In the framework of online convex optimization, most iterative algorithms require the computation of projections onto convex sets, which can be computationally expensive. To tackle this problem HK12 proposed the study of projection-free methods that replace projections with less expensive computations. The most common approach is based on the Frank-Wolfe method, that uses linear optimization computation in lieu of projections. Recent work by GK22 gave sublinear adaptive regret guarantees with projection free algorithms based on the Frank Wolfe approach. In this work we give projection-free algorithms that are based on a different technique, inspired by Mhammedi22, that replaces projections by set-membership computations. We propose a simple lazy gradient-based algorithm with a Minkowski regularization that attains near-optimal adaptive regret bounds. For general convex loss functions we improve previous adaptive regret bounds from $O(T^{3/4})$ to $O(\sqrt{T})$, and further to tight interval dependent bound $\tilde{O}(\sqrt{I})$ where $I$ denotes the interval length. For strongly convex functions we obtain the first poly-logarithmic adaptive regret bounds using a projection-free algorithm.
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在矩阵完成问题中,人们希望根据一组(可能是嘈杂的)条目重建一个低级别矩阵。先前的工作考虑完成整个矩阵,在条目分布不均匀的情况下,这可能是高度不准确的。我们正式化了部分矩阵完成的问题,目标是完成大量条目,或等效地完成整个矩阵并指定条目的准确子集。有趣的是,即使分布未知且任意复杂,我们的有效算法也能够保证:(a)在所有完成的条目上高精度,以及(b)高覆盖范围,这意味着它至少涵盖了与该矩阵的范围一样多。观察的分布。
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在在线凸优化中,玩家旨在最大程度地减少对整个重复游戏中固定比较器的遗憾。最小化标准遗憾的算法可能会收敛到固定决策,这在改变或动态环境中是不受欢迎的。这激发了更强的适应性遗憾指标,或者及时对任何连续的次互相关的最大遗憾。现有的自适应遗憾算法受到计算罚款的损失 - 通常是按照乘法因素的顺序在游戏迭代次数中对数增长的。在本文中,我们展示了如何在游戏迭代次数中减少这种计算惩罚,以使其在游戏次数的数量中倍加对数,并且由于最佳可达到的适应性遗憾界限而减少了最小的降级。
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机械通气是ICU中最广泛使用的疗法中最广泛的疗法之一。然而,尽管在麻醉与科迪德相关的终身支持中具有广泛的应用,但仍有许多有害挑战。我们将这些视为控制问题:呼吸机必须根据规定的气道压力轨迹进出患者的肺部。基于PID方法的行业标准控制器既不是最佳的也不是强大的。我们的数据驱动方法学习通过在从呼吸机收集的数据上培训的模拟器本身进行培训来控制侵入式呼吸机。该方法优于流行的加固学习算法,甚至比PID更精确且强大地控制物理呼吸机。这些结果强调了有效的数据驱动方法可以用于侵入性通风,并表明更通用的通风形式(例如,无侵入性,适应性)也可能是可享受的。
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Boosting是一种著名的机器学习方法,它基于将弱和适度不准确假设与强烈而准确的假设相结合的想法。我们研究了弱假设属于界限能力类别的假设。这个假设的灵感来自共同的惯例,即虚弱的假设是“易于学习的类别”中的“人数规则”。 (Schapire和Freund〜 '12,Shalev-Shwartz和Ben-David '14。)正式,我们假设弱假设类别具有有界的VC维度。我们关注两个主要问题:(i)甲骨文的复杂性:产生准确的假设需要多少个弱假设?我们设计了一种新颖的增强算法,并证明它绕过了由Freund和Schapire('95,'12)的经典下限。虽然下限显示$ \ omega({1}/{\ gamma^2})$弱假设有时是必要的,而有时则需要使用$ \ gamma $ -margin,但我们的新方法仅需要$ \ tilde {o}({1})({1}) /{\ gamma})$弱假设,前提是它们属于一类有界的VC维度。与以前的增强算法以多数票汇总了弱假设的算法不同,新的增强算法使用了更复杂(“更深”)的聚合规则。我们通过表明复杂的聚合规则实际上是规避上述下限是必要的,从而补充了这一结果。 (ii)表现力:通过提高有限的VC类的弱假设可以学习哪些任务?可以学到“遥远”的复杂概念吗?为了回答第一个问题,我们{介绍组合几何参数,这些参数捕获增强的表现力。}作为推论,我们为认真的班级的第二个问题提供了肯定的答案,包括半空间和决策树桩。一路上,我们建立并利用差异理论的联系。
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此手稿将优化作为过程进行描绘。在许多实际应用中,环境非常复杂,可以阐述一个综合理论模型,并使用经典算法理论和数学优化是不可行的。通过应用一项学习的优化方法,采取稳健的方法是有必要的,并且由于观察到的问题,从经验中学习,从经验中学习。作为一个过程的这种优化观点在各种领域中突出了突出,并导致了现在的建模和系统中的一些壮观成功,现在是我们日常生活的一部分。
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Conventional wisdom in deep learning states that increasing depth improves expressiveness but complicates optimization. This paper suggests that, sometimes, increasing depth can speed up optimization. The effect of depth on optimization is decoupled from expressiveness by focusing on settings where additional layers amount to overparameterization -linear neural networks, a wellstudied model. Theoretical analysis, as well as experiments, show that here depth acts as a preconditioner which may accelerate convergence. Even on simple convex problems such as linear regression with p loss, p > 2, gradient descent can benefit from transitioning to a non-convex overparameterized objective, more than it would from some common acceleration schemes. We also prove that it is mathematically impossible to obtain the acceleration effect of overparametrization via gradients of any regularizer.
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Neural Representations have recently been shown to effectively reconstruct a wide range of signals from 3D meshes and shapes to images and videos. We show that, when adapted correctly, neural representations can be used to directly represent the weights of a pre-trained convolutional neural network, resulting in a Neural Representation for Neural Networks (NeRN). Inspired by coordinate inputs of previous neural representation methods, we assign a coordinate to each convolutional kernel in our network based on its position in the architecture, and optimize a predictor network to map coordinates to their corresponding weights. Similarly to the spatial smoothness of visual scenes, we show that incorporating a smoothness constraint over the original network's weights aids NeRN towards a better reconstruction. In addition, since slight perturbations in pre-trained model weights can result in a considerable accuracy loss, we employ techniques from the field of knowledge distillation to stabilize the learning process. We demonstrate the effectiveness of NeRN in reconstructing widely used architectures on CIFAR-10, CIFAR-100, and ImageNet. Finally, we present two applications using NeRN, demonstrating the capabilities of the learned representations.
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Action recognition models have achieved impressive results by incorporating scene-level annotations, such as objects, their relations, 3D structure, and more. However, obtaining annotations of scene structure for videos requires a significant amount of effort to gather and annotate, making these methods expensive to train. In contrast, synthetic datasets generated by graphics engines provide powerful alternatives for generating scene-level annotations across multiple tasks. In this work, we propose an approach to leverage synthetic scene data for improving video understanding. We present a multi-task prompt learning approach for video transformers, where a shared video transformer backbone is enhanced by a small set of specialized parameters for each task. Specifically, we add a set of ``task prompts'', each corresponding to a different task, and let each prompt predict task-related annotations. This design allows the model to capture information shared among synthetic scene tasks as well as information shared between synthetic scene tasks and a real video downstream task throughout the entire network. We refer to this approach as ``Promptonomy'', since the prompts model a task-related structure. We propose the PromptonomyViT model (PViT), a video transformer that incorporates various types of scene-level information from synthetic data using the ``Promptonomy'' approach. PViT shows strong performance improvements on multiple video understanding tasks and datasets.
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In this short paper, we present our ongoing work on the veriFIRE project -- a collaboration between industry and academia, aimed at using verification for increasing the reliability of a real-world, safety-critical system. The system we target is an airborne platform for wildfire detection, which incorporates two deep neural networks. We describe the system and its properties of interest, and discuss our attempts to verify the system's consistency, i.e., its ability to continue and correctly classify a given input, even if the wildfire it describes increases in intensity. We regard this work as a step towards the incorporation of academic-oriented verification tools into real-world systems of interest.
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