分析学习算法的挑战之一是客观值和随机噪声之间的循环纠缠。这也被称为“鸡肉和鸡蛋”现象,传统上,没有原则解决这个问题的方法。人们通过利用动态的特殊结构来解决问题,因此很难概括分析。在这项工作中,我们提出了一个简化的三步食谱,以解决“鸡肉和鸡蛋”问题,并为分析学习算法的随机动力学提供了一般框架。我们的框架构成了概率理论的标准技术,例如停止时间和Martingale浓度。我们通过对三个截然不同的学习问题进行统一分析,并具有强大的统一高概率收敛保证,从而证明了我们框架的力量和灵活性。这些问题是强烈凸功能,流主成分分析和带有随机梯度下降更新的线性匪徒的随机梯度下降。我们要么在所有三个动态上都改进或匹配最新界限。
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联合学习(FL),其中多个机构在不共享数据的情况下协作训练机器学习模型正在变得流行。参与机构可能不会平等地做出贡献,有些贡献了更多的数据,一些更好的质量数据或一些更多样化的数据。为了公平地排名不同机构的贡献,沙普利价值(SV)已成为选择方法。精确的SV计算非常昂贵,尤其是在有数百个贡献者的情况下。现有的SV计算技术使用近似值。但是,在医疗保健中,贡献机构的数量可能不是巨大的规模,计算精确的SVS仍然很昂贵,但并非不可能。对于此类设置,我们提出了一种称为Safe的高效SV计算技术(用于使用Enembly的联合学习的Shapley值)。我们从经验上表明,安全计算接近精确SV的值,并且其性能优于当前SV近似值。这在医学成像环境中尤其重要,在医学成像环境中,整个机构之间的广泛异质性猖ramp,并且需要快速准确的数据评估来确定每个参与者在多机构协作学习中的贡献。
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本文提出了一种新型的固定时间积分滑动模式控制器,以用于增强物理人类机器人协作。所提出的方法结合了遵守入学控制的外部力量和对整体滑动模式控制(ISMC)不确定性的高度鲁棒性的好处,从而使系统可以在不确定的环境中与人类伴侣合作。首先,在ISMC中应用固定时间滑动表面,以使系统的跟踪误差在固定时间内收敛,无论初始条件如何。然后,将固定的后台控制器(BSP)集成到ISMC中,作为标称控制器,以实现全局固定时间收敛。此外,为了克服奇异性问题,设计并集成到控制器中,这对于实际应用很有用。最后,提出的控制器已被验证,用于具有不确定性和外部力量的两连锁机器人操纵器。结果表明,在跟踪误差和收敛时间的意义上,所提出的控制器是优越的,同时,可以在共享工作区中遵守人类运动。
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身体机器人的合作需要严格的安全保证,因为机器人和人类在共享工作区中工作。这封信提出了一个新颖的控制框架,以处理针对人类机器人互动的基于安全至关重要的位置的约束。所提出的方法基于入学控制,指数控制屏障功能(ECBF)和二次计划(QP),以在人与机器人之间的力相互作用期间达到合规性,同时保证安全约束。特别是,入学控制的配方被重写为二阶非线性控制系统,并且人与机器人之间的相互作用力被视为控制输入。通过使用欧洲央行-QP框架作为外部人类力量的补偿器,实时提供了用于入学控制的虚拟力反馈。因此,安全轨迹是从建议的低级控制器进行跟踪的建议的自适应入学控制方案中得出的。拟议方法的创新是,拟议的控制器将使机器人能够自然流动性遵守人类力量,而无需违反任何安全限制,即使在人类外部力量偶然迫使机器人违反约束的情况下。在对两链平面机器人操纵器的仿真研究中,我们的方法的有效性得到了证明。
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In this paper, we propose a robust 3D detector, named Cross Modal Transformer (CMT), for end-to-end 3D multi-modal detection. Without explicit view transformation, CMT takes the image and point clouds tokens as inputs and directly outputs accurate 3D bounding boxes. The spatial alignment of multi-modal tokens is performed implicitly, by encoding the 3D points into multi-modal features. The core design of CMT is quite simple while its performance is impressive. CMT obtains 73.0% NDS on nuScenes benchmark. Moreover, CMT has a strong robustness even if the LiDAR is missing. Code will be released at https://github.com/junjie18/CMT.
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Knowledge graphs (KG) have served as the key component of various natural language processing applications. Commonsense knowledge graphs (CKG) are a special type of KG, where entities and relations are composed of free-form text. However, previous works in KG completion and CKG completion suffer from long-tail relations and newly-added relations which do not have many know triples for training. In light of this, few-shot KG completion (FKGC), which requires the strengths of graph representation learning and few-shot learning, has been proposed to challenge the problem of limited annotated data. In this paper, we comprehensively survey previous attempts on such tasks in the form of a series of methods and applications. Specifically, we first introduce FKGC challenges, commonly used KGs, and CKGs. Then we systematically categorize and summarize existing works in terms of the type of KGs and the methods. Finally, we present applications of FKGC models on prediction tasks in different areas and share our thoughts on future research directions of FKGC.
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Few Shot Instance Segmentation (FSIS) requires models to detect and segment novel classes with limited several support examples. In this work, we explore a simple yet unified solution for FSIS as well as its incremental variants, and introduce a new framework named Reference Twice (RefT) to fully explore the relationship between support/query features based on a Transformer-like framework. Our key insights are two folds: Firstly, with the aid of support masks, we can generate dynamic class centers more appropriately to re-weight query features. Secondly, we find that support object queries have already encoded key factors after base training. In this way, the query features can be enhanced twice from two aspects, i.e., feature-level and instance-level. In particular, we firstly design a mask-based dynamic weighting module to enhance support features and then propose to link object queries for better calibration via cross-attention. After the above steps, the novel classes can be improved significantly over our strong baseline. Additionally, our new framework can be easily extended to incremental FSIS with minor modification. When benchmarking results on the COCO dataset for FSIS, gFSIS, and iFSIS settings, our method achieves a competitive performance compared to existing approaches across different shots, e.g., we boost nAP by noticeable +8.2/+9.4 over the current state-of-the-art FSIS method for 10/30-shot. We further demonstrate the superiority of our approach on Few Shot Object Detection. Code and model will be available.
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Graph Neural Networks (GNNs) have shown satisfying performance on various graph learning tasks. To achieve better fitting capability, most GNNs are with a large number of parameters, which makes these GNNs computationally expensive. Therefore, it is difficult to deploy them onto edge devices with scarce computational resources, e.g., mobile phones and wearable smart devices. Knowledge Distillation (KD) is a common solution to compress GNNs, where a light-weighted model (i.e., the student model) is encouraged to mimic the behavior of a computationally expensive GNN (i.e., the teacher GNN model). Nevertheless, most existing GNN-based KD methods lack fairness consideration. As a consequence, the student model usually inherits and even exaggerates the bias from the teacher GNN. To handle such a problem, we take initial steps towards fair knowledge distillation for GNNs. Specifically, we first formulate a novel problem of fair knowledge distillation for GNN-based teacher-student frameworks. Then we propose a principled framework named RELIANT to mitigate the bias exhibited by the student model. Notably, the design of RELIANT is decoupled from any specific teacher and student model structures, and thus can be easily adapted to various GNN-based KD frameworks. We perform extensive experiments on multiple real-world datasets, which corroborates that RELIANT achieves less biased GNN knowledge distillation while maintaining high prediction utility.
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This paper focuses on designing efficient models with low parameters and FLOPs for dense predictions. Even though CNN-based lightweight methods have achieved stunning results after years of research, trading-off model accuracy and constrained resources still need further improvements. This work rethinks the essential unity of efficient Inverted Residual Block in MobileNetv2 and effective Transformer in ViT, inductively abstracting a general concept of Meta-Mobile Block, and we argue that the specific instantiation is very important to model performance though sharing the same framework. Motivated by this phenomenon, we deduce a simple yet efficient modern \textbf{I}nverted \textbf{R}esidual \textbf{M}obile \textbf{B}lock (iRMB) for mobile applications, which absorbs CNN-like efficiency to model short-distance dependency and Transformer-like dynamic modeling capability to learn long-distance interactions. Furthermore, we design a ResNet-like 4-phase \textbf{E}fficient \textbf{MO}del (EMO) based only on a series of iRMBs for dense applications. Massive experiments on ImageNet-1K, COCO2017, and ADE20K benchmarks demonstrate the superiority of our EMO over state-of-the-art methods, \eg, our EMO-1M/2M/5M achieve 71.5, 75.1, and 78.4 Top-1 that surpass \textbf{SoTA} CNN-/Transformer-based models, while trading-off the model accuracy and efficiency well.
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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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