Single-cell technologies are revolutionizing the entire field of biology. The large volumes of data generated by single-cell technologies are high-dimensional, sparse, heterogeneous, and have complicated dependency structures, making analyses using conventional machine learning approaches challenging and impractical. In tackling these challenges, deep learning often demonstrates superior performance compared to traditional machine learning methods. In this work, we give a comprehensive survey on deep learning in single-cell analysis. We first introduce background on single-cell technologies and their development, as well as fundamental concepts of deep learning including the most popular deep architectures. We present an overview of the single-cell analytic pipeline pursued in research applications while noting divergences due to data sources or specific applications. We then review seven popular tasks spanning through different stages of the single-cell analysis pipeline, including multimodal integration, imputation, clustering, spatial domain identification, cell-type deconvolution, cell segmentation, and cell-type annotation. Under each task, we describe the most recent developments in classical and deep learning methods and discuss their advantages and disadvantages. Deep learning tools and benchmark datasets are also summarized for each task. Finally, we discuss the future directions and the most recent challenges. This survey will serve as a reference for biologists and computer scientists, encouraging collaborations.
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多元时间序列中的异常检测在监视各种现实世界系统(例如IT系统运营或制造业)的行为方面起着重要作用。先前的方法对关节分布进行建模,而无需考虑多元时间序列的潜在机制,使它们变得复杂且饥饿。在本文中,我们从因果的角度提出异常检测问题,并将异常视为未遵循常规因果机制来生成多元数据的情况。然后,我们提出了一种基于因果关系的异常检测方法,该方法首先从数据中学习因果结构,然后渗透实例是否是相对于局部因果机制的异常,以从其直接原因产生每个变量,其条件分布可以直接估计从数据。鉴于因果系统的模块化特性,原始问题被分为一系列单独的低维异常检测问题,因此可以直接识别出异常的地方。我们通过模拟和公共数据集以及有关现实世界中AIOPS应用程序的案例研究评估我们的方法,显示其功效,鲁棒性和实际可行性。
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我们介绍了Omnixai(Omni可解释的AI缩写),这是一个可解释AI(XAI)的开源Python库,它提供了可解释的AI功能和各种可解释的机器学习技术,以解决理解和解释做出的决策的痛苦点通过机器学习(ML)实践。 Omnixai的目标是成为一个一站式综合图书馆,使数据科学家,ML研究人员和从业人员易于解释,他们需要在ML流程的不同阶段进行各种类型的数据,模型和解释方法解释(数据探索,功能工程,模型,模型,发展,评估和决策等)。特别是,我们的库包括一个集成在统一界面中的丰富的解释方法,该方法支持多种数据类型(表格数据,图像,文本,时间序列),多种类型的ML模型(Scikit-Learn中的传统ML和Deep中的传统ML) Pytorch/Tensorflow中的学习模型,以及一系列不同的解释方法,包括“模型特定”和“模型 - 敏捷”的方法(例如特征 - 属性解释,反事实说明,基于梯度的解释,基于梯度的解释等)。对于从业人员而言,图书馆提供了一个易于使用的统一界面,仅通过编写几行代码来生成其应用程序的解释,以及一个GUI仪表板,用于可视化不同的解释,以提供有关决策的更多见解。在此技术报告中,我们介绍了Omnixai的设计原理,系统体系结构和主要功能,并在不同类型的数据,任务和模型中演示了几个示例用例。
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Multi-modal fusion is a basic task of autonomous driving system perception, which has attracted many scholars' interest in recent years. The current multi-modal fusion methods mainly focus on camera data and LiDAR data, but pay little attention to the kinematic information provided by the bottom sensors of the vehicle, such as acceleration, vehicle speed, angle of rotation. These information are not affected by complex external scenes, so it is more robust and reliable. In this paper, we introduce the existing application fields of vehicle bottom information and the research progress of related methods, as well as the multi-modal fusion methods based on bottom information. We also introduced the relevant information of the vehicle bottom information data set in detail to facilitate the research as soon as possible. In addition, new future ideas of multi-modal fusion technology for autonomous driving tasks are proposed to promote the further utilization of vehicle bottom information.
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当没有光学信息可用时,在不确定环境下的机器人探索具有挑战性。在本文中,我们提出了一种自主解决方案,即仅基于触觉感测,探索一个未知的任务空间。我们首先根据MEMS晴雨表设备设计了晶须传感器。该传感器可以通过非侵入性与环境进行交互来获取联系信息。该传感器伴随着一种计划技术,可以通过使用触觉感知来产生探索轨迹。该技术依赖于触觉探索的混合政策,其中包括用于对象搜索的主动信息路径计划,以及用于轮廓跟踪的反应性HOPF振荡器。结果表明,混合勘探政策可以提高对象发现的效率。最后,通过细分对象和分类来促进场景的理解。开发了一个分类器,以根据晶须传感器收集的几何特征识别对象类别。这种方法证明了晶须传感器以及触觉智能,可以提供足够的判别特征来区分对象。
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Dataset distillation has emerged as a prominent technique to improve data efficiency when training machine learning models. It encapsulates the knowledge from a large dataset into a smaller synthetic dataset. A model trained on this smaller distilled dataset can attain comparable performance to a model trained on the original training dataset. However, the existing dataset distillation techniques mainly aim at achieving the best trade-off between resource usage efficiency and model utility. The security risks stemming from them have not been explored. This study performs the first backdoor attack against the models trained on the data distilled by dataset distillation models in the image domain. Concretely, we inject triggers into the synthetic data during the distillation procedure rather than during the model training stage, where all previous attacks are performed. We propose two types of backdoor attacks, namely NAIVEATTACK and DOORPING. NAIVEATTACK simply adds triggers to the raw data at the initial distillation phase, while DOORPING iteratively updates the triggers during the entire distillation procedure. We conduct extensive evaluations on multiple datasets, architectures, and dataset distillation techniques. Empirical evaluation shows that NAIVEATTACK achieves decent attack success rate (ASR) scores in some cases, while DOORPING reaches higher ASR scores (close to 1.0) in all cases. Furthermore, we conduct a comprehensive ablation study to analyze the factors that may affect the attack performance. Finally, we evaluate multiple defense mechanisms against our backdoor attacks and show that our attacks can practically circumvent these defense mechanisms.
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Blind image quality assessment (BIQA) remains challenging due to the diversity of distortion and image content variation, which complicate the distortion patterns crossing different scales and aggravate the difficulty of the regression problem for BIQA. However, existing BIQA methods often fail to consider multi-scale distortion patterns and image content, and little research has been done on learning strategies to make the regression model produce better performance. In this paper, we propose a simple yet effective Progressive Multi-Task Image Quality Assessment (PMT-IQA) model, which contains a multi-scale feature extraction module (MS) and a progressive multi-task learning module (PMT), to help the model learn complex distortion patterns and better optimize the regression issue to align with the law of human learning process from easy to hard. To verify the effectiveness of the proposed PMT-IQA model, we conduct experiments on four widely used public datasets, and the experimental results indicate that the performance of PMT-IQA is superior to the comparison approaches, and both MS and PMT modules improve the model's performance.
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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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Given the increasingly intricate forms of partial differential equations (PDEs) in physics and related fields, computationally solving PDEs without analytic solutions inevitably suffers from the trade-off between accuracy and efficiency. Recent advances in neural operators, a kind of mesh-independent neural-network-based PDE solvers, have suggested the dawn of overcoming this challenge. In this emerging direction, Koopman neural operator (KNO) is a representative demonstration and outperforms other state-of-the-art alternatives in terms of accuracy and efficiency. Here we present KoopmanLab, a self-contained and user-friendly PyTorch module of the Koopman neural operator family for solving partial differential equations. Beyond the original version of KNO, we develop multiple new variants of KNO based on different neural network architectures to improve the general applicability of our module. These variants are validated by mesh-independent and long-term prediction experiments implemented on representative PDEs (e.g., the Navier-Stokes equation and the Bateman-Burgers equation) and ERA5 (i.e., one of the largest high-resolution data sets of global-scale climate fields). These demonstrations suggest the potential of KoopmanLab to be considered in diverse applications of partial differential equations.
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A recent study has shown a phenomenon called neural collapse in that the within-class means of features and the classifier weight vectors converge to the vertices of a simplex equiangular tight frame at the terminal phase of training for classification. In this paper, we explore the corresponding structures of the last-layer feature centers and classifiers in semantic segmentation. Based on our empirical and theoretical analysis, we point out that semantic segmentation naturally brings contextual correlation and imbalanced distribution among classes, which breaks the equiangular and maximally separated structure of neural collapse for both feature centers and classifiers. However, such a symmetric structure is beneficial to discrimination for the minor classes. To preserve these advantages, we introduce a regularizer on feature centers to encourage the network to learn features closer to the appealing structure in imbalanced semantic segmentation. Experimental results show that our method can bring significant improvements on both 2D and 3D semantic segmentation benchmarks. Moreover, our method ranks 1st and sets a new record (+6.8% mIoU) on the ScanNet200 test leaderboard. Code will be available at https://github.com/dvlab-research/Imbalanced-Learning.
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