土匪算法已成为交互式建议的参考解决方案。但是,由于这种算法直接与用户进行改进的建议,因此对其实际使用提出了严重的隐私问题。在这项工作中,我们通过基于树的机制提出了一种差异性的线性上下文匪徒算法,以将拉普拉斯或高斯噪声添加到模型参数中。我们的关键见解是,随着模型在在线更新过程中收敛时,其参数的全局灵敏度随着时间的推移而缩小(因此命名为动态全局灵敏度)。与现有解决方案相比,我们动态的全球敏感性分析使我们能够减少噪声以获得$(\ epsilon,\ delta)$ - 差异隐私,并具有$ \ tilde o(\ log {t} \ sqrt中的噪声注入引起的额外遗憾) {t}/\ epsilon)$。我们通过动态全局灵敏度和我们提出的算法的相应上后悔界限提供了严格的理论分析。合成和现实世界数据集的实验结果证实了该算法对现有解决方案的优势。
translated by 谷歌翻译
在线影响最大化旨在通过选择一些种子节点,最大程度地利用未知网络模型的社交网络中内容的影响。最近的研究遵循非自适应设置,在扩散过程开始之前选择种子节点,并且在扩散停止时更新网络参数。我们考虑了与内容相关的在线影响最大化问题的自适应版本,其中种子节点是根据实时反馈依次激活的。在本文中,我们将问题提出为无限马在线性扩散过程中的折扣MDP,并提出了基于模型的增强学习解决方案。我们的算法维护网络模型估算,并适应种子用户,探索社交网络,同时乐观地改善最佳策略。我们建立了$ \ widetilde o(\ sqrt {t})$遗憾的算法。合成网络的经验评估证明了我们的算法效率。
translated by 谷歌翻译
我们应对在分布式环境中学习内核上下文匪徒的沟通效率挑战。尽管最近的沟通效率分布式强盗学习取得了进步,但现有的解决方案仅限于简单的模型,例如多臂匪徒和线性匪徒,这阻碍了其实用性。在本文中,我们没有假设存在从功能到预期奖励的线性奖励映射,而是通过让代理商在复制的内核希尔伯特(RKHS)中协作搜索来考虑非线性奖励映射。由于分布式内核学习需要传输原始数据,因此引入了沟通效率的重大挑战,从而导致沟通成本增长线性W.R.T.时间范围$ t $。我们通过装备所有代理通过通用的nystr \“ {o} m嵌入,随着收集更多的数据点的收集。我们严格地证明我们的算法可以以遗憾和通信成本达到次线性率,我们可以通过适应性更新的嵌入来解决这个问题。 。
translated by 谷歌翻译
我们研究对线性随机匪徒的对抗攻击:通过操纵奖励,对手旨在控制匪徒的行为。也许令人惊讶的是,我们首先表明某些攻击目标永远无法实现。这与无上下文的随机匪徒形成了鲜明的对比,并且本质上是由于线性随机陆上的臂之间的相关性。在这一发现的激励下,本文研究了$ k $武装的线性匪徒环境的攻击性。我们首先根据武器上下文向量的几何形状提供了攻击性的完全必要性和充分性表征。然后,我们提出了针对Linucb和鲁棒相消除的两阶段攻击方法。该方法首先断言给定环境是否可攻击;而且,如果是的话,它会付出巨大的奖励,以强迫算法仅使用sublinear成本来拉动目标臂线性时间。数值实验进一步验证了拟议攻击方法的有效性和成本效益。
translated by 谷歌翻译
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.
translated by 谷歌翻译
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.
translated by 谷歌翻译
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.
translated by 谷歌翻译
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.
translated by 谷歌翻译
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.
translated by 谷歌翻译
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.
translated by 谷歌翻译