Nan Hu
Author directoryPapers on this page may belong to the following people: Nan Hu, Nan Hu, Nan Hu, Nan Hu
2024
Exploring the Impact of Table-to-Text Methods on Augmenting LLM-based Question Answering with Domain Hybrid Data
Dehai Min | Nan Hu | Rihui Jin | Nuo Lin | Jiaoyan Chen | Yongrui Chen | Yu Li | Guilin Qi | Yun Li | Nijun Li | Qianren Wang
Proceedings of the 2024 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 6: Industry Track)
Dehai Min | Nan Hu | Rihui Jin | Nuo Lin | Jiaoyan Chen | Yongrui Chen | Yu Li | Guilin Qi | Yun Li | Nijun Li | Qianren Wang
Proceedings of the 2024 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 6: Industry Track)
Augmenting Large Language Models (LLMs) for Question Answering (QA) with domain specific data has attracted wide attention. However, domain data often exists in a hybrid format, including text and semi-structured tables, posing challenges for the seamless integration of information. Table-to-Text Generation is a promising solution by facilitating the transformation of hybrid data into a uniformly text-formatted corpus. Although this technique has been widely studied by the NLP community, there is currently no comparative analysis on how corpora generated by different table-to-text methods affect the performance of QA systems.In this paper, we address this research gap in two steps. First, we innovatively integrate table-to-text generation into the framework of enhancing LLM-based QA systems with domain hybrid data. Then, we utilize this framework in real-world industrial data to conduct extensive experiments on two types of QA systems (DSFT and RAG frameworks) with four representative methods: Markdown format, Template serialization, TPLM-based method, and LLM-based method. Based on the experimental results, we draw some empirical findings and explore the underlying reasons behind the success of some methods. We hope the findings of this work will provide a valuable reference for the academic and industrial communities in developing robust QA systems.
The Fourth Evaluation on Chinese Spatial Cognition
Liming Xiao | Nan Hu | Weidong Zhan | Yuhang Qin | Sirui Deng | Chunhui Sun | Qixu Cai | Nan Li
Proceedings of the 23rd Chinese National Conference on Computational Linguistics (Volume 3: Evaluations)
Liming Xiao | Nan Hu | Weidong Zhan | Yuhang Qin | Sirui Deng | Chunhui Sun | Qixu Cai | Nan Li
Proceedings of the 23rd Chinese National Conference on Computational Linguistics (Volume 3: Evaluations)
“The Fourth Chinese Spatial Cognition Evaluation Task (SpaCE 2024) presents the first comprehensive Chinese benchmark to assess spatial semantic understanding and reasoning capabilities of Large Language Models (LLMs). It comprises five subtasks in the form of multiple-choice questions: (1) identifying spatial semantic roles; (2) retrieving spatial referents; (3) detecting spatial semantic anomalies; (4) recognizing synonymous spatial expression with different forms; (5) conducting spatial position reasoning. In addition to proposing new tasks, SpaCE 2024 applied a rule-based method to generate high-quality synthetic data with difficulty levels for the reasoning task. 12 teams submitted their models and results, and the top-performing team attained an accuracy of 60.24%, suggesting that there is still significant room for current LLMs to improve, especially in tasks requiring high spatial cognitive processing.”
2023
Enhancing Structured Evidence Extraction for Fact Verification
Zirui Wu | Nan Hu | Yansong Feng
Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing
Zirui Wu | Nan Hu | Yansong Feng
Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing
Open-domain fact verification is the task of verifying claims in natural language texts against extracted evidence. FEVEROUS is a benchmark that requires extracting and integrating both unstructured and structured evidence to verify a given claim. Previous models suffer from low recall of structured evidence extraction, i.e., table extraction and cell selection. In this paper, we propose a simple but effective method to enhance the extraction of structured evidence by leveraging the row and column semantics of tables. Our method comprises two components: (i) a coarse-grained table extraction module that selects tables based on rows and columns relevant to the claim and (ii) a fine-grained cell selection graph that combines both formats of evidence and enables multi-hop and numerical reasoning. We evaluate our method on FEVEROUS and achieve an evidence recall of 60.01% on the test set, which is 6.14% higher than the previous state-of-the-art performance. Our results demonstrate that our method can extract tables and select cells effectively, and provide better evidence sets for verdict prediction. Our code is released at https://github.com/WilliamZR/see-st
UnifEE: Unified Evidence Extraction for Fact Verification
Nan Hu | Zirui Wu | Yuxuan Lai | Chen Zhang | Yansong Feng
Proceedings of the 17th Conference of the European Chapter of the Association for Computational Linguistics
Nan Hu | Zirui Wu | Yuxuan Lai | Chen Zhang | Yansong Feng
Proceedings of the 17th Conference of the European Chapter of the Association for Computational Linguistics
FEVEROUS is a fact extraction and verification task that requires systems to extract evidence of both sentences and table cells from a Wikipedia dump, then predict the veracity of the given claim accordingly. Existing works extract evidence in the two formats separately, ignoring potential connections between them. In this paper, we propose a Unified Evidence Extraction model (UnifEE), which uses a mixed evidence graph to extract the evidence in both formats. With the carefully-designed unified evidence graph, UnifEE allows evidence interactions among all candidates in both formats at similar granularity. Experiments show that, with information aggregated from related evidence candidates in the fusion graph, UnifEE can make better decisions about which evidence should be kept, especially for claims requiring multi-hop reasoning or a combination of tables and texts. Thus it outperforms all previous evidence extraction methods and brings significant improvement in the subsequent claim verification step.
2022
HiCLRE: A Hierarchical Contrastive Learning Framework for Distantly Supervised Relation Extraction
Dongyang Li | Taolin Zhang | Nan Hu | Chengyu Wang | Xiaofeng He
Findings of the Association for Computational Linguistics: ACL 2022
Dongyang Li | Taolin Zhang | Nan Hu | Chengyu Wang | Xiaofeng He
Findings of the Association for Computational Linguistics: ACL 2022
Distant supervision assumes that any sentence containing the same entity pairs reflects identical relationships. Previous works of distantly supervised relation extraction (DSRE) task generally focus on sentence-level or bag-level de-noising techniques independently, neglecting the explicit interaction with cross levels. In this paper, we propose a hierarchical contrastive learning Framework for Distantly Supervised relation extraction (HiCLRE) to reduce noisy sentences, which integrate the global structural information and local fine-grained interaction. Specifically, we propose a three-level hierarchical learning framework to interact with cross levels, generating the de-noising context-aware representations via adapting the existing multi-head self-attention, named Multi-Granularity Recontextualization. Meanwhile, pseudo positive samples are also provided in the specific level for contrastive learning via a dynamic gradient-based data augmentation strategy, named Dynamic Gradient Adversarial Perturbation. Experiments demonstrate that HiCLRE significantly outperforms strong baselines in various mainstream DSRE datasets.