数据增强技术广泛用于通过解决类别不平衡问题和数据稀疏性来增强机器学习模型的性能。已显示最先进的生成语言模型在不同的NLP任务中提供了显着的增益。但是,它们对几张拍摄设置中的文本分类任务的数据增强的适用性尚未完全探索,特别是对于专门域。在本文中,我们利用GPT-2(Radford A等,2019)来产生人工训练实例,以提高分类性能。我们的目的是分析种子训练示例的选择过程对GPT生成的样品的质量以及因此分类器性能的影响。我们使用几种种子选择策略进行实验,其中包括利用课程分层结构和域专家选择。我们的结果表明,少数标签实例中的微调GPT-2导致一致的分类改进和优于竞争性基线。最后,我们展示通过域专家选择指导这一过程可能会导致进一步的改进,这开辟了有趣的研究途径,用于结合生成模型和主动学习。
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This paper utilizes an anomaly detection algorithm to check if underwater gliders are operating normally in the unknown ocean environment. Glider pilots can be warned of the detected glider anomaly in real time, thus taking over the glider appropriately and avoiding further damage to the glider. The adopted algorithm is validated by two valuable sets of data in real glider deployments, the University of South Florida (USF) glider Stella and the Skidaway Institute of Oceanography (SkIO) glider Angus.
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We seek methods to model, control, and analyze robot teams performing environmental monitoring tasks. During environmental monitoring, the goal is to have teams of robots collect various data throughout a fixed region for extended periods of time. Standard bottom-up task assignment methods do not scale as the number of robots and task locations increases and require computationally expensive replanning. Alternatively, top-down methods have been used to combat computational complexity, but most have been limited to the analysis of methods which focus on transition times between tasks. In this work, we study a class of nonlinear macroscopic models which we use to control a time-varying distribution of robots performing different tasks throughout an environment. Our proposed ensemble model and control maintains desired time-varying populations of robots by leveraging naturally occurring interactions between robots performing tasks. We validate our approach at multiple fidelity levels including experimental results, suggesting the effectiveness of our approach to perform environmental monitoring.
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Imitation learning (IL) is a simple and powerful way to use high-quality human driving data, which can be collected at scale, to identify driving preferences and produce human-like behavior. However, policies based on imitation learning alone often fail to sufficiently account for safety and reliability concerns. In this paper, we show how imitation learning combined with reinforcement learning using simple rewards can substantially improve the safety and reliability of driving policies over those learned from imitation alone. In particular, we use a combination of imitation and reinforcement learning to train a policy on over 100k miles of urban driving data, and measure its effectiveness in test scenarios grouped by different levels of collision risk. To our knowledge, this is the first application of a combined imitation and reinforcement learning approach in autonomous driving that utilizes large amounts of real-world human driving data.
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Any strategy used to distribute a robot ensemble over a set of sequential tasks is subject to inaccuracy due to robot-level uncertainties and environmental influences on the robots' behavior. We approach the problem of inaccuracy during task allocation by modeling and controlling the overall ensemble behavior. Our model represents the allocation problem as a stochastic jump process and we regulate the mean and variance of such a process. The main contributions of this paper are: Establishing a structure for the transition rates of the equivalent stochastic jump process and formally showing that this approach leads to decoupled parameters that allow us to adjust the first- and second-order moments of the ensemble distribution over tasks, which gives the flexibility to decrease the variance in the desired final distribution. This allows us to directly shape the impact of uncertainties on the group allocation over tasks. We introduce a detailed procedure to design the gains to achieve the desired mean and show how the additional parameters impact the covariance matrix, which is directly associated with the degree of task allocation precision. Our simulation and experimental results illustrate the successful control of several robot ensembles during task allocation.
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Microprocessor architects are increasingly resorting to domain-specific customization in the quest for high-performance and energy-efficiency. As the systems grow in complexity, fine-tuning architectural parameters across multiple sub-systems (e.g., datapath, memory blocks in different hierarchies, interconnects, compiler optimization, etc.) quickly results in a combinatorial explosion of design space. This makes domain-specific customization an extremely challenging task. Prior work explores using reinforcement learning (RL) and other optimization methods to automatically explore the large design space. However, these methods have traditionally relied on single-agent RL/ML formulations. It is unclear how scalable single-agent formulations are as we increase the complexity of the design space (e.g., full stack System-on-Chip design). Therefore, we propose an alternative formulation that leverages Multi-Agent RL (MARL) to tackle this problem. The key idea behind using MARL is an observation that parameters across different sub-systems are more or less independent, thus allowing a decentralized role assigned to each agent. We test this hypothesis by designing domain-specific DRAM memory controller for several workload traces. Our evaluation shows that the MARL formulation consistently outperforms single-agent RL baselines such as Proximal Policy Optimization and Soft Actor-Critic over different target objectives such as low power and latency. To this end, this work opens the pathway for new and promising research in MARL solutions for hardware architecture search.
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The outbreak of the SARS-CoV-2 pandemic has put healthcare systems worldwide to their limits, resulting in increased waiting time for diagnosis and required medical assistance. With chest radiographs (CXR) being one of the most common COVID-19 diagnosis methods, many artificial intelligence tools for image-based COVID-19 detection have been developed, often trained on a small number of images from COVID-19-positive patients. Thus, the need for high-quality and well-annotated CXR image databases increased. This paper introduces POLCOVID dataset, containing chest X-ray (CXR) images of patients with COVID-19 or other-type pneumonia, and healthy individuals gathered from 15 Polish hospitals. The original radiographs are accompanied by the preprocessed images limited to the lung area and the corresponding lung masks obtained with the segmentation model. Moreover, the manually created lung masks are provided for a part of POLCOVID dataset and the other four publicly available CXR image collections. POLCOVID dataset can help in pneumonia or COVID-19 diagnosis, while the set of matched images and lung masks may serve for the development of lung segmentation solutions.
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In the era of big astronomical surveys, our ability to leverage artificial intelligence algorithms simultaneously for multiple datasets will open new avenues for scientific discovery. Unfortunately, simply training a deep neural network on images from one data domain often leads to very poor performance on any other dataset. Here we develop a Universal Domain Adaptation method DeepAstroUDA, capable of performing semi-supervised domain alignment that can be applied to datasets with different types of class overlap. Extra classes can be present in any of the two datasets, and the method can even be used in the presence of unknown classes. For the first time, we demonstrate the successful use of domain adaptation on two very different observational datasets (from SDSS and DECaLS). We show that our method is capable of bridging the gap between two astronomical surveys, and also performs well for anomaly detection and clustering of unknown data in the unlabeled dataset. We apply our model to two examples of galaxy morphology classification tasks with anomaly detection: 1) classifying spiral and elliptical galaxies with detection of merging galaxies (three classes including one unknown anomaly class); 2) a more granular problem where the classes describe more detailed morphological properties of galaxies, with the detection of gravitational lenses (ten classes including one unknown anomaly class).
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在我们不断变化的气候中,使用模型来评估天气和气候对社会和企业的后续后果的风险及其后续后果至关重要。这种模型的操作在历史上是定制的,并限制在特定的计算基础架构,驱动数据集和预定义的配置上。这些约束通过缩放模型运行并将模型掌握在感兴趣的用户手中。在这里,我们提出了一个基于云的模块化框架,用于部署和操作地理空间模型,最初应用于气候影响。气候冲击建模框架(CIMF)可以以动态和灵活的方式部署模块化工作流程。用户可以以简化的方式指定工作流程组件,然后可以轻松地将这些组件组织成不同的配置,以以不同的方式和不同的尺度评估风险。这还可以使不同的模型(物理模拟或机器学习模型)和工作流程连接以产生合并的风险评估。洪水建模被用作端到端的示例,以证明CIMF的操作。
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平行操纵器的配置歧管比串行操纵器表现出更多的非线性。从定性上讲,它们可以看到额外的褶皱。通过将这种歧管投射到工程相关性的空间上,例如输出工作区或输入执行器空间,这些折叠式的边缘呈现出表现非滑动行为的边缘。例如,在五杆链接的全局工作空间边界内显示了几个局部工作空间边界,这些边界仅限于该机制的某些输出模式。当专门研究这些投影而不是配置歧管本身时,这种边界的存在在输入和输出投影中都表现出来。特别是,非对称平行操纵器的设计已被其输入和输出空间中的外来投影所困扰。在本文中,我们用半径图表示配置空间,然后通过使用同型延续来量化传输质量来解决每个边缘。然后,我们采用图路径计划器来近似于避免传输质量区域的配置点之间的大地测量。我们的方法会自动生成能够在非邻居输出模式之间过渡的路径,该运动涉及示波多个工作空间边界(局部,全局或两者)。我们将技术应用于两个非对称五杆示例,这些示例表明如何通过切换输出模式来选择工作空间的传输属性和其他特征。
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