案可以简单地应用于随机策略来满足所优化的目标和预期限制。最后,在线A / B测试显示我们所提出的算法稳定地优于先前的工业级流量整形算法。
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通过直接将感知输入映射到机器人控制命令中,深入的强化学习(DRL)算法已被证明在机器人导航中有效,尤其是在未知环境中。但是,大多数现有方法忽略导航中的局部最小问题,从而无法处理复杂的未知环境。在本文中,我们提出了第一个基于DRL的导航方法,该方法由具有连续动作空间,自适应向前模拟时间(AFST)的SMDP建模,以克服此问题。具体而言,我们通过修改其GAE来更好地估计SMDP中的策略梯度,改善了指定SMDP问题的分布式近端策略优化(DPPO)算法。我们在模拟器和现实世界中评估了我们的方法。
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胰腺癌是世界上最严重恶性的癌症之一,这种癌症迅速迅速,具有很高的死亡率。快速的现场评估(玫瑰)技术通过立即分析与现场病理学家的快速染色的细胞影析学形象来创新工作流程,这使得在这种紧压的过程中能够更快的诊断。然而,由于缺乏经验丰富的病理学家,玫瑰诊断的更广泛的扩张已经受到阻碍。为了克服这个问题,我们提出了一个混合高性能深度学习模型,以实现自动化工作流程,从而释放占据病理学家的宝贵时间。通过使用我们特定的多级混合设计将变压器块引入该字段,由卷积神经网络(CNN)产生的空间特征显着增强了变压器全球建模。转向多级空间特征作为全球关注指导,这种设计将鲁棒性与CNN的感应偏差与变压器的复杂全球建模功能相结合。收集4240朵Rose图像的数据集以评估此未开发领域的方法。所提出的多级混合变压器(MSHT)在分类精度下实现95.68%,其鲜明地高于最先进的模型。面对对可解释性的需求,MSHT以更准确的关注区域表达其对应物。结果表明,MSHT可以以前所未有的图像规模精确地区分癌症样本,奠定了部署自动决策系统的基础,并在临床实践中扩大玫瑰。代码和记录可在:https://github.com/sagizty/multi-stage-ybrid-transformer。
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Deep learning models can achieve high accuracy when trained on large amounts of labeled data. However, real-world scenarios often involve several challenges: Training data may become available in installments, may originate from multiple different domains, and may not contain labels for training. Certain settings, for instance medical applications, often involve further restrictions that prohibit retention of previously seen data due to privacy regulations. In this work, to address such challenges, we study unsupervised segmentation in continual learning scenarios that involve domain shift. To that end, we introduce GarDA (Generative Appearance Replay for continual Domain Adaptation), a generative-replay based approach that can adapt a segmentation model sequentially to new domains with unlabeled data. In contrast to single-step unsupervised domain adaptation (UDA), continual adaptation to a sequence of domains enables leveraging and consolidation of information from multiple domains. Unlike previous approaches in incremental UDA, our method does not require access to previously seen data, making it applicable in many practical scenarios. We evaluate GarDA on two datasets with different organs and modalities, where it substantially outperforms existing techniques.
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The development of social media user stance detection and bot detection methods rely heavily on large-scale and high-quality benchmarks. However, in addition to low annotation quality, existing benchmarks generally have incomplete user relationships, suppressing graph-based account detection research. To address these issues, we propose a Multi-Relational Graph-Based Twitter Account Detection Benchmark (MGTAB), the first standardized graph-based benchmark for account detection. To our knowledge, MGTAB was built based on the largest original data in the field, with over 1.55 million users and 130 million tweets. MGTAB contains 10,199 expert-annotated users and 7 types of relationships, ensuring high-quality annotation and diversified relations. In MGTAB, we extracted the 20 user property features with the greatest information gain and user tweet features as the user features. In addition, we performed a thorough evaluation of MGTAB and other public datasets. Our experiments found that graph-based approaches are generally more effective than feature-based approaches and perform better when introducing multiple relations. By analyzing experiment results, we identify effective approaches for account detection and provide potential future research directions in this field. Our benchmark and standardized evaluation procedures are freely available at: https://github.com/GraphDetec/MGTAB.
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As one of the prevalent methods to achieve automation systems, Imitation Learning (IL) presents a promising performance in a wide range of domains. However, despite the considerable improvement in policy performance, the corresponding research on the explainability of IL models is still limited. Inspired by the recent approaches in explainable artificial intelligence methods, we proposed a model-agnostic explaining framework for IL models called R2RISE. R2RISE aims to explain the overall policy performance with respect to the frames in demonstrations. It iteratively retrains the black-box IL model from the randomized masked demonstrations and uses the conventional evaluation outcome environment returns as the coefficient to build an importance map. We also conducted experiments to investigate three major questions concerning frames' importance equality, the effectiveness of the importance map, and connections between importance maps from different IL models. The result shows that R2RISE successfully distinguishes important frames from the demonstrations.
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Compressed videos often exhibit visually annoying artifacts, known as Perceivable Encoding Artifacts (PEAs), which dramatically degrade video visual quality. Subjective and objective measures capable of identifying and quantifying various types of PEAs are critical in improving visual quality. In this paper, we investigate the influence of four spatial PEAs (i.e. blurring, blocking, bleeding, and ringing) and two temporal PEAs (i.e. flickering and floating) on video quality. For spatial artifacts, we propose a visual saliency model with a low computational cost and higher consistency with human visual perception. In terms of temporal artifacts, self-attention based TimeSFormer is improved to detect temporal artifacts. Based on the six types of PEAs, a quality metric called Saliency-Aware Spatio-Temporal Artifacts Measurement (SSTAM) is proposed. Experimental results demonstrate that the proposed method outperforms state-of-the-art metrics. We believe that SSTAM will be beneficial for optimizing video coding techniques.
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We propose a distributionally robust return-risk model for Markov decision processes (MDPs) under risk and reward ambiguity. The proposed model optimizes the weighted average of mean and percentile performances, and it covers the distributionally robust MDPs and the distributionally robust chance-constrained MDPs (both under reward ambiguity) as special cases. By considering that the unknown reward distribution lies in a Wasserstein ambiguity set, we derive the tractable reformulation for our model. In particular, we show that that the return-risk model can also account for risk from uncertain transition kernel when one only seeks deterministic policies, and that a distributionally robust MDP under the percentile criterion can be reformulated as its nominal counterpart at an adjusted risk level. A scalable first-order algorithm is designed to solve large-scale problems, and we demonstrate the advantages of our proposed model and algorithm through numerical experiments.
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