知识库问题应答(KBQA)旨在在外部知识库的帮助下回答自然语言问题。核心思想是找到内部知识与知识库的已知三元组之间的内部知识之间的联系。 KBQA任务管道包含几个步骤,包括实体识别,关系提取和实体链接。这种管道方法意味着任何过程中的错误将不可避免地传播到最终预测。为了解决上述问题,本文提出了一种具有预培训语言模型(PLM)和知识图(KG)的语料库生成 - 检索方法(CGRM)。首先,基于MT5模型,我们设计了两个新的预训练任务:基于段落的知识屏蔽语言建模和问题,以获取知识增强型T5(KT5)模型。其次,在用一系列启发式规则预处理知识图的预处理之后,KT5模型基于处理的三元组生成自然语言QA对。最后,我们通过检索合成数据集直接解决QA。我们在NLPCC-ICCPOL 2016 KBQA数据集上测试我们的方法,结果表明,我们的框架提高了KBQA的性能,直接向前的方法与最先进的方法竞争。
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Denoising Diffusion Probabilistic Models (DDPMs) are emerging in text-to-speech (TTS) synthesis because of their strong capability of generating high-fidelity samples. However, their iterative refinement process in high-dimensional data space results in slow inference speed, which restricts their application in real-time systems. Previous works have explored speeding up by minimizing the number of inference steps but at the cost of sample quality. In this work, to improve the inference speed for DDPM-based TTS model while achieving high sample quality, we propose ResGrad, a lightweight diffusion model which learns to refine the output spectrogram of an existing TTS model (e.g., FastSpeech 2) by predicting the residual between the model output and the corresponding ground-truth speech. ResGrad has several advantages: 1) Compare with other acceleration methods for DDPM which need to synthesize speech from scratch, ResGrad reduces the complexity of task by changing the generation target from ground-truth mel-spectrogram to the residual, resulting into a more lightweight model and thus a smaller real-time factor. 2) ResGrad is employed in the inference process of the existing TTS model in a plug-and-play way, without re-training this model. We verify ResGrad on the single-speaker dataset LJSpeech and two more challenging datasets with multiple speakers (LibriTTS) and high sampling rate (VCTK). Experimental results show that in comparison with other speed-up methods of DDPMs: 1) ResGrad achieves better sample quality with the same inference speed measured by real-time factor; 2) with similar speech quality, ResGrad synthesizes speech faster than baseline methods by more than 10 times. Audio samples are available at https://resgrad1.github.io/.
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In this work, we investigate improving the generalizability of GAN-generated image detectors by performing data augmentation in the fingerprint domain. Specifically, we first separate the fingerprints and contents of the GAN-generated images using an autoencoder based GAN fingerprint extractor, followed by random perturbations of the fingerprints. Then the original fingerprints are substituted with the perturbed fingerprints and added to the original contents, to produce images that are visually invariant but with distinct fingerprints. The perturbed images can successfully imitate images generated by different GANs to improve the generalization of the detectors, which is demonstrated by the spectra visualization. To our knowledge, we are the first to conduct data augmentation in the fingerprint domain. Our work explores a novel prospect that is distinct from previous works on spatial and frequency domain augmentation. Extensive cross-GAN experiments demonstrate the effectiveness of our method compared to the state-of-the-art methods in detecting fake images generated by unknown GANs.
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Error correction in automatic speech recognition (ASR) aims to correct those incorrect words in sentences generated by ASR models. Since recent ASR models usually have low word error rate (WER), to avoid affecting originally correct tokens, error correction models should only modify incorrect words, and therefore detecting incorrect words is important for error correction. Previous works on error correction either implicitly detect error words through target-source attention or CTC (connectionist temporal classification) loss, or explicitly locate specific deletion/substitution/insertion errors. However, implicit error detection does not provide clear signal about which tokens are incorrect and explicit error detection suffers from low detection accuracy. In this paper, we propose SoftCorrect with a soft error detection mechanism to avoid the limitations of both explicit and implicit error detection. Specifically, we first detect whether a token is correct or not through a probability produced by a dedicatedly designed language model, and then design a constrained CTC loss that only duplicates the detected incorrect tokens to let the decoder focus on the correction of error tokens. Compared with implicit error detection with CTC loss, SoftCorrect provides explicit signal about which words are incorrect and thus does not need to duplicate every token but only incorrect tokens; compared with explicit error detection, SoftCorrect does not detect specific deletion/substitution/insertion errors but just leaves it to CTC loss. Experiments on AISHELL-1 and Aidatatang datasets show that SoftCorrect achieves 26.1% and 9.4% CER reduction respectively, outperforming previous works by a large margin, while still enjoying fast speed of parallel generation.
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We shed light on a pitfall and an opportunity in physics-informed neural networks (PINNs). We prove that a multilayer perceptron (MLP) only with ReLU (Rectified Linear Unit) or ReLU-like Lipschitz activation functions will always lead to a vanished Hessian. Such a network-imposed constraint contradicts any second- or higher-order partial differential equations (PDEs). Therefore, a ReLU-based MLP cannot form a permissible function space for the approximation of their solutions. Inspired by this pitfall, we prove that a linear PDE up to the $n$-th order can be strictly satisfied by an MLP with $C^n$ activation functions when the weights of its output layer lie on a certain hyperplane, as called the out-layer-hyperplane. An MLP equipped with the out-layer-hyperplane becomes "physics-enforced", no longer requiring a loss function for the PDE itself (but only those for the initial and boundary conditions). Such a hyperplane exists not only for MLPs but for any network architecture tailed by a fully-connected hidden layer. To our knowledge, this should be the first PINN architecture that enforces point-wise correctness of a PDE. We give the closed-form expression of the out-layer-hyperplane for second-order linear PDEs and provide an implementation.
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激活函数是元素的数学函数,在深神经网络(DNN)中起着至关重要的作用。已经提出了许多新颖和复杂的激活功能来提高DNN的准确性,但在训练过程中还可以通过反向传播消耗大量记忆。在这项研究中,我们提出了嵌套的正向自动分化(正向AD),专门针对用于记忆效率的DNN训练的元素激活函数。我们在两个广泛使用的深度学习框架(Tensorflow和Pytorch)中部署了嵌套的AD,分别支持静态和动态计算图。我们的评估表明,在相同的记忆降低率下,嵌套的前AD嵌套将记忆足迹降低到1.97倍,比基线模型降低了20%。
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尽管目前基于深度学习的方法在盲目的单图像超分辨率(SISR)任务中已获得了有希望的表现,但其中大多数主要集中在启发式上构建多样化的网络体系结构,并更少强调对Blur之间的物理发电机制的明确嵌入内核和高分辨率(HR)图像。为了减轻这个问题,我们提出了一个模型驱动的深神经网络,称为blind SISR。具体而言,为了解决经典的SISR模型,我们提出了一种简单的效果迭代算法。然后,通过将所涉及的迭代步骤展开到相应的网络模块中,我们自然构建了KXNET。所提出的KXNET的主要特异性是整个学习过程与此SISR任务的固有物理机制完全合理地集成在一起。因此,学习的模糊内核具有清晰的物理模式,并且模糊内核和HR图像之间的相互迭代过程可以很好地指导KXNET沿正确的方向发展。关于合成和真实数据的广泛实验很好地证明了我们方法的卓越准确性和一般性超出了当前代表性的最先进的盲目SISR方法。代码可在:\ url {https://github.com/jiahong-fu/kxnet}中获得。
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分布式隐私的回归方案已在各个领域开发和扩展,在这些领域中,多方协作和私人运行优化算法,例如梯度下降,以学习一组最佳参数。但是,传统的基于梯度的方法无法解决包含具有L1正则化的客观功能的问题,例如LASSO回归。在本文中,我们介绍了一个名为FCD的新分布式方案联合坐标下降,旨在在多方场景下安全地解决此问题。具体而言,通过安全的聚合和添加的扰动,我们的方案确保:(1)没有向其他方泄漏本地信息,并且(2)全局模型参数不会暴露于云服务器。最终,各方可以消除附加的扰动,以得出具有高性能的全球模型。我们表明,FCD方案填补了多方安全坐标下降方法的空白,并且适用于一般线性回归,包括线性,脊和拉索回归。理论安全分析和实验结果表明,可以有效,有效地执行FCD,并以低MAE度量作为在现实世界UCI数据集的三种线性回归的任务下作为集中方法提供的低MAE度量。
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最近,卷积神经网络(CNN)已被广泛用于图像DeNoising。现有方法受益于剩余学习并获得高性能。许多研究都注意到优化CNN的网络体系结构,但忽略了残留学习的局限性。本文提出了两个局限性。一个是残留学习的重点是估计噪声,从而忽略图像信息。另一个是图像自相似性没有被有效考虑。本文提出了一个组成剥落网络(CDN),其图像信息路径(IIP)和噪声估计路径(NEP)将分别解决这两个问题。 IIP通过图像到图像的方法来培训图像信息。对于NEP,它从训练的角度利用了图像自相似性。这种基于相似性的训练方法将NEP限制为输出具有特定类型噪声的不同图像贴片的相似估计噪声分布。最后,将全面考虑图像信息和噪声分布信息,以进行图像denoising。实验表明,CDN达到最新的结果会导致合成和现实世界图像降解。我们的代码将在https://github.com/jiahongz/cdn上发布。
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量化是一种降低DNN模型的计算和记忆成本的技术,DNN模型越来越大。现有的量化解决方案使用固定点整数或浮点类类型,这些量子的好处有限,因为两者都需要更多位以保持原始型号的准确性。另一方面,可变长度量化使用低位量化对正常值和高精度的分数对异常值的一部分。即使这项工作带来了算法的好处,但由于长度的编码和解码,它也引入了重要的硬件开销。在这项工作中,我们提出了一种称为ANT的固定长度自适应数值数据类型,以通过微小的硬件开销实现低位量化。我们的数据类型ANT利用了两项关键创新来利用DNN模型中的张贴内和调整的自适应机会。首先,我们提出了一种特定的数据类型Flint,该数据类型结合了Float和INT的优势,以适应张量中不同值的重要性。其次,我们提出了一个自适应框架,该框架根据其分布特性选择每个张量的最佳类型。我们为蚂蚁设计了统一的处理元件体系结构,并显示其与现有DNN加速器的易于集成。我们的设计导致2.8 $ \ times $速度和2.5 $ \ times $ $ $ $ $ \ times $ $ \ times $ $ \ times $ $ \ times $ $ \ times $ $ \ times $ $ \ times $ $ \ times $比最先进的量化加速器提高了能源效率。
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