Fu Zhang


2024

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SRF: Enhancing Document-Level Relation Extraction with a Novel Secondary Reasoning Framework
Fu Zhang | Qi Miao | Jingwei Cheng | Hongsen Yu | Yi Yan | Xin Li | Yongxue Wu
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing

Document-level Relation Extraction (DocRE) aims to extract relations between entity pairs in a document and poses many challenges as it involves multiple mentions of entities and cross-sentence inference. However, several aspects that are important for DocRE have not been considered and explored. Existing work ignores bidirectional mention interaction when generating relational features for entity pairs. Also, sophisticated neural networks are typically designed for cross-sentence evidence extraction to further enhance DocRE. More interestingly, we reveal a noteworthy finding: If a model has predicted a relation between an entity and other entities, this relation information may help infer and predict more relations between the entity’s adjacent entities and these other entities. Nonetheless, none of existing methods leverage secondary reasoning to exploit results of relation prediction. To this end, we propose a novel Secondary Reasoning Framework (SRF) for DocRE. In SRF, we initially propose a DocRE model that incorporates bidirectional mention fusion and a simple yet effective evidence extraction module (incurring only an additional learnable parameter overhead) for relation prediction. Further, for the first time, we elaborately design and propose a novel secondary reasoning method to discover more relations by exploring the results of the first relation prediction. Extensive experiments show that SRF achieves SOTA performance and our secondary reasoning method is both effective and general when integrated into existing models.

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ATAP: Automatic Template-Augmented Commonsense Knowledge Graph Completion via Pre-Trained Language Models
Fu Zhang | Yifan Ding | Jingwei Cheng
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing

The mission of commonsense knowledge graph completion (CKGC) is to infer missing facts from known commonsense knowledge. CKGC methods can be roughly divided into two categories: triple-based methods and text-based methods. Due to the imbalanced distribution of entities and limited structural information, triple-based methods struggle with long-tail entities. Text-based methods alleviate this issue, but require extensive training and fine-tuning of language models, which reduces efficiency. To alleviate these problems, we propose ATAP, the first CKGC framework that utilizes automatically generated continuous prompt templates combined with pre-trained language models (PLMs). Moreover, ATAP uses a carefully designed new prompt template training strategy, guiding PLMs to generate optimal prompt templates for CKGC tasks. Combining the rich knowledge of PLMs with the template automatic augmentation strategy, ATAP effectively mitigates the long-tail problem and enhances CKGC performance. Results on benchmark datasets show that ATAP achieves state-of-the-art performance overall.

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AlignRE: An Encoding and Semantic Alignment Approach for Zero-Shot Relation Extraction
Zehan Li | Fu Zhang | Jingwei Cheng
Findings of the Association for Computational Linguistics: ACL 2024

Zero-shot Relation Extraction (ZSRE) aims to predict unseen relations between entity pairs from input sentences. Existing prototype-based ZSRE methods encode relation descriptions into prototype embeddings and predict by measuring the similarity between sentence embeddings and prototype embeddings. However, these methods often overlook abundant side information of relations and suffer from a significant encoding gap between prototypes and sentences, limiting performance. To this end, we propose a framework named AlignRE, based on two Alignment methods for ZSRE. Specifically, we present a novel perspective centered on encoding schema alignment to enhance prototype-based ZSRE methods. We utilize well-designed prompt-tuning to bridge the encoding gap. To improve prototype quality, we explore and leverage multiple side information and propose a prototype aggregation method based on semantic alignment to create comprehensive relation prototype representations. We conduct experiments on FewRel and Wiki-ZSL datasets and consistently outperform state-of-the-art methods. Moreover, our method exhibits substantially faster performance and reduces the need for extensive manual labor in prototype construction. Code is available at https://github.com/lizehan1999/AlignRE.

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Advancing Cross-Lingual Entity Alignment with Large Language Models: Tailored Sample Segmentation and Zero-Shot Prompts
Linyan Yang | Jingwei Cheng | Fu Zhang
Findings of the Association for Computational Linguistics: EMNLP 2024

In recent years, the advent of large language models (LLMs) like GPT and Llama has significantly influenced numerous domains, particularly in advancing natural language processing (NLP) capabilities. LLMs have shown remarkable performance in NLP tasks such as relation extraction (RE) and knowledge graph completion (KGC), enhancing activities related to knowledge graphs. As a result, there is a growing interest in integrating LLMs into cross-lingual entity alignment (EA) task, which aims to identify equivalent entities across various knowledge graphs, thereby improving the performance of current baselines. However, employing LLMs for entity alignment poses challenges in efficiently handling large-scale data, generating suitable data samples, and adapting prompts for the EA task. To tackle these challenges, we propose Seg-Align, an innovative framework that integrating distance feature extraction, sample **Seg**mentation, and zero-shot prompts. Through extensive experiments on two widely used cross-lingual benchmark datasets, we have not only demonstrated the effectiveness of our proposed sample segmentation algorithm but also highlighted the state-of-the-art performance of Seg-Align. Code is available at https://github.com/yangxiaoxiaoly/Seg-Align.

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SALMON: A Structure-Aware Language Model with logicality and densification strategy for Temporal Knowledge Graph Reasoning
Fu Zhang | Jinghao Lin | Jingwei Cheng
Findings of the Association for Computational Linguistics: EMNLP 2024

Temporal knowledge graph reasoning (TKGR) is a crucial task that involves reasoning at known timestamps to complete the future facts and has attracted more and more attention in recent years. The current TKGR models are mainly based on graph neural networks or tensor decomposition techniques. Few works in TKGR focus on pre-trained language models (PLMs) which have powerful sequence modeling capabilities to capture the temporal associations between facts. In this paper, we propose a model SALMON: a Structure-Aware Language Model with logicality and densification strategy. Specifically, we design a PLM-based framework with a structure-aware layer inside to jointly capture the temporal evolving pattern and structural information in TKGs. To further enhance the model’s ability to infer causal associations of facts, we propose a logical judging module, which can guide the model to prioritize learning the most relevant evolving information of logical causal associations in TKGs during the training process. Moreover, we propose a densification strategy based on large language models, through a carefully crafted Chain of Thought prompt, to dig out some knowledge necessary for reasoning about fact associations, thereby making the model perform better. Extensive experimental results demonstrate the superiority of our model over the state-of-the-art baselines.

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NALA: an Effective and Interpretable Entity Alignment Method
Chuanhao Xu | Jingwei Cheng | Fu Zhang
Findings of the Association for Computational Linguistics: EMNLP 2024

Entity alignment (EA) aims to find equivalent entities between two Knowledge Graphs. Existing embedding-based EA methods usually encode entities as embeddings, triples as embeddings’ constraint and learn to align the embeddings. However, the details of the underlying logical inference steps among the alignment process are usually omitted, resulting in inadequate inference process. In this paper, we introduce NALA, an entity alignment method that captures three types of logical inference paths with Non-Axiomatic Logic (NAL). Type 1&2 align the entity pairs and type 3 aligns relations. NALA iteratively aligns entities and relations by integrating the conclusions of the inference paths. Our method is logically interpretable and extensible by introducing NAL, and thus suitable for various EA settings. Experimental results show that NALA outperforms state-of-the-art methods in terms of Hits@1, achieving 0.98+ on all three datasets of DBP15K with both supervised and unsupervised settings. We offer a pioneering in-depth analysis of the fundamental principles of entity alignment, approaching the subject from a unified and logical perspective. Our code is available at https://github.com/13998151318/NALA.