arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2308.03212cs.CLcs.CCcs.LG
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平均硬注意力Transformer是常数深度均匀阈值电路

Average-Hard Attention Transformers are Constant-Depth Uniform Threshold Circuits

Umeå University(于默奥大学);Department of Computing Science(计算机科学系)

Lena Strobl

AI总结:

该研究拓展了平均硬注意力Transformer与常数深度阈值电路的关联结论,证明其对应的电路结果也可扩展为均匀电路,完善了Transformer的计算复杂度理论分析。

摘要:

Transformer已成为各类自然语言处理任务中广泛使用的神经网络模型。既往研究探索了其与常数深度阈值电路的关联,作出两项假设:平均硬注意力,以及内部计算相对于输入长度的对数精度。Merrill等人(2022)证明,平均硬注意力Transformer可识别的语言属于复杂度类TC0,即能被常数深度、多项式规模阈值电路识别的语言集合。同样,Merrill与Sabharwal(2023)表明,对数精度Transformer可识别的语言属于均匀TC0类。这说明两种Transformer模型都可被常数深度阈值电路模拟,后者因能生成均匀电路族而更具鲁棒性。本文证明,第一项结果也可扩展得到均匀电路。

英文摘要:

Transformers have emerged as a widely used neural network model for various natural language processing tasks. Previous research explored their relationship with constant-depth threshold circuits, making two assumptions: average-hard attention and logarithmic precision for internal computations relative to input length. Merrill et al. (2022) prove that average-hard attention transformers recognize languages that fall within the complexity class TC0, denoting the set of languages that can be recognized by constant-depth polynomial-size threshold circuits. Likewise, Merrill and Sabharwal (2023) show that log-precision transformers recognize languages within the class of uniform TC0. This shows that both transformer models can be simulated by constant-depth threshold circuits, with the latter being more robust due to generating a uniform circuit family. Our paper shows that the first result can be extended to yield uniform circuits as well.

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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