Adversarial machine learning has been both a major concern and a hot topic recently, especially with the ubiquitous use of deep neural networks in the current landscape. Adversarial attacks and defenses are usually likened to a cat-and-mouse game in which defenders and attackers evolve over the time. On one hand, the goal is to develop strong and robust deep networks that are resistant to malicious actors. On the other hand, in order to achieve that, we need to devise even stronger adversarial attacks to challenge these defense models. Most of existing attacks employs a single $\ell_p$ distance (commonly, $p\in\{1,2,\infty\}$) to define the concept of closeness and performs steepest gradient ascent w.r.t. this $p$-norm to update all pixels in an adversarial example in the same way. These $\ell_p$ attacks each has its own pros and cons; and there is no single attack that can successfully break through defense models that are robust against multiple $\ell_p$ norms simultaneously. Motivated by these observations, we come up with a natural approach: combining various $\ell_p$ gradient projections on a pixel level to achieve a joint adversarial perturbation. Specifically, we learn how to perturb each pixel to maximize the attack performance, while maintaining the overall visual imperceptibility of adversarial examples. Finally, through various experiments with standardized benchmarks, we show that our method outperforms most current strong attacks across state-of-the-art defense mechanisms, while retaining its ability to remain clean visually.
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Diabetic Retinopathy (DR) is a leading cause of vision loss in the world, and early DR detection is necessary to prevent vision loss and support an appropriate treatment. In this work, we leverage interactive machine learning and introduce a joint learning framework, termed DRG-Net, to effectively learn both disease grading and multi-lesion segmentation. Our DRG-Net consists of two modules: (i) DRG-AI-System to classify DR Grading, localize lesion areas, and provide visual explanations; (ii) DRG-Expert-Interaction to receive feedback from user-expert and improve the DRG-AI-System. To deal with sparse data, we utilize transfer learning mechanisms to extract invariant feature representations by using Wasserstein distance and adversarial learning-based entropy minimization. Besides, we propose a novel attention strategy at both low- and high-level features to automatically select the most significant lesion information and provide explainable properties. In terms of human interaction, we further develop DRG-Net as a tool that enables expert users to correct the system's predictions, which may then be used to update the system as a whole. Moreover, thanks to the attention mechanism and loss functions constraint between lesion features and classification features, our approach can be robust given a certain level of noise in the feedback of users. We have benchmarked DRG-Net on the two largest DR datasets, i.e., IDRID and FGADR, and compared it to various state-of-the-art deep learning networks. In addition to outperforming other SOTA approaches, DRG-Net is effectively updated using user feedback, even in a weakly-supervised manner.
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For solving a broad class of nonconvex programming problems on an unbounded constraint set, we provide a self-adaptive step-size strategy that does not include line-search techniques and establishes the convergence of a generic approach under mild assumptions. Specifically, the objective function may not satisfy the convexity condition. Unlike descent line-search algorithms, it does not need a known Lipschitz constant to figure out how big the first step should be. The crucial feature of this process is the steady reduction of the step size until a certain condition is fulfilled. In particular, it can provide a new gradient projection approach to optimization problems with an unbounded constrained set. The correctness of the proposed method is verified by preliminary results from some computational examples. To demonstrate the effectiveness of the proposed technique for large-scale problems, we apply it to some experiments on machine learning, such as supervised feature selection, multi-variable logistic regressions and neural networks for classification.
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Pareto Front Learning (PFL) was recently introduced as an effective approach to obtain a mapping function from a given trade-off vector to a solution on the Pareto front, which solves the multi-objective optimization (MOO) problem. Due to the inherent trade-off between conflicting objectives, PFL offers a flexible approach in many scenarios in which the decision makers can not specify the preference of one Pareto solution over another, and must switch between them depending on the situation. However, existing PFL methods ignore the relationship between the solutions during the optimization process, which hinders the quality of the obtained front. To overcome this issue, we propose a novel PFL framework namely \ourmodel, which employs a hypernetwork to generate multiple solutions from a set of diverse trade-off preferences and enhance the quality of the Pareto front by maximizing the Hypervolume indicator defined by these solutions. The experimental results on several MOO machine learning tasks show that the proposed framework significantly outperforms the baselines in producing the trade-off Pareto front.
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3D hand pose estimation from RGB images suffers from the difficulty of obtaining the depth information. Therefore, a great deal of attention has been spent on estimating 3D hand pose from 2D hand joints. In this paper, we leverage the advantage of spatial-temporal Graph Convolutional Neural Networks and propose LG-Hand, a powerful method for 3D hand pose estimation. Our method incorporates both spatial and temporal dependencies into a single process. We argue that kinematic information plays an important role, contributing to the performance of 3D hand pose estimation. We thereby introduce two new objective functions, Angle and Direction loss, to take the hand structure into account. While Angle loss covers locally kinematic information, Direction loss handles globally kinematic one. Our LG-Hand achieves promising results on the First-Person Hand Action Benchmark (FPHAB) dataset. We also perform an ablation study to show the efficacy of the two proposed objective functions.
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有效的量子控制对于使用当前技术的实用量子计算实施是必需的。用于确定最佳控制参数的常规算法在计算上是昂贵的,在很大程度上将它们排除在模拟之外。构成作为查找表的现有硬件解决方案不精确且昂贵。通过设计机器学习模型来近似传统工具的结果,可以生成更有效的方法。然后可以将这样的模型合成为硬件加速器以用于量子系统。在这项研究中,我们演示了一种用于预测最佳脉冲参数的机器学习算法。该算法的轻量级足以适合低资源FPGA,并以175 ns的延迟和管道间隔为5 ns,$〜>〜>〜$〜>〜$ 0.99。从长远来看,这种加速器可以在传统计算机无法运行的量子计算硬件附近使用,从而在低潜伏期以合理的成本实现量子控制,而不会在低温环境之外产生大型数据带宽。
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深度监督或称为“中间监督”或“辅助监督”是在神经网络的隐藏层上增加监督。最近,该技术越来越多地应用于深层神经网络学习系统中,以用于各种计算机视觉应用。人们达成共识,即深层监督有助于通过减轻梯度消失的问题来改善神经网络的性能,这是深层监督的众多优势之一。此外,在不同的计算机视觉应用程序中,可以以不同的方式应用深度监督。如何最大程度地利用深度监督来改善不同应用程序中的网络性能。在本文中,我们对理论和应用程序中的深入监督进行了全面的深入审查。我们建议对不同深度监督网络进行新的分类,并讨论计算机视觉应用程序中当前深层监督网络的优势和局限性。
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尽管大多数微型机器人在坚固耐用的地形上都面临困难,但甲虫可以在复杂的底物上平稳行走而不会滑倒或粘在地面上,因为它们的刚度可变可变的塔西(Tarsi)和可在塔西(Tarsi)的尖端上伸展的钩子。在这项研究中,我们发现甲虫会积极弯曲并定期扩大爪子以在网状表面上自由爬行。受甲虫的爬行机制的启发,我们设计了一个8厘米的微型攀岩机器人,以与天然甲虫相同的循环方式打开和弯曲的人造爪。机器人可以在网格表面上以可控步态自由攀爬,陡峭的斜角60 {\ deg},甚至过渡表面。据我们所知,这是第一个可以同时攀登网格表面和悬崖倾斜的微型机器人。
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Split学习(SL)通过允许客户在不共享原始数据的情况下协作培训深度学习模型来实现数据隐私保护。但是,SL仍然有限制,例如潜在的数据隐私泄漏和客户端的高计算。在这项研究中,我们建议将SL局部层进行二线以进行更快的计算(在移动设备上的培训和推理阶段的前进时间少17.5倍)和减少内存使用情况(最多减少32倍的内存和带宽要求) 。更重要的是,二进制的SL(B-SL)模型可以减少SL污染数据中的隐私泄漏,而模型精度的降解仅小。为了进一步增强隐私保护,我们还提出了两种新颖的方法:1)培训额外的局部泄漏损失,2)应用差异隐私,可以单独或同时集成到B-SL模型中。与多种基准模型相比,使用不同数据集的实验结果肯定了B-SL模型的优势。还说明了B-SL模型针对功能空间劫持攻击(FSHA)的有效性。我们的结果表明,B-SL模型对于具有高隐私保护要求(例如移动医疗保健应用程序)的轻巧的物联网/移动应用程序很有希望。
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从非规范目标分布中抽样是概率推断中许多应用的基本问题。 Stein变异梯度下降(SVGD)已被证明是一种强大的方法,它迭代地更新一组粒子以近似关注的分布。此外,在分析其渐近性特性时,SVGD会准确地减少到单目标优化问题,并可以看作是此单目标优化问题的概率版本。然后出现一个自然的问题:“我们可以得出多目标优化的概率版本吗?”。为了回答这个问题,我们提出了随机多重目标采样梯度下降(MT-SGD),从而使我们能够从多个非差异目标分布中采样。具体而言,我们的MT-SGD进行了中间分布的流动,逐渐取向多个目标分布,这使采样颗粒可以移动到目标分布的关节高样区域。有趣的是,渐近分析表明,正如预期的那样,我们的方法准确地减少了多级下降算法以进行多目标优化。最后,我们进行全面的实验,以证明我们进行多任务学习方法的优点。
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