Combinatorics, q-series and special functions
Refined enumeration of vertices among all rooted ordered d-trees (with Sangwook Kim and Seunghyun Seo), arXiv:1806.06417, Bulletin of the Korean Mathematical Society, 56(4), 899-910, 2019. / MR3992745
Symmetric unimodal expansions of excedances in colored permutations (with Jiang Zeng), arXiv:1411.6184, European Journal of Combinatorics, 52, part A, 174-196, 2016. / MR3425973
Signed a-polynomials of graphs and Poincaré polynomials of real toric manifolds (with Seunghyun Seo), arXiv:1212.6307, Bulletin of the Korean Mathematical Society, 52(2), 467-481, 2015. / MR3338206
Annular noncrossing permutations and minimal transitive factorizations (with Jang Soo Kim and Seunghyun Seo), arXiv:1201.5703, Journal of Combinatorial Theory, Series A, 124, 251-262, 2014. / MR3176201
Context-dependent transcriptional regulations between signal transduction pathways (with Sohyun Hwang et al), BMC Bioinformatics 2011, 12:19, 2011.
A bijective enumeration of labeled trees with given indegree sequence (with Jiang Zeng), arXiv:0805.0067, Journal of Combinatorial Theory, Series A, 118(1), 115-128, 2011. / MR2737188
The q-tangent and q-secant numbers via continued fractions (with Jiang Zeng), arXiv:0911.4658, European Journal of Combinatorics, 31(7), 1689-1705, 2010. / MR2673011
A generalized enumeration of labeled trees and reverse prüfer algorithm (with Seunghyun Seo), arXiv:math/0601009, Journal of Combinatorial Theory, Series A, 114(7), 1357-1361, 2007. / MR2353128
Schöder paths without triple descents and (101,102)-avoiding inversion sequences, 2023 Combinatorics Workshop, Yonsei University, Seoul, Korea, August 16-18, 2023.
(Plenary Talk) Sage Tutorial, Sage Days 116, Sol Beach, Yangyang, Korea, December 27-30, 2022.
(Invited Talk) On Delannoy paths without peaks and valleys, The 24th KIAS Combinatorics Workshop, Shilla Stay Haeundae, Busan, Korea, February 23, 2022.
(Invited Talk) Symmetric unimodal expansions of Eulerian polynomials, 2019 KMS Spring Meeting, Kangwon National University, Chuncheon, Korea, April 20, 2019.
Convolutional Neural Networks in Keras with CIFAR-10 dataset, Optimization and Learning Tutorial 2018, Ajou University, Suwon, Korea, March 31, 2018.
Hot to use JupyterHub for mathematics, Math Colloquium, Inha University, Incheon, Korea, March 29, 2017.
Welcome to Python and SageMath, SageMath Developers Meeting 2017, Sungkyunkwan University, Korea, February 1, 2017
Hot to use JupyterHub for data analysis, Setup of JupyterHub and its application, Korea University, Korea, December 9, 2016.
Education and research by SageMath, Mathematical Software Working Seminar, Korea University, Seoul, Korea, June 12, 2015.
Continued fractions and generalized Fibonacci numbers, 2014 Combinatorics Workshop, Ajou University, Suwon, Korea, October 31, 2014.
Simsun permuations and Entringer families, Enumerative Combinatorics mini Workshop 2013, Ladena Condominium, Chuncheon, March 30, 2013.
(Poster) Minimal transitive factorizations of a permutation of type (p,q), FPSAC 2012, Nagoya, Japan, 2012.
Bijections for Entringer families, 9th Japan-Korea Workshop on Algebra and Combinatorics, Tohoku University, Sendai, Japan, January 25, 2011.
(Poster) A further correspondence between (bc,b)-parking functions and (bc,b)-forests, FPSAC 2009, Hagenberg, Austria, July 20-24, 2009.
Counting labelled trees with given indegree sequence, Journées du GDR Informatique Mathématique, Lyon, France, June 15-16, 2009.
Permutation patterns, ordered trees and continued fractions, 2002 KMS Spring Meeting, Hoseo University, Cheonan, Korea, April 27, 2002.
June - Nov. 2017 (6 months): Advanced distributed data analysis system and its applications, NIMS, Korea.
March 2017 - Feb. 2022 (5 years): Analysis of statistics for combinatorical objects using Multi-layer Neural Network, NRF, Korea.
Sep. - Dec. 2016 (3 months): Optimization of system for data analytics in industrial mathematics and its applications, NIMS, Korea.
May 2012 - April 2015 (3 years): Minimal transitive factorizations of a permutation, NRF, Korea.
Oct. 2008 - Sep. 2010 (2 years): Combinatorics of q-series and orthogonal polynomials, CNRS, France
Sep. 2007 - Sep. 2008 (1 year): The refined bijection between the combinatorial objects, Korea Research Foundation (KRF), Korea.