轨迹预测是自动车辆(AVS)执行安全规划和导航的关键组件。然而,很少有研究分析了轨迹预测的对抗性稳健性,或者调查了最坏情况的预测是否仍然可以导致安全规划。为了弥合这种差距,我们通过提出普通车辆轨迹来最大化预测误差来研究轨迹预测模型的对抗鲁棒性。我们在三个模型和三个数据集上的实验表明,对手预测将预测误差增加超过150%。我们的案例研究表明,如果对手在对手轨迹之后驱动靠近目标AV的车辆,则AV可以进行不准确的预测,甚至不安全的驾驶决策。我们还通过数据增强和轨迹平滑探索可能的缓解技术。
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尽管基于模型的增强学习(RL)方法被认为是更具样本的高效,但现有算法通常依赖于复杂的规划算法与模型学习过程紧密粘合。因此,学习模型可能缺乏与更专业规划者重新使用的能力。在本文中,我们解决了这个问题,并提供了在没有奖励信号的指导的情况下有效地学习RL模型的方法。特别是,我们采取了一个插件求解器方法,我们专注于在探索阶段学习模型,并要求在学习模型上的\ emph {任何规划算法}可以给出近最佳的政策。具体而言,我们专注于线性混合MDP设置,其中概率转换矩阵是一组现有模型的(未知)凸面组合。我们表明,通过建立新的探索算法,即插即用通过\ tilde {o}来学习模型(d ^ 2h ^ 3 / epsilon ^ 2)$与环境交互,\ emph {任何} $ \ epsilon $ -optimal Planner在模型上给出$ O(\ epsilon)$ - 原始模型上的最佳政策。此示例复杂性与非插入方法的下限与下限匹配,并且是\ EMPH {统计上最佳}。我们通过利用使用伯尔斯坦不等式和指定的线性混合MDP的属性来实现仔细的最大总差异来实现这一结果。
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A crucial issue of current text generation models is that they often uncontrollably generate factually inconsistent text with respective of their inputs. Limited by the lack of annotated data, existing works in evaluating factual consistency directly transfer the reasoning ability of models trained on other data-rich upstream tasks like question answering (QA) and natural language inference (NLI) without any further adaptation. As a result, they perform poorly on the real generated text and are biased heavily by their single-source upstream tasks. To alleviate this problem, we propose a weakly supervised framework that aggregates multiple resources to train a precise and efficient factual metric, namely WeCheck. WeCheck first utilizes a generative model to accurately label a real generated sample by aggregating its weak labels, which are inferred from multiple resources. Then, we train the target metric model with the weak supervision while taking noises into consideration. Comprehensive experiments on a variety of tasks demonstrate the strong performance of WeCheck, which achieves a 3.4\% absolute improvement over previous state-of-the-art methods on TRUE benchmark on average.
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The number of international benchmarking competitions is steadily increasing in various fields of machine learning (ML) research and practice. So far, however, little is known about the common practice as well as bottlenecks faced by the community in tackling the research questions posed. To shed light on the status quo of algorithm development in the specific field of biomedical imaging analysis, we designed an international survey that was issued to all participants of challenges conducted in conjunction with the IEEE ISBI 2021 and MICCAI 2021 conferences (80 competitions in total). The survey covered participants' expertise and working environments, their chosen strategies, as well as algorithm characteristics. A median of 72% challenge participants took part in the survey. According to our results, knowledge exchange was the primary incentive (70%) for participation, while the reception of prize money played only a minor role (16%). While a median of 80 working hours was spent on method development, a large portion of participants stated that they did not have enough time for method development (32%). 25% perceived the infrastructure to be a bottleneck. Overall, 94% of all solutions were deep learning-based. Of these, 84% were based on standard architectures. 43% of the respondents reported that the data samples (e.g., images) were too large to be processed at once. This was most commonly addressed by patch-based training (69%), downsampling (37%), and solving 3D analysis tasks as a series of 2D tasks. K-fold cross-validation on the training set was performed by only 37% of the participants and only 50% of the participants performed ensembling based on multiple identical models (61%) or heterogeneous models (39%). 48% of the respondents applied postprocessing steps.
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Recent advances in operator learning theory have improved our knowledge about learning maps between infinite dimensional spaces. However, for large-scale engineering problems such as concurrent multiscale simulation for mechanical properties, the training cost for the current operator learning methods is very high. The article presents a thorough analysis on the mathematical underpinnings of the operator learning paradigm and proposes a kernel learning method that maps between function spaces. We first provide a survey of modern kernel and operator learning theory, as well as discuss recent results and open problems. From there, the article presents an algorithm to how we can analytically approximate the piecewise constant functions on R for operator learning. This implies the potential feasibility of success of neural operators on clustered functions. Finally, a k-means clustered domain on the basis of a mechanistic response is considered and the Lippmann-Schwinger equation for micro-mechanical homogenization is solved. The article briefly discusses the mathematics of previous kernel learning methods and some preliminary results with those methods. The proposed kernel operator learning method uses graph kernel networks to come up with a mechanistic reduced order method for multiscale homogenization.
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Behavior constrained policy optimization has been demonstrated to be a successful paradigm for tackling Offline Reinforcement Learning. By exploiting historical transitions, a policy is trained to maximize a learned value function while constrained by the behavior policy to avoid a significant distributional shift. In this paper, we propose our closed-form policy improvement operators. We make a novel observation that the behavior constraint naturally motivates the use of first-order Taylor approximation, leading to a linear approximation of the policy objective. Additionally, as practical datasets are usually collected by heterogeneous policies, we model the behavior policies as a Gaussian Mixture and overcome the induced optimization difficulties by leveraging the LogSumExp's lower bound and Jensen's Inequality, giving rise to a closed-form policy improvement operator. We instantiate offline RL algorithms with our novel policy improvement operators and empirically demonstrate their effectiveness over state-of-the-art algorithms on the standard D4RL benchmark.
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Universal Image Segmentation is not a new concept. Past attempts to unify image segmentation in the last decades include scene parsing, panoptic segmentation, and, more recently, new panoptic architectures. However, such panoptic architectures do not truly unify image segmentation because they need to be trained individually on the semantic, instance, or panoptic segmentation to achieve the best performance. Ideally, a truly universal framework should be trained only once and achieve SOTA performance across all three image segmentation tasks. To that end, we propose OneFormer, a universal image segmentation framework that unifies segmentation with a multi-task train-once design. We first propose a task-conditioned joint training strategy that enables training on ground truths of each domain (semantic, instance, and panoptic segmentation) within a single multi-task training process. Secondly, we introduce a task token to condition our model on the task at hand, making our model task-dynamic to support multi-task training and inference. Thirdly, we propose using a query-text contrastive loss during training to establish better inter-task and inter-class distinctions. Notably, our single OneFormer model outperforms specialized Mask2Former models across all three segmentation tasks on ADE20k, CityScapes, and COCO, despite the latter being trained on each of the three tasks individually with three times the resources. With new ConvNeXt and DiNAT backbones, we observe even more performance improvement. We believe OneFormer is a significant step towards making image segmentation more universal and accessible. To support further research, we open-source our code and models at https://github.com/SHI-Labs/OneFormer
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Adaptive mesh refinement (AMR) is necessary for efficient finite element simulations of complex physical phenomenon, as it allocates limited computational budget based on the need for higher or lower resolution, which varies over space and time. We present a novel formulation of AMR as a fully-cooperative Markov game, in which each element is an independent agent who makes refinement and de-refinement choices based on local information. We design a novel deep multi-agent reinforcement learning (MARL) algorithm called Value Decomposition Graph Network (VDGN), which solves the two core challenges that AMR poses for MARL: posthumous credit assignment due to agent creation and deletion, and unstructured observations due to the diversity of mesh geometries. For the first time, we show that MARL enables anticipatory refinement of regions that will encounter complex features at future times, thereby unlocking entirely new regions of the error-cost objective landscape that are inaccessible by traditional methods based on local error estimators. Comprehensive experiments show that VDGN policies significantly outperform error threshold-based policies in global error and cost metrics. We show that learned policies generalize to test problems with physical features, mesh geometries, and longer simulation times that were not seen in training. We also extend VDGN with multi-objective optimization capabilities to find the Pareto front of the tradeoff between cost and error.
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对移动障碍的检测和细分,以及对当地环境的未来占用状态的预测,对于自动驾驶汽车,必不可少的自动驾驶行动至关重要。在本文中,我们提出了一个框架,该框架使用深层神经网络体系结构将两个功能集成在一起。我们的方法首先检测到现场移动对象的段,并使用此信息来预测自动驾驶汽车周围环境的时空演化。为了解决静态动态对象分割和环境预测模型直接集成的问题,我们建议在整个框架中使用基于占用的环境表示。我们的方法在现实Waymo打开数据集上进行了验证,并证明了比基线方法更高的预测准确性。
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与2D车道相比,实际3D车道数据很难准确收集。在本文中,我们提出了一种仅使用2D车道标签训练3D车道的新方法,称为弱监督的3D车道检测WS-3D车道。通过在相邻车道上的恒定车道宽度和相等高度的假设,我们间接监督训练中的3D车道高度。为了克服数据收集过程中相机音调动态变化的问题,提出了相机音调自校准方法。在锚固表示中,我们提出了一个具有改进的非限量抑制(NMS)方法的双层锚,该方法使基于锚的方法可以预测两条接近的车道线。实验是在两种监督方法下在3D-LANENEN的基础上进行的。在弱监督的环境下,我们的WS-3D车道的表现优于先前的3D-LANEN:APOLLO 3D合成数据集的F得分上升到92.3%,而F1在3DDLANES上上升到74.5%。同时,在纯监督环境中的WS-3D车道可以提高更多的增量,并且优于最先进的设置。据我们所知,WS-3D车道是在弱监督环境下进行3D车道检测的第一次尝试。
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