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Hwanjun Song

41 accepted papers

2026

Breaking the Reference Bottleneck via Learning to Rewrite Conversational Queries without Gold Reference Passages

ICML 2026poster

Conversational query reformulation (CQR) has become indispensable for improving retrieval in dialogue-based applications. However, existing approaches typically rely on reference passages for optimization, which are **impractical** to acquire in real-world scenarios. To address this limitation, we i…

Cited by 0SourceScholar
2026

Completing Missing Annotation: Multi-Agent Debate for Accurate and Scalable Relevant Assessment for IR Benchmarks

ICLR 2026poster

Information retrieval (IR) evaluation remains challenging due to incomplete IR benchmark datasets that contain unlabeled relevant chunks. While LLMs and LLM-human hybrid strategies reduce costly human effort, they remain prone to LLM overconfidence and ineffective AI-to-human escalation. To address…

Cited by 0SourcecodeScholar
2025

Faithful, Unfaithful or Ambiguous? Multi-Agent Debate with Initial Stance for Summary Evaluation

NAACL 2025long

Faithfulness evaluators based on Large Language Models (LLMs) are often fooled by the fluency of the text and struggle with identifying errors in the summaries, usually leading to high false negative rate. We propose an approach to summary faithfulness evaluation in which multiple LLM-based agents a…

2025

Learning to Summarize from LLM-generated Feedback

NAACL 2025long

Developing effective text summarizers remains a challenge due to issues like hallucinations, key information omissions, and verbosity in LLM-generated summaries. This work explores using LLM-generated feedback to improve summary quality by aligning the summaries with human preferences for faithfulne…

Cited by 4SourcePDFScholar
2025

Learning to Verify Summary Facts with Fine-Grained LLM Feedback

COLING 2025main

Training automatic summary fact verifiers often faces the challenge of a lack of human-labeled data. In this paper, we explore alternative way of leveraging Large Language Model (LLM) generated feedback to address the inherent limitation of using human-labeled data. We introduce FineSumFact, a large…

2025

RA-TTA: Retrieval-Augmented Test-Time Adaptation for Vision-Language Models

ICLR 2025poster

Vision-language models (VLMs) are known to be susceptible to distribution shifts between pre-training data and test data, and test-time adaptation (TTA) methods for VLMs have been proposed to mitigate the detrimental impact of the distribution shifts. However, the existing methods solely rely on th…

Cited by 0SourcePDFScholar
2025

Rethinking LLM-Based Recommendations: A Personalized Query-Driven Parallel Integration

EMNLP 2025

Recent studies have explored integrating large langucage models (LLMs) into recommendation systems but face several challenges, including training-induced bias and bottlenecks from serialized architecture.To effectively address these issues, we propose a Query-to-Recommendation, a parallel recommend

2025

Towards Multi-dimensional Evaluation of LLM Summarization across Domains and Languages

ACL 2025long

Evaluation frameworks for text summarization have evolved in terms of both domain coverage and metrics. However, existing benchmarks still lack domain-specific assessment criteria, remain predominantly English-centric, and face challenges with human annotation due to the complexity of reasoning. To…

2025

Towards a Holistic and Automated Evaluation Framework for Multi-Level Comprehension of LLMs in Book-Length Contexts

EMNLP 2025

We introduce HAMLET, a holistic and automated framework for evaluating the long-context comprehension of large language models (LLMs). HAMLET structures key information of source texts into a three-level hierarchy at root-, branch-, and leaf-levels, and employs query-focused summarization to evaluat

2025

Word2Passage: Word-level Importance Re-weighting for Query Expansion

ACL 2025finding

Retrieval-augmented generation (RAG) enhances the quality of LLM generation by providing relevant chunks, but retrieving accurately from external knowledge remains challenging due to missing contextually important words in query. We present Word2Passage, a novel approach that improves retrieval accu…

2024

Adaptive Shortcut Debiasing for Online Continual Learning

AAAI 2024technical

We propose a novel framework DropTop that suppresses the shortcut bias in online continual learning (OCL) while being adaptive to the varying degree of the shortcut bias incurred by continuously changing environment. By the observed high-attention property of the shortcut bias, highly-activated feat…

2024

Can Your Model Tell a Negation from an Implicature? Unravelling Challenges With Intent Encoders

ACL 2024long

Conversational systems often rely on embedding models for intent classification and intent clustering tasks. The advent of Large Language Models (LLMs), which enable instructional embeddings allowing one to adjust semantics over the embedding space using prompts, are being viewed as a panacea for th…

Cited by 2SourcePDFScholar
2024

Controllable Contextualized Image Captioning: Directing the Visual Narrative through User-Defined Highlights

ECCV 2024poster

"(CIC) evolves traditional image captioning into a more complex domain, necessitating the ability for multimodal reasoning. It aims to generate image captions given specific contextual information. This paper further introduces a novel domain of (). Unlike CIC, which solely relies on broad context,…

2024

Exploiting Representation Curvature for Boundary Detection in Time Series

NeurIPS 2024poster

*Boundaries* are the timestamps at which a class in a time series changes. Recently, representation-based boundary detection has gained popularity, but its emphasis on consecutive distance difference backfires, especially when the changes are gradual. In this paper, we propose a boundary detection m…

Cited by 1SourcePDFScholar
2024

FineSurE: Fine-grained Summarization Evaluation using LLMs

ACL 2024long

Automated evaluation is crucial for streamlining text summarization benchmarking and model development, given the costly and time-consuming nature of human evaluation. Traditional methods like ROUGE do not correlate well with human judgment, while recently proposed LLM-based metrics provide only sum…

2024

MAGID: An Automated Pipeline for Generating Synthetic Multi-modal Datasets

NAACL 2024long

Development of multimodal interactive systems is hindered by the lack of rich, multimodal (text, images) conversational data, which is needed in large quantities for LLMs. Previous approaches augment textual dialogues with retrieved images, posing privacy, diversity, and quality constraints. In this…

2024

One Size Fits All for Semantic Shifts: Adaptive Prompt Tuning for Continual Learning

ICML 2024poster

In real-world continual learning (CL) scenarios, tasks often exhibit intricate and unpredictable semantic shifts, posing challenges for *fixed* prompt management strategies which are tailored to only handle semantic shifts of *uniform* degree (i.e., uniformly mild or uniformly abrupt). To address th…

2024

Semi-Supervised Dialogue Abstractive Summarization via High-Quality Pseudolabel Selection

NAACL 2024long

Semi-supervised dialogue summarization (SSDS) leverages model-generated summaries to reduce reliance on human-labeled data and improve the performance of summarization models. While addressing label noise, previous works on semi-supervised learning primarily focus on natural language understanding t…

2024

TofuEval: Evaluating Hallucinations of LLMs on Topic-Focused Dialogue Summarization

NAACL 2024long

Single document news summarization has seen substantial progress on faithfulness in recent years, driven by research on the evaluation of factual consistency, or hallucinations. We ask whether these advances carry over to other text summarization domains. We propose a new evaluation benchmark on top…

2024

Toward Robustness in Multi-Label Classification: A Data Augmentation Strategy against Imbalance and Noise

AAAI 2024technical

Multi-label classification poses challenges due to imbalanced and noisy labels in training data. In this paper, we propose a unified data augmentation method, named BalanceMix, to address these challenges. Our approach includes two samplers for imbalanced labels, generating minority-augmented instan…

2024

UniSumEval: Towards Unified, Fine-grained, Multi-dimensional Summarization Evaluation for LLMs

EMNLP 2024finding

Existing benchmarks for summarization quality evaluation often lack diverse input scenarios, focus on narrowly defined dimensions (e.g., faithfulness), and struggle with subjective and coarse-grained annotation schemes. To address these shortcomings, we create UniSumEval benchmark, which extends the…

2023

Context Consistency Regularization for Label Sparsity in Time Series

ICML 2023poster

Labels are typically sparse in real-world time series due to the high annotation cost. Recently, consistency regularization techniques have been used to generate artificial labels from unlabeled augmented instances. To fully exploit the sequential characteristic of time series in consistency regular…

Cited by 11SourcePDFScholar
2023

Enhancing Abstractiveness of Summarization Models through Calibrated Distillation

EMNLP 2023long findings

In this paper, we propose a novel approach named DisCal to enhance the level of abstractiveness (measured by n-gram overlap) without sacrificing the informativeness (measured by ROUGE) of generated summaries. DisCal exposes diverse pseudo summaries with two supervision to the student model. Firstly,…

Cited by 0SourceScholar
2023

Fast and Robust Early-Exiting Framework for Autoregressive Language Models with Synchronized Parallel Decoding

EMNLP 2023long main

To tackle the high inference latency exhibited by autoregressive language models, previous studies have proposed an early-exiting framework that allocates adaptive computation paths for each token based on the complexity of generating the subsequent token. However, we observed several shortcomings,…

Cited by 0SourcecodeScholar
2023

Generating Instance-level Prompts for Rehearsal-free Continual Learning

ICCV 2023oral

We introduce Domain-Adaptive Prompt (DAP), a novel method for continual learning using Vision Transformers (ViT). Prompt-based continual learning has recently gained attention due to its rehearsal-free nature. Currently, the prompt pool, which is suggested by prompt-based continual learning, is key…

Cited by 53PDFcodeScholar
2023

Online Boundary-Free Continual Learning by Scheduled Data Prior

ICLR 2023poster

Typical continual learning setup assumes that the dataset is split into multiple discrete tasks. We argue that it is less realistic as the streamed data would have no notion of task boundary in real-world data. Here, we take a step forward to investigate more realistic online continual learning – le…

Cited by 24SourcePDFScholar
2023

Re-Thinking Federated Active Learning Based on Inter-Class Diversity

CVPR 2023poster

Although federated learning has made awe-inspiring advances, most studies have assumed that the client's data are fully labeled. However, in a real-world scenario, every client may have a significant amount of unlabeled instances. Among the various approaches to utilizing unlabeled data, a federated…

2023

Robust Data Pruning under Label Noise via Maximizing Re-labeling Accuracy

NeurIPS 2023poster

Data pruning, which aims to downsize a large training set into a small informative subset, is crucial for reducing the enormous computational costs of modern deep learning. Though large-scale data collections invariably contain annotation noise and numerous robust learning methods have been develope…

2022

Coherence-based Label Propagation over Time Series for Accelerated Active Learning

ICLR 2022poster

Time-series data are ubiquitous these days, but lack of the labels in time-series data is regarded as a hurdle for its broad applicability. Meanwhile, active learning has been successfully adopted to reduce the labeling efforts in various tasks. Thus, this paper addresses an important issue, time-se…

Cited by 18SourcePDFScholar
2022

Dataset Condensation via Efficient Synthetic-Data Parameterization

ICML 2022spotlight

The great success of machine learning with massive amounts of data comes at a price of huge computation costs and storage for training and tuning. Recent studies on dataset condensation attempt to reduce the dependence on such massive data by synthesizing a compact training dataset. However, the exi…

2022

Meta-Learning for Online Update of Recommender Systems

AAAI 2022technical

Online recommender systems should be always aligned with users' current interest to accurately suggest items that each user would like. Since user interest usually evolves over time, the update strategy should be flexible to quickly catch users' current interest from continuously generated new user-…

2022

Meta-Query-Net: Resolving Purity-Informativeness Dilemma in Open-set Active Learning

NeurIPS 2022accept

Unlabeled data examples awaiting annotations contain open-set noise inevitably. A few active learning studies have attempted to deal with this open-set noise for sample selection by filtering out the noisy examples. However, because focusing on the purity of examples in a query set leads to overlook…

2022

Online Continual Learning on a Contaminated Data Stream With Blurry Task Boundaries

CVPR 2022poster

Learning under a continuously changing data distribution with incorrect labels is a desirable real-world problem yet challenging. Large body of continual learning (CL) methods, however, assumes data streams with clean labels, and online learning scenarios under noisy data streams are yet underexplor…

Cited by 61PDFcodeScholar
2022

Time Is MattEr: Temporal Self-supervision for Video Transformers

ICML 2022spotlight

Understanding temporal dynamics of video is an essential aspect of learning better video representations. Recently, transformer-based architectural designs have been extensively explored for video tasks due to their capability to capture long-term dependency of input sequences. However, we found tha…

2022

Understanding Cross-Domain Few-Shot Learning Based on Domain Similarity and Few-Shot Difficulty

NeurIPS 2022accept

Cross-domain few-shot learning (CD-FSL) has drawn increasing attention for handling large differences between the source and target domains--an important concern in real-world scenarios. To overcome these large differences, recent works have considered exploiting small-scale unlabeled data from the…

2022

ViDT: An Efficient and Effective Fully Transformer-based Object Detector

ICLR 2022poster

Transformers are transforming the landscape of computer vision, especially for recognition tasks. Detection transformers are the first fully end-to-end learning systems for object detection, while vision transformers are the first fully transformer-based architecture for image classification. In thi…

2021

PREMERE: Meta-Reweighting via Self-Ensembling for Point-of-Interest Recommendation

AAAI 2021technical

Point-of-interest (POI) recommendation has become an important research topic in these days. The user check-in history used as the input to POI recommendation is very imbalanced and noisy because of sparse and missing check-ins. Although sample reweighting is commonly adopted for addressing this cha…

2021

Task-Agnostic Undesirable Feature Deactivation Using Out-of-Distribution Data

NeurIPS 2021poster

A deep neural network (DNN) has achieved great success in many machine learning tasks by virtue of its high expressive power. However, its prediction can be easily biased to undesirable features, which are not essential for solving the target task and are even imperceptible to a human, thereby resul…