On April 14, 2020, Casey Tompkins from IBS discrete mathematics group gave a talk on the saturation version of the problems related to the Erdős-Szekeres theorem on convex k-gons, sequences, and posets. The title of his talk is “Saturation problems in the Ramsey theory of graphs, posets and point sets“.

## Pascal Gollin gave a talk on variants of Woodall’s conjecture at the Discrete Math Seminar

On April 7, 2020, Pascal Gollin presented his work on the relation between the packing of edge sets intersecting all directed cuts in some class B and the maximum size of a minimal nonempty directed cut in B, motivated by Woodall’s conjecture. The title of his talk is “Disjoint dijoins for classes of dibonds in finite and infinite digraphs“.

## Hiring: IBS Young Scientist Fellowship (Due: May 31, 2020)

IBS is inviting applications for Young Scientist Fellowship. The application due is May 31, 2020. To be eligible, one should be within 7 years of obtaining a Ph.D. or under the age of 40 with a Ph.D. (born no earlier than 1 January 1980).

This is a full-time research position and the appointment is for 3 years with a possible 2-year extension depending on the performance review results. *(If a current IBS researcher is appointed as YSF, then the maximum duration is 3 years.)*

Please check https://www.ibs.re.kr/ysf/ and https://dimag.ibs.re.kr/ysf/ for more information.

IBS DIMAG will also have a few openings. The successful candidate will join the discrete mathematics group with his or her own separate research budget.

## Hiring: THE IBS Discrete Mathematics Group (DIMAG) Postdoctoral Research Fellowship (Due: April 26, 2020)

The IBS Discrete Mathematics Group (DIMAG) in Daejeon, Korea invites applications for several postdoctoral research fellowship positions.

URL: https://dimag.ibs.re.kr/hiring/

DIMAG is a new research group that was established in December 1, 2018 at the Institute for Basic Science (IBS), led by Prof. Sang-il Oum. DIMAG is located at the headquarters of the Institute for Basic Science (IBS) in Daejeon, South Korea, a city of 1.5 million people.

Successful candidates for postdoctoral research fellowship positions will be new or recent Ph.D.’s with outstanding research potential in all fields of **discrete mathematics** with emphasis on **structural graph theory, extremal graph theory, combinatorial optimization, matroid theory, or fixed-parameter tractable algorithms**.

These non-tenure-track appointments are for two or three years, and the starting salary is no less than KRW 57,000,000. The appointment is one time renewable up to 5 years in total contingent upon the outstanding performance of the researcher.

These are purely research positions and research fellows will have no teaching duties.

A complete application packet should include:

- AMS standard cover sheet (preferred) or cover letter (PDF format)
- Curriculum vitae including a publication list (PDF format)
- Research statement (PDF format)
- Consent to Collection and Use of Personal Information (PDF file)
- At least 3 recommendation letters

For full consideration, applicants should email items 1, 2, 3, and 4 and arrange their recommendation letters emailed to **dimag@ibs.re.kr** by **April 26, 2020, Sunday**. Recommendations letters forwarded by an applicant will not be considered.

DIMAG encourages applications from individuals of diverse backgrounds.

*For Korean citizens who have not yet completed their military duty: IBS는 병역특례지정기관입니다. IBS is a designated institute for alternative military service.*

## Ringi Kim (김린기) gave a talk on the strong clique number of graphs at the Discrete Math Seminar

On March 31, 2020, Ringi Kim (김린기) from KAIST presented his work on the strong clique number of graphs with Eun-Kyung Cho, Ilkyoo Choi, and Boram Park. The title of his talk is “The strong clique number of graphs with forbidden cycles“.

## Due to COVID-19, the organizers decided to postpone the conference “Seymour is Seventy” to be held in Lyon, France, June 15-19, 2020

Due to COVID-19, the organizers decided to postpone the conference “Seymour is Seventy” to be held in Lyon, France, June 15-19, 2020. We hope to run a similar event in the summer of 2021 instead. Specific decisions on the dates are to be made when the situation clarifies.

Conference website: https://dimag.ibs.re.kr/seymour70/

## Kevin Hendrey gave a talk on covering the space of permutations by Hamming balls of small radius at the Discrete Math Seminar

On March 24, 2020, Kevin Hendrey from IBS discrete mathematics group presented a talk on his work on covering the Hamming permutation space by balls of small radius. The title of his talk was “Covering radius in the Hamming permutation space“.

## Dabeen Lee (이다빈) gave a talk on the generalization of the Chvátal-Gomory closure at the Discrete Math Seminar

On March 17, 2020, Dabeen Lee (이다빈) from IBS discrete mathematics group presented a talk on his result proving that the closure of a polyhedron by some generalization of the Chvátal-Gomory cuts gives a polyhedron. The title of his talk is “On a generalization of the Chvátal-Gomory closure“.

## Eun-Kyung Cho (조은경) gave a talk on the problem of decomposing a graph into a d-degenerate graph and a graph of bounded maximum degree at the Discrete Math Seminar

On March 3, 2020, Eun-Kyung Cho (조은경) from Hankuk University of Foreign Studies presented a talk on the existence of a decomposition of a planar graph into two edge-disjoint subgraphs, one of which is d-degenerate and the other has maximum degree at most h at the discrete math seminar. The title of her talk was “Decomposition of a planar graph into a *d*-degenerate graph and a graph with maximum degree at most *h*“. She will visit the IBS discrete math group until March 6.

## Xin Zhang (张欣) gave a talk on the problem of partitioning a graph into forests of the almost equal size at the Discrete Math Seminar

On February 25, 2020, Xin Zhang (张欣) from Xidian University, China gave a talk on the problem of equitable tree-k-coloring of graphs and its variations. The title of his talk is “On the equitable tree-coloring of graphs with low degeneracy“. He is currently visiting the IBS discrete mathematics group for 1 year until August 2020 for his sabbatical leave.