用于图像分割的深卷卷卷神经网络不会明确学习标签结构,并且可能会在类似树状结构(例如气道或血管)分割的圆柱形结构中产生不正确的结构(例如,具有断开的圆柱形结构)的分割。在本文中,我们提出了一种新型的标签改进方法,以从初始分割中纠正此类错误,并隐含地包含有关标签结构的信息。该方法具有两个新颖的部分:1)生成合成结构误差的模型,以及2)产生合成分割(带有误差)的标签外观仿真网络,其外观与实际初始分段相似。使用这些合成分割和原始图像,对标签改进网络进行了训练,以纠正错误并改善初始分割。该方法对两个分割任务进行了验证:来自胸部计算机断层扫描(CT)扫描和大脑3D CT血管造影(CTA)图像的脑血管分割的气道分割。在这两种应用中,我们的方法都大大优于标准的3D U-NET和其他先前的改进方法。当使用其他未标记的数据进行模型培训时,改进甚至更大。在消融研究中,我们证明了所提出方法的不同组成部分的值。
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对应匹配是计算机视觉和机器人技术应用中的一个基本问题。最近使用神经网络解决对应匹配问题最近正在上升。旋转等级和比例等级性在对应匹配应用中都至关重要。经典的对应匹配方法旨在承受缩放和旋转转换。但是,使用卷积神经网络(CNN)提取的功能仅在一定程度上是翻译等值的。最近,研究人员一直在努力改善基于群体理论的CNN的旋转均衡性。 SIM(2)是2D平面中的相似性转换组。本文介绍了专门用于评估SIM(2) - 等级对应算法的专门数据集。我们比较了16个最先进(SOTA)对应匹配方法的性能。实验结果表明,在各种SIM(2)转换条件下,组模棱两可算法对于对应匹配的重要性。由于基于CNN的对应匹配方法达到的子像素精度不令人满意,因此该特定领域需要在未来的工作中获得更多关注。我们的数据集可公开可用:mias.group/sim2e。
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脑小血管疾病的成像标记提供了有关脑部健康的宝贵信息,但是它们的手动评估既耗时又受到实质性内部和间际变异性的阻碍。自动化评级可能受益于生物医学研究以及临床评估,但是现有算法的诊断可靠性尚不清楚。在这里,我们介绍了\ textIt {血管病变检测和分割}(\ textit {v textit {where valdo?})挑战,该挑战是在国际医学图像计算和计算机辅助干预措施(MICCAI)的卫星事件中运行的挑战(MICCAI) 2021.这一挑战旨在促进大脑小血管疾病的小而稀疏成像标记的自动检测和分割方法的开发,即周围空间扩大(EPVS)(任务1),脑微粒(任务2)和预先塑造的鞋类血管起源(任务3),同时利用弱和嘈杂的标签。总体而言,有12个团队参与了针对一个或多个任务的解决方案的挑战(任务1 -EPVS 4,任务2 -Microbleeds的9个,任务3 -lacunes的6个)。多方数据都用于培训和评估。结果表明,整个团队和跨任务的性能都有很大的差异,对于任务1- EPV和任务2-微型微型且对任务3 -lacunes尚无实际的结果,其结果尤其有望。它还强调了可能阻止个人级别使用的情况的性能不一致,同时仍证明在人群层面上有用。
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“搜索”或“导航到”?当找到一个物体时,这两个选择总是在我们的潜意识中出现。在看到目标之前,我们根据经验搜索目标。看到目标后,我们记住目标位置并导航到。但是,最近在对象导航字段中的方法几乎仅考虑使用对象关联来增强“搜索”阶段,同时忽略了“导航到”阶段的重要性。因此,本文提出了双重自适应思维(DAT)方法,以灵活调整不同导航阶段的不同思维策略。双重思考包括具有目标位置能力的对象关联能力和导航思维的搜索思维。为了使导航思维更有效,我们设计了面向目标的内存图(TOMG)来存储历史目标信息和目标感知的多规模聚合器(TAMSA)以编码相对目标位置。我们在AI2-数据集上评估我们的方法。与最先进的方法(SOTA)方法相比,我们的方法报告成功率10.8%,21.5%和15.7%(SR),成功按路径长度(SPL)加权(SPL)和成功通过导航效率加权(SNE) ), 分别。
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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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For Prognostics and Health Management (PHM) of Lithium-ion (Li-ion) batteries, many models have been established to characterize their degradation process. The existing empirical or physical models can reveal important information regarding the degradation dynamics. However, there is no general and flexible methods to fuse the information represented by those models. Physics-Informed Neural Network (PINN) is an efficient tool to fuse empirical or physical dynamic models with data-driven models. To take full advantage of various information sources, we propose a model fusion scheme based on PINN. It is implemented by developing a semi-empirical semi-physical Partial Differential Equation (PDE) to model the degradation dynamics of Li-ion-batteries. When there is little prior knowledge about the dynamics, we leverage the data-driven Deep Hidden Physics Model (DeepHPM) to discover the underlying governing dynamic models. The uncovered dynamics information is then fused with that mined by the surrogate neural network in the PINN framework. Moreover, an uncertainty-based adaptive weighting method is employed to balance the multiple learning tasks when training the PINN. The proposed methods are verified on a public dataset of Li-ion Phosphate (LFP)/graphite batteries.
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Hybrid unmanned aerial vehicles (UAVs) integrate the efficient forward flight of fixed-wing and vertical takeoff and landing (VTOL) capabilities of multicopter UAVs. This paper presents the modeling, control and simulation of a new type of hybrid micro-small UAVs, coined as lifting-wing quadcopters. The airframe orientation of the lifting wing needs to tilt a specific angle often within $ 45$ degrees, neither nearly $ 90$ nor approximately $ 0$ degrees. Compared with some convertiplane and tail-sitter UAVs, the lifting-wing quadcopter has a highly reliable structure, robust wind resistance, low cruise speed and reliable transition flight, making it potential to work fully-autonomous outdoor or some confined airspace indoor. In the modeling part, forces and moments generated by both lifting wing and rotors are considered. Based on the established model, a unified controller for the full flight phase is designed. The controller has the capability of uniformly treating the hovering and forward flight, and enables a continuous transition between two modes, depending on the velocity command. What is more, by taking rotor thrust and aerodynamic force under consideration simultaneously, a control allocation based on optimization is utilized to realize cooperative control for energy saving. Finally, comprehensive Hardware-In-the-Loop (HIL) simulations are performed to verify the advantages of the designed aircraft and the proposed controller.
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Through a study of multi-gas mixture datasets, we show that in multi-component spectral analysis, the number of functional or non-functional principal components required to retain the essential information is the same as the number of independent constituents in the mixture set. Due to the mutual in-dependency among different gas molecules, near one-to-one projection from the principal component to the mixture constituent can be established, leading to a significant simplification of spectral quantification. Further, with the knowledge of the molar extinction coefficients of each constituent, a complete principal component set can be extracted from the coefficients directly, and few to none training samples are required for the learning model. Compared to other approaches, the proposed methods provide fast and accurate spectral quantification solutions with a small memory size needed.
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Participants in political discourse employ rhetorical strategies -- such as hedging, attributions, or denials -- to display varying degrees of belief commitments to claims proposed by themselves or others. Traditionally, political scientists have studied these epistemic phenomena through labor-intensive manual content analysis. We propose to help automate such work through epistemic stance prediction, drawn from research in computational semantics, to distinguish at the clausal level what is asserted, denied, or only ambivalently suggested by the author or other mentioned entities (belief holders). We first develop a simple RoBERTa-based model for multi-source stance predictions that outperforms more complex state-of-the-art modeling. Then we demonstrate its novel application to political science by conducting a large-scale analysis of the Mass Market Manifestos corpus of U.S. political opinion books, where we characterize trends in cited belief holders -- respected allies and opposed bogeymen -- across U.S. political ideologies.
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While inferring common actor states (such as position or velocity) is an important and well-explored task of the perception system aboard a self-driving vehicle (SDV), it may not always provide sufficient information to the SDV. This is especially true in the case of active emergency vehicles (EVs), where light-based signals also need to be captured to provide a full context. We consider this problem and propose a sequential methodology for the detection of active EVs, using an off-the-shelf CNN model operating at a frame level and a downstream smoother that accounts for the temporal aspect of flashing EV lights. We also explore model improvements through data augmentation and training with additional hard samples.
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