评估网络协议的真实表现是具有挑战性的。随机控制试验(RCT)对大多数研究人员来说是昂贵的并且无法进入,而专业设计的模拟器则无法捕获真实网络中的复杂行为。我们呈现MaunAlim,一种数据驱动的模拟器,用于解决这一挑战的网络协议。由于数据收集期间使用的协议引入的偏差,从观察数据中学习网络行为是复杂的。 MakAlAIM在一组协议下使用来自初始RCT的迹线来学习因果网络模型,有效地去除数据中存在的偏差。然后,使用此模型,可以在同一迹线上模拟任何协议(即,用于反事实预测)。因果的关键是对来自来自RCT的训练数据引起的分布修正因的对抗性神经网络培训进行了新的使用。我们对实际和合成数据集的MAURALAIM的广泛评估以及来自河豚视频流系统的两种用例,包括来自河豚视频流系统的超过九个月的实际数据,表明它提供了准确的反事预测,将预测误差降低了44%和53%平均值与专家设计和标准的监督学习基线相比。
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即使是最精确的经济数据集也具有嘈杂,丢失,离散化或私有化的变量。实证研究的标准工作流程涉及数据清理,然后是数据分析,通常忽略数据清洁的偏差和方差后果。我们制定了具有损坏数据的因果推理的半造型模型,以包括数据清洁和数据分析。我们提出了一种新的数据清洁,估计和推理的新的端到端程序,以及数据清洁调整的置信区间。通过有限的示例参数,我们证明了因果关系参数的估算器的一致性,高斯近似和半游戏效率。 Gaussian近似的速率为N ^ { - 1/2} $,如平均治疗效果,如平均治疗效果,并且优雅地为当地参数劣化,例如特定人口统计的异构治疗效果。我们的关键假设是真正的协变量是较低的等级。在我们的分析中,我们为矩阵完成,统计学习和半统计统计提供了非对症的理论贡献。我们验证了数据清洁调整的置信区间隔的覆盖范围校准,以类似于2020年美国人口普查中实施的差异隐私。
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我们考虑在严重数据稀缺下具有异质代理的离线强化学习(RL),即,我们只观察一个未知潜在的次优政策下的每个代理的单一历史轨迹。我们发现,即使对于常见的“解决”基准设置(如“Makescar”和“Cartpole”),我们发现最先进的离线和基于模型的RL方法的性能显着降低了显着的数据可用性。为了解决这一挑战,我们提出了一种基于模型的离线RL方法,该方法首先通过在学习政策之前共同使用所有代理商的历史轨迹来学习每个代理的个性化模拟器。我们这样做是这样做的,指出代理商的过渡动态可以表示为与代理商,州和行动相关的潜在因子的潜在函数;随后,理论上,理论上建立了这种函数通过可分离代理,状态和动作潜在函数的“低级”分解良好地近似。此表示表明,一个简单的正则化的神经网络架构,以有效地学习每个代理的过渡动态,即使具有稀缺,离线数据。我们在多个基准环境和RL方法中执行大量实验。我们的方法的一致性提高,在国家动态预测和最终奖励方面衡量,确认了我们框架在利用有限的历史数据方面的效力,以同时学习跨代理商的个性化政策。
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我们在具有固定设计的高维错误设置中分析主组件回归(PCR)。在适当的条件下,我们表明PCR始终以最小$ \ ell_2 $ -norm识别唯一模型,并且是最小的最佳模型。这些结果使我们能够建立非质子化的样本外预测,以确保提高最著名的速率。在我们的分析中,我们在样本外协变量之间引入了天然的线性代数条件,这使我们能够避免分布假设。我们的模拟说明了即使在协变量转移的情况下,这种条件对于概括的重要性。作为副产品,我们的结果还导致了合成控制文献的新结果,这是政策评估的主要方法。特别是,我们的minimax结果表明,在众多变体中,基于PCR的方法具有吸引力。据我们所知,我们对固定设计设置的预测保证在高维错误和合成控制文献中都是难以捉摸的。
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我们介绍和分析了多元奇异频谱分析(MSSA)的变体,这是一种流行的时间序列方法,用于启用和预测多元时间序列。在我们介绍的时空因素模型下,给定$ n $时间序列和$ t $观测时间序列,我们为插补和样本外预测均有效地扩展为$ 1 / \ sqrt,为预测和样本预测有效地缩放均值{\ min(n,t)t} $。这是一个改进:(i)$ 1 /\ sqrt {t} $ SSA的错误缩放,MSSA限制对单变量时间序列; (ii)$ 1/\ min(n,t)$对于不利用数据中时间结构的矩阵估计方法的错误缩放。我们引入的时空模型包括:谐波,多项式,可区分的周期函数和持有人连续函数的任何有限总和和产物。在时空因素模型下,我们的样本外预测结果可能对在线学习具有独立的兴趣。从经验上讲,在基准数据集上,我们的MSSA变体通过最先进的神经网络时间序列方法(例如,DEEPAR,LSTM)竞争性能,并且明显优于诸如矢量自动化(VAR)之类的经典方法。最后,我们提出了MSSA的扩展:(i)估计时间序列的时变差异的变体; (ii)一种张量变体,对于$ n $和$ t $的某些制度具有更好的样本复杂性。
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We introduce Argoverse 2 (AV2) - a collection of three datasets for perception and forecasting research in the self-driving domain. The annotated Sensor Dataset contains 1,000 sequences of multimodal data, encompassing high-resolution imagery from seven ring cameras, and two stereo cameras in addition to lidar point clouds, and 6-DOF map-aligned pose. Sequences contain 3D cuboid annotations for 26 object categories, all of which are sufficiently-sampled to support training and evaluation of 3D perception models. The Lidar Dataset contains 20,000 sequences of unlabeled lidar point clouds and map-aligned pose. This dataset is the largest ever collection of lidar sensor data and supports self-supervised learning and the emerging task of point cloud forecasting. Finally, the Motion Forecasting Dataset contains 250,000 scenarios mined for interesting and challenging interactions between the autonomous vehicle and other actors in each local scene. Models are tasked with the prediction of future motion for "scored actors" in each scenario and are provided with track histories that capture object location, heading, velocity, and category. In all three datasets, each scenario contains its own HD Map with 3D lane and crosswalk geometry - sourced from data captured in six distinct cities. We believe these datasets will support new and existing machine learning research problems in ways that existing datasets do not. All datasets are released under the CC BY-NC-SA 4.0 license.
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Parkinson's disease is marked by altered and increased firing characteristics of pathological oscillations in the brain. In other words, it causes abnormal synchronous oscillations and suppression during neurological processing. In order to examine and regulate the synchronization and pathological oscillations in motor circuits, deep brain stimulators (DBS) are used. Although machine learning methods have been applied for the investigation of suppression, these models require large amounts of training data and computational power, both of which pose challenges to resource-constrained DBS. This research proposes a novel reinforcement learning (RL) framework for suppressing the synchronization in neuronal activity during episodes of neurological disorders with less power consumption. The proposed RL algorithm comprises an ensemble of a temporal representation of stimuli and a twin-delayed deep deterministic (TD3) policy gradient algorithm. We quantify the stability of the proposed framework to noise and reduced synchrony using RL for three pathological signaling regimes: regular, chaotic, and bursting, and further eliminate the undesirable oscillations. Furthermore, metrics such as evaluation rewards, energy supplied to the ensemble, and the mean point of convergence were used and compared to other RL algorithms, specifically the Advantage actor critic (A2C), the Actor critic with Kronecker-featured trust region (ACKTR), and the Proximal policy optimization (PPO).
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Problem statement: Standardisation of AI fairness rules and benchmarks is challenging because AI fairness and other ethical requirements depend on multiple factors such as context, use case, type of the AI system, and so on. In this paper, we elaborate that the AI system is prone to biases at every stage of its lifecycle, from inception to its usage, and that all stages require due attention for mitigating AI bias. We need a standardised approach to handle AI fairness at every stage. Gap analysis: While AI fairness is a hot research topic, a holistic strategy for AI fairness is generally missing. Most researchers focus only on a few facets of AI model-building. Peer review shows excessive focus on biases in the datasets, fairness metrics, and algorithmic bias. In the process, other aspects affecting AI fairness get ignored. The solution proposed: We propose a comprehensive approach in the form of a novel seven-layer model, inspired by the Open System Interconnection (OSI) model, to standardise AI fairness handling. Despite the differences in the various aspects, most AI systems have similar model-building stages. The proposed model splits the AI system lifecycle into seven abstraction layers, each corresponding to a well-defined AI model-building or usage stage. We also provide checklists for each layer and deliberate on potential sources of bias in each layer and their mitigation methodologies. This work will facilitate layer-wise standardisation of AI fairness rules and benchmarking parameters.
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Supervised approaches generally rely on majority-based labels. However, it is hard to achieve high agreement among annotators in subjective tasks such as hate speech detection. Existing neural network models principally regard labels as categorical variables, while ignoring the semantic information in diverse label texts. In this paper, we propose AnnoBERT, a first-of-its-kind architecture integrating annotator characteristics and label text with a transformer-based model to detect hate speech, with unique representations based on each annotator's characteristics via Collaborative Topic Regression (CTR) and integrate label text to enrich textual representations. During training, the model associates annotators with their label choices given a piece of text; during evaluation, when label information is not available, the model predicts the aggregated label given by the participating annotators by utilising the learnt association. The proposed approach displayed an advantage in detecting hate speech, especially in the minority class and edge cases with annotator disagreement. Improvement in the overall performance is the largest when the dataset is more label-imbalanced, suggesting its practical value in identifying real-world hate speech, as the volume of hate speech in-the-wild is extremely small on social media, when compared with normal (non-hate) speech. Through ablation studies, we show the relative contributions of annotator embeddings and label text to the model performance, and tested a range of alternative annotator embeddings and label text combinations.
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Dense retrievers have made significant strides in obtaining state-of-the-art results on text retrieval and open-domain question answering (ODQA). Yet most of these achievements were made possible with the help of large annotated datasets, unsupervised learning for dense retrieval models remains an open problem. In this work, we explore two categories of methods for creating pseudo query-document pairs, named query extraction (QExt) and transferred query generation (TQGen), to augment the retriever training in an annotation-free and scalable manner. Specifically, QExt extracts pseudo queries by document structures or selecting salient random spans, and TQGen utilizes generation models trained for other NLP tasks (e.g., summarization) to produce pseudo queries. Extensive experiments show that dense retrievers trained with individual augmentation methods can perform comparably well with multiple strong baselines, and combining them leads to further improvements, achieving state-of-the-art performance of unsupervised dense retrieval on both BEIR and ODQA datasets.
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