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arXiv 2305.04465cs.CL
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扩散模型能否在文本生成中实现更优性能?弥合训练与推理之间的差距!

Can Diffusion Model Achieve Better Performance in Text Generation? Bridging the Gap between Training and Inference!

Soochow University(苏州大学)

Zecheng Tang, Pinzheng Wang, Keyan Zhou, Juntao Li, Ziqiang Cao, Min Zhang

AI总结:

本文针对扩散模型在文本生成中训练与推理不一致的问题,提出距离惩罚和自适应衰减采样两种方法,在6个任务上实现100-200倍加速且性能更优。

摘要:

扩散模型通过将离散文本映射到连续空间,已成功应用于文本生成任务。然而,由于推理过程中缺少前向过程,训练与推理之间存在不可忽视的差距。因此,模型仅基于先前生成的反向噪声进行预测,而非基于前向过程计算的噪声。此外,推理加速中广泛使用的下采样策略会导致训练与推理之间的扩散轨迹不匹配。为了理解并缓解上述两类训练-推理差异,我们进行了全面的初步研究。基于我们的观察,我们提出了两种简单而有效的方法来弥合上述差距,分别命名为距离惩罚和自适应衰减采样。在6个生成任务上的大量实验证实了我们方法的优越性,这些方法能够实现100倍到200倍的加速,同时获得更好的性能。

英文摘要:

Diffusion models have been successfully adapted to text generation tasks by mapping the discrete text into the continuous space. However, there exist nonnegligible gaps between training and inference, owing to the absence of the forward process during inference. Thus, the model only predicts based on the previously generated reverse noise rather than the noise computed by the forward process. Besides, the widely-used downsampling strategy in speeding up the inference will cause the mismatch of diffusion trajectories between training and inference. To understand and mitigate the above two types of training-inference discrepancies, we launch a thorough preliminary study. Based on our observations, we propose two simple yet effective methods to bridge the gaps mentioned above, named Distance Penalty and Adaptive Decay Sampling. Extensive experiments on \textbf{6} generation tasks confirm the superiority of our methods, which can achieve $100\times \rightarrow 200\times$ speedup with better performance.

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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