👨‍🔬Jinseok Ryu, PhD

E-mail : jinseuk56@gmail.com
ORCID : 0000-0002-9558-3469
GitHub Repository : https://github.com/jinseuk56

🔰Education

PhD
Materials Science and Engineering, Seoul National University, South Korea
2017.03-2022.08 Combined MS/PhD
(Advisor: Prof. Miyoung Kim)

BS
Materials Science and Engineering, Seoul National University, South Korea
2009.03-2015.08

🔰Research Experience

Postdoctoral Research Associate (2024.03-Present)
Funded by the InFUSE Prosperity partnership
electron Physical Science Imaging Centre (ePSIC)
Diamond Light Source, Harwell Campus, Didcot, United Kingdom

Postdoctoral Research Associate (2022.09-2024.02)
Electron Microscopy and Spectroscopy Laboratory Research Institute of Advanced Materials
Seoul National University, Seoul, South Korea

🔰Teaching Experience

Workshop | Lecturer | Jul. 20. 2023 | Korean Society of Microscopy

• 28th TEM Workshop, Jul. 18. 2023–Jul. 21. 2023, Korean Society of Microscopy
• Lecture Title: Machine learning in TEM analysis: Basics and Applications

Workshop | Lecturer | Jul. 28. 2022–Jul. 29. 2022 | Korean Society of Microscopy

• 27th TEM Workshop, Jul. 26. 2022–Jul. 29. 2022, Korean Society of Microscopy
• Lecture Title: STEM-derived multi-dimensional data processing in Python-integrated GMS 3

Lecture | Lecturer | 2020 Fall Semester | Seoul National University

• Lecture Title: Fundamentals of Computer Science (Department of Materials Science and Engineering)

🔰Industry Experience

Semiconductor Engineer (2015.07-2016.07)
SK Hynix (2091, Gyeongchung-daero, Bubal-eup, Icheon-si, Gyeonggi-do, South Korea)
Process integration and wafer-level reliability test for NAND flash memories

🔰Skills

(S)TEM Experiment/Analysis

• Imaging (TEM/STEM/4D-STEM) & analytical techniques (EELS/EDS)
• Analysis of structure-property relationship
  • Atomic structure & structural defect analysis
  • Amorphous structure analysis (RDF & FEM)
  • Electronic structure & quantitative chemical analysis
  • Tomographic reconstruction & visualization

Development of Computational Tools for (S)TEM Analysis

• Programming (Python) for (S)TEM analysis
• Application of machine learning algorithms to (S)TEM data analysis
  • Extraction of fundamental/hidden features from microscopy datasets
  • Deep learning, dimensionality reduction, cluster analysis, and their combinations
• Data processing/analysis of STEM-derived multi-dimensional data
  • Electron tomography
  • 4D-STEM data processing/analysis

🔰Research Interests

Data Science for Microscopy Analysis

• Machine learning application to microscopy data analysis
• Multi-modal data fusion

Development of Computational Methods for Post-processing of Microscopy Data

• Enhancement of SNR for low-dose experiments
• Correction of scanning artifacts
• Overcoming the lack of projections in electron tomography

Investigation of 3D Structure-Property Relationships of Materials through Multi-dimensional STEM Techniques

• Electron tomography, multislice ptychography, and their combination

🔰Publication

(†: first author or co-first authors, *: corresponding author)

• Jo, J.†, J. Ryu†, J.-H. Huh, H. Kim, D. H. Seo, J. Lee, M. Kwon, S. Lee*, K. T. Nam*, M. Kim*. “Direct three-dimensional observation of the plasmonic near-fields of a nanoparticle with circular dichroism”, ACS Nano, 18, 47 (2024)
• Kim, I.†, J. Ryu, E. Lee, S. Lee, S. Lee, W. Suh, J. Lee, M. Kim, H. S. Oh, G.-C. Yi*. “Molecular beam epitaxial In2Te3 electronic devices.”, NPG Asia Materials, 16, 1, 59 (2024)
• Hein, P.†, T. Romstadt, F. Draber, J. Ryu, T. Boger, A. Falkenstein, M. Kim, M. Martin*, “Variable-Range Hopping Conduction in Amorphous, Non-Stoichiometric Gallium Oxide”, Advanced Electronic Materials (2024)
• Park, S.†, T. Jang†, S. Choi†, Y. H. Lee, K. H. Cho, M. Y. Lee, H. Seo, H.-K. Lim, Y. Kim, J. Ryu, S. W. Im, M. Kim, G.-S. Park, M. Kim, K. Jin, S. H. Kim, H. Kim, K. T. Nam*, “Iridium-Cooperated, Symmetry-Broken Manganese Oxide Nanocatalyst for Water Oxidation”, Journal of the American Chemical Society, 145, 49, 26632–26644 (2023)
• Kim, S.†, U.-G. Kim, J. Ryu, D.-K. Kim, M. Kim, Y.-C. Joo*, S.-Y. Lee*, “Boron-doped amorphous carbon deposited by DC sputtering for a hardmask: microstructure and dry etching properties”, Applied Surface Science, 637, 157895 (2023)
• Ryu, J.†, S. Lee†, S. Kim, Y.-C. Joo, M. Kim*, “Correlative study between the local atomic and electronic structures of amorphous carbon materials via 4D-STEM and STEM-EELS”, Applied Physics Letters, 121, 042101 (2022)
• Oh, J.†, S.-Y. Lee, H. Kim, J. Ryu, B. Gil, J. Lee, M. Kim*, “Overcharge-induced Phase Heterogeneity and Resultant Twin-like (0003) Layer Deformation in Lithium Cobalt Oxide Cathode for Lithium-ion Batteries”, Advanced Science, 9, 32, 2203639 (2022)
• Yoon, S.†, H. Seo, K. Jin, H. G. Kim, S.-Y. Lee, J. Jo, K. H. Cho, J. Ryu, A. Yoon, Y.-W. Kim, J.-M. Zuo, Y.-K. Kwon, K. T. Nam, M. Kim*, “Atomic reconstruction and Oxygen Evolution Reaction of Mn₃O₄ nanoparticles”, The Journal of Physical Chemistry, 13, 8336-8343 (2022)
• Ryu, J.†, H. Kim, R. M. Kim, S. Kim, J. Jo, S. Lee, K. T. Nam, Y.-C. Joo, G.-C. Yi, J. Lee, M. Kim*, “Dimensionality reduction and unsupervised clustering for EELS-SI”, Ultramicroscopy, 231, 113314 (2021)

🔰Conference & Award

(†: presenter, *: corresponding author)

• (Oral Presentation) Ryu, J.†, AA. Sheader, M. Danaie, DG. Hopkinson, KE. MacArthur, NK. Noel, and CS. Allen*, “Automation of Simultaneous 4DSTEM-EDX Acquisition and Data Analysis for Beam-sensitive Materials”, 13th Asia Pacific Microscopy Congress, Brisbane, Queensland, Australia (2025)
• (Oral Presentation) Lee, S.†, J. Ryu, S. Lee, P. Hein, M. Martin, Y. Kim, M. Kim*, “Mapping Electrical Properties Using STEM-EBIC for Electric Field-Induced Resistance Changes in Amorphous Gallium Oxide”, 13th Asia Pacific Microscopy Congress, Brisbane, Queensland, Australia (2025)
• (Oral Presentation) Lee, S.†, J. Ryu, H. Philipp, M. Martin, M. Kim*, “In-Situ Biasing TEM Analysis of Resistive Switching in Amorphous GaOx for Next-Generation Memory Applications”, 2024 Materials Research Society Fall Meeting, Boston, Massachusetts, United States (2024)
• (Oral Presentation) Chang, Y.†, J. Ryu, H. Yoo, H. N. Han, M. Kim*, “Ptychography Optimization for Atomic Analysis of Bending Mode in Bilayer Transition Metal Dichalcogenide Translational Motion”, 17th European Microscopy Congress, Copenhagen, Denmark (2024)
• (Oral Presentation) Ryu, J.†, J. Jo, H. Kim, K. T. Nam, M. Kim*, “GPU-based fast reconstruction and DL-based feature extraction for EELS tomography”, 20th International Microscopy Congress, Busan, South Korea (2023)
• (Invited talk) Ryu, J.† (on behalf of Prof. Miyoung Kim), G. Kim, S. Lee, M. Kim*, “Exploring ionic migration and structural evolution in dielectric devices”, 20th International Microscopy Congress, Busan, South Korea (2023)
• (Oral Presentation) Ryu, J.†, S. Lee, S. Kim, Y.-C. Joo, M. Kim*, “A comprehensive nanoscale characterization of amorphous carbon films through STEM-EELS and 4D-STEM”, 20th International Microscopy Congress, Busan, South Korea (2023)
• (Oral Presentation) Lee, S.†, J. Ryu., S. Y. kim, G. Park, S. D. Hyun, S. Y. Yang, M. Kim*, “Revealing the Resistive Switching Mechanism in Transition Metal Oxide Film Using In-situ Biasing TEM”, 20th International Microscopy Congress, Busan, South Korea (2023)
• (Poster presentation) Jo, J.†, J. Ryu., M. Kim*, “Unraveling surface plasmon peak splitting in silver nanoparticles decorated on ZnO nanorods via monochromated STEM EELS tomography”, 20th International Microscopy Congress, Busan, South Korea (2023)
• (Invited talk) Ryu, J.†, J. Jo, S. Lee, M. Kim, “Unsupervised learning strategies for extracting features from STEM-derived multi-dimensional data”, 2023 Korea Society of Microscopy Spring Conference, Daejeon, South Korea (2023)
• (Poster presentation) Ryu, J.†, S. Lee, S. Kim, I. Yoo, Y.-C. Joo, M. Kim*, “A machine-learning approach to characterization of amorphous materials with EELS-SI and 4D-STEM”, 2022 Materials Research Society Spring Meeting, Hawaii, United States (2022)
• (Poster presentation) Jo, J.†, K. MacArthur, J. Ryu, H. Kim, S. Collins, K. Müller-Caspary, K. Nam, M. Kim, R. E. Dunin-Borkowski*, “Three-dimensional characterization of nanoparticles with simultaneously acquired bright-field, dark-field, and secondary electron signals in STEM”, PICO 2021, Virtual Meeting (2021)
• (Oral presentation) Ryu, J., J. Jo, J. Lee†, M. Kim*, “Feature extraction and reconstruction of electron energy loss spectroscopy by non-negative matrix factorization”, 12th Asia Pacific Microscopy Congress, Hyderabad, India (2020)
• Excellence Prize, Best Paper Award, Seoul National University & Samsung Electronics R&DB Foundation, South Korea (2021)