News

October 28, 2025October 29, 2025

2025 Call for IBS Young Scientist Fellowship (Due December 5, 2025)

The IBS Discrete Mathematics Group has an opening for the 1 IBS Young Scientist Fellowship.

1. Introduction

With the vision of “Making discoveries for humanity and society,” the Institute for Basic Science (IBS) was founded in 2011 by the Korean government topromote basic science in Korea. To date, IBS operates 30 Research Centers which have been yielding outstanding results in various research fields.

The IBS started to select Young Scientist Fellow (YSF) in 2016 to play an active role in fostering the next generation of basic science leaders. This program offers young scientists opportunities to conduct independent research with state-of-the-art research infrastructure of the IBS and to grow on the basis of research collaborations with leading researchers.

We hope that the YSF program serves as a stepping stone for our researchers to mature into leading researchers in basic science.

2. Eligibility

Within seven years of obtaining a Ph.D. (obtained no earlier than 1 January 2018) or under the age of 40 with a Ph.D. (born no earlier than 1 January 1985)
Ph.D. candidates must be conferred with a Ph.D. degree no later than 30 June 2026.

3. Hiring Research Centers

Discrete Mathematics Group has an opening. Budget: Up to KRW 180 million per year.

For other centers and groups, please visit the IBS website https://www.ibs.re.kr/ysf/.

4. Benefits and Conditions

Full-time work and 100% research participation in principle
– If successful candidates for the YSF are selected for other projects (e.g., Sejong Science Fellowship and Young Researcher Program of the National Research Foundation), their selection may be cancelled. During the research term, participating in other projects funded by sources outside the IBS are not allowed.
Annual fund of KRW 180–300 mil. (up to KRW 180 mil. for theoretical fields and up to KRW 300 mil. for experimental fields), including salary of KRW 60–70 mil.
Appointment for three years with a possible two-year extension depending on the performance review results
* When current IBS researchers are selected as a YSF of their Center, support will be offered for up to three years.
YSFs will work at one of the IBS Centers and conduct independent research with research facilities and equipment of their Centers. They may organize small research groups.
– YSFs should prioritize using the advanced research infrastructure of their Centers in conducting research. Although they may construct research equipment and facilities within their budget, the construction scale and timing may be adjusted through review.
Successful candidates must be appointed and commence their research within 1 July – 16 December 2026
– If their appointment and research commencement are not completed within 1 July – 16 December 2026, their selection may be cancelled.
When the Center (PRC Group) to which a YSF group belongs is closed, the YSF group will also be closed in principle.
– Please refer to the FAQ for details.

5. Selection Process (The schedule may change depending on the circumstances of IBS.)

First phase: Letter of intent (approx. three pages) acceptance and evaluation
1. Submission deadline: 5 December 2025
2. Review of each letter of intent by the director and the selection and evaluation panel concerned
3. Invitation to submit full research proposals: January 2026
  – Applicants who pass the first phase will be requested to submit an approx. 10-page full research proposal, up to three reference letters and presentation materials.
Second phase: Full research proposal acceptance and in-depth evaluation by field
1. Submission deadline: February 2026
2. Review of each full proposal and reference letter by the director concerned
3. Interview (on-site presentation) by the selection and evaluation panel concerned: March 2026
  – If candidates reside abroad or have difficulty attending on site, the evaluation will be held via video conference.
Third phase: Comprehensive evaluation and notification of the results
1. Comprehensive evaluation by panel chairs
2. Final selection and notification of the results: ~ June 2026

6. How to Apply: IBS website by 5 December 2025, 17:59(KST)

https://www.ibs.re.kr/ysf/apply

7. Inquiries

Research Evaluation Team at ysf@ibs.re.kr
IBS website at https://www.ibs.re.kr/ysf/juniorci

October 23, 2025

William Cook gave a public lecture in Seoul on the Traveling Salesman Problem

On October 22, 2025, William Cook from the University of Waterloo gave a public lecture on the traveling salesman problem at the ST Center, Seoul during the 2025 KMS Annual Meeting. The title of his talk was “The Traveling Salesman Problem: Package Deliveries, Pub Walks, and Astro Tours.” This public lecture was co-organized by the IBS Discrete Mathematics Group.

Poster

October 21, 2025October 21, 2025

William Cook gave a talk on using branch-decompositions for discrete optimization problems, such as the traveling salesman problem, at the Discrete Math Seminar

On October 21, 2025, William Cook from University of Waterloo gave a talk at the Discrete Math Seminar on using branch-decompositions for discrete optimization problems, including the traveling salesman problem. The title of his talk was “Optimization via Branch Decomposition“.

October 17, 2025October 17, 2025

Ilkyoo Choi (최일규) gave a talk on the average degree of list-color-critical graphs and DP-color-critical graphs at the Discrete Math Seminar

On October 14, 2025, Ilkyoo Choi (최일규) from Hankuk University of Foreign Studies and IBS Discrete Mathematics Group gave a talk at the Discrete Math Seminar on the average degree of list-color-critical graphs and DP-color-critical graphs. The title of his talk was “An improved lower bound on the number of edges in list critical graphs via DP coloring“.

October 1, 2025September 25, 2025

Welcome Jigang Choi (최지강), a new graduate student of the IBS Discrete Mathematics Group

The IBS Discrete Mathematics Group welcomes Jigang Choi (최지강), a new graduate student of the Discrete Mathematics Group from October 1, 2025. He received his B.S. degree from Hanyang University and entered the Department of Mathematical Sciences at KAIST as a graduate student on March 2025. His advisor is Jaehoon Kim (김재훈).

September 30, 2025September 30, 2025

Marcelo Sales gave a talk on proving lower bounds on the Ramsey numbers of some hypergraphs

On September 30, 2025, Marcelo Sales from the University of California, Irvine, gave a talk at the Discrete Math Seminar about proving lower bounds on the Ramsey numbers of some hypergraphs. His talk was titled “On the Ramsey number of Daisies and other hypergraphs.”

September 26, 2025

Upcoming Public Lecture: The Traveling Salesman Problem — Package Deliveries, Pub Walks, and Astro Tours on October 22, 2025 in Seoul near Gangnam Station

We are pleased to share an exciting public lecture as part of the 2025 Annual Meeting of the Korean Mathematical Society (KMS), featuring one of the world’s leading researchers in combinatorial optimization. This event is sponsored by the IBS Discrete Mathematics Group.

🧭 The Traveling Salesman Problem: Package Deliveries, Pub Walks, and Astro Tours

👤 Speaker: William Cook
🏛 Affiliation: Department of Combinatorics and Optimization, University of Waterloo
📅 Date: October 22, 2025 (Wednesday), 7:00 PM
📍 Venue: ST Center, Seoul (near Gangnam Station)
한국과학기술회관 B1, 과학기술컨벤션센터, 대회의실 2 (강남역 인근)
🗣 Language: English
🎟 Admission: Free of charge

🌍 About the Talk

The Traveling Salesman Problem (TSP) asks a deceptively simple question:

What is the shortest possible route that visits a set of locations exactly once and returns to the starting point?

Despite its simplicity, the TSP is a cornerstone of combinatorial optimization and theoretical computer science, long considered difficult due to its computational complexity.

In this public lecture, William Cook, a leading authority on the TSP, will discuss:

Modern algorithmic techniques capable of solving TSP instances with tens of thousands of stops
Applications from package delivery to pub crawls and even space tours
Real-world case studies, including optimization over 80,000 pubs in Korea and routes through over 100 million stars

The TSP remains a central example in complexity theory, showing how sustained mathematical effort can solve problems once deemed impossible.

👨‍🏫 About the Speaker

William Cook is a professor emeritus at the University of Waterloo and an internationally recognized expert on combinatorial optimization.
He is the author of the acclaimed book In Pursuit of the Traveling Salesman and has contributed extensively to both the theory and computation of hard optimization problems.

🔗 Join Us!

Whether you’re a student interested in algorithms, a researcher in discrete mathematics, or simply curious about how math solves real-world problems — this is a lecture not to be missed.

📍 Location: ST Center, Seoul
🕖 Time: 7:00 PM, Wednesday, October 22, 2025
🎟 Admission: Free | 🗣 Language: English

Registration

🔗 More info about KMS 2025 Annual Meeting
📧 For inquiries: contact@kms.or.kr

September 22, 2025

Rong Luo gave a survey talk on the nowhere-zero flows on signed graphs at the Discrete Math Seminar

On September 22, 2025, Rong Luo from West Virginia University gave a talk at the Discrete Math Seminar on nowhere-zero flows on signed graphs. His talk was titled “Modulo flows and Integer flows of signed graphs“.

September 16, 2025September 16, 2025

Mujin Choi (최무진) gave a talk on unavoidable induced minors in graphs of large tree-independence number without a fixed star induced subgraph

On September 16, 2025, Mujin Choi (최무진) from KAIST and the IBS Discrete Mathematics Group gave a talk at the Discrete Math Seminar on unavoidable induced minors in graphs of large tree-independence number without a fixed induced star. The title of his talk was “Excluding ladder and wheel as induced minor in graphs without induced stars“.

September 9, 2025September 9, 2025

Katherine Perry gave a talk on the distinguishing number and the fixing number of trees at the Discrete Math Seminar

On September 9, 2025, Katherine Perry from the Soka University of America gave a talk at the Discrete Math Seminar on the relationship between the distinguishing number and the fixing number of trees. The title of her talk was “Symmetry breaking in trees“.