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PRODID:-//Discrete Mathematics Group - ECPv4.9.11//NONSGML v1.0//EN
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METHOD:PUBLISH
X-WR-CALNAME:Discrete Mathematics Group
X-ORIGINAL-URL:https://dimag.ibs.re.kr
X-WR-CALDESC:Events for Discrete Mathematics Group
BEGIN:VTIMEZONE
TZID:Asia/Seoul
BEGIN:STANDARD
TZOFFSETFROM:+0900
TZOFFSETTO:+0900
TZNAME:KST
DTSTART:20190101T000000
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BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20191121T163000
DTEND;TZID=Asia/Seoul:20191121T173000
DTSTAMP:20191120T091603
CREATED:20191028T154322Z
LAST-MODIFIED:20191028T154322Z
UID:1641-1574353800-1574357400@dimag.ibs.re.kr
SUMMARY:Frédéric Meunier\, Topological bounds for graph representations over any field
DESCRIPTION:Haviv (European Journal of Combinatorics\, 2019) has recently proved that some topological lower bounds on the chromatic number of graphs are also lower bounds on their orthogonality dimension over R. We show that this holds actually for all known topological lower bounds and all fields. We also improve the topological bound he obtained for the minrank parameter over R – an important graph invariant from coding theory – and show that this bound is actually valid for all fields as well. The notion of independent representation over a matroid is introduced and used in a general theorem having these results as corollaries. Related complexity results are also discussed.This is joint work with Meysam Alishahi. \n
URL:https://dimag.ibs.re.kr/event/2019-11-21/
LOCATION:Room B232\, IBS (기초과학연구원)
CATEGORIES:Discrete Math Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20191210T163000
DTEND;TZID=Asia/Seoul:20191210T173000
DTSTAMP:20191120T091603
CREATED:20191004T104834Z
LAST-MODIFIED:20191004T104834Z
UID:1488-1575995400-1575999000@dimag.ibs.re.kr
SUMMARY:Jakub Gajarský\, First-order interpretations of bounded expansion classes
DESCRIPTION:The notion of bounded expansion captures uniform sparsity of graph classes and renders various algorithmic problems that are hard in general tractable. In particular\, the model-checking problem for first-order logic is fixed-parameter tractable over such graph classes. With the aim of generalizing such results to dense graphs\, we introduce classes of graphs with structurally bounded expansion\, defined as first-order interpretations of classes of bounded expansion. As a first step towards their algorithmic treatment\, we provide their characterization analogous to the characterization of classes of bounded expansion via low treedepth decompositions\, replacing treedepth by its dense analogue called shrubdepth. \n
URL:https://dimag.ibs.re.kr/event/2019-12-10/
LOCATION:Room B232\, IBS (기초과학연구원)
CATEGORIES:Discrete Math Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20191212T163000
DTEND;TZID=Asia/Seoul:20191212T173000
DTSTAMP:20191120T091603
CREATED:20191119T013103Z
LAST-MODIFIED:20191119T014257Z
UID:1801-1576168200-1576171800@dimag.ibs.re.kr
SUMMARY:Attila Joó\, Base partition for finitary-cofinitary matroid families
DESCRIPTION:Let ${\mathcal{M} = (M_i \colon i\in K)}$ be a finite or infinite family consisting of finitary and cofinitary matroids on a common ground set $E$. \nWe prove the following Cantor-Bernstein-type result: if $E$ can be covered by sets ${(B_i \colon i\in K)}$ which are bases in the corresponding matroids and there are also pairwise disjoint bases of the matroids $M_i$ then $E$ can be partitioned into bases with respect to $\mathcal{M}$. \n
URL:https://dimag.ibs.re.kr/event/2019-12-12/
LOCATION:Room B232\, IBS (기초과학연구원)
CATEGORIES:Discrete Math Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20200615
DTEND;VALUE=DATE:20200620
DTSTAMP:20191120T091603
CREATED:20190607T162650Z
LAST-MODIFIED:20190607T162650Z
UID:947-1592179200-1592611199@dimag.ibs.re.kr
SUMMARY:Seymour is Seventy
DESCRIPTION:A conference honouring the seventieth birthday of Paul Seymour \n\nTo be held in ENS de Lyon\, France\, June 15 – 19\, 2020 \nConference Website: https://dimag.ibs.re.kr/seymour70/ \nSponsors: \n\nIBS Discrete Mathematics Group.\nLIP\, ENS de Lyon\, France.\nDepartment of Mathematics\, Princeton University.\n\n\n
URL:https://dimag.ibs.re.kr/event/seymour-is-seventy/
LOCATION:ENS de Lyon\, Lyon\, France
CATEGORIES:Workshops and Conferences
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