On October 1, 2019, Casey Tompkins at IBS discrete mathematics group presented a seminar talk on an extension of Turán’s theorem to hypergraphs. The title of his talk was “Extremal problems for Berge hypergraphs“.

## Cory Palmer gave a survey talk on the Turán-type subgraph counting problems at the discrete math seminar

On September 19, 2019, Cory Palmer from University of Montana presented a survey talk on the Turán-type subgraph counting problems at the discrete math seminar. The title of his talk was “A survey of Turán-type subgraph counting problems“. He will stay at the IBS discrete mathematics group until October 3, 2019.

## Kevin Hendrey presented his work on the minimum connectivity to force a minor isomorphic to a fixed forest in a large graph at the discrete math seminar

On September 10, 2019, Kevin Hendrey at IBS Discrete Mathematics Group presented his work on the minimum connectivity to force a minor isomorphic to a fixed forest in a large graph. The title of his talk was “The minimum connectivity forcing forest minors in large graphs”.

## Welcome Xin Zhang from Xidian University, a new visiting scholar in the IBS discrete mathematics group

The IBS discrete mathematics group welcomes Prof. Xin Zhang (张欣), a new visiting scholar from Xidian University, China. He is visiting the IBS discrete mathematics group for one year from August 22, 2019.

He received his Ph.D. from Shandong University in China and is currently an associate professor in the School of Mathematics and Statistics, Xidian University, Xi’an, China.

## Mihyun Kang (강미현) presented her work on the genus of random graphs and randomly perturbed graphs at the Discrete Math Seminar

On August 20, 2019, Mihyun Kang (강미현) from Graz University of Technology, Austria presented her work on the genus of random graphs and randomly perturbed graphs at the Discrete Math Seminar. The title of her talk was “The genus of a random graph and the fragile genus property”. She will stay until August 22, 2019 at the IBS Discrete Mathematics Group.

## “2019 Combinatorics Workshop” was held from August 13 to August 15, 2019 at Incheon.

The **2019 Combinatorics Workshop (2019 조합론 학술대회)** was held from August 13, 2019 to August 15, 2019 at the SKYPARK Hotel, Songdo, Incheon. There were 16 talks.

### Plenary Speaker

- Mihyun Kang (강미현), Graz University of Technology

### Keynote Speakers

- Jaehoon Kim (김재훈), KAIST
- Seung Jin Lee (이승진), Seoul National University
- Meesue Yoo (유미수), Dankook University

### Invited Speakers

- Eun-Kyung Cho (조은경), Hankuk University of Foreign Studies
- Soogang Eoh (어수강), Seoul National University
- JiSun Huh (허지선), Sungkyunkwan University
- Jihyeug Jang (장지혁), Sungkyunkwan University
- Dong Yeap Kang (강동엽), KAIST and IBS Discrete Mathematics Group
- Min Jeong Kang (강민정), Incheon National University
- Dabeen Lee (이다빈), IBS Discrete Mathematics Group
- Kang-Ju Lee (이강주), Seoul National University
- Myeonghwan Lee (이명환), Incheon National University
- Jihye Park (박지혜), Yeungnam University
- Sun-mi Yun (윤선미), Sungkyunkwan University

## “2019-2 IBS One-Day Conference on Extremal Graph Theory” was held on August 12, 2019.

The 2019-2 IBS One-Day Conference on Extremal Graph Theory was held on August 12, 2019 at the IBS Discrete Mathematics Group. There were four talks. Here is a list of talks.

- Jaehoon Kim (김재훈), KAIST:
*Tree decompositions of graphs without large bipartite holes* - Hong Liu (刘鸿), University of Warwick:
*Recent advance in Ramsey-Turán theory* - Abhishek Methuku, IBS Discrete Mathematics Group:
*Bipartite Turán problems for ordered graphs* - Péter Pál Pach, Budapest University of Technology and Economics:
*On some applications of graph theory to number theoretic problems*

## “2019 IBS Summer Research Program on Algorithms and Complexity in Discrete Structures” was held for three weeks from July 22 to August 10

The **2019 IBS Summer Research Program on Algorithms and Complexity in Discrete Structures** was held from July 22, 2019 to August 10, 2019 at the IBS Discrete Mathematics Group. Over the three weeks, 15 talks were given and there was ample time for discussion. It was organized by Eunjung Kim (CNRS) and Sang-il Oum. Here is a list of major participants.

#### Major Participants

**Pierre Aboulker**, ENS Ulm, France**Jungho Ahn**, KAIST and IBS Discrete Mathematics Group**Rémy Belmonte**, University of Electro-Communications, Japan**Benjamin Bergougnoux**, University of Paris Diderot, France**Édouard Bonnet**, ENS Lyon, France**Nick Brettell**, Durham University, UK**Yixin Cao**, Hong Kong Polytechnic University, China**Michael Dobbins**, Binghamton University, USA**Chris Eppolito**, Binghamton University, USA**Archontia Giannopoulou**, National and Kapodistrian University of Athens, Greece**Sang-il Oum**, IBS Discrete Mathematics Group and KAIST**William Overman**, California Institute of Technology**Mamadou M. Kante**, University Clermont Auvergne, France**Donggyu Kim**, KAIST and IBS Discrete Mathematics Group**Eunjung Kim (김은정)**, LAMSADE-CNRS, France**Stefan Kratsch**, Humboldt-Universität zu Berlin, Germany**O-joung Kwon (권오정)**, Incheon National University, Korea**Michael Lampis**, Université Paris-Dauphine, France**Dabeen Lee**, IBS Discrete Mathematics Group**Duksang Lee**, KAIST and IBS Discrete Mathematics Group**Euiwoong Lee (이의웅)**, NYU, USA**Valia Mitsou**, Université Paris-Diderot, France**Florian Sikora**, University Paris Dauphine, France**Magnus Wahlström**, Royal Holloway, University of London, UK

## Dabeen Lee (이다빈) presented his work on algorithmic problems of finding a clutter minor at the Discrete Math Seminar

On July 16, 2019, Dabeen Lee (이다빈) from IBS Discrete Mathematics Group presented his work on identifying a clutter minor related to ideal clutters at the Discrete Math Seminar. The title of his talk was “Integrality of set covering polyhedra and clutter minors”.

## Patrice Ossona de Mendez presented his work on the structural sparsity of graphs in terms of a model theoretic notion at the discrete math seminar

On June 25, 2019, Patrice Ossona de Mendez from CNRS, France presented a talk on the structural sparsity of graphs in terms of the model theoretic notion of first-order transduction. The title of his talk was “A model theoretical approach to sparsity”.