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arXiv 2212.09412cs.CLcs.AIcs.LG
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在嵌入空间上赋能扩散模型用于文本生成

Empowering Diffusion Models on the Embedding Space for Text Generation

School of Computer Science and Technology, University of Science and Technology of China(中国科学技术大学计算机科学与技术学院);State Key Laboratory of Cognitive Intelligence(认知智能国家重点实验室);Microsoft Research Asia(微软亚洲研究院)

Zhujin Gao, Junliang Guo, Xu Tan, Yongxin Zhu, Fang Zhang, Jiang Bian, Linli Xu

AI总结:

本文系统研究了嵌入空间扩散模型在文本生成中的优化挑战,提出了锚点损失和噪声重缩放框架以解决训练不稳定和退化问题,并基于Transformer构建了Difformer模型,在多种文本生成任务上取得了优于基线的性能。

摘要:

扩散模型在视觉和音频任务上取得了最先进的合成质量,近期的工作进一步通过在嵌入空间上进行扩散将其应用于文本数据。在本文中,我们对嵌入空间和去噪模型所遇到的优化挑战进行了系统研究,这些问题此前尚未被仔细探讨。首先,嵌入的数据分布是可学习的,这可能导致嵌入空间的崩溃和训练的不稳定。为了缓解这一问题,我们提出了一种名为锚点损失的新目标,它比以前的方法更高效。其次,我们发现传统调度方案的噪声水平不足以训练出理想的去噪模型,从而引入了不同程度的退化。为了应对这一挑战,我们提出了一种名为噪声重缩放的新框架。基于上述分析,我们提出了Difformer,一种基于Transformer的嵌入扩散模型。在多种开创性文本生成任务上的实验表明,所提出方法的有效性以及Difformer相较于先前最先进嵌入扩散基线的优越性。

英文摘要:

Diffusion models have achieved state-of-the-art synthesis quality on both visual and audio tasks, and recent works further adapt them to textual data by diffusing on the embedding space. In this paper, we conduct systematic studies of the optimization challenges encountered with both the embedding space and the denoising model, which have not been carefully explored. Firstly, the data distribution is learnable for embeddings, which may lead to the collapse of the embedding space and unstable training. To alleviate this problem, we propose a new objective called the anchor loss which is more efficient than previous methods. Secondly, we find the noise levels of conventional schedules are insufficient for training a desirable denoising model while introducing varying degrees of degeneration in consequence. To address this challenge, we propose a novel framework called noise rescaling. Based on the above analysis, we propose Difformer, an embedding diffusion model based on Transformer. Experiments on varieties of seminal text generation tasks show the effectiveness of the proposed methods and the superiority of Difformer over previous state-of-the-art embedding diffusion baselines.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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