Key Information Extraction (KIE) is a challenging multimodal task aimed at extracting structured value entities from visually rich documents. Despite recent advancements, two major challenges remain. First, existing datasets typically feature fixed layouts and a limited set of entity categories, while current methods are based on a full-shot setting that is difficult to apply in real-world scenarios, where new entity categories frequently emerge. Secondly, current methods often treat key entities simply as parts of the OCR-parsed context, neglecting the positive impact of the relationships between key-value entities. To address the first challenge, we introduce a new large-scale, human-annotated dataset, Complex Layout document for Key Information Extraction (CLEX). Comprising 5,860 images with 1,162 entity categories, CLEX is larger and more complex than existing datasets. It also primarily focuses on the zero-shot and few-shot KIE tasks, which are more aligned with real-world applications. To tackle the second challenge, we propose the Parallel Pointer-based Network (P²Net). This model frames KIE as a pointer-based classification task and effectively leverages implicit relationships between key-value entities to enhance extraction. Its parallel extraction mechanism enables simultaneous and efficient extraction of multiple results. Experiments on widely-used datasets, including SROIE, CORD, and the newly introduced CLEX, demonstrate that P²Net outperforms existing state-of-the-art methods (including GPT-4V) while maintaining fast inference speeds.

Existing sentiment analysis models have achieved great advances with the help of sufficient sentiment annotations. Unfortunately, many languages do not have sufficient sentiment corpus. To this end, recent studies have proposed cross-lingual sentiment analysis to transfer sentiment analysis models from resource-rich languages to low-resource languages. However, these studies either rely on external cross-lingual supervision (e.g., parallel corpora and translation model), or are limited by the cross-lingual gaps. In this work, based on the intuitive assumption that the relationships between emojis and sentiments are consistent across different languages, we investigate transferring sentiment knowledge across languages with the help of emojis. To this end, we propose a novel cross-lingual sentiment analysis approach dubbed Curriculum Knowledge Distiller (CKD). The core idea of CKD is to use emojis to bridge the source and target languages. Note that, compared with texts, emojis are more transferable, but cannot reveal the precise sentiment. Thus, we distill multiple Intermediate Sentiment Classifiers (ISC) on source language corpus with emojis to get ISCs with different attention weights of texts. To transfer them into the target language, we distill ISCs into the Target Language Sentiment Classifier (TSC) following the curriculum learning mechanism. In this way, TSC can learn delicate sentiment knowledge, meanwhile, avoid being affected by cross-lingual gaps. Experimental results on five cross-lingual benchmarks clearly verify the effectiveness of our approach.