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Samuel Mensah

12 accepted papers

2025

A Variational Approach for Mitigating Entity Bias in Relation Extraction

ACL 2025short

Mitigating entity bias is a critical challenge in Relation Extraction (RE), where models often rely excessively on entities, resulting in poor generalization. This paper presents a novel approach to address this issue by adapting a Variational Information Bottleneck (VIB) framework. Our method compr…

Cited by 0SourcePDFScholar
2025

FinNLI: Novel Dataset for Multi-Genre Financial Natural Language Inference Benchmarking

NAACL 2025findings

We introduce FinNLI, a benchmark dataset for Financial Natural Language Inference (FinNLI) across diverse financial texts like SEC Filings, Annual Reports, and Earnings Call transcripts. Our dataset framework ensures diverse premise-hypothesis pairs while minimizing spurious correlations. FinNLI com…

Cited by 1SourcePDFScholar
2025

VERO: Verification and Zero-Shot Feedback Acquisition for Few-Shot Multimodal Aspect-Level Sentiment Classification

AAAI 2025technical

Deep learning approaches for multimodal aspect-level sentiment classification (MALSC) often require extensive data, which is costly and time-consuming to obtain. To mitigate this, current methods typically fine-tune small-scale pretrained models like BERT and BART with few-shot examples. While these…

2023

Trading Syntax Trees for Wordpieces: Target-oriented Opinion Words Extraction with Wordpieces and Aspect Enhancement

ACL 2023short

State-of-the-art target-oriented opinion word extraction (TOWE) models typically use BERT-based text encoders that operate on the word level, along with graph convolutional networks (GCNs) that incorporate syntactic information extracted from syntax trees. These methods achieve limited gains with GC…

2022

A Hierarchical N-Gram Framework for Zero-Shot Link Prediction

EMNLP 2022finding

Knowledge graphs typically contain a large number of entities but often cover only a fraction of all relations between them (i.e., incompleteness). Zero-shot link prediction (ZSLP) is a popular way to tackle the problem by automatically identifying unobserved relations between entities. Most recent…

2022

A Transformational Biencoder with In-Domain Negative Sampling for Zero-Shot Entity Linking

ACL 2022findings

Recent interest in entity linking has focused in the zero-shot scenario, where at test time the entity mention to be labelled is never seen during training, or may belong to a different domain from the source domain. Current work leverage pre-trained BERT with the implicit assumption that it bridges…

2022

Contrastive Learning with Expectation-Maximization for Weakly Supervised Phrase Grounding

EMNLP 2022main

Weakly supervised phrase grounding aims to learn an alignment between phrases in a caption and objects in a corresponding image using only caption-image annotations, i.e., without phrase-object annotations. Previous methods typically use a caption-image contrastive loss to indirectly supervise the a…

2022

DropMix: A Textual Data Augmentation Combining Dropout with Mixup

EMNLP 2022main

Overfitting is a notorious problem when there is insufficient data to train deep neural networks in machine learning tasks. Data augmentation regularization methods such as Dropout, Mixup, and their enhanced variants are effective and prevalent, and achieve promising performance to overcome overfitt…

Cited by 12SourcePDFScholar
2022

Explicit Role Interaction Network for Event Argument Extraction

EMNLP 2022finding

Event argument extraction is a challenging subtask of event extraction, aiming to identify and assign roles to arguments under a certain event. Existing methods extract arguments of each role independently, ignoring the relationship between different roles. Such an approach hinders the model from le…

2022

Unsupervised Sentence Representation via Contrastive Learning with Mixing Negatives

AAAI 2022technical

Unsupervised sentence representation learning is a fundamental problem in natural language processing. Recently, contrastive learning has made great success on this task. Existing constrastive learning based models usually apply random sampling to select negative examples for training. Previous work…

Cited by 65SourcePDFScholar
2021

An Empirical Study on Leveraging Position Embeddings for Target-oriented Opinion Words Extraction

EMNLP 2021main

Target-oriented opinion words extraction (TOWE) (Fan et al., 2019b) is a new subtask of target-oriented sentiment analysis that aims to extract opinion words for a given aspect in text. Current state-of-the-art methods leverage position embeddings to capture the relative position of a word to the ta…

2021

Progressive Multi-task Learning with Controlled Information Flow for Joint Entity and Relation Extraction

AAAI 2021technical

Multitask learning has shown promising performance in learning multiple related tasks simultaneously, and variants of model architectures have been proposed, especially for supervised classification problems. One goal of multitask learning is to extract a good representation that sufficiently captur…