Monday 18 December 2023

2024 Online Informatics Olympiad Training, Road To NOI 2024

This is posted on behalf of Mr. Tran. 

Mr. Tran is currently pursuing a Bachelor of Computing degree in Computer Science at NUS. He has 4.5 years of experience in competitive programming. His achievements were as follows: 
- Silver Medal at Asia-Pacific Informatics Olympiad (APIO) 2022 
- Highest score, 1st place at Vietnam Olympiad Informatics (VOI) 2022
- Silver Medal (7th place) at The 2023 International Collegiate Programming Contest (ICPC) Asia Hue City Regional Contest
- Co-First Prize at The 2022 International Collegiate Programming Contest (ICPC) Asia Ho Chi Minh City Regional Contest

Specifically, he also has nearly 2 years of experience in teaching IO teams in Vietnam, and his students' achievements were as follows:
- 2 First Prize in Vietnam Olympiad Informatics (VOI) 2023
- 4 Second Prize in Vietnam Olympiad Informatics (VOI) 2023
- 1 Asia-Pacific Informatics Olympiad (APIO) contestant 2023

The 1-1 lessons will be held online via Google Meet. Every student will enjoy 2 free trial 1-1 sessions. 


If you are interested, please contact Mr. Tran via WhatsApp 89371076.

Thursday 16 November 2023

1st ECOPRO Combinatorial Week Workshop 2023

The 1st workshop ECOPRO (Extremal Combinatorics and Probability) Combinatorial Week is held at IBS. This workshop aims to get together experts and junior researchers to tackle challenging problems in extremal and probabilistic combinatorics, as well as problems in related fields.

Dates and venue: November 8 to 17, 2023, ECOPRO group, IBS headquarter, Daejeon, South Korea.

Workshop Problems 


1Jozsef BaloghUniversity of Illinois Urbana-Champaign
2Felix ClemenKarlsruhe Institute of Technology
3Jialin HeThe Hong Kong University of Science and Technology
4Yifan JingOxford University
5Jeck LimCalifornia Institute of Technology
6Weichan LiuChinese Academy of Sciences
7Haoran LuoUniversity of Illinois Urbana-Champaign
8Sam MattheusUniversity of California San Diego
9Leticia MattosUniversity of Illinois Urbana-Champaign
10Minghui OuyangPeking University
11Fei PengNational University of Singapore
12Eero RätyUmeå University
13Chong ShangguanShandong University
14Shumin SunUniversity of Warwick
15Tuan TranUniversity of Science and Technology of China
16Ethan WhiteUniversity of Illinois Urbana-Champaign
17Michael WigalUniversity of Illinois Urbana-Champaign
18Menglong ZhangBeijing Jiaotong University
19Tao ZhangZhejiang Lab
20Yuqi ZhaoShandong University
21Xiangxiang ZhengHamburg University

Tuesday 10 October 2023

2023 November/December School Holidays Online Maths Olympiad Training

This is posted on behalf of Ms Tang. 

Ms Tang graduated with a Masters in Mathematics and was a former university Maths lecturer. She helped her children prepare for Mathematical Olympiads. Their achievements were as follows: 

 • Gold, 3rd place in NMOS (National Mathematical Olympiad of Singapore) 
 • High Distinction, 2nd place in RIPMWC (Raffles Institution Primary Mathematics World Contest) 
 • Perfect score in PMWC in Hong Kong 
 • Platinum, 3rd place in SMOPS (Singapore Mathematical Olympiad for Primary School)
 • Perfect score in AMC 8 (American Mathematics Contest 8) 
 • High Distinction, Medalist in ICAS (International Competitions and Assessments for School)
 • Gold, 1st place in Singapore in SASMO (Singapore and Asian School Math Olympiad) 
 • Gold, 2nd place in SMO Junior 

She will be teaching the following classes in small groups (2 to 4 students). The lessons will be held on the online platform ZOOM. 

1. Math Olympiad Training for SMOPS/APMOPS 2024: 11 November to 9 December 2023 (Wed, Sat)
2. Math Olympiad Training for SMO Junior 2024: 5 November to 10 December 2023 (Sun)


If you are interested, please contact Ms Tang via WhatsApp 85758636.

Monday 9 October 2023

Tuesday 19 September 2023

Everywhere Unbalanced Configurations by David Conlon and Jeck Lim

Source: Cheerful news in difficult times: David Conlon and Jeck Lim settled Kupitz’s planar discrepancy problem for pseudolines by Gil Kalai

Everywhere unbalanced configurations, by David Conlon and Jeck Lim

Some years ago I blogged about the following question of Yaakov Kupitz

What is the smallest number C such that for every configuration of n points in the plane there is a line containing two or more points from the configuration for which the difference between the number of points on the two sides of the line is at most C?

Kupitz asked, in particular, if every point set has a line through at least two of its points which is balanced in the sense that the number of points on either side differ by at most some fixed constant c. David Conlon and Jeck Lim showed that if you allow pseudolines rather than lines, the answer is no!

Kupitz’s question extends to pseudolines where it can be formulated using the method of  allowable sequence of permutations introduced by Goodman in Pollack. The best known upper bound C = O(log log n) was proved by Rom Pinchasi and Rom’s proof uses the method of allowable sequence of permutations and applies to pseudolines. Conlon and Lim’s proof shows that for pseudolines, CΩ(log log n) .

Congratulations David and Jeck!


Some papers by Lim Jeck on ArXiv