Sang-il Oum (엄상일)

Category: Language

  • Hong Liu is moving to IBS as a Chief Investigator to start the IBS Extremal Combinatorics and Probability Group (ECOPRO) on April 2022 and is hiring up to 5 postdocs (Application Deadline: January 14, 2022)

    Hong Liu is moving to IBS as a Chief Investigator to start the IBS Extremal Combinatorics and Probability Group (ECOPRO) on April 2022 and is hiring up to 5 postdocs (Application Deadline: January 14, 2022)

    News: The Institute for Basic Science (IBS) in Korea is expanding further into discrete mathematics by establishing a new “IBS Extremal Combinatorics and Probability Group (ECOPRO)” led by Hong Liu from the University of Warwick, UK on April 2022. This new group will also be located in the IBS headquarter and is expected to work closely with the IBS Discrete Mathematics Group (DIMAG).

    The IBS Extremal Combinatorics and Probability Group posted the hiring announcement for up to 5 postdocs. The application due is on January 14, 2022.

    Please check their job posting on mathjobs.org: 2021-1 Recruitment Announcement for Postdoctoral Research Associate Positions at the Extremal Combinatorics and Probability Group

    The position is available for individuals who are within the first five years after obtaining their Ph.D at the date of appointment or expecting to obtain a Ph.D. within three months from the date of appointment.

  • List of upcoming conferences and workshops

    Each month I’m compiling a list of upcoming conferences and workshops. Here is the list for November 2021.

    Update in 2022: This post will be no longer updated. Instead, I made a new page that contains a list of upcoming meetings automatically generated from mathmeetings.net.

    Organized by IBS DIMAG

    • November 28-30, 2021: International Conference on Discrete Mathematics and Computer Science, Dalat, Vietnam. http://icdmcs.dlu.edu.vn
      • Tuan Tran is one of the organizers.
      • Invited Speakers: Alexis DROGOUL (IRD, France), HO Tu Bao (VIASM, Vietnam), LE Hoai Bac (HCMUS, Vietnam), Sang-il OUM (IBS and KAIST, South Korea), Ingo SCHIERMEYER (TU Freiberg/Germany), Patrick TALLAINDIER (INRA, France), VU Ha Van (VinBigdata, Vietnam; Yale University/America).
      • A hybrid meeting. (postponed)
    • December 20-22, 2021: 2021 Combinatorics Workshop.
    • March 20-27, 2022: MATRIX-IBS Workshop: Structural Graph Theory Downunder II, Parkville, Australia https://www.matrix-inst.org.au/events/structural-graph-theory-downunder-ll/
      • Will be postponed to November 2022.
    • June 20-24, 2022: Seymour is Seventy, Lyon, France https://dimag.ibs.re.kr/seymour70/ (postponed from 2020)
      • There is some chance of adjusting the format or the schedule.

    In Korea

    • December 2-5, 2021: 2021 KSIAM Annual Meeting, Korean Society for Industrial and Applied Mathematics, Busan. (hybrid meeting). http://ksiam.org/Conference/ConferenceView.asp?AC=0&CODE=CC20210901&CpPage=#CONF
      • Jaehoon Kim at KAIST is organizing a special session on Extremal Combinatorics. The speakers include Hong Liu, Debsoumya Chakraborti, Tuan Tran, Joonkyung Lee, and Linda Cook.
      • Deadline for contributed talks: November 11.
      • Registration for offline attendance: November 18.

    Online

    • November 13-14, 2021: China-Korea Young Scholars’ Symposium on Discrete Mathematics, Statistics and Optimization, Online.
      • Organized by Yongtang Shi (Nankai University) and Suil O (SUNY Korea).
    • December 13-17, 2021: 43rd Australasian Combinatorics Conference (43ACC), Online. https://43acc.ms.unimelb.edu.au/

    Hybrid: In-person + Online

    Out of Korea

    Let me know if you want to add anything to the list next month.

  • Postdoc positions available at the IBS Discrete Mathematics Group, South Korea (Due: December 5, 2021)

    Postdoc positions available at the IBS Discrete Mathematics Group, South Korea (Due: December 5, 2021)

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

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

    DIMAG is a 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. 

    The position is available for individuals who are within the first five years after obtaining their Ph.D. at the date of appointment or expecting to obtain a Ph.D. within three months from the date of appointment. 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.

    This appointment is for two years, and the starting salary is no less than KRW 57,000,000. The appointment is one time renewable up to 3 years in total contingent upon the outstanding performance of the researcher. The expected appointment date is September 1, 2022. This is a purely research position and will have no teaching duties.

    A complete application packet should include:

    1. AMS standard cover sheet (preferred) or cover letter (PDF format)
    2. Curriculum vitae including a publication list (PDF format)
    3. Research statement (PDF format)
    4. Consent to Collection and Use of Personal Information (PDF file)
    5. 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 December 5, 2021, Sunday. 

    Recommendations letters forwarded by an applicant will not be considered.

    DIMAG encourages applications from individuals of diverse backgrounds.

  • Department of Mathematical Sciences at KAIST invites applications for a tenured and tenure-track faculty position beginning from Spring 2022 to Spring 2023.

    Department of Mathematical Sciences at KAIST invites applications for a tenured and tenure-track faculty position beginning from Spring 2022 to Spring 2023.

    Professorships at KAIST

    The Department of Mathematical Sciences at KAIST invites applications for a tenured and tenure-track faculty position beginning from Spring 2022 to Spring 2023.

    In recent years, KAIST, one of the top research universities in Korea, has been recruiting distinguished scholars of both Korean and foreign nationalities. KAIST is located in Daejeon, a city with a population of 1.5 million, and its operation is financially supported by the Korean government. Most of the courses at KAIST are taught in English.

    Applications are accepted from any areas of pure, applied, and interdisciplinary mathematics including artificial intelligence (AI) and data science. Successful applicants must demonstrate outstanding accomplishments or potential in research and teaching.

    An internationally competitive salary commensurate with qualifications will be offered with attractive remuneration packages including relocation assistance, a start-up grant for research, health insurance, and housing benefit. The regular teaching load is two courses for the first year, and three courses a year thereafter.

    All applications must include the following:

    • KAIST faculty application form (A separate paper for major achievements, teaching plan, and research accomplishments is acceptable.) 
    • Cover letter (An AMS standard cover sheet is acceptable. The names of three (3) recommenders must be listed therein.)
    • Curriculum vitae with a publication list
    • Research statement of previous work and future plans
    • Teaching statement of previous work and future plans
    • A minimum of three (3) recommendation letters (Recommenders should send their letters directly to the email address below.)

    After the screening process, candidates may need to submit additional documents.

    All applications should be sent to recruit@mathsci.kaist.ac.kr or to the mailing address below by Thursday, September 30, 2021: 


    Jaeyoung Byeon
    Head of the Department of Mathematical Sciences
    KAIST
    291 Daehak-ro, Yuseong-gu, 

    Daejeon
    Republic of Korea 
    Zip Code: 34141

    https://mathsci.kaist.ac.kr/home/en/

    For any inquiries, please contact Lan Yoon at +82-42-350-2703 or recruit@mathsci.kaist.ac.kr.

  • KIAS 웹진 Horizon에 기고한 글 “2021 아벨상 수상자 로바스 라슬로”

    2021년 아벨상 수상자 두 분 중 한 분인 로바스(Lovász László) 교수의 업적을 소개하는 글을 써서 KIAS 웹진 Horizon에 실었습니다.

    2021 아벨상 수상자 로바스 라슬로

  • 수학동아xIBS, 나의 삶 나의 수학 시리즈 인터뷰+기고

    수학동아xIBS, 나의 삶 나의 수학 시리즈 인터뷰+기고

    수학동아와 기초과학연구원(IBS)이 설립 10주년을 맞아 공동으로 IBS 내의 수학자들의 연구와 삶을 소개하는 시리즈를 시작하였습니다. 제 이야기로 그 시리즈 시작이 되었습니다. 내용은 수학동아 2021년 5월호나 IBS 홈페이지에서 볼 수 있습니다. 글을 다듬어주신 홍아름 수학동아 기자님, 그리고 멋진 사진을 찍어주신 AZA 스튜디오 남윤중 실장님 감사드립니다. 내용은 아래에서 볼 수 있습니다.

    1편: 기자의 인터뷰

    2편: 연구 경험담

    제가 하던 수학 연구는 길게는 수년, 짧게는 수일 만에 완성되기도 했습니다. 그중 독일의 한 소도시에서 했던 연구는 단 하루 만에 답을 얻었습니다. 그래프 알고리듬 분야에서 유명한 브루노 쿠르셀 프랑스 보르도컴퓨터과학연구소(LaBRI) 교수님과 만났던 2004년 5월에 생긴 일입니다…

  • How to configure Perl to run latexindent on Mac OS Catalina

    How to configure Perl to run latexindent on Mac OS Catalina

    The “latexindent” is a Perl script that indents a LaTeX file to make it easier to read, and is included in MacTeX. As most of us install the MacTeX, it should be easy to use latexindent. However, the default installation does not work because it requires extra configuration on Perl. To make it worse, this install isn’t trivial at all. You can find questions on Stackoverflow. Here’s what I did in order to set up the latexindent on MacOS without using brew to install Perl again.

    Install xcode command line tools

    In order to use C compilers or git on Mac, it is necessary to install command line tools. On the terminal, run this command.

    xcode-select --install

    Configure the CPATH environment

    Due to some weird reasons, some necessary files for compiling some packages are hidden on Mac OS Catalina. In order to make some header files to be available for compilers, we need to set up the CPATH variable. Otherwise, there will be an error message saying “Fatal error: ‘EXTERN.h’ file not found”.

    To find this file, one can run the following command.

    find /Library/Developer/CommandLineTools/SDKs -name EXTERN.h -print

    There may be many versions; you can choose the one that matches the version of Perl installed on Mac. In my case, the version of Perl was v5.18.4. The version of Perl can be found by “perl -v”. On my Mac, EXTERN.h for this version was in /Library/Developer/CommandLineTools/SDKs/MacOSX11.0.sdk/System/Library/Perl/5.18/darwin-thread-multi-2level/CORE/EXTERN.h. Thus, I set the CPATH environment as follows.

    export CPATH=/Library/Developer/CommandLineTools/SDKs/MacOSX11.0.sdk/System/Library/Perl/5.18/darwin-thread-multi-2level/CORE

    Install Perl packages by cpan

    The latexindent requires a few Perl packages to be installed. Here is the command to run.

    cpan -i Log::Log4perl Log::Dispatch::File YAML::Tiny File::HomeDir Unicode::GCString

    Like me, most of you will see many questions, because in its first run, it requires to configure itself. Here’s what I chose. 

    What approach do you want?  (Choose 'local::lib', 'sudo' or 'manual')
 [local::lib] sudo

    After all this, latexindent should be ready. If not, then you can try to install missing Perl packages again by using “cpan -i”.

    I use latexindent on Visual Studio Code. The standard extension for LaTeX, LaTeX Workshop, uses latexindent to indent a LaTeX file.

  • List of YouTube Channels for research talks on discrete mathematics

    Due to the COVID-19 pandemic, many seminars are now held online. Many of them made a YouTube channel to post their videos. But it is very difficult to search for such videos. In this post, I’d like to share a few of them. Please suggest more in the comment.

    Here’s a list of YouTube channels for online seminars.

    Here’s a list of some recent conferences or workshops posting videos online.

    Other collections

  • 소소한 정보: BibTeX으로 참고 문헌 모으기

    LaTeX으로 논문을 쓸때 참고문헌은 보통 BibTeX으로 처리합니다. 여러 논문의 서지 정보를 mybib.bib처럼 확장자가 .bib인 파일로 한 곳에 모아두면 논문마다 따로 참고문헌을 정리할 필요없이 \cite 명령으로 인용만 해주면 참고문헌 부분이 자동으로 생성되어 편리합니다. 이 글은 (쉽게 배울 수 있는) BibTeX을 쓰는 법을 설명하려는 것은 아니고, 몇 가지 주의점만 정리해두려고 합니다.

    bib 파일에 넣을 서지 정보는 구글 스칼라나 dblp에서 받은 것을 쓰지 말자!

    구글 스칼라나 dblp에서 받는 bib 포맷 정보는 자동으로 생성되어 품질이 좋지 않습니다. 저는 항상 미국수학회 MathSciNet에서 받아서 씁니다. 유료 사이트이긴 하지만 대부분의 대학과 연구소에서는 구독료를 지불하고 있습니다. 구독하는 곳에서 미리 Remote Access라고 적힌 지구본 그림 아이콘을 눌러 “원격 접속 인증”을 웹브라우저에서 받아두면 집에 노트북이나 휴대폰을 가지고 가더라도 90일간은 접속이 되어 편리합니다.

    MathSciNet에서 논문을 검색한 후 Select alternative format에서 BibTeX을 선택하면 아래처럼 내용이 나옵니다.

    @article {MR2232389,
        AUTHOR = {Oum, Sang-il and Seymour, Paul},
         TITLE = {Approximating clique-width and branch-width},
       JOURNAL = {J. Combin. Theory Ser. B},
      FJOURNAL = {Journal of Combinatorial Theory. Series B},
        VOLUME = {96},
          YEAR = {2006},
        NUMBER = {4},
         PAGES = {514--528},
          ISSN = {0095-8956},
       MRCLASS = {05C70 (05B35 05C85 68Q25 68R10 68W25)},
      MRNUMBER = {2232389},
    MRREVIEWER = {Dillon Mayhew},
           DOI = {10.1016/j.jctb.2005.10.006},
           URL = {https://doi.org/10.1016/j.jctb.2005.10.006},
    }

    이렇게 받은 것을 mybib.bib 파일에 붙여넣고, 첫 번째 줄에 있는 키 부분만 원하는 것으로 바꿉니다.

    서지 정보의 키는 일정한 규칙으로 정하자.

    키는 항상 일정한 규칙으로 정하고 한 번 정하면 바꾸지 않는 것이 좋습니다. 예를 들어 박사과정 중에 논문을 4편을 썼는데 모아서 박사논문 하나로 정리한다고 생각해봅시다. 논문마다 키가 달랐다면 나중에 통합할 때 키를 다시 합쳐야 해서 대폭 수정을 해야 합니다.

    BibDesk

    예전에는 일일이 논문 키를 저자의 성 알파벳 첫 글자를 모은 것 + 연도로 손으로 설정하곤 하였는데, 지금은 bib파일을 BibDesk라는 프로그램으로 관리하고 있어서, BibDesk 설정으로 제가 원하는 방식으로 생성하게 해둡니다. BibDesk는 Mac OS에서 mactex으로 TeX을 설치하면 /Applications/TeX 안에 설치가 되어 있습니다.

    논문은 여러 개라도 bib 파일은 하나로 모아두자

    저의 경우 mybib.bib이라는 파일을 항상 하드디스크의 ~/my/bib에 저장해두고, 거의 대부분의 논문을 쓸때 같은 bib파일을 참고하도록 설정해서 씁니다. 이를 위해서 BIBINPUTS라는 환경변수에 bib파일이 저장된 디렉토리를 지정해 놓습니다. 따라서 논문을 어느 디렉토리에서 쓰던지 bib 파일은 하나만 쓰게 됩니다.

    만일 arXiv에만 있던 논문이 출판이 되면 mybib.bib에서 같은 키에서 내용만 고쳐줍니다. 그러면 이 논문이 인용된 논문마다 새로 컴파일만 해주면 참고문헌이 정확하게 나오게 되겠지요. 같은 논문이 다른 키로 두 번 인용되는 사고를 막아줍니다.

    물론 요즘은 여러 저자들과 함께 논문 작업을 overleaf나 git (주로 bitbucket)으로 하다보니 수 천개의 논문 서지 정보가 적힌 파일 전체를 공유하기는 어렵습니다. 저는 mybib.bib에 있는 논문에서 사용될법한 논문만 모아서 git 프로젝트 안에 따로 저장하여 공유하고 씁니다.

    한편 BibDesk 프로그램으로 bib 파일을 관리하면 논문 원문 파일도 함께 관리할 수 있게 해주어서 편리합니다. BibDesk 설정을 잘 보면 논문 원문 파일을 어떤 디렉토리에 어떻게 저장할 지 상세하게 설정할 수 있어서 편리합니다. 또한 BibDesk 프로그램을 실행할 때 처음에 어느 bib 파일을 열 것인지도 미리 설정할 수 있어서 저의 경우 ~/my/bib/mybib.bib을 열도록 미리 설정해 둡니다.

  • Big Congratulations to Bruno Courcelle for the first S. Barry Cooper Prize

    Big Congratulations to Bruno Courcelle for the first S. Barry Cooper Prize

    “The 2020 S. Barry Cooper Prize is awarded to Bruno Courcelle for his work on the definability of graph properties in Monadic Second Order Logic, through a sequence of seminal papers and a book (joint with Joost Engelfriet). This forms an outstanding example of theory building, bringing together logic, computability, graph grammars, and various notions of graph width (tree-width, clique-width and rank-width) and opening new avenues in our understanding of graph structure theory and the computability and complexity of graph algorithms. Besides its foundational character, the work has had great impact on a number of areas of computer science, including in parameterized algorithmics, verification and other areas, and has influenced a generation of researchers in this field. It has straddled the divide between the logical and algorithmic aspects of theoretical computer science.”

    The ACiE President
    Paola Bonizzoni

    Big Congratulations to Bruno Courcelle for the first S. Barry Cooper Prize. I was very fortunate to meet him at Dagstuhl in 2004, resulting a nice paper on Seese’s conjecture and an algorithm to decide rank-width≤k, making two chapters of my Ph.D. thesis. 

    In the photo, you can find me and Bruno.