Knot Theory3-dimensional TopologyEnumerative Combinatorics Deep Learning Deep Reinforcement LearningLarge Language Model
Employment 2002 – present Professor at Korea University2023 Visiting Scholar at KAIST 김재철AI대학원2012 – 2013 Visiting Scholar at Georgia Institute of Technology2000 – 2002 Assistant Professor at Chonbuk National University 1999Researcher at KAIST1996Researcher at MSRI, University of California at Berkeley
Education 1996 Ph.D. at University of Texas at Austin (advisor : Cameron McA Gordon)1992 B.S. at KAIST
Awards 고려대학교 석탑강의상 (Granite Tower Best Teaching Award, Top 5%) 12회 수상 고려대학교 우수강의상 (Best Teaching Award, Top 20%) 17회 수상2024Editors' Choice Award 2024 - an outstanding paper published in Discrete Mathematics2023IJCAI 2023 Competition and Challenge Award on 2nd Audio Deepfake Detection Challenge (ADD 2023) (3rd)2022ICASSP 2022 Grand Challenge Award on 1st Audio Deep Synthesis Detection Challenge (ADD 2022) (3rd)2004한국과학재단 우수연구성과 30선 (30 Excellent Research Result Award from KOSEF)1992 – 1994 Dodd Fellowships from University of Texas at Austin1991전국대학생 수학경시대회 2등(2nd in National Undergraduate Mathematics Competition)1989전국대학생 수학경시대회 8등 (8th in National Undergraduate Mathematics Competition)
Projects 2025(주)텔레컨스산학공동개발 (열화상 이미지 기반행동인식 AI 딥러닝 모델 개발)2024 - 2029한국연구재단 중견연구 (음성 데이터 판별용 딥러닝 개발 및 양자매듭의 계수와 DNA 슈퍼코일의 공간적 안정성)2022 - 2024한국연구재단 기본연구 (DNA 슈퍼코일 모형의 활용과 3차원 격자모델의 계수)2019 - 2026정보통신기획평가원 혁신도약형 (미래컴퓨팅 환경에 대비한 계산 복잡도 기반 암호 안전성 검증 기술개발)2017 - 2022한국연구재단 중견연구 (DNA 고차코일의 조밀성과격자 모델 계수 알고리즘 개발)2014- 2017한국연구재단 중견연구 (그래프의 다양한 불변량들과 DNA 이중나선구조에 관한 연구)2011- 2014한국연구재단 기본연구 (에눌러스와 토러스형 덴-채움들)2009 - 2012한국학술진흥재단 기본연구 (소곡면들을 포함하게 하는 덴-채움들)2007 - 2010한국과학재단 특정기초연구 (삼차원 다양체의 위상 및 대수적 구조)2006- 2009한국학술진흥재단 기초연구 (다양체의 쌍곡성과 부분다양체의 분류)2003 - 2006한국과학재단 젊은과학자연구 (분해 덴-채움들과 소곡면들)2001 - 2003한국과학재단 지역대학우수과학자연구 (덴-채움으로 얻어지는 예외적 다양체들)
Publications 70. Honeycomb-lattice monomer-dimer mixtures, Journal of Statistical Physics (2025)69.Experimental Study: Enhancing Spoofing Detection with Fine-tuned Large Voice Models, Statistics (2025)68.Enhancing voice spoofing detection in noisy environments using frequency feature masking augmentation, Engineering Science and Technology, an International Journal 63, 101972 (2025)67. Lattice stick number 15 is unattainable for non-splittable links, Physica Scripta 99, 105250 (2024)66. Efficiency of non-identical double helix patterns in minimizing ropelength of torus knot, Physica Scripta 99, 075240 (2024)65. Quantum knot mosaics and bounds of the growth constant, Reviews in Mathematical Physics, 2450025 (2024)64.TB-ResNet: Bridging the gap from TDNN to ResNet in Automatic Speaker Verification with Temporal-bottleneck enhancement, Proc. ICASSP 2024, 10291-10295 (2024)63. Topology-based optimization of handcuff graphs on 3D lattice, Physica Scripta 99, 015221 (2024)62. Augmented Aztec bipyramid and dicube tilings, Discrete Mathematics, 347, 113735 (2024) *Editors' Choice Award 202461.CAU KU deep fake detection system for ADD 2023 challenge, Proc. IJCAI 2023, 23-30 (2023)60. Tetromino tilings on the Tetris board, Physica Scripta98, 075228 (2023)59. Domino tilings of Aztec octagons, Graphs and Combinatorics39, 45 (2023)58.Light-weight frequency information aware neural network architecture for voice spoofing detection, Proc. ICPR 2022, 477-483 (2022)57. Lattice conformation of theta-curves accompanied with Brunnian property, Journal of Physics A: Mathematical and Theoretical55, 435207 (2022)56.Low-quality fake audio detection through frequency feature masking, Proc. DDAM 2022, 9-17 (2022)55.Overlapped frequency-distributed network: frequency-aware voice spoofing countermeasure,Proc. Interspeech 2022, 3558-3562 (2022)54. Dimer coverings of 1-slab cubic lattices, Graphs and Combinatorics38, 117 (2022)53. Bipartite intrinsically knotted graphs with 23 edges, Discrete Mathematics345, 113022 (2022)52. Counting dissections into integral squares, Discrete Mathematics345, 112803 (2022)51. Tight conformation of 2-bridge knots using superhelices, Journal of Mathematical Physics62, 113504 (2021)50. Topological aspects of theta-curves in cubic lattice, Journal of Physics A: Mathematical and Theoretical54, 455204 (2021)49. Stick numbers of Montesinos knots and links, Journal of Knot Theory and Its Ramifications30, 2150013 (2021) 48. Number of dominating sets in cylindric square grid graphs, Graphs and Combinatorics37, 1357-1372 (2021)47. Enumeration of 1-slab lattice links, Topology and its Applications264, 158-166 (2019)46. Growth rate of quantum knot mosaics, Quantum Information Processing18, 238 (2019)45. Domino tilings for augmented Aztec rectangles and their chains, Electronic Journal of Combinatorics26, #P3.2 (2019)44. State matrix recursion method and monomer-dimer problem, Discrete Mathematics342, 1434-1445 (2019)43. Arc index of spatial graphs, Journal of Graph Theory90, 406-415 (2019)42. Ropelength of superhelices and (2, n)-torus knots, Journal of Physics A: Mathematical and Theoretical51, 485203 (2018)41. More intrinsically knotted graphs with 22 edges and the restoring method, Journal of Knot Theory and Its Ramifications27, 1850059 (2018)40. Lattice stick number of spatial graphs, Journal of Knot Theory and Its Ramifications27, 1850048 (2018)39. Bisected vertex leveling of plane graphs: braid index, arc index and delta diagrams, Journal of Knot Theory and Its Ramifications27,1850044 (2018)38. Bounds on multiple self-avoiding polygons, Canadian Mathematical Bulletin61, 518-530 (2018)37. Domino tilings of the expanded Aztec diamond, Discrete Mathematics341, 1185-1191 (2018)36. Stick number of spatial graphs, Journal of Knot Theory and Its Ramifications26, 1750100 (2017)35. Maximal independent sets on a grid graph, Discrete Mathematics340, 2762-2768 (2017)34. A new intrinsically knotted graph with 22 edges, Topology and its Applications228, 303-317 (2017)33. Bipartite intrinsically knotted graphs with 22 edges, Journal of Graph Theory85, 568-584 (2017)32. Enumeration on graph mosaics, Journal of Knot Theory and Its Ramifications26, 1750032 (2017)31. Period and toroidal knot mosaics, Journal of Knot Theory and Its Ramifications26, 1750031 (2017)30. Enumerating independent vertex sets in grid graphs, Linear Algebra and Its Applications 510, 192-204 (2016)29. Best packing of identical helices, Journal of Physics A: Mathematical and Theoretical49, 415205 (2016)28. Quantum knot mosaics and the growth constant, Topology and its Applications210, 311-316 (2016)27. Exactly fourteen intrinsically knotted graphs have 21 edges, Algebraic and Geometric Topology15, 3305-3322 (2016) 26. Quantum knots and the number of knot mosaics, Quantum Information Processing14, 801-811 (2015)25. Link lengths and their growth powers, Journal of Physics A: Mathematical and Theoretical48, 035202 (2015)24. Mosaic number of knots, Journal of Knot Theory and Its Ramifications23, 1450069 (2014)23. Upper bound on the total number of knot n-mosaics, Journal of Knot Theory and Its Ramifications23, 1450065 (2014)22. Minimum lattice length and ropelength of 2-bridge knots and links, Journal of Mathematical Physics55, 113503 (2014)21. Small knot mosaics and partition matrices, Journal of Physics A: Mathematical and Theoretical47, 435201 (2014)20. Minimum lattice length and ropelength of knots, Journal of Knot Theory and Its Ramifications23, 1460009 (2014)19. Equilateral stick number of knots, Journal of Knot Theory and Its Ramifications23, 1460008 (2014)18. Links with small lattice stick numbers, Journal of Physics A: Mathematical and Theoretical47, 155202 (2014)17. Upper bound on lattice stick number of knots, Mathematical Proceedings of the Cambridge Philosophical Society155, 173-179 (2013)16. Upper bounds on the minimum length of cubic lattice knots, Journal of Physics A: Mathematical and Theoretical46, 125001 (2013) 15. Stick numbers of 2-bridge knots and links, Proceedings of the American Mathematical Society139, 4143-4152 (2011)14. An upper bound on stick number of knots, Journal of Knot Theory and Its Ramifications20, 741-747 (2011)13. Knots with small lattice stick numbers, Journal of Physics A: Mathematical and Theoretical43, 265002 (2010)12. Reducing Dehn fillings and small surfaces, Proceedings of London Mathematical Society92, 203-223 (2006)11. Lattice stick numbers of small knots, Journal of Knot Theory and Its Ramifications14, 859-867 (2005)10. Planar graphs producing no strongly almost trivial embedding, Journal of Graph Theory43, 319-326 (2003)9. Reducing spheres and Klein bottles after Dehn fillings, Canadian Mathematical Bulletin46, 265-267 (2003) 8. P2 reducing and toroidal Dehn fillings, Mathematical Proceedings of the Cambridge Philosophical Society134, 271-288 (2003)7. An elementary set for theta-n-curve projections, Journal of Knot Theory and Its Ramifications11, 1243-1250 (2002) 6. Constructing persistently laminar knots, Topology and its Applications124, 139-143 (2002)5. Dehn fillings creating essential spheres and tori, Journal of Knot Theory and Its Ramifications11, 887-890 (2002)4. Strongly almost trivial theta-curves, Journal of Knot Theory and Its Ramifications11, 153-164 (2002)3. Dehn filling, reducible 3-manifolds, and Klein bottles, Proceedings of the American Mathematical Society126, 289-296 (1998) 2. Reducible and toroidal 3-manifolds obtained by Dehn fillings, Topology and its Applications75, 93-104 (1997) 1. Knotted solid tori decompositions of B^3 and S^3, Journal of Knot Theory and Its Ramifications5, 405-416 (1996)
Talks 83.Understanding Large Language Models,Invited talk, University of Ulsan (2025.9.19) 82.Large Language Models : ChatGPT,Invited talk, FIXXGEN (2025.8.7) 81. Transformer-based audio representation pre-training models,Invited talk, Chung-Ang University (2025.7.7)80.Understanding ChatGPT and the basics of Large Language Models (LLMs),9th School on Advanced Deep Learning, Jeonbuk National University (2025.7.1) 79.Introduction to Topological Data Analysis, Invited talk, University of Guam, USA (2025.6.17) 78.A Survey of Large Language Models, 2nd Mini Workshop on Combinatorial Knot theory, Yeosu (2025.5.10) 77. Knot-tilings of Euclidean space, 8th School on Advanced Deep Learning, Dongguk University WISE (2024.11.16)76.인공지능과 딥러닝,Invited talk, Dongguk University WISE (2024.11.15) 75.인공지능 기초, 통일정책지도자과정, 국립통일교육원 (2024.9.2) 74. 3-dimensional dicube tilings in bipyramidal shape, 7th School on Advanced Deep Learning, Yeosu (2024.8.20) 73. Transformer architecture,Invited talk, Chung-Ang University (2024.7.3)72. Perfect matchings in the 3-dimensional cubic lattice, 2024 HMS Annual Meeting and Conference, Jeonbuk National University (2024.6.21)71. Toroidal perfect matchings in the torus grid graph, 31st KIAS Combinatorics Workshop, Jeju (2024.5.30)70. Augmented Aztec bipyramid and dicube tilings,2024 KMS Spring Meeting, KAIST (2024.4.20)69.Deep Image Stitching, Invited talk, FIXXGEN (2024.1.11) 68.Fundamental concepts of Deep Learning and DLmath team's research results 1 & 2, Mini Workshop on Low-Dimensional Topology, UNIST (2023.12.27-28) 67.Attention and Transformer AI, Invited talk, SCIEN, Ulsan (2023.12.26) 66.머신러닝과 딥러닝, 통일정책지도자과정, 국립통일교육원 (2023.10.5) 65. Deep Reinforcement Learning (12 lectures),Invited lecture, KAIST 김재철AI대학원 (2023.9.8-12.1)64. Aztec bipyramid and dicube tilings,Invited talk, Nihon University, Japan (2023.8.22) 63.Introduction to Deep Reinforcement Learning, Invited talk, University of Ulsan (2023.7.12) 62. Counting Perfect Matchings in Torus Grid Graphs, 5th Meeting on Spatial Graph Theory, Yangpyoung (2023.7.25) 61.Graph Neural Network (3 lectures),6th School on Advanced Deep Learning, Korea University (2023.6.23-7.14) 60.Blockchain and Bitcoin,Invited talk, Seoul National University(2023.4.7) 59.GAN applied to Drug Design,KITOX Seminar, KITOX, Daejeon (2022.10.31) 58. 딥러닝의 이해, 통일정책지도자과정, 국립통일교육원 (2022.10.19) 57. InfoGAN: Information Maximizing Generative Adversarial Network, 5th School on Advanced Deep Learning, Pusan (2022.6.28) 56. Introduction to Deep Learning (4 lectures),Invited talk, Chung-Ang University (2022.1.4-25)55. Lattice Brunnian Theta-curves,HYU Low-dimensional Topology Winter Workshop, Hanyang University (2021.12.28) 54. Introduction to Blockchain (2 lectures),4th School on Advanced Deep Learning, Chonbuk National University (2021.11.26-27)53. State matrix recursion method for lattice model enumeration,4th Meeting on Spatial Graph Theory, Pusan (2021.8.24) 52. AE, VAE, GAN, Wasserstein GAN (3 lectures),Invited talk, Chung-Ang University (2021.7.13-8.17)51. Transformer and Attention-augmented Convolution (2 lectures),Invited talk, Chung-Ang University (2021.4.8, 5.6)50. Deep Learning and Mathematics (2 lectures), Knots and Spatial Graphs 2021, Dongguk University - Gyeongju (2021.2.2-3)49. Deep Reinforcement Learning: DQN and A3C (2 lectures), Winter School of Elementary Quantum Computing, Yangpyeong (2021.1.27-28)48. Tilings of Euclidean space by Knotted Tiles, Seminar on Knot Theory, Hanyang University (2021.1.25)47. Spatial Graphs and Lattice Stick Numbers I & II, 3rd Meeting on Spatial Graph Theory, Yangpyeong (2020.11.15-16)46. Maximum a Posteriori Policy Optimisation (MPO) (4 lectures), 2nd School on Deep Reinforcement Learning, Korea University (2020.9.25-10.23)45. Mathematics in Blockchain (3 lectures),5th Mini Workshop on Knot Theory, Jeju (2020.7.20-22)44. Quantum knot mosaics,ETRI, Daejeon (2020.6.15) 43. Quantum knot mosaics and bounds of the growth constant,15th East Asian Conference on Geometric Topology, RIMS, Kyoto University, Japan (2020.2.10) 42. Deep Learning for beginners and experts (20 lectures),3rd School on Advanced Deep Learning, Korea University (2020.1.6-21) 41. Lattice model enumeration using state matrix recursion method,Invited talk, Chung-Ang University (2019.11.14) 40. Molecular Fingerprints,KITOX Seminar, KITOX, Daejeon (2019.11.12) 39. Quantum knot mosaics and the growth rate,2019 KMS Fall Meeting, Hongik University (2019.10.26)38. Natural Language Processing, Visual Attention and Graph Representation Learning (6 lectures),Seminar on Recent Trends of Deep Learning, Korea University (2019.9.9-11.11)37. Advanced Deep Learning 24 hours: CNN, LSTM, VAE, GAN, DQN, A3C, DDPG, TRPO, PPO (12 lectures),2nd School on Advanced Deep Learning, Korea University (2019.7.15-25) 36. Growth rate of quantum knot mosaics,2nd Meeting on Spatial Graph Theory, Waseda University, Japan (2019.7.1)35. Entropy of Knot Mosaics,4th Mini Workshop on Knot Theory, Dongguk University - Gyeongju (2019.6.7)34. Generative Deep Learning: VAE, GAN and its variants(2 lectures),Seminar on Generative Deep Learning, Korea University (2019.6.4, 25) 33. Introduction to Topological Quantum Computing,Q-Crypton Kick-off Workshop, Busan (2019.5.15)32. Deep Reinforcement Learning: from DQN, A3C to DDPG, PPO (5 lectures),1st School on Deep Reinforcement Learning, Korea University (2019.3.14-5.21) 31. Introduction to Deep Learning (7 lectures),1st School on Advanced Deep Learning, Pukyong National University (2019.2.12-15) 30. Graph Convolutional Networks,NIMS Seminar, NIMS(2019.1.8)29. Bijection between domino tilings and Delannoy paths on various Aztec diamonds,Spatial Graph School, Williams College, USA (2018.6.21) 28. State matrix recursion method to enumerate various lattice models,Spatial Graph School, Williams College, USA (2018.6.20) 27. Aztec diamonds and domino tilings,2018 KMS Spring Meeting, Kyung Hee University (2018.4.21) 26. Domino tilings on various Aztec diamonds and Delannoy paths,19th KIAS Combinatorics Workshop, KIAS (2018.2.26) 25. Upper bounds on the number of crossings of Delta diagrams,School of Spatial Graph Theory, Nihon University, Japan (2018.1.23) 24. Upper Bounds on Braid Index and Arc Index,2nd Pan Pacific International Conference on Topology and Applications, Pusan (2017.11.15) 23. Number of Independent Vertex Sets,1st Meeting on Spatial Graph Theory, Chonbuk National University (2017.8.17) 22. Enumeration of rigid lattice links,2nd Mini Workshop on Knot Theory, POSTECH (2016.12.17) 21. Enumerative Combinatorics of various Lattice Models,Invited talk, Sungkyunkwan University (2016.10.6) 20. Enumeration algorithm for lattice model,International Workshop on Spatial Graphs 2016, Waseda University, Japan (2016.8.5) 19. Enumeration of various 2-dimensional lattice models,11th KIAS Combinatorics Workshop, KIAS (2016.2.26) 18. Combinatorics on 2-dimensional lattice models,11th East Asian School of Knots and Related Topics, Osaka City University, Japan (2016.1.28) 17. New enumeration algorithm on lattice combinatorics,Knots and Spacial Graphs 2015 at KAIST, KAIST (2015.11.6) 16. Lattice model enumeration by the state matrix recursion algorithm,AMS Special Session on Spacial Graphs, California State University, USA (2015.10.25)15. Introduction to the state matrix algorithm,10th East Asian School of Knots and Related Topics, East China Normal University, Shanghai, China (2015.1.27)14. Census of knot mosaics,Knots and Low Dimensional Manifolds: Satellite conference Seoul ICM 2014, Busan (2014.8.25)13. Total number of Knot mosaics,International Workshop on Spatial Graphs 2013, TWCU, Tokyo, Japan (2013.8.13) 12. Dehn fillings and small surfaces,Conference in Geometric Topology, Shanxi Normal University, Xi’an, China (2002.8.15) 11. Reducible, annular and toroidal Dehn fillings,2002 KMS Spring Meeting, Hoseo University (2002.4.27) 10. Dehn fillings and small surfaces,9th Japan-Korea School of Knots and Links, Nara Women’s University, Japan (2002.1.16) 9. Dehn fillings and small surfaces,2001 KMS Fall Meeting, Ewha Womans University (2001.10.20) 8. Dehn fillings producing small surfaces,MathNet Colloquium Series (Topology), Yangpyong (2001.8.24) 7. Dehn fillings and small surfaces, I,On Heegaard Splittings of 3-manifolds, RIMS, Kyoto University, Japan (2001.6.12) 6. Dehn fillings and small surfaces,2001 KMS Spring Meeting, Dong Eui University (2001.4.21) 5. Reducing and toroidal Dehn fillings,Art of low dimensional Topology VII, Kansai, Japan (2001.2.16) 4. Dehn fillings producing exceptional manifolds,Mathematics in the New Millennium, Yonsei University (2000.10.20) 3. Toroidal and P2-reducible Dehn fillings,Knots 2000, Yongpyong (2000.8.2) 2. A remark on persistent lamination,Daewoo Workshop (Topology), POSTECH(1999.7.21)1. Knotted solid tori decompositions of B3 and S3,7th Japan-Korea School of Knots & Links, Kobe Institute, Japan (1999.2.15)