Chanjun Park is a Research Professor at Korea University. Prior to joining Korea University, he was a Principal Research Engineer and Technical Leader of the Large Language Models (LLMs) team at Upstage, where he contributed to building an ecosystem for LLMs. He also worked as a Research Engineer at SYSTRAN, contributing to advancements in machine translation (MT) and automatic speech recognition (ASR) systems. He earned his Ph.D. in the Department of Computer Science and Engineering at Korea University under the supervision of Professor Heuiseok Lim. He received the Naver Ph.D. Fellowship and was selected for the Forbes 30 Under 30 Korea. For more details, please see his CV.
My research philosophy is centered on service-driven research, aiming to bridge the gap between foundational theories in natural language processing (NLP) and their real-world applications. My primary interests include the development of efficient, purpose-trained Large Language Models (LLMs), with a focus on exploring their capability landscape across parameter regions and understanding how model scale and architecture shape emergent behaviors. I am also actively investigating how real-world phenomena can be systematically represented as text to enhance reasoning capabilities in LLMs. In addition, I am deeply engaged in cross-lingual NLP and multidisciplinary research that integrates insights from diverse domains to broaden the scope and impact of NLP technologies.
Please see my CV or Google Scholar profiles for the full list.
Rethinking KenLM: Good and Bad Model Ensembles for Efficient Text Quality Filtering in Large Web Corpora
Yungi Kim, Hyunsoo Ha, Sukyung Lee, Jihoo Kim, Seonghoon Yang, Chanjun Park (✝)
ACL 2025
Enhancing Automatic Term Extraction in Large Language Models via Syntactic Retrieval
Yongchan Chun, Minhyuk Kim, Dongjun Kim, Chanjun Park (✝), Heuiseok Lim (✝)
ACL 2025-Findings
From Ambiguity to Accuracy: The Transformative Effect of Coreference Resolution on RAG systems
Youngjoon Jang, Seongtae Hong, Junyoung Son, Sungjin Park, Chanjun Park (✝), Heuiseok Lim (✝)
ACL 2025 - Student Research Workshop
LCIRC: A Recurrent Compression Approach for Efficient Long-form Context and Query Dependent Modeling in LLMs
Sumin An, Junyoung Sung, Wonpyo Park, Chanjun Park (✝), Paul Hongsuck Seo (✝)
NAACL 2025 (Oral)
CoME: A Unlearning-based Approach to Conflict-free Model Editing
Dahyun Jung, Jaehyung Seo, Jaewook Lee, Chanjun Park (✝), Heuiseok Lim (✝)
NAACL 2025
MIRAGE: A Metric-Intensive Benchmark for Retrieval-Augmented Generation Evaluation
Chanhee Park, Hyeonseok Moon, Chanjun Park (✝), Heuiseok Lim (✝)
NAACL 2025-Findings
FLEX: A Benchmark for Evaluating Robustness of Fairness in Large Language Models
Dahyun Jung, Seungyoon Lee, Hyeonseok Moon, Chanjun Park (✝), Heuiseok Lim (✝)
NAACL 2025-Findings
Find the Intention of Instruction: Comprehensive Evaluation of Instruction Understanding for Large Language Models
Hyeonseok Moon, Jaehyung Seo, Seungyoon Lee, Chanjun Park (✝), Heuiseok Lim (✝)
NAACL 2025-Findings
Open Ko-LLM Leaderboard2: Bridging Foundational and Practical Evaluation for Korean LLMs
Hyeonwoo Kim, Dahyun Kim, Jihoo Kim, Sukyung Lee, Yungi Kim, Chanjun Park (✝)
NAACL 2025 - Industry, 2025
Understanding LLM Development Through Longitudinal Study: Insights from the Open Ko-LLM Leaderboard
Chanjun Park (✝), Hyeonwoo Kim
NAACL 2025 - Industry, 2025
CharacterGPT: A Persona Reconstruction Framework for Role-Playing Agents
Jeiyoon Park, Chanjun Park (✝), Heuiseok Lim (✝)
NAACL 2025 - Industry, 2025
Dataverse: Open-Source ETL (Extract, Transform, Load) Pipeline for Large Language Models
Hyunbyung Park, Sukyung Lee, Gyoungjin Gim, Yungi Kim, Dahyun Kim, Chanjun Park (✝)
NAACL 2025 - Demo, 2025
Representing the Under-Represented: Cultural and Core Capability Benchmarks for Developing Thai Large Language Models
Dahyun Kim, Sukyung Lee, Yungi Kim, Attapol Rutherford, Chanjun Park (✝)
COLING 2025
sDPO: Don’t Use Your Data All at Once
Dahyun Kim, Yungi Kim, Wonho Song, Hyeonwoo Kim, Yunsu Kim, Sanghoon Kim, Chanjun Park (✝)
COLING 2025 - Industry
An analysis on language transfer of pre-trained language model with cross-lingual post-training
Suhyune Son (*), Chanjun Park (*), Jungseob Lee (*), Midan Shim (*), Chanhee Lee, Yoonna Jang, Jaehyung Seo, Jungwoo Lim, Heuiseok Lim
Expert Systems with Applications, 2025
Where am I? Large Language Models Wandering between Semantics and Structures in Long Contexts
Seonmin Koo, Jinsung Kim, YoungJoon Jang, Chanjun Park (✝), Heuiseok Lim (✝)
EMNLP 2024
Search if you don’t know! Knowledge-Augmented Korean Grammatical Error Correction with Large Language Models
Seonmin Koo, Jinsung Kim, Chanjun Park (✝), Heuiseok Lim (✝)
EMNLP 2024-Findings
Translation of Multifaceted Data without Re-Training of Machine Translation Systems
Hyeonseok Moon, Seungyoon Lee, Seongtae Hong, Seungjun Lee, Chanjun Park , Heuiseok Lim
EMNLP 2024-Findings
SAAS: Solving Ability Amplification Strategy for Enhanced Mathematical Reasoning in Large Language Models
Hyeonwoo Kim, Gyoungjin Gim, Yungi Kim, Jihoo Kim, Byungju Kim, Wonseok Lee, Chanjun Park (✝)
EMNLP 2024 - Industry
Evalverse: Unified and Accessible Library for Large Language Model Evaluation
Jihoo Kim, Wonho Song, Dahyun Kim, Yunsu Kim, Yungi Kim, Chanjun Park (✝)
EMNLP 2024 - Demo
Open Ko-LLM Leaderboard: Evaluating Large Language Models in Korean with Ko-H5 Benchmark
Chanjun Park, Hyeonwoo Kim, Dahyun Kim, SeongHwan Cho, Sanghoon Kim, Sukyung Lee, Yungi Kim, Hwalsuk Lee
ACL 2024
KoCommonGEN v2: A Benchmark for Navigating Korean Commonsense Reasoning Challenges in Large Language Models
Jaehyung Seo, Jaewook Lee, Chanjun Park, SeongTae Hong, Seungjun Lee, Heuiseok Lim
ACL 2024 - Findings
Length-aware Byte Pair Encoding for Mitigating Over-segmentation in Korean Machine Translation
Jungseob Lee, Hyeonseok Moon, Seungjun Lee, Chanjun Park (✝), Sugyeong Eo, Hyunwoong Ko, Jaehyung Seo, Seungyoon Lee, Heuiseok Lim (✝)
ACL 2024 - Findings
SOLAR 10.7B: Scaling Large Language Models with Simple yet Effective Depth Up-Scaling
Sanghoon Kim (*, ✝), Dahyun Kim (*), Chanjun Park (*, ✝), Wonsung Lee (*, ✝), Wonho Song (*), Yunsu Kim (*), Hyeonwoo Kim (*), Yungi Kim, Hyeonju Lee, Jihoo Kim, Changbae Ahn, Seonghoon Yang, Sukyung Lee, Hyunbyung Park, Gyoungjin Gim, Mikyoung Cha, Hwalsuk Lee (✝), Sunghun Kim (✝)
NAACL 2024 - Industry
Exploring Inherent Biases in LLMs within Korean Social Context: A Comparative Analysis of ChatGPT and GPT-4
Seungyoon Lee, Dongjun Kim, Dahyun Jung, Chanjun Park (✝), Heuiseok Lim (✝)
NAACL 2024 - Student Research Workshop
Explainable CED: A Dataset for Explainable Critical Error Detection in Machine Translation
Dahyun Jung, Sugyeong Eo, Chanjun Park (✝), Heuiseok Lim (✝)
NAACL 2024 - Student Research Workshop
Leveraging Pre-existing Resources for Data-Efficient Counter-Narrative Generation in Korean
Seungyoon Lee, Chanjun Park (✝), DaHyun Jung, Hyeonseok Moon, Jaehyung Seo, Sugyeong Eo, Heuiseok Lim (✝)
LREC-COLING 2024, Oral
Detecting Critical Errors Considering Cross-Cultural Factors in English-Korean Translation
Sugyeong Eo, Jungwoo Lim, Chanjun Park, Hyeonseok Moon, Jaehyung Seo, Heuiseok Lim
LREC-COLING 2024, Oral
Model-Based Data-Centric AI: Bridging the Divide Between Academic Ideals and Industrial Pragmatism
Chanjun Park (*, ✝), Minsoo Khang (*), Dahyun Kim (*)
ICLR 2024 - Data-centric Machine Learning Research (DMLR) Workshop
Hyper-BTS Dataset: Scalability and Enhanced Analysis of Back TranScription (BTS) for ASR Post-Processing
Chanjun Park, Jaehyung Seo, Seolhwa Lee, Junyoung Son, Hyeonseok Moon, Sugyeong Eo, Chanhee Lee, Heuiseok Lim
EACL 2024 - Findings
Generative Interpretation: Toward Human-Like Evaluation for Educational Question-Answer Pair Generation
Hyeonseok Moon, Jaewook Lee, Sugyeong Eo, Chanjun Park, Jaehyung Seo, Heuiseok Lim
EACL 2024 - Findings
Exploiting Hanja-based Resources in Processing Korean Historic Documents written by Common Literati
Hyeonseok Moon, Myunghoon Kang, Jaehyung Seo, Sugyeong Eo, Chanjun Park, Yeongwook Yang, Heuiseok Lim
IEEE Access, 2024
KEBAP: Korean Error Explainable Benchmark Dataset for ASR and Post-processing
Seonmin Koo (*), Chanjun Park (*), Jinsung Kim, Jaehyung Seo, Sugyeong Eo, Hyeonseok Moon, Heuiseok Lim
EMNLP 2023
CHEF in the Language Kitchen: A Generative Data Augmentation Leveraging Korean Morpheme Ingredients
Jaehyung Seo, Hyeonseok Moon, Jaewook Lee, Sugyeong Eo, Chanjun Park, Heuiseok Lim
EMNLP 2023
Proceedings of the Seventh Widening NLP Workshop (WiNLP 2023)
Bonaventure F. P. Dossou, Isidora Tourni, Hatem Haddad, Shaily Bhatt, Fatemehsadat Mireshghallah, Sunipa Dev, Tanvi Anand, Weijia Xu, Atnafu Lambebo Tonja, Alfredo Gomez, Chanjun Park
EMNLP 2023-Widening NLP Workshop
Alternative Speech: Complementary Method to Counter-Narrative for Better Discourse
Seungyoon Lee (*), DaHyun Jung (*), Chanjun Park (*), Seolhwa Lee, Heuiseok Lim
ICDM 2023 - The First Workshop on Data-Centric AI
Synthetic Alone: Exploring the Dark Side of Synthetic Data for Grammatical Error Correction
Chanjun Park (*), Seonmin Koo (*), Seolhwa Lee, Jaehyung Seo, Sugyeong Eo, Hyeonseok Moon, Heuiseok Lim
ICML 2023 - Data-centric Machine Learning Research (DMLR) Workshop
DMOps: Data Management Operation and Recipes
Eujeong Choi, Chanjun Park (*, ✝)
ICML 2023 - Data-centric Machine Learning Research (DMLR) Workshop
Inter-Annotator Agreement in the Wild: Uncovering Its Emerging Roles and Considerations in Real-World Scenarios
NamHyeok Kim, Chanjun Park (*, ✝)
ICML 2023 - Data-centric Machine Learning Research (DMLR) Workshop
Transcending Traditional Boundaries: Leveraging Inter-Annotator Agreement (IAA) for Enhancing Data Management Operations
Damrin Kim, NamHyeok Kim, Chanjun Park (✝) , Harksoo Kim (✝)
ICML 2023 - Data-centric Machine Learning Research (DMLR) Workshop
Data-Driven Approach for Formality-Sensitive Machine Translation: Language-Specific Handling and Synthetic Data Generation
Seugnjun Lee, Hyeonseok Moon, Chanjun Park, Heuiseok Lim
ICML 2023 - Data-centric Machine Learning Research (DMLR) Workshop
Toward Practical Automatic Speech Recognition and Post-Processing: a Call for Explainable Error Benchmark Guideline
Seonmin Koo (*), Chanjun Park (*), Jinsung Kim, Jaehyung Seo, Sugyeong Eo, Hyeonseok Moon, Heuiseok Lim
ICML 2023 - Data-centric Machine Learning Research (DMLR) Workshop
Knowledge Graph-Augmented Korean Generative Commonsense Reasoning
Dahyun Jung, Jaehyung Seo, Jaewook Lee, Chanjun Park, Heuiseok Lim
ICML 2023 - Data-centric Machine Learning Research (DMLR) Workshop
Informative Evidence-guided Prompt-based Fine-tuning for English-Korean Critical Error Detection
DaHyun Jung, Sugyeong Eo, Chanjun Park, Hyeonseok Moon, Jaehyung Seo, Heuiseok Lim
IJCNLP-AACL 2023
Improving Formality-Sensitive Machine Translation using Data-Centric Approaches and Prompt Engineering
Seugnjun Lee, Hyeonseok Moon, Chanjun Park, Heuiseok Lim
IWSLT 2023
PEEP-Talk: A Situational Dialogue-based Chatbot for English Education
Seugnjun Lee, Yoonna Jang, Chanjun Park, Jungseob Lee, Jaehyung Seo, Hyeonseok Moon, Sugyeong Eo, Seounghoon Lee, Bernardo Nugroho Yahya, Heuiseok Lim
ACL 2023 - Demo
Doubts on the Reliability of Parallel Corpus Filtering
Hyeonseok Moon, Chanjun Park , Seonmin Koo, Jungseob Lee, Seungjun Lee, Jaehyung Seo, Sugyeong Eo, Yoonna Jang, Hyunjoong Kim, Hyoung-gyu Lee, Heuiseok Lim
Expert Systems With Applications, 2023
Uncovering the Risks and Drawbacks Associated with the Use of Synthetic Data for Grammatical Error Correction
Seonmin Koo (*), Chanjun Park (*), Seolhwa Lee, Jaehyung Seo, Sugyeong Eo, Hyeonseok Moon, Heuiseok Lim
IEEE Access, 2023
Data-Centric Neural Machine Translation - A Real-World Approaches
Chanjun Park
Ph.D. Dissertation
PicTalky: Augmentative and Alternative Communication for Language Developmental Disabilities
Chanjun Park (*), Yoonna Jang (*), Seolhwa Lee (*), Jaehyung Seo (*), Kisu Yang, Heuiseok Lim
AACL-IJCNLP 2022 - Demo
KU X Upstage’s submission for the WMT22 Quality Estimation: Critical Error Detection Shared Task
Sugyeong Eo, Chanjun Park, Hyeonseok Moon, Jaehyung Seo, Heuiseok Lim
WMT 2022
QUAK: A Synthetic Quality Estimation Dataset for Korean-English Neural Machine Translation
Sugyeong Eo, Chanjun Park, Hyeonseok Moon, Jaehyung Seo, Gyeongmin Kim, Jungseob Lee, Heuiseok Lim
COLING 2022
Focus on FoCus: Is FoCus focused on Context, Knowledge and Persona?
SeungYoon Lee, Jungseob Lee, Chanjun Park, Sugyeong Eo, Hyeonseok Moon, Jaehyung Seo, Jeongbae Park, Heuiseok Lim
COLING 2022 - The 1st Workshop on Customized Chat Grounding Persona and Knowledge
A Dog Is Passing Over The Jet? A Text-Generation Dataset for Korean Commonsense Reasoning and Evaluation
Jaehyung Seo, Seounghoon Lee, Chanjun Park, Yoonna Jang, Hyeonseok Moon, Sugyeong Eo, Seonmin Koo, Heuiseok Lim
NAACL 2022 - Findings
Priming Ancient Korean Neural Machine Translation
Chanjun Park (*), Seolhwa Lee (*), Hyeonseok Moon, Sugyeong Eo, Jaehyung Seo, Heuiseok Lim
LREC 2022, Oral
FreeTalky: Don’t Be Afraid! Conversations Made Easier by a Humanoid Robot using Persona-based Dialogue
Chanjun Park (*), Yoonna Jang (*), Seolhwa Lee (*), Sungjin Park (*), Heuiseok Lim
LREC 2022
Empirical Analysis of Synthetic Data Generation Using Noising Strategies for Automatic Post-editing
Hyeonseok Moon, Chanjun Park, Seolhwa Lee, Jaehyung Seo, Jeongsub Lee, Sugyeong Eo, Heuiseok Lim
LREC 2022
PU-GEN: Enhancing Generative Commonsense Reasoning for Language Models with Human-Centered Knowledge
Jaehyung Seo, Dongsuk Oh, Sugyeong Eo, Chanjun Park, Kisu Yang, Hyeonseok Moon, Kinam Park, Heuiseok Lim
Knowledge-Based Systems, 2022
K-NCT: Korean Neural Grammatical Error Correction Gold-Standard Test Set Using Novel Error Type Classification Criteria
Seonmin Koo (*), Chanjun Park (*), Jaehyung Seo, Seungjun Lee, Hyeonseok Moon, Jungseob Lee, Heuiseok Lim
IEEE Access, 2022
Plain Template Insertion: Korean-Prompt-based Engineering for Few-shot Learners
Jaehyung Seo, Hyeonseok Moon, Chanhee Lee, Sugyeong Eo, Chanjun Park, Jihoon Kim, Changwoo Chun, Heuiseok Lim
IEEE Access, 2022
Utilization Strategy of User Engagements in Korean Fake News Detection
Myunghoon Kang, Jaehyung Seo, Chanjun Park, Heuiseok Lim
IEEE Access, 2022
AI for Patents: A Novel yet Effective and Efficient Framework for Patent Analysis
Junyoung Son, Hyeonseok Moon, Jeongwoo Lee, Seolhwa Lee, Chanjun Park, Wonkyung Jung, Heuiseok Lim
IEEE Access, 2022
Word-level Quality Estimation for Korean-English Neural Machine Translation
Sugyeong Eo (*), Chanjun Park (*), Hyeonseok Moon, Jaehyung Seo, Heuiseok Lim
IEEE Access, 2022
Mimicking Infants’ Bilingual Language Acquisition for Domain Specialized Neural Machine Translation
Chanjun Park, Woo-Young Go, Sugyeong Eo, Hyeonseok Moon, Seolhwa Lee, Heuiseok Lim
IEEE Access, 2022
An Automatic Post Editing with Efficient and Simple Data Generation Method
Hyeonseok Moon (*), Chanjun Park (*), Jaehyung Seo, Sugyeong Eo, Heuiseok Lim
IEEE Access, 2022
Should we find another model?: Improving Neural Machine Translation Performance with ONE-Piece Tokenization Method without Model Modification
Chanjun Park (*), Sugyeong Eo (*), Hyeonseok Moon (*), Heuiseok Lim
NAACL-HLT 2021 - Industry
Two Heads are Better than One? Verification of Ensemble Effect in Neural Machine Translation
Chanjun Park, Sungjin Park, Seolhwa Lee, Taesun Whang, Heuiseok Lim
EMNLP 2021 -The Second Workshop on Insights from Negative Results in NLP
BTS: Back TranScription for Speech-to-Text Post-Processor using Text-to-Speech-to-Text
Chanjun Park, Jaehyung Seo, Seolhwa Lee, Chanhee Lee, Hyeonseok Moon, Sugyeong Eo, Heuiseok Lim
ACL 2021 -Workshop on Asian Translation (WAT)
Who speaks like a style of Vitamin: Towards Syntax-Aware Dialogue Summarization using Multi-task Learning
Seolhwa Lee, Kisu Yang, Chanjun Park, João Sedoc, Heuiseok Lim
IEEE Access, 2021
Grounded Vocabulary for Image Retrieval Using a Modified Multi-Generator Generative Adversarial Network
Kuekyeng Kim, Chanjun Park, Jaehyung Seo, Heuiseok Lim
IEEE Access, 2021
An Empirical Study on Automatic Post Editing for Neural Machine Translation
Hyeonseok Moon (*), Chanjun Park (*), Sugyeong Eo, Jaehyung Seo, Heuiseok Lim
IEEE Access, 2021
Ancient Korean Neural Machine Translation
Chanjun Park, Chanhee Lee, YeongWookYang, Heuiseok Lim
IEEE Access, 2020
Comparison of the evaluation metrics for Neural Grammatical Error Correction with Overcorrection
Chanjun Park, YeongWookYang, Chanhee Lee, Heuiseok Lim
IEEE Access, 2020
Neural Spelling Correction: Translating Incorrect sentences to Correct sentences for Multimedia
Chanjun Park, Kuekyeng Kim, YeongWookYang, Minho Kang, Heuiseok Lim
Multimedia Tools and Applications, 2020
Year | Award |
---|---|
2024.02 | Forbes 30 Under 30 Korea |
2023.02 | Best Paper Award at Korea University |
2022.12 | 1st Place at WMT Quality Estimation Shared Task 2022 - Sentence-level Critical Error Detection |
2021.12 | Naver Ph.D. Fellowship |
2019.10 | 1st Place at Microsoft AI Accessibility Hackathon in Korea, Microsoft |
Year | Place | Contents |
---|---|---|
2025.02 | NIA | Redefining Evaluation and Korea’s Leaderboards in the LLM Era |
2024.11 | LG Electronics | Large Language Model Data and Evaluation in the Wild |
2024.11 | U.S. Department of State-2024 Tech Camp Korea | Large Language Model in the Wild |
2024.10 | Republic of Korea Army Headquarters | Large Language Model in the Wild |
2024.09 | Seoul National University | Large Language Model in the Wild |
2024.09 | Embassy of the United States in Seoul | The entire journey to becoming a natural language processing researcher |
2024.06 | KCC 2024 | SOLAR: The Next Frontier in Large Language Models by Upstage and its Ecosystem |
2024.05 | Applied ML: LLMs and Knowledge Graphs- Tokyo | The Ecosystem of LLMs from a Real-World Perspective |
2024.05 | AI Safety Compass Conference 2024 | Data and Evaluation Methods for Trustworthy AI |
2024.05 | ETRI | SOLAR: The Next Frontier in Large Language Models by Upstage and its Ecosystem |
2024.05 | AI Tech 2024 - AI Frontier for AI Era | SOLAR: The Next Frontier in Large Language Models by Upstage and its Ecosystem |
2024.05 | No code·Low code Hyper-automation Conference 2024 | The Ecosystem of LLMs from a Real-World Perspective |
2024.01 | The University of Tokyo | SOLAR: The Next Frontier in Large Language Models by Upstage |
2023.12 | Seoul Metropolitan Office of Education-AI & Digital Education Conference | Reset Moment by Large Language Model |
2023.12 | Korean-English Joint Seminar on Artificial Intelligence (AI) Safety and Reliability | Upstage Vision for Ethical and Trustworthy Large Language Models |
2023.08 | Google I/O Extended 2023 Incheon | From Language Model to Large Language Model |
2023.07 | Google I/O Extended 2023 Seoul | From Language Model to Large Language Model |
2023.07 | TensorFlow Korea LLM Day | Language Model to Large Language Model |
2023.06 | AI EDucation Alliance Policy lab (AIEDAP) | Deep Learning Understanding and Practice |
2023.02 | AI·DATA SUMMIT 2023 | Real-World Centric AI, (Video) |
2019.08 | NAVER | Machine Translation for everyone |