我们提出了一个新的框架,用于对凸函数的差异私有优化,这些功能是任意规范$ \ normx {\ cdot} $中的Lipschitz。我们的算法基于一种正规的指数机制,该机制从密度$ \ propto \ exp(-k(f+\ mu r))$中进行样品,其中$ f $是经验损失,$ r $是一种常规化器,它与强烈的convex convex converize尊重$ \ normx {\ cdot} $,将\ cite {gll22}的最新作品推广到非Euclidean设置。我们表明,这种机制可以满足高斯差异隐私,并通过使用凸几何形状的本地化工具来解决DP-MER(经验风险最小化)和DP-SCO(随机凸优化)。我们的框架是第一个在一般规范空间中适用于私有凸优化的框架,并直接恢复了镜下下降的非私有SCO率,作为隐私参数$ \ eps \ to \ infty $。作为应用程序,对于LipsChitz优化了$ \ ell_p $ norms for(1,2)$中的所有$ p \ norms,我们获得了第一个最佳隐私性权衡权衡;对于$ p = 1 $,我们提高了最近的作品\ cite {asifkt21,bassilygn21}获得的权衡,至少通过对数因素。我们的$ \ ell_p $ norm和schatten- $ p $规范优化框架与多项式时间采样器相辅相成,我们的查询复杂性明确绑定。
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数据增强是机器学习管道的基石,但其理论基础尚不清楚。它只是人为增加数据集大小的一种方法吗?还是鼓励模型满足某些不变性?在这项工作中,我们考虑了另一个角度,我们研究了数据增强对学习过程动态的影响。我们发现,数据增强可以改变各种功能的相对重要性,从而有效地使某些信息性但难以学习的功能更有可能在学习过程中捕获。重要的是,我们表明,对于非线性模型,例如神经网络,这种效果更为明显。我们的主要贡献是对Allen-Zhu和Li [2020]最近提出的多视图数据模型中两层卷积神经网络的学习动态数据的详细分析。我们通过进一步的实验证据来补充这一分析,证明数据增加可以看作是特征操纵。
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经典地,连续时间兰富文队扩散在唯一的假设下迅速迅速迅速迅速迅速,以至于$ \ PI $满足POINCAR的不平等。使用这一事实来为离散时间Langevin Monte Carlo(LMC)算法提供保证,因此由于需要与Chi Squared或R \'enyi分歧的需要,并且在很大程度上主要重点关注日志凹形目标。在这项工作中,我们为LMC提供了第一个收敛保证,假设$ \ PI $满足Lata {\ l} a - oleszkiewicz或修改的log-sobolev不等式,它在Poincar \ e和log-sobolev设置之间插值。与现有作品不同,我们的结果允许弱滑性,并且不需要凸起或耗散条件。
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我们在加固学习中使用汤普森采样(TS) - 样算法中的随机价值函数研究探索。这种类型的算法享有有吸引力的经验性能。我们展示当我们使用1)每一集中的单个随机种子,而2)伯尼斯坦型噪声幅度,我们获得了最坏的情况$ \ widetilde {o}左(h \ sqrt {sat} \右)$遗憾绑定了焦点时间 - 不均匀的马尔可夫决策过程,其中$ S $是国家空间的大小,$ a $的是行动空间的大小,$ h $是规划地平线,$ t $是互动的数量。这种绑定的多项式基于随机值函数的TS样算法的所有现有界限,并且首次匹配$ \ Omega \左(H \ SQRT {SAT}右)$下限到对数因子。我们的结果强调随机勘探可以近乎最佳,这是以前仅通过乐观算法实现的。为了实现所需的结果,我们开发1)新的剪辑操作,以确保持续持续的概率和悲观的概率是较低的常数,并且2)用于分析估计误差的绝对值的新递归公式。后悔。
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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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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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Nowadays, time-stamped web documents related to a general news query floods spread throughout the Internet, and timeline summarization targets concisely summarizing the evolution trajectory of events along the timeline. Unlike traditional document summarization, timeline summarization needs to model the time series information of the input events and summarize important events in chronological order. To tackle this challenge, in this paper, we propose a Unified Timeline Summarizer (UTS) that can generate abstractive and extractive timeline summaries in time order. Concretely, in the encoder part, we propose a graph-based event encoder that relates multiple events according to their content dependency and learns a global representation of each event. In the decoder part, to ensure the chronological order of the abstractive summary, we propose to extract the feature of event-level attention in its generation process with sequential information remained and use it to simulate the evolutionary attention of the ground truth summary. The event-level attention can also be used to assist in extracting summary, where the extracted summary also comes in time sequence. We augment the previous Chinese large-scale timeline summarization dataset and collect a new English timeline dataset. Extensive experiments conducted on these datasets and on the out-of-domain Timeline 17 dataset show that UTS achieves state-of-the-art performance in terms of both automatic and human evaluations.
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In this tutorial paper, we look into the evolution and prospect of network architecture and propose a novel conceptual architecture for the 6th generation (6G) networks. The proposed architecture has two key elements, i.e., holistic network virtualization and pervasive artificial intelligence (AI). The holistic network virtualization consists of network slicing and digital twin, from the aspects of service provision and service demand, respectively, to incorporate service-centric and user-centric networking. The pervasive network intelligence integrates AI into future networks from the perspectives of networking for AI and AI for networking, respectively. Building on holistic network virtualization and pervasive network intelligence, the proposed architecture can facilitate three types of interplay, i.e., the interplay between digital twin and network slicing paradigms, between model-driven and data-driven methods for network management, and between virtualization and AI, to maximize the flexibility, scalability, adaptivity, and intelligence for 6G networks. We also identify challenges and open issues related to the proposed architecture. By providing our vision, we aim to inspire further discussions and developments on the potential architecture of 6G.
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In this paper, we investigate the joint device activity and data detection in massive machine-type communications (mMTC) with a one-phase non-coherent scheme, where data bits are embedded in the pilot sequences and the base station simultaneously detects active devices and their embedded data bits without explicit channel estimation. Due to the correlated sparsity pattern introduced by the non-coherent transmission scheme, the traditional approximate message passing (AMP) algorithm cannot achieve satisfactory performance. Therefore, we propose a deep learning (DL) modified AMP network (DL-mAMPnet) that enhances the detection performance by effectively exploiting the pilot activity correlation. The DL-mAMPnet is constructed by unfolding the AMP algorithm into a feedforward neural network, which combines the principled mathematical model of the AMP algorithm with the powerful learning capability, thereby benefiting from the advantages of both techniques. Trainable parameters are introduced in the DL-mAMPnet to approximate the correlated sparsity pattern and the large-scale fading coefficient. Moreover, a refinement module is designed to further advance the performance by utilizing the spatial feature caused by the correlated sparsity pattern. Simulation results demonstrate that the proposed DL-mAMPnet can significantly outperform traditional algorithms in terms of the symbol error rate performance.
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Deploying reliable deep learning techniques in interdisciplinary applications needs learned models to output accurate and ({even more importantly}) explainable predictions. Existing approaches typically explicate network outputs in a post-hoc fashion, under an implicit assumption that faithful explanations come from accurate predictions/classifications. We have an opposite claim that explanations boost (or even determine) classification. That is, end-to-end learning of explanation factors to augment discriminative representation extraction could be a more intuitive strategy to inversely assure fine-grained explainability, e.g., in those neuroimaging and neuroscience studies with high-dimensional data containing noisy, redundant, and task-irrelevant information. In this paper, we propose such an explainable geometric deep network dubbed as NeuroExplainer, with applications to uncover altered infant cortical development patterns associated with preterm birth. Given fundamental cortical attributes as network input, our NeuroExplainer adopts a hierarchical attention-decoding framework to learn fine-grained attentions and respective discriminative representations to accurately recognize preterm infants from term-born infants at term-equivalent age. NeuroExplainer learns the hierarchical attention-decoding modules under subject-level weak supervision coupled with targeted regularizers deduced from domain knowledge regarding brain development. These prior-guided constraints implicitly maximizes the explainability metrics (i.e., fidelity, sparsity, and stability) in network training, driving the learned network to output detailed explanations and accurate classifications. Experimental results on the public dHCP benchmark suggest that NeuroExplainer led to quantitatively reliable explanation results that are qualitatively consistent with representative neuroimaging studies.
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