Despite the known limitations, most machine translation systems today still
operate on the sentence-level. One reason for this is, that most parallel
training data is only sentence-level aligned, without document-level meta
information available. In this work, we set out to build context-aware
translation systems utilizing document-level monolingual data instead. This can
be achieved by combining any existing sentence-level translation model with a
document-level language model. We improve existing approaches by leveraging
recent advancements in model combination. Additionally, we propose novel
weighting techniques that make the system combination more flexible and
significantly reduce computational overhead. In a comprehensive evaluation on
four diverse translation tasks, we show that our extensions improve
document-targeted scores substantially and are also computationally more
efficient. However, we also find that in most scenarios, back-translation gives
even better results, at the cost of having to re-train the translation system.
Finally, we explore language model fusion in the light of recent advancements
in large language models. Our findings suggest that there might be strong
potential in utilizing large language models via model combination.

本研究针对机器翻译系统在句子级别上操作的限制，提出了利用文档级单语数据构建上下文感知翻译系统的方法，并通过结合现有句子级翻译模型和文档级语言模型，改进了现有方法，并提出了新的权重技术以提高系统组合的灵活性和降低计算开销。通过对四个不同的翻译任务进行全面评估，结果显示我们的改进能够显著提高面向文档的评分，并在计算上更高效。但在大多数情况下，通过再训练翻译系统进行反向翻译可以获得更好的结果。最后，我们探索了基于大语言模型的语言模型融合，在最新的大语言模型进展的基础上取得了一定的潜力。