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Sungjin Lee

13 accepted papers

2025

FaVe: Factored and Verified Search Rationale for Long-form Answer

ACL 2025finding

Targeting long-form question-answering, chain-of-query (CoQ) has been studied, integrating chain-of-thought (CoT) with retrieval-augmented generation. CoQ answers the complex question step-by-step, through simpler subquestions (SQs) from which relevant knowledge is retrieved. By doing so, CoQ aims t…

Cited by 0SourcePDFScholar
2023

Constrained Policy Optimization for Controlled Self-Learning in Conversational AI Systems

ACL 2023industry

Recently, self-learning methods based on user satisfaction metrics and contextual bandits have shown promising results to enable consistent improvements in conversational AI systems. However, directly targeting such metrics by off-policy bandit learning objectives often increases the risk of making…

Cited by 2SourcePDFScholar
2023

Grounding Counterfactual Explanation of Image Classifiers to Textual Concept Space

CVPR 2023poster

Concept-based explanation aims to provide concise and human-understandable explanations of an image classifier. However, existing concept-based explanation methods typically require a significant amount of manually collected concept-annotated images. This is costly and runs the risk of human biases…

Cited by 11SourcePDFScholar
2023

Large-scale Lifelong Learning of In-context Instructions and How to Tackle It

ACL 2023long

Jointly fine-tuning a Pre-trained Language Model (PLM) on a pre-defined set of tasks with in-context instructions has been proven to improve its generalization performance, allowing us to build a universal language model that can be deployed across task boundaries. In this work, we explore for the f…

Cited by 15SourcePDFScholar
2023

Weakly Supervised Referring Image Segmentation with Intra-Chunk and Inter-Chunk Consistency

ICCV 2023poster

Referring image segmentation (RIS) aims to localize the object in an image referred by a natural language expression. Most previous studies learn RIS with a large-scale dataset containing segmentation labels, but they are costly. We present a weakly supervised learning method for RIS that only uses…

Cited by 29PDFScholar
2022

Open World Classification with Adaptive Negative Samples

EMNLP 2022main

Open world classification is a task in natural language processing with key practical relevance and impact.Since the open or unknown category data only manifests in the inference phase, finding a model with a suitable decision boundary accommodating for the identification of known classes and discri…

Cited by 6SourcePDFScholar
2022

PENTATRON: PErsonalized coNText-Aware Transformer for Retrieval-based cOnversational uNderstanding

EMNLP 2022industry

Conversational understanding is an integral part of modern intelligent devices. In a large fraction of the global traffic from customers using smart digital assistants, frictions in dialogues may be attributed to incorrect understanding of the entities in a customer’s query due to factors including…

Cited by 6SourcePDFScholar
2022

Scalable and Robust Self-Learning for Skill Routing in Large-Scale Conversational AI Systems

NAACL 2022industry

Skill routing is an important component in large-scale conversational systems. In contrast to traditional rule-based skill routing, state-of-the-art systems use a model-based approach to enable natural conversations. To provide supervision signal required to train such models, ideas such as human an…

Cited by 3SourcePDFScholar
2021

A Scalable Framework for Learning From Implicit User Feedback to Improve Natural Language Understanding in Large-Scale Conversational AI Systems

EMNLP 2021main

Natural Language Understanding (NLU) is an established component within a conversational AI or digital assistant system, and it is responsible for producing semantic understanding of a user request. We propose a scalable and automatic approach for improving NLU in a large-scale conversational AI sys…

Cited by 21SourcePDFScholar
2021

AugNLG: Few-shot Natural Language Generation using Self-trained Data Augmentation

ACL 2021long

Natural Language Generation (NLG) is a key component in a task-oriented dialogue system, which converts the structured meaning representation (MR) to the natural language. For large-scale conversational systems, where it is common to have over hundreds of intents and thousands of slots, neither temp…

2021

Self-Supervised Contrastive Learning for Efficient User Satisfaction Prediction in Conversational Agents

NAACL 2021long

Turn-level user satisfaction is one of the most important performance metrics for conversational agents. It can be used to monitor the agent’s performance and provide insights about defective user experiences. While end-to-end deep learning has shown promising results, having access to a large numbe…

Cited by 34SourcePDFScholar