Pandemic(epidemic) modeling, aiming at disease spreading analysis, has always been a popular research topic especially following the outbreak of COVID-19 in 2019. Some representative models including SIR-based deep learning prediction models have shown satisfactory performance. However, one major drawback for them is that they fall short in their long-term predictive ability. Although graph convolutional networks (GCN) also perform well, their edge representations do not contain complete information and it can lead to biases. Another drawback is that they usually use input features which they are unable to predict. Hence, those models are unable to predict further future. We propose a model that can propagate predictions further into the future and it has better edge representations. In particular, we model the pandemic as a spatial-temporal graph whose edges represent the transition of infections and are learned by our model. We use a two-stream framework that contains GCN and recursive structures (GRU) with an attention mechanism. Our model enables mobility analysis that provides an effective toolbox for public health researchers and policy makers to predict how different lock-down strategies that actively control mobility can influence the spread of pandemics. Experiments show that our model outperforms others in its long-term predictive power. Moreover, we simulate the effects of certain policies and predict their impacts on infection control.
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自主表面容器(ASV)代表了自动化湖泊水质监测的有前途的技术。在这项工作中,我们使用卫星图像作为粗图,并计划机器人的采样路线。但是,卫星图像与实际湖泊之间的不一致以及环境干扰(例如风,水生植被和不断变化的水位)可能使机器人难以参观先前地图建议的地方。本文提出了一种强大的路线规划算法,鉴于这些环境干扰,该算法可最大程度地减少预期的总行驶距离,从而引起地图中的不确定性。我们验证了算法在一千多个加拿大湖泊中的模拟中的功效,并在加拿大安大略省北部的一个湖泊中证明了我们在3.7 km长的现实世界机器人实验中应用算法的应用。
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基于内部语言模型估计(ILME)语言模型(LM)融合已显示出明显改善的识别结果,而识别域内和跨域语音识别任务的常规浅融合。在本文中,我们试图将ILME方法应用于跨域代码转换语音识别(CSSR)工作。具体而言,我们的好奇心来自几个方面。首先,我们很好奇基于ILME的LM融合对内域和跨域CSSR任务的有效性。我们在不合并两个代码转换域的情况下对此进行验证。更重要的是,我们通过合并两个单语言数据集训练端到端(E2E)语音识别模型,并观察到拟议的基于ILME的LM Fusion对CSSR的功效。来自东南亚和另一个中国大陆CS数据集的SEAME的实验结果证明了拟议的基于ILME的LM融合方法的有效性。
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数字医学图像的机器学习和流行的最新进展已经开辟了通过使用深卷积神经网络来解决挑战性脑肿瘤细分(BTS)任务的机会。然而,与非常广泛的RGB图像数据不同,在脑肿瘤分割中使用的医学图像数据在数据刻度方面相对稀缺,但在模态属性方面包含更丰富的信息。为此,本文提出了一种新的跨模型深度学习框架,用于从多种方式MRI数据分段脑肿瘤。核心思想是通过多模态数据挖掘丰富的模式以弥补数据量表不足。所提出的跨型号深度学习框架包括两个学习过程:跨模型特征转换(CMFT)过程和跨模型特征融合(CMFF)过程,其目的是通过跨越不同模态的知识来学习丰富的特征表示数据和融合知识分别来自不同的模态数据。在Brats基准上进行了综合实验,表明,与基线方法和最先进的方法相比,所提出的跨模型深度学习框架可以有效地提高大脑肿瘤分割性能。
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随着传感技术的进步,多元时间序列分类(MTSC)最近受到了相当大的关注。基于深度学习的MTSC技术主要依赖于卷积或经常性神经网络,主要涉及单时间序列的时间依赖性。结果,他们努力直接在多变量变量中表达成对依赖性。此外,基于图形神经网络(GNNS)的当前空间 - 时间建模(例如,图形分类)方法本质上是平的,并且不能以分层方式聚合集线器数据。为了解决这些限制,我们提出了一种基于新的图形汇集框架MTPOOL,以获得MTS的表现力全球表示。我们首先通过采用通过图形结构学习模块的相互作用来将MTS切片转换为曲线图,并通过时间卷积模块获得空间 - 时间图节点特征。为了获得全局图形级表示,我们设计了基于“编码器 - 解码器”的变形图池池模块,用于为群集分配创建自适应质心。然后我们将GNN和我们所提出的变分图层汇集层组合用于联合图表示学习和图形粗糙化,之后该图逐渐赋予一个节点。最后,可差异化的分类器将此粗糙的表示来获取最终预测的类。 10个基准数据集的实验表明MTPOOL优于MTSC任务中最先进的策略。
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Unsupervised domain adaptation (UDA) for semantic segmentation is a promising task freeing people from heavy annotation work. However, domain discrepancies in low-level image statistics and high-level contexts compromise the segmentation performance over the target domain. A key idea to tackle this problem is to perform both image-level and feature-level adaptation jointly. Unfortunately, there is a lack of such unified approaches for UDA tasks in the existing literature. This paper proposes a novel UDA pipeline for semantic segmentation that unifies image-level and feature-level adaptation. Concretely, for image-level domain shifts, we propose a global photometric alignment module and a global texture alignment module that align images in the source and target domains in terms of image-level properties. For feature-level domain shifts, we perform global manifold alignment by projecting pixel features from both domains onto the feature manifold of the source domain; and we further regularize category centers in the source domain through a category-oriented triplet loss and perform target domain consistency regularization over augmented target domain images. Experimental results demonstrate that our pipeline significantly outperforms previous methods. In the commonly tested GTA5$\rightarrow$Cityscapes task, our proposed method using Deeplab V3+ as the backbone surpasses previous SOTA by 8%, achieving 58.2% in mIoU.
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Recent advances in self-supervised learning (SSL) in computer vision are primarily comparative, whose goal is to preserve invariant and discriminative semantics in latent representations by comparing siamese image views. However, the preserved high-level semantics do not contain enough local information, which is vital in medical image analysis (e.g., image-based diagnosis and tumor segmentation). To mitigate the locality problem of comparative SSL, we propose to incorporate the task of pixel restoration for explicitly encoding more pixel-level information into high-level semantics. We also address the preservation of scale information, a powerful tool in aiding image understanding but has not drawn much attention in SSL. The resulting framework can be formulated as a multi-task optimization problem on the feature pyramid. Specifically, we conduct multi-scale pixel restoration and siamese feature comparison in the pyramid. In addition, we propose non-skip U-Net to build the feature pyramid and develop sub-crop to replace multi-crop in 3D medical imaging. The proposed unified SSL framework (PCRLv2) surpasses its self-supervised counterparts on various tasks, including brain tumor segmentation (BraTS 2018), chest pathology identification (ChestX-ray, CheXpert), pulmonary nodule detection (LUNA), and abdominal organ segmentation (LiTS), sometimes outperforming them by large margins with limited annotations.
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Learning 3D human pose prior is essential to human-centered AI. Here, we present GFPose, a versatile framework to model plausible 3D human poses for various applications. At the core of GFPose is a time-dependent score network, which estimates the gradient on each body joint and progressively denoises the perturbed 3D human pose to match a given task specification. During the denoising process, GFPose implicitly incorporates pose priors in gradients and unifies various discriminative and generative tasks in an elegant framework. Despite the simplicity, GFPose demonstrates great potential in several downstream tasks. Our experiments empirically show that 1) as a multi-hypothesis pose estimator, GFPose outperforms existing SOTAs by 20% on Human3.6M dataset. 2) as a single-hypothesis pose estimator, GFPose achieves comparable results to deterministic SOTAs, even with a vanilla backbone. 3) GFPose is able to produce diverse and realistic samples in pose denoising, completion and generation tasks. Project page https://sites.google.com/view/gfpose/
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Sequential recommendation is an important task to predict the next-item to access based on a sequence of interacted items. Most existing works learn user preference as the transition pattern from the previous item to the next one, ignoring the time interval between these two items. However, we observe that the time interval in a sequence may vary significantly different, and thus result in the ineffectiveness of user modeling due to the issue of \emph{preference drift}. In fact, we conducted an empirical study to validate this observation, and found that a sequence with uniformly distributed time interval (denoted as uniform sequence) is more beneficial for performance improvement than that with greatly varying time interval. Therefore, we propose to augment sequence data from the perspective of time interval, which is not studied in the literature. Specifically, we design five operators (Ti-Crop, Ti-Reorder, Ti-Mask, Ti-Substitute, Ti-Insert) to transform the original non-uniform sequence to uniform sequence with the consideration of variance of time intervals. Then, we devise a control strategy to execute data augmentation on item sequences in different lengths. Finally, we implement these improvements on a state-of-the-art model CoSeRec and validate our approach on four real datasets. The experimental results show that our approach reaches significantly better performance than the other 11 competing methods. Our implementation is available: https://github.com/KingGugu/TiCoSeRec.
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In this paper, we propose an end-to-end Retrieval-Augmented Visual Language Model (REVEAL) that learns to encode world knowledge into a large-scale memory, and to retrieve from it to answer knowledge-intensive queries. REVEAL consists of four key components: the memory, the encoder, the retriever and the generator. The large-scale memory encodes various sources of multimodal world knowledge (e.g. image-text pairs, question answering pairs, knowledge graph triplets, etc) via a unified encoder. The retriever finds the most relevant knowledge entries in the memory, and the generator fuses the retrieved knowledge with the input query to produce the output. A key novelty in our approach is that the memory, encoder, retriever and generator are all pre-trained end-to-end on a massive amount of data. Furthermore, our approach can use a diverse set of multimodal knowledge sources, which is shown to result in significant gains. We show that REVEAL achieves state-of-the-art results on visual question answering and image captioning.
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