神经文本排名模型已经见证了显着的进步,并越来越多地在实践中部署。不幸的是,它们还继承了一般神经模型的对抗性脆弱性,这些神经模型已被检测到,但仍未被先前的研究所忽视。此外,Blackhat SEO可能会利用继承的对抗性漏洞来击败受保护的搜索引擎。在这项研究中,我们提出了对黑盒神经通道排名模型的模仿对抗攻击。我们首先表明,可以通过列举关键查询/候选者,然后训练排名模仿模型来透明和模仿目标段落排名模型。利用排名模仿模型,我们可以精心操纵排名结果并将操纵攻击转移到目标排名模型。为此,我们提出了一种由成对目标函数授权的基于创新的基于梯度的攻击方法,以产生对抗性触发器,该触发器会导致有预谋的混乱,而具有很少的令牌。为了配备触发器的伪装,我们将下一个句子预测损失和语言模型流利度限制添加到目标函数中。对通过排名的实验结果证明了对各种SOTA神经排名模型的排名模仿攻击模型和对抗触发器的有效性。此外,各种缓解分析和人类评估表明,在面对潜在的缓解方法时,伪装的有效性。为了激励其他学者进一步研究这一新颖和重要的问题,我们将实验数据和代码公开可用。
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虽然注释大量的数据以满足复杂的学习模型,但对于许多现实世界中的应用程序可能会过于良好。主动学习(AL)和半监督学习(SSL)是两个有效但经常被隔离的方法,可以减轻渴望数据的问题。最近的一些研究探索了将AL和SSL相结合以更好地探测未标记数据的潜力。但是,几乎所有这些当代的SSL-AL作品都采用了简单的组合策略,忽略了SSL和AL的固有关系。此外,在处理大规模,高维数据集时,其他方法则遭受高计算成本。通过标记数据的行业实践的激励,我们提出了一种基于创新的基于不一致的虚拟对抗性积极学习(理想)算法,以进一步研究SSL-AL的潜在优势,并实现Al和SSL的相互增强,即SSL,即SSL宣传标签信息,以使标签信息无标记的样本信息并为Al提供平滑的嵌入,而AL排除了具有不一致的预测和相当不确定性的样品。我们通过不同粒度的增强策略(包括细粒度的连续扰动探索和粗粒数据转换)来估计未标记的样品的不一致。在文本和图像域中,广泛的实验验证了所提出的算法的有效性,并将其与最先进的基线进行了比较。两项实际案例研究可视化应用和部署所提出的数据采样算法的实际工业价值。
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对话摘要已被广泛研究和应用,其中,先前的作品主要集中在探索卓越的模型结构方面,以对准输入对话和输出摘要。然而,对于专业对话(例如,法律辩论和医学诊断),语义/统计对齐可能几乎不会填补输入对话话语话语和外部知识的摘要输出之间的逻辑/事实差距。在本文中,我们主要研究了非预介绍和预用环境下对话检验摘要(DIS)的事实不一致问题。创新的端到端对话摘要生成框架是有两个辅助任务:预期事实方面正规化(EFAR)和缺少事实实体歧视(MFED)。综合实验表明,该模型可以以准确的事实方面的覆盖率来产生更可读的总结,以及通知用户从输入对话中检测到的潜在缺失事实以获得进一步的人为干预。
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Global power systems are increasingly reliant on wind energy as a mitigation strategy for climate change. However, the variability of wind energy causes system reliability to erode, resulting in the wind being curtailed and, ultimately, leading to substantial economic losses for wind farm owners. Wind curtailment can be reduced using battery energy storage systems (BESS) that serve as onsite backup sources. Yet, this auxiliary role may significantly hamper the BESS's capacity to generate revenues from the electricity market, particularly in conducting energy arbitrage in the Spot market and providing frequency control ancillary services (FCAS) in the FCAS markets. Ideal BESS scheduling should effectively balance the BESS's role in absorbing onsite wind curtailment and trading in the electricity market, but it is difficult in practice because of the underlying coordination complexity and the stochastic nature of energy prices and wind generation. In this study, we investigate the bidding strategy of a wind-battery system co-located and participating simultaneously in both the Spot and Regulation FCAS markets. We propose a deep reinforcement learning (DRL)-based approach that decouples the market participation of the wind-battery system into two related Markov decision processes for each facility, enabling the BESS to absorb onsite wind curtailment while simultaneously bidding in the wholesale Spot and FCAS markets to maximize overall operational revenues. Using realistic wind farm data, we validated the coordinated bidding strategy for the wind-battery system and find that our strategy generates significantly higher revenue and responds better to wind curtailment compared to an optimization-based benchmark. Our results show that joint-market bidding can significantly improve the financial performance of wind-battery systems compared to individual market participation.
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Driven by the global decarbonization effort, the rapid integration of renewable energy into the conventional electricity grid presents new challenges and opportunities for the battery energy storage system (BESS) participating in the energy market. Energy arbitrage can be a significant source of revenue for the BESS due to the increasing price volatility in the spot market caused by the mismatch between renewable generation and electricity demand. In addition, the Frequency Control Ancillary Services (FCAS) markets established to stabilize the grid can offer higher returns for the BESS due to their capability to respond within milliseconds. Therefore, it is crucial for the BESS to carefully decide how much capacity to assign to each market to maximize the total profit under uncertain market conditions. This paper formulates the bidding problem of the BESS as a Markov Decision Process, which enables the BESS to participate in both the spot market and the FCAS market to maximize profit. Then, Proximal Policy Optimization, a model-free deep reinforcement learning algorithm, is employed to learn the optimal bidding strategy from the dynamic environment of the energy market under a continuous bidding scale. The proposed model is trained and validated using real-world historical data of the Australian National Electricity Market. The results demonstrate that our developed joint bidding strategy in both markets is significantly profitable compared to individual markets.
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Script event prediction aims to predict the subsequent event given the context. This requires the capability to infer the correlations between events. Recent works have attempted to improve event correlation reasoning by using pretrained language models and incorporating external knowledge~(e.g., discourse relations). Though promising results have been achieved, some challenges still remain. First, the pretrained language models adopted by current works ignore event-level knowledge, resulting in an inability to capture the correlations between events well. Second, modeling correlations between events with discourse relations is limited because it can only capture explicit correlations between events with discourse markers, and cannot capture many implicit correlations. To this end, we propose a novel generative approach for this task, in which a pretrained language model is fine-tuned with an event-centric pretraining objective and predicts the next event within a generative paradigm. Specifically, we first introduce a novel event-level blank infilling strategy as the learning objective to inject event-level knowledge into the pretrained language model, and then design a likelihood-based contrastive loss for fine-tuning the generative model. Instead of using an additional prediction layer, we perform prediction by using sequence likelihoods generated by the generative model. Our approach models correlations between events in a soft way without any external knowledge. The likelihood-based prediction eliminates the need to use additional networks to make predictions and is somewhat interpretable since it scores each word in the event. Experimental results on the multi-choice narrative cloze~(MCNC) task demonstrate that our approach achieves better results than other state-of-the-art baselines. Our code will be available at \url{https://github.com/zhufq00/mcnc}.
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我们研究了顺序预测和在线minimax遗憾的问题,并在一般损失函数下具有随机生成的特征。我们介绍了一个预期的最坏情况下的概念minimax遗憾,它概括并涵盖了先前已知的minimax遗憾。对于这种极匹马的遗憾,我们通过随机全局顺序覆盖的新颖概念建立了紧密的上限。我们表明,对于VC-Dimension $ \ Mathsf {Vc} $和$ I.I.D. $生成的长度$ t $的假设类别,随机全局顺序覆盖的基数可以在上限上限制高概率(WHP) e^{o(\ mathsf {vc} \ cdot \ log^2 t)} $。然后,我们通过引入一种称为Star-Littlestone维度的新复杂度度量来改善这种束缚,并显示与Star-Littlestone dimension $ \ Mathsf {Slsf {sl} $类别的类别允许订单的随机全局顺序覆盖$ e^{o(\ Mathsf) {sl} \ cdot \ log t)} $。我们进一步建立了具有有限脂肪的数字的真实有价值类的上限。最后,通过应用固定设计的Minimax遗憾的信息理论工具,我们为预期的最坏情况下的Minimax遗憾提供了下限。我们通过在预期的最坏情况下对对数损失和一般可混合损失的遗憾建立紧密的界限来证明我们的方法的有效性。
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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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Given the increasingly intricate forms of partial differential equations (PDEs) in physics and related fields, computationally solving PDEs without analytic solutions inevitably suffers from the trade-off between accuracy and efficiency. Recent advances in neural operators, a kind of mesh-independent neural-network-based PDE solvers, have suggested the dawn of overcoming this challenge. In this emerging direction, Koopman neural operator (KNO) is a representative demonstration and outperforms other state-of-the-art alternatives in terms of accuracy and efficiency. Here we present KoopmanLab, a self-contained and user-friendly PyTorch module of the Koopman neural operator family for solving partial differential equations. Beyond the original version of KNO, we develop multiple new variants of KNO based on different neural network architectures to improve the general applicability of our module. These variants are validated by mesh-independent and long-term prediction experiments implemented on representative PDEs (e.g., the Navier-Stokes equation and the Bateman-Burgers equation) and ERA5 (i.e., one of the largest high-resolution data sets of global-scale climate fields). These demonstrations suggest the potential of KoopmanLab to be considered in diverse applications of partial differential equations.
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Rankings are widely collected in various real-life scenarios, leading to the leakage of personal information such as users' preferences on videos or news. To protect rankings, existing works mainly develop privacy protection on a single ranking within a set of ranking or pairwise comparisons of a ranking under the $\epsilon$-differential privacy. This paper proposes a novel notion called $\epsilon$-ranking differential privacy for protecting ranks. We establish the connection between the Mallows model (Mallows, 1957) and the proposed $\epsilon$-ranking differential privacy. This allows us to develop a multistage ranking algorithm to generate synthetic rankings while satisfying the developed $\epsilon$-ranking differential privacy. Theoretical results regarding the utility of synthetic rankings in the downstream tasks, including the inference attack and the personalized ranking tasks, are established. For the inference attack, we quantify how $\epsilon$ affects the estimation of the true ranking based on synthetic rankings. For the personalized ranking task, we consider varying privacy preferences among users and quantify how their privacy preferences affect the consistency in estimating the optimal ranking function. Extensive numerical experiments are carried out to verify the theoretical results and demonstrate the effectiveness of the proposed synthetic ranking algorithm.
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