多变量时间序列(MTS)预测在智能应用的自动化和优化中起着重要作用。这是一个具有挑战性的任务,因为我们需要考虑复杂的变量依赖关系和可变间依赖关系。现有的作品仅在单个可变依赖项的帮助下学习时间模式。然而,许多真实世界MTS中有多种时间模式。单个可变间依赖项使模型更倾向于学习一种类型的突出和共享的时间模式。在本文中,我们提出了一个多尺度自适应图形神经网络(MOLDN)来解决上述问题。 MOLDN利用多尺度金字塔网络,以在不同的时间尺度上保留潜在的时间依赖关系。由于可变间依赖关系可以在不同的时间尺度下不同,所以自适应图学习模块被设计为在没有预先定义的前沿的情况下推断规模特定的可变依赖关系。鉴于多尺度特征表示和规模特定的可变间依赖关系,引入了一个多尺度的时间图神经网络,以共同模拟帧内依赖性和可变间依赖性。之后,我们开发一个尺度明智的融合模块,以在不同时间尺度上有效地促进协作,并自动捕获贡献的时间模式的重要性。四个真实数据集的实验表明,Magnn在各种设置上表明了最先进的方法。
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多变量时间序列(MTS)预测在许多智能应用中引起了很多关注。它不是一个琐碎的任务,因为我们需要考虑一个可变的依赖关系和可变间依赖关系。但是,现有的作品是针对特定场景设计的,需要很多域知识和专家努力,这难以在不同的场景之间传输。在本文中,我们提出了一种尺度意识的神经结构,用于MTS预测(SNAS4MTF)的搜索框架。多尺度分解模块将原始时间序列转换为多尺度子系列,可以保留多尺度的时间模式。自适应图形学习模块在没有任何先前知识的情况下,在不同的时间尺度下递送不同的变量间依赖关系。对于MTS预测,搜索空间旨在在每次尺度上捕获可变的可变依赖性和可变间依赖关系。在端到端框架中共同学习多尺度分解,自适应图学习和神经架构搜索模块。两个现实世界数据集的大量实验表明,与最先进的方法相比,SNAS4MTF实现了有希望的性能。
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从一个非常少数标记的样品中学习新颖的课程引起了机器学习区域的越来越高。最近关于基于元学习或转移学习的基于范例的研究表明,良好特征空间的获取信息可以是在几次拍摄任务上实现有利性能的有效解决方案。在本文中,我们提出了一种简单但有效的范式,该范式解耦了学习特征表示和分类器的任务,并且只能通过典型的传送学习培训策略从基类嵌入体系结构的特征。为了在每个类别内保持跨基地和新类别和辨别能力的泛化能力,我们提出了一种双路径特征学习方案,其有效地结合了与对比特征结构的结构相似性。以这种方式,内部级别对齐和级别的均匀性可以很好地平衡,并且导致性能提高。三个流行基准测试的实验表明,当与简单的基于原型的分类器结合起来时,我们的方法仍然可以在电感或转换推理设置中的标准和广义的几次射击问题达到有希望的结果。
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传统的检测网络通常需要丰富的标记训练样本,而人类可以只有几个例子逐步学习新概念。本文侧重于更具挑战性,而是逼真的类渐进的少量对象检测问题(IFSD)。它旨在逐渐逐渐地将新型对象的模型转移到几个注释的样本中,而不会灾难性地忘记先前学识的样本。为了解决这个问题,我们提出了一种新的方法,最小的方法可以减少遗忘,更少的培训资源和更强的转移能力。具体而言,我们首先介绍转移策略,以减少不必要的重量适应并改善IFSD的传输能力。在此基础上,我们使用较少的资源消耗方法整合知识蒸馏技术来缓解遗忘,并提出基于新的基于聚类的示例选择过程,以保持先前学习的更多辨别特征。作为通用且有效的方法,最多可以在很大程度上提高各种基准测试的IFSD性能。
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许多应用程序需要在许多系统性能指标上收集不同变量或测量的数据。我们将这些措施或变量广泛地术语。沿着每种测量的数据收集通常会引发成本,因此希望考虑建模中的措施成本。这是成本敏感学习领域的一个相当新的问题。已经尝试结合和选择措施来纳入成本。然而,现有的研究要么不严格执行预算限制,或者不是“大多数人”的成本效益。随着专注于分类问题,我们提出了一种计算有效的方法,可以通过探索解决空间的最多的“有希望”部分来找到给定预算下的近最佳模式。我们而不是输出单个模型,我们生成模型计划 - 通过模型成本和预期预测精度排序的模型列表。这可用于在给定预算下选择具有最佳预测准确性的模型,或在预算和预测准确性之间进行换算。在一些基准数据集上的实验表明,我们的方法对竞争方法有利地进行了比较。
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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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