Neural Radiance Field (NeRF) is a powerful tool to faithfully generate novel views for scenes with only sparse captured images. Despite its strong capability for representing 3D scenes and their appearance, its editing ability is very limited. In this paper, we propose a simple but effective extension of vanilla NeRF, named PaletteNeRF, to enable efficient color editing on NeRF-represented scenes. Motivated by recent palette-based image decomposition works, we approximate each pixel color as a sum of palette colors modulated by additive weights. Instead of predicting pixel colors as in vanilla NeRFs, our method predicts additive weights. The underlying NeRF backbone could also be replaced with more recent NeRF models such as KiloNeRF to achieve real-time editing. Experimental results demonstrate that our method achieves efficient, view-consistent, and artifact-free color editing on a wide range of NeRF-represented scenes.
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Causal inference is the process of using assumptions, study designs, and estimation strategies to draw conclusions about the causal relationships between variables based on data. This allows researchers to better understand the underlying mechanisms at work in complex systems and make more informed decisions. In many settings, we may not fully observe all the confounders that affect both the treatment and outcome variables, complicating the estimation of causal effects. To address this problem, a growing literature in both causal inference and machine learning proposes to use Instrumental Variables (IV). This paper serves as the first effort to systematically and comprehensively introduce and discuss the IV methods and their applications in both causal inference and machine learning. First, we provide the formal definition of IVs and discuss the identification problem of IV regression methods under different assumptions. Second, we categorize the existing work on IV methods into three streams according to the focus on the proposed methods, including two-stage least squares with IVs, control function with IVs, and evaluation of IVs. For each stream, we present both the classical causal inference methods, and recent developments in the machine learning literature. Then, we introduce a variety of applications of IV methods in real-world scenarios and provide a summary of the available datasets and algorithms. Finally, we summarize the literature, discuss the open problems and suggest promising future research directions for IV methods and their applications. We also develop a toolkit of IVs methods reviewed in this survey at https://github.com/causal-machine-learning-lab/mliv.
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The security of artificial intelligence (AI) is an important research area towards safe, reliable, and trustworthy AI systems. To accelerate the research on AI security, the Artificial Intelligence Security Competition (AISC) was organized by the Zhongguancun Laboratory, China Industrial Control Systems Cyber Emergency Response Team, Institute for Artificial Intelligence, Tsinghua University, and RealAI as part of the Zhongguancun International Frontier Technology Innovation Competition (https://www.zgc-aisc.com/en). The competition consists of three tracks, including Deepfake Security Competition, Autonomous Driving Security Competition, and Face Recognition Security Competition. This report will introduce the competition rules of these three tracks and the solutions of top-ranking teams in each track.
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The success of deep learning is partly attributed to the availability of massive data downloaded freely from the Internet. However, it also means that users' private data may be collected by commercial organizations without consent and used to train their models. Therefore, it's important and necessary to develop a method or tool to prevent unauthorized data exploitation. In this paper, we propose ConfounderGAN, a generative adversarial network (GAN) that can make personal image data unlearnable to protect the data privacy of its owners. Specifically, the noise produced by the generator for each image has the confounder property. It can build spurious correlations between images and labels, so that the model cannot learn the correct mapping from images to labels in this noise-added dataset. Meanwhile, the discriminator is used to ensure that the generated noise is small and imperceptible, thereby remaining the normal utility of the encrypted image for humans. The experiments are conducted in six image classification datasets, consisting of three natural object datasets and three medical datasets. The results demonstrate that our method not only outperforms state-of-the-art methods in standard settings, but can also be applied to fast encryption scenarios. Moreover, we show a series of transferability and stability experiments to further illustrate the effectiveness and superiority of our method.
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In task-oriented dialogs such as MultiWoZ (Budzianowski et al., 2018), an informative and/or successful system response needs to include necessary key information such as the phone number of a hotel. Therefore, we hypothesize that by helping the model to focus more on learning key quantities in the dialog, the model can generative more informative and helpful responses. In this paper, we propose a new training algorithm, Reinforced Language Modeling (RLM), that aims to use a fine-grained reward function and reinforcement learning to help the model focus more on generating key quantities correctly during test time. Empirical results show our proposed RLM achieves state-of-the-art performance on the inform rate, success rate, and combined score in MultiWoZ.
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在移动设备上部署机器学习模型已引起越来越多的关注。为了解决设备上硬件资源的局限性解决模型概括问题,设备模型需要通过诸如云模型的模型压缩等技术轻量级。但是,改善设备模型概括的主要障碍是云数据和设备模型数据之间的分布变化,因为设备模型上的数据分布通常会随着时间而变化(例如,用户在建议系统中可能具有不同的偏好)。尽管实时微调和蒸馏方法考虑到了这种情况,但这些方法需要进行设备训练,由于计算能力较低和设备上缺乏实时标记样品,因此实际上是不可行的。在本文中,我们提出了一个名为Metanetwork的新型任务无关框架,用于从云中生成自适应设备模型参数,而无需进行设备训练。具体而言,我们的元网络部署在云上,由元培养剂和转移器模块组成。 Metagenerator旨在学习从样本到模型参数的映射函数,并且可以根据从设备上传到云的样本生成和传递自适应参数到设备。转移剂旨在减少元烯剂的振荡,加速收敛并在训练和推理过程中提高模型性能。我们使用三个数据集评估了两个任务的方法。广泛的实验表明,元网可以以不同的方式实现竞争性能。
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人类的姿势估计旨在弄清不同场景中所有人的关键。尽管结果有希望,但目前的方法仍然面临一些挑战。现有的自上而下的方法单独处理一个人,而没有不同的人与所在的场景之间的相互作用。因此,当发生严重闭塞时,人类检测的表现会降低。另一方面,现有的自下而上方法同时考虑所有人,并捕获整个图像的全局知识。但是,由于尺度变化,它们的准确性不如自上而下的方法。为了解决这些问题,我们通过整合自上而下和自下而上的管道来探索不同接受场的视觉线索并实现其互补性,提出了一种新颖的双皮线整合变压器(DPIT)。具体而言,DPIT由两个分支组成,自下而上的分支介绍了整个图像以捕获全局视觉信息,而自上而下的分支则从单人类边界框中提取本地视觉的特征表示。然后,从自下而上和自上而下的分支中提取的特征表示形式被馈入变压器编码器,以交互融合全局和本地知识。此外,我们定义了关键点查询,以探索全景和单人类姿势视觉线索,以实现两个管道的相互互补性。据我们所知,这是将自下而上和自上而下管道与变压器与人类姿势估计的变压器相结合的最早作品之一。关于可可和MPII数据集的广泛实验表明,我们的DPIT与最先进的方法相当。
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在存在未衡量的混杂因素的情况下,我们解决了数据融合的治疗效应估计问题,即在不同的治疗分配机制下收集的多个数据集。例如,营销人员可以在不同时间/地点为相同产品分配不同的广告策略。为了处理由未衡量的混杂因素和数据融合引起的偏见,我们建议将观察数据分为多组(每个组具有独立治疗分配机制),然后将组指标显式地模拟为潜在的组仪器变量(LATGIV),将其模拟为实施基于IV的回归。在本文中,我们概念化了这种思想,并开发了一个统一的框架,以(1)估计跨群体观察到的变量的分布差异; (2)对不同治疗分配机制的LATGIV模型; (3)插入latgivs以估计治疗响应函数。经验结果证明了与最新方法相比,LATGIV的优势。
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在信息爆炸的时代,推荐系统通过促进内容探索在人们的日常生活中起着重要作用。众所周知,用户的活动性,即行为数量,倾向于遵循长尾分布,大多数用户的积极性低。在实践中,我们观察到,在联合培训后,尾巴用户的质量推荐率明显低于首席用户。我们进一步确定,由于数据有限,因此在尾巴用户上训练的模型仍然取得了较低的结果。尽管长尾分布在推荐系统中无处不在,但在研究和行业中,提高尾巴用户的推荐性能仍然仍然是挑战。直接应用长尾分配的相关方法可能有可能伤害首席用户的经验,这是不起作用的,因为一小部分具有高积极性的首席用户贡献了平台收入的一部分。在本文中,我们提出了一种新颖的方法,可以显着提高尾巴用户的建议性能,同时至少在基本模型上为首席用户提供至少可比的性能。这种方法的本质是一种新颖的梯度聚合技术,该技术将所有用户共享的常识知识分为主干模型,然后为Head用户和Tail用户个性化提供单独的插件预测网络。至于常识学习,我们利用因果关系理论的向后调整来消除梯度估计,从而掩盖了混杂因素的骨干训练,即用户的积极性。我们对两个公共建议基准数据集和一个从支撑台平台收集的大规模工业数据集进行了广泛的实验。实证研究验证了我们方法的合理性和有效性。
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深度神经网络(DNNS)的广泛应用要求越来越多的关注对其现实世界的鲁棒性,即DNN是否抵抗黑盒对抗性攻击,其中包括基于得分的查询攻击(SQA)是最威胁性的。由于它们的实用性和有效性:攻击者只需要在模型输出上进行数十个查询即可严重伤害受害者网络。针对SQA的防御需要对用户的服务目的而略有但巧妙的输出变化,这些用户与攻击者共享相同的输出信息。在本文中,我们提出了一种称为统一梯度(UNIG)的现实世界防御,以统一不同数据的梯度,以便攻击者只能探究不同样本相似的较弱的攻击方向。由于这种普遍的攻击扰动的验证与投入特定的扰动相比,Unig通过指示攻击者一个扭曲且信息不足的攻击方向来保护现实世界中的DNN。为了增强Unig在现实世界应用中的实际意义,我们将其实现为Hadamard产品模块,该模块具有计算效率且很容易插入任何模型。根据对5个SQA和4个防御基线的广泛实验,Unig显着改善了现实世界的鲁棒性,而不会伤害CIFAR10和Imagenet上的清洁准确性。例如,Unig在2500 Query Square攻击下保持了77.80%精度的CIFAR-10模型,而最先进的对手训练的模型仅在CIFAR10上具有67.34%的速度。同时,Unig在清洁精度和输出的修改程度上大大超过了所有基准。代码将发布。
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