Large-Language-Model-Enhanced Adaptive Optimization for Data-Limited Multi-Domain Machine Translation

Abstract

Data-limited multi-domain machine translation remains challenging because parallel corpora are scarce in specialized domains, domain terminology is highly constrained, and large language models may generate fluent but unfaithful translations. Direct prompting or ordinary fine-tuning is therefore insufficient for domain-sensitive translation scenarios. To address these issues, this paper proposes DKA-LLM-MT, a large-language-model-enhanced adaptive optimization framework for data-limited multi-domain machine translation. The framework follows a data–model–reliability design. First, a domain-knowledge-constrained data augmentation strategy generates pseudo-parallel corpora under terminology, semantic consistency, and domain-style constraints. Second, a retrieval-augmented parameter-efficient adaptation mechanism integrates domain memory retrieval, lightweight LoRA adapters, and dynamic domain routing. Third, a reliability-aware optimization mechanism incorporates semantic fidelity, terminology consistency, and hallucination risk into both training-time data selection and inference-time candidate reranking. Experiments are conducted on five public data-limited domain translation benchmarks covering medical, legal, technical, news, and spoken-style texts. The proposed method achieves an average BLEU of 36.18, chrF of 62.14, COMET of 0.816, and TER of 40.62, consistently outperforming strong neural, multilingual, and LLM-based baselines. Additional matched-backbone and same-language-pair analyses are included to separate the effect of domain adaptation from language-pair variation. Reliability evaluation further shows that DKA-LLM-MT improves terminology accuracy to 89.6% and reduces hallucination rate to 3.2%. The proposed framework provides an effective and reliable solution for domain-sensitive machine translation under limited bilingual supervision and offers practical support for bilingual reading, specialized translation assistance, and domain-oriented language learning.