## Service to the research community

### Editor

- SIAM Journal on Computing, January 2024-.
*Journal of the Korean Mathematical Society*. 2011-.- Special issue on “the Seventh Workshop on Graph Classes, Optimization, and Width Parameters, Aussois, France (GROW2015)”,
*Discrete Applied Mathematics*. 2016-2017. Call for Papers for GROW 2015. - Special issue on “the Fifth Workshop on Graph Classes, Optimization, and Width Parameters, Daejeon, Korea, October 2011 (GROW2011)”,
*Discrete Applied Mathematics*. 2012-2013.

### Steering Committee

- ACM-SIAM Symposium on Discrete Algorithms (SODA), 2022-.
- Workshop on Graph Classes, Optimization, and Width Parameters (GROW), 2011-.

### Program Committee

- CanaDAM 2025 (Canadian Discrete and Algorithmic Mathematics), Ottawa, Canada, May, 2025. (Chair)
- 19th Scandinavian Symposium and Workshops on Algorithm Theory (SWAT 2024), Helsinki, Finland, June 12-14, 2024.
- 24th International Symposium on Fundamentals of Computation Theory (FCT 2023), Trier, Germany, September 18-21, 2023.
- 33rd International Symposium on Algorithms and Computation (ISAAC 2022), Seoul, December 19-21, 2022.
- 47th International Symposium on Mathematical Foundations of Computer Science (MFCS 2022), Vienna, August 22-26, 2022,
- 48th International Workshop on Graph-Theoretic Concepts in Computer Science (WG 2022), Tübingen, June 22-24, 2022.
- 31st International Symposium on Algorithms and Computation (ISAAC 2020), Hong Kong, December 14-18, 2020.
- 46th International Workshop on Graph-Theoretic Concepts in Computer Science (WG 2020), Leeds, June 2020.
- WADS (Algorithms and Data Structures Symposium) 2019, University of Alberta, Calgary, August 5-7, 2019.
- 11th International Conference on Algorithms and Complexity (CIAC 2019), Rome, Italy, May 27-29, 2019.
- 16th Scandinavian Symposium and Workshops on Algorithm Theory (SWAT 2018), Malmö, Sweden, June 18-20, 2018.
- 13th International Symposium on Parameterized and Exact Computation (IPEC2018), Helsinki, Finland, August 20-24, 2018.
- 43rd International Workshop on Graph-Theoretic Concepts in Computer Science (WG2017), Heeze, the Netherlands, June 21-23, 2017.
- 27th International Symposium on Algorithms and Computation (ISAAC2016), Sydney, Australia, December 12-14, 2016.
- 21st European Symposium on Algorithms (ESA2013), Sophia Antipolis, France, September 2-4, 2013.
- 37th International Workshop on Graph-Theoretic Concepts in Computer Science (WG2011), Czech Republic, June 21-23, 2011.
- 7th Annual Conference on Theory and Applications of Models of Computation (TAMC 2010), Prague , Czech Republic, June 7-11, 2010.
- 35th International Workshop on Graph-Theoretic Concepts in Computer Science (WG2009), Montpellier, France, June 24-26, 2009.
- 2nd Canadian Discrete and Algorithmic Mathematics Conference (CanaDAM 2009), Montréal, Canada, May 25-28, 2009.

### Prize Committee

- Award Committee for the EATCS-IPEC Nerode Prize, 2023-2025.
- 2020 Dénes König Prize Selection Committee, SIAM Activity Group on Discrete Mathematics, 2020.

### Organizing Committee or Local Organizing Committee

- I co-organized an invited minisympoisium Structural Grpah Theory at the CanaDAM 2023 (Canadian Discrete and Algorithmic Mathematics Conference) with Sebastian Wiederrecht, Winnipeg, Canada, June 5-8,2023.
- Structural Graph Theory Downunder III, Creswick, Victoria, Australia, April 17-23, 2023.
- Structural Graph Theory Downunder II, Creswick, Victoria, Australia, March 20-27, 2022.
- 2021 Combinatorics Workshop, Yangpyeong, Korea, December 20-22, 2021.
- 2020 Combinatorics Workshop, Online, Korea, August 24, 2021.
- The 2nd East Asia Workshop on Extremal and Structural Graph Theory, Jeju, October 31-November 4, 2019.
- Special session on extremal and structural graph theory at the 2019 Korean Mathematical Society Annual Meeting, Hongik University, October 26-27, 2019.
- 2019-2 IBS One-Day Conference on Extremal Graph Theory, IBS Discrete Mathematics Group, August 12, 2019.
- 2019 Combinatorics Workshop, Songdo, Incheon, August 13-15, 2019.
- 2019-1 IBS Workshop on Graph Theory, IBS Discrete Mathematics Group, February 11-12, 2019.
- 2016 Combinatorics Workshop, KAIST, July 21-23, 2016.
- 1st Korean Workshop on Graph Theory, August 26-28, 2015 at KAIST.
- 27th International Conference on Formal Power Series and Algebraic Combinatorics (FPSAC2015), July 6-10, 2015 at KAIST.
- ICM2014 Satellite Conference on Extremal and Structural Graph Theory, Gyeongju, August 5-9, 2014.

- Member of ICM2014 Local Organizing Committee for ICM (International Congress of Mathematicians) 2014 at Seoul.
- 12th Annual Korea-Japan workshop on algebra and combinatorics, January 23-25, 2014, KAIST.
*5th workshop on Graph Classes, Optimization, and Width Parameters (GROW 2011)*, October 27-29, 2011, KAIST. This is a continuation of the series of meetings: Barcelona 2001, Prague 2005, Eugene 2007, and Bergen 2009.*Special session on graph theory*at the 2010 Korean Mathematical Society Spring Meeting (with Seog-Jin Kim), April 2010.- I co-organized the
*Winter School on Algorithms and Combinatorics*, January 13-16, 2010 in Korea. - I co-organized the
*2009 Combinatorics Workshop*, August 20-21, 2009 at KAIST. - Organizer of the minisymposium “Graph Minors” (MS4), SIAM Conference on Discrete Mathematics, June 16-19, 2008 at the University of Vermont.
- Co-organizer of the minisympoisum “Graph Structure Theory” (MS4), SIAM Conference on Discrete Mathematics, June 25-28, 2006 at the University of Victoria.

### Misc.

- Committee Chair of Discrete Mathematics, Korean Mathematical Society, 2024.1.1.-2026.12.31.
- Committee Member of Discrete Mathematics, Korean Mathematical Society, 2009.3.1.-2023.12.31.
- Chair for Combinatorics, Korean Society for Industrial and Applied Mathematics. 2015.1.1.-2023.12.31.

## Service to the society

### Mathematical Olympiads

I was involved in selecting and educating highly gifted students in Korea to compete in International Mathematical Olympiad (IMO). For 2011-2012 and 2017-2018, I was an executive member of the Board of Trustees, Korean Mathematical Society in charge of the Korean Mathematical Olympiad (KMO).

- I’ve been to IMO2009 Bremen (Observer B), IMO2011 Amsterdam (Observer B), and IMO2012 Mar del Plata (Deputy Leader), IMO2016 Hong Kong (Observer B), IMO2017 Brasil (Observer B), IMO2018 Cluj-Napoca (Deputy Leader).
- I was also the deputy leader for the South Korean CGMO (China Girl’s Math Olympiad) team for 2012, held in Guangzhou, China.
- I was the deputy leader for the South Korean RMM (Romanian Master of Mathematics) team for 2017 and 2018.
- Member of Korean Math Olympiad Committee, 2011-2018.

### KAIST Math Problem of the Week

I managed the KAIST Math Problem of the Week (2008-2012, 2014-2018), jointly with Prof. Ji Oon Lee.

### Horizon

Until the end of November 2018, I had been one of the founding editors of the Horizon, a math and science blog run by KIAS.

### Writing articles

- “2012년 아벨상 수상자의 업적 – 헝가리 출신 수학자 세머레디 교수”, The Newsletter of KMS, Korean Mathematical Society, vol. 148, pp. 7-9, March 2013.
- “2012년 국제수학올림피아드(IMO) 참가 보고”, The Newsletter of KMS, Korean Mathematical Society, vol. 145, pp. 13-22, Sep. 2012.
- “불규칙에서 규칙성 찾은’수학자, 아벨상 수상자로“, 사이언스 온, 한겨레신문(주), March 23, 2012.

(explaining the work of E. Szemerédi after he was announced as the Abel prize winner of 2012.) - Hot Math (따끈따끈한 수학), Math Donga, 2016.1-2019.12 (Monthly articles on a mathematics magazine called the Math Donga 수학동아.)
- “수학자의 시선” (Viewpoint from a mathematician), 서울신문 (Seoul Shinmun), 2019.8-2020.5.

### Public talks

- 2017 Fall KAOS Lecture, KAOS Foundation, 2017.
- KAIST 명강 4기 대중강연, 2015.

### Other services

- IBS Rules and Regulations Review Committee (원규심의위원회), 2019.7.-.
- KAIST 영재교육위원회 위원, 2015.4.9-.
- KAIST Press 편집기획위원회 위원, 2012.12.1-2016.11.30.
- KAIST 정보기술위원회 위원, 2011.5.1-2015.5.31.
- KAIST 정원 및 캠퍼스혁신 소위원회, 2014.3.1-2014.6.30.
- KAIST 홍보위원회, 2011.2.21-2013.2.20.
- Director of Graduate Studies (대학원주임), Department of Mathematical Sciences, 2017.3.13.-2018.10.31.
- 아슬라 심포지엄 학술위원회(구. 국제학술심층토론회 운영위원회), KIST, 2016.10.-2019.7.