arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2501.02547stat.MLcs.LG
收藏

Transformer在贝叶斯网络中模拟序列生成的极大似然估计

Transformers Simulate MLE for Sequence Generation in Bayesian Networks

The University of Hong Kong(香港大学);Princeton University(普林斯顿大学);Northwestern University(西北大学)

Yuan Cao, Yihan He, Dennis Wu, Hong-Yu Chen, Jianqing Fan, Han Liu

AI总结:

本文证明Transformer可通过上下文极大似然估计在贝叶斯网络中自回归生成序列,并通过实验验证其可训练获得,凸显其学习复杂概率模型的潜力。

摘要:

Transformer已在各个领域取得了显著成功,尤其在自然语言处理等涉及序列数据的任务中表现卓越。尽管取得了这些成就,但对Transformer能力的理论理解仍然有限。本文中,我们研究了Transformer基于上下文极大似然估计(MLE)在贝叶斯网络中自回归生成序列的理论能力。具体而言,我们考虑一个设置,其中上下文由根据贝叶斯网络生成的一组独立序列构成。我们证明存在一个简单的Transformer模型,它可以(i)根据上下文估计贝叶斯网络的条件概率,以及(ii)根据估计的条件概率自回归生成符合贝叶斯网络的新样本。我们进一步通过大量实验证明,这样的Transformer不仅在理论上存在,而且可以通过训练有效获得。我们的分析凸显了Transformer学习复杂概率模型的潜力,并有助于更好地理解大型语言模型作为一类强大的序列生成器。

英文摘要:

Transformers have achieved significant success in various fields, notably excelling in tasks involving sequential data like natural language processing. Despite these achievements, the theoretical understanding of transformers' capabilities remains limited. In this paper, we investigate the theoretical capabilities of transformers to autoregressively generate sequences in Bayesian networks based on in-context maximum likelihood estimation (MLE). Specifically, we consider a setting where a context is formed by a set of independent sequences generated according to a Bayesian network. We demonstrate that there exists a simple transformer model that can (i) estimate the conditional probabilities of the Bayesian network according to the context, and (ii) autoregressively generate a new sample according to the Bayesian network with estimated conditional probabilities. We further demonstrate in extensive experiments that such a transformer does not only exist in theory, but can also be effectively obtained through training. Our analysis highlights the potential of transformers to learn complex probabilistic models and contributes to a better understanding of large language models as a powerful class of sequence generators.

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。

↑