Most of the successful and predominant methods for bilingual lexicon induction (BLI) are mapping-based, where a linear mapping function is learned with the assumption that the word embedding spaces of different languages exhibit similar geometric structures (i.e., approximately isomorphic). However, several recent studies have criticized this simplified assumption showing that it does not hold in general even for closely related languages. In this work, we propose a novel semi-supervised method to learn cross-lingual word embeddings for BLI. Our model is independent of the isomorphic assumption and uses nonlinear mapping in the latent space of two independently trained auto-encoders. Through extensive experiments on fifteen (15) different language pairs (in both directions) comprising resource-rich and low-resource languages from two different datasets, we demonstrate that our method outperforms existing models by a good margin. Ablation studies show the importance of different model components and the necessity of non-linear mapping.

提出了一种新的半监督方法，通过两个独立训练的自编码器的潜在空间使用非线性映射，学习用于双语词汇识别的跨语言词嵌入表示，并在15种不同方向的语言对（包括资源丰富和低资源语言）的两个数据集上进行了广泛的实验，结果表明该方法优于现有模型。

LNMap: 基于潜空间非线性映射的双语词典感应中的同构假设偏移