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X-WR-CALNAME:Discrete Mathematics Group
X-ORIGINAL-URL:https://dimag.ibs.re.kr
X-WR-CALDESC:Events for Discrete Mathematics Group
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BEGIN:VTIMEZONE
TZID:Asia/Seoul
BEGIN:STANDARD
TZOFFSETFROM:+0900
TZOFFSETTO:+0900
TZNAME:KST
DTSTART:20230101T000000
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BEGIN:VEVENT
DTSTART;VALUE=DATE:20240828
DTEND;VALUE=DATE:20240831
DTSTAMP:20260419T164111
CREATED:20240117T144439Z
LAST-MODIFIED:20240705T154134Z
UID:8135-1724803200-1725062399@dimag.ibs.re.kr
SUMMARY:2024 Combinatorics Workshop (2024 조합론 학술대회)
DESCRIPTION:Website: https://cw2024.combinatorics.kr/ \nLocation\nChungbuk National University\, Cheongju\, Korea. \nAdvisory Committee\n\nCommittee of Discrete Mathematics\, The Korean Mathematical Society (Chair: Sang-il Oum\, IBS Discrete Mathematics Group / KAIST)\n\nSponsors\n\nIBS Discrete Mathematics Group.\nKorean Mathematical Society
URL:https://dimag.ibs.re.kr/event/2024-08-28/
LOCATION:Chungbuk National University
CATEGORIES:Workshops and Conferences
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20241111T110000
DTEND;TZID=Asia/Seoul:20241111T173000
DTSTAMP:20260419T164111
CREATED:20241101T055140Z
LAST-MODIFIED:20241111T080120Z
UID:10031-1731322800-1731346200@dimag.ibs.re.kr
SUMMARY:IBS-DIMAG Workshop on Topology and Combinatorics
DESCRIPTION:The IBS-DIMAG Workshop on Topology and Combinatorics will be held on November 11\, 2024 at Room B332\, Institute for Basic Science (IBS)\, Daejeon\, South Korea. \nInvited Speakers (tentative)\n\nKarim Adiprasito (Jussieu Institute of Mathematics)\nMinho Cho조민호 (IBS Extremal Combinatorics and Probability Group)\nNiloufar Fuladi (INRIA Center of Université de Lorraine)\nMinki Kim김민기 (GIST)\nDohyeon Lee이도현 (KAIST & IBS Discrete Mathematics Group)\nGeunho Lim임근호 (Jussieu Institute of Mathematics)\nSemin Yoo유세민 (IBS Discrete Mathematics Group)\n\nTentative Schedule\n\n11:00-11:30 Karim Adiprasito\, The Charney Davis conjecture and Boolean decompositions\n12:00-14:00 Lunch Break\n14:00-14:30 Niloufar Fuladi\, Universal families of arcs and curves on surfaces\n14:30-15:00 Semin Yoo유세민\, The Charney-Davis conjecture and its related complexes (survey)\n15:00-15:30 Geunho Lim임근호\, Bounds on Cheeger-Gromov invariants and simplicial complexity of triangulated manifolds\n15:30-16:00 Break\n16:00-16:30 Minki Kim김민기\, Some extensions of the colorful Helly theorem\n16:30-17:00 Minho Cho조민호\, Fractional Helly theorems via weak saturation\n17:00-17:30 Dohyeon Lee이도현\, Betti number of clique complex of H-free graphs (survey)\n18:00-20:00 Banquet\n\nOrganizer\n\nSemin Yoo유세민\, IBS Discrete Mathematics Group\n\nAbstracts\nKarim Adiprasito\, The Charney Davis conjecture and Boolean decompositions\nI will present a novel approach to the Charney Davis conjecture by introducing anticommutative Lefschetz properties\, and studying them on the Danzer complex of flag spheres. \nSemin Yoo\, The Charney-Davis conjecture and its related complexes (survey)\nThe Charney-Davis conjecture lies in the intersection between topology and combinatorics. The conjecture is a special case of the Hopf-Chern-Thurston conjecture for all nonpositively curved\, piecewise Euclidean manifolds which are cellulated by regular Euclidean cubes. In 2001\, Davis and Okun solved the conjecture for a 4-dimensional case\, and some other partial results are also known. However\, the conjecture is still open so far. \nIn this talk\, I will describe five statements that solve the Charney-Davis conjecture and explain some complexes to achieve this goal. \nNiloufar Fuladi\, Universal families of arcs and curves on surfaces\nIn this talk I introduce a family of curves that realize all pants decomposition of a surface: a family of simple closed curves Γ on a surface realizes all types of pants decompositions if for any pants decomposition of the surface\, there exists a homeomorphism sending it to a subset of the curves in Γ. The study of such universal families of curves is motivated by questions on graph embeddings\, joint crossing numbers and finding an elusive center of moduli space. I will discuss the case of surfaces without punctures\, where we establish an exponential upper bound and a superlinear lower bound on the minimum size of the family of curves with this universal property. I also talk about a similar concept of universality for triangulations of polygons\, where we provide bounds which are tight up to logarithmic factors. In this talk\, I will explain the background and context and no prior knowledge in topology or surfaces is needed. \nThis is joint work with Arnaud de Mesmay and Hugo Parlier. \nGeunho Lim\, Bounds on Cheeger-Gromov invariants and simplicial complexity of triangulated manifolds\nUsing L^2 cohomology\, Cheeger and Gromov define the L^2 rho-invariant on manifolds with arbitrary fundamental groups\, as a generalization of the Atiyah-Singer rho-invariant. There are many interesting applications in geometry\, topology\, and combinatorics. In this talk\, we show linear bounds on the rho-invariants in terms of simplicial complexity of manifolds by using hyperbolization methods. As applications\, we give new concrete examples in the complexity theory of high-dimensional (homotopy) lens spaces. This is a joint work with Shmuel Weinberger. \nMinki Kim\, Some extensions of the colorful Helly theorem\nGiven $k > d$ finite families of convex sets in $\mathbb{R}^d$\, if every colorful $(d+1)$-tuple is intersecting\, then the union of $k-d$ color classes is intersecting. This is known as the colorful Helly theorem. Based on recent joint work with Alan Lew\, I will present some extensions of the colorful Helly theorem and their applications. \nMinho Cho\, Fractional Helly theorems via weak saturation\nTwo celebrated extensions of the classical Helly’s theorem are the fractional Helly theorem and the colorful Helly theorem. Bulavka\, Goodarzi\, and Tancer recently established the optimal bound for the unified generalization of the fractional and the colorful Helly theorems using a colored extension of the exterior algebra. In this talk\, we introduce a combinatorial reduction of both the fractional Helly theorem and its colorful version to a classical problem in extremal combinatorics known as weak saturation. No such results connecting the fractional Helly theorem and weak saturation are known in the long history of literature. These reductions\, along with basic linear algebraic arguments for the reduced weak saturation problems\, let us give new short proofs of the optimal bounds for both the fractional Helly theorem and its colorful version without using exterior algebra. \nThis is joint work with Debsoumya Chakraborti\, Jinha Kim\, and Minki Kim. \nDohyeon Lee\, Betti number of clique complex of H-free graphs (survey)\nThe clique complex of a graph is a simplicial complex whose faces correspond to cliques of the given graph. In this talk\, we investigate extremal properties of the Betti numbers of clique complexes. While general simplicial complexes with n vertices can have a total Betti number approximately $2^n$\, Adamaszek showed that Betti number of clique complex is bounded by around $1.32^n$. Furthermore\, if the underlying graph has an independence number at most two\, the bound tightens to $1.25^n$. Adiprasito\, Nevo\, and Tancer established additional bounds on the total Betti number for clique complexes of (induced) H-free graphs for various graph H\, along with constructions of graphs with large total Betti number. In another direction\, Zhang and Wu demonstrated that for ternary graphs (whose with no induced cycles of length 3n)\, the Betti number of the independence complex (the clique complex of the complement of a graph) is at most one. Indeed\, Jinha Kim showed that these independence complexes are either contractible or homotopy spheres.
URL:https://dimag.ibs.re.kr/event/2024-11-11/
LOCATION:Room B332\, IBS (기초과학연구원)
CATEGORIES:Workshops and Conferences
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20250203
DTEND;VALUE=DATE:20250206
DTSTAMP:20260419T164111
CREATED:20250121T050727Z
LAST-MODIFIED:20250121T050727Z
UID:10456-1738540800-1738799999@dimag.ibs.re.kr
SUMMARY:IBS-DIMAG Winter School on Graph Minors\, Week 1
DESCRIPTION:
URL:https://dimag.ibs.re.kr/event/graph-minors-week-1/
LOCATION:Room B109\, IBS (기초과학연구원)
CATEGORIES:Workshops and Conferences
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20250210
DTEND;VALUE=DATE:20250213
DTSTAMP:20260419T164111
CREATED:20250121T050854Z
LAST-MODIFIED:20250121T050854Z
UID:10460-1739145600-1739404799@dimag.ibs.re.kr
SUMMARY:IBS-DIMAG Winter School on Graph Minors\, Week 2
DESCRIPTION:
URL:https://dimag.ibs.re.kr/event/graph-minors-week-2/
LOCATION:Room B109\, IBS (기초과학연구원)
CATEGORIES:Workshops and Conferences
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20250217
DTEND;VALUE=DATE:20250220
DTSTAMP:20260419T164111
CREATED:20250121T051001Z
LAST-MODIFIED:20250121T051001Z
UID:10462-1739750400-1740009599@dimag.ibs.re.kr
SUMMARY:IBS-DIMAG Winter School on Graph Minors\, Week 3
DESCRIPTION:
URL:https://dimag.ibs.re.kr/event/graph-minors-week-3/
LOCATION:Room B109\, IBS (기초과학연구원)
CATEGORIES:Workshops and Conferences
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250714T140000
DTEND;TZID=Asia/Seoul:20250718T170000
DTSTAMP:20260419T164111
CREATED:20250421T055000Z
LAST-MODIFIED:20250706T061119Z
UID:10816-1752501600-1752858000@dimag.ibs.re.kr
SUMMARY:2025 Summer School on Combinatorics and Algorithms (2025 조합론 및 알고리즘 여름학교)
DESCRIPTION:The 2025 Summer School on Combinatorics and Algorithms is a venue for students and early-career researchers to learn selected topics in theoretical computer science and discrete mathematics. It will be a great opportunity for young and aspiring researchers to study topics which are important but not covered during the lectures in the university classes. \nWebsite: https://combialgo.dimag.kr/ \nLecturers and Topics\n\nÉdouard Bonnet\, LIP\, CNRS.\n\nInduced Subgraphs and Induced Minors of Graphs\n\n\nMichał Pilipczuk\, University of Warsaw.\n\nStructural Theory of Sparse Graphs\n\n\n\nSchedule\n\nStart on 14 July 2025 Monday\, 2 PM\nEnd on 18 July 2025 Friday\, 5 PM
URL:https://dimag.ibs.re.kr/event/2025-07-14/
LOCATION:POSTECH\, Pohang\, Korea
CATEGORIES:Workshops and Conferences
ORGANIZER;CN="Eunjung Kim (%EA%B9%80%EC%9D%80%EC%A0%95)":MAILTO:eunjungkim78@gmail.com
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20250818
DTEND;VALUE=DATE:20250821
DTSTAMP:20260419T164111
CREATED:20250322T120039Z
LAST-MODIFIED:20250818T042052Z
UID:10706-1755475200-1755734399@dimag.ibs.re.kr
SUMMARY:2025 Combinatorics Workshop (2025 조합론 학술대회)
DESCRIPTION:Website: https://cw2025.combinatorics.kr \nInvited Speakers\n\nDongsu Kim (KAIST)\nEun Jung Kim (KAIST)\nO-joung Kwon (Hanyang University)\nAe Ja Lee (Pennsylvania State University)\nZhicong Lin (Shandong University)\n\nOrganizing Committee\n\nSang-il Oum (엄상일)\, IBS Discrete Mathematics Group\nJang Soo Kim (김장수)\, Sungkyunkwan University\nSeunghyun Seo (서승현)\, Kangwon National University
URL:https://dimag.ibs.re.kr/event/cw2025/
LOCATION:IBS Science Culture Center
CATEGORIES:Workshops and Conferences
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20250820
DTEND;VALUE=DATE:20250825
DTSTAMP:20260419T164111
CREATED:20250722T052942Z
LAST-MODIFIED:20250722T053013Z
UID:11276-1755648000-1756079999@dimag.ibs.re.kr
SUMMARY:2025 Korean Student Combinatorics Workshop (KSCW2025: 2025 조합론 학생 워크샵)
DESCRIPTION:Venue\nThe K-Hotel Gyeongju \nWebsite\nhttps://indico.ibs.re.kr/e/kscw2025 \nOrganizers\n\nSeokbeom Kim (김석범)\, KAIST and IBS Discrete Mathematics Group\nHyunwoo Lee (이현우)\, KAIST and IBS Extremal Combinatorics and Probability Group\nJaehyeon Seo (서재현)\, Yonsei University\nKyungjin Cho (조경진)\, POSTECH
URL:https://dimag.ibs.re.kr/event/kscw2025/
LOCATION:The K-Hotel Gyeongju
CATEGORIES:Workshops and Conferences
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20251127
DTEND;VALUE=DATE:20251201
DTSTAMP:20260419T164111
CREATED:20250421T055422Z
LAST-MODIFIED:20251130T005151Z
UID:10819-1764201600-1764547199@dimag.ibs.re.kr
SUMMARY:5th East Asia Workshop on Extremal and Structural Graph Theory
DESCRIPTION:The 5th East Asia Workshop on Extremal and Structural Graph Theory is a workshop to bring active researchers in the field of extremal and structural graph theory\, especially in the East Asia such as China\, Japan\, and Korea. \n \nDate\nNovember 27\, 2025 Thursday (Arrival Day) — November 30\, 2025 Sunday (Departure Day) \nVenue\nFraser Place Namdaemun\, Seoul \nProgram Book\nInvited Speakers\n\nShinya Fujita (Yokohama City University)\nJie Han (Beijing Institute of Technology)\nTony Huynh (IBS Discrete Mathematics Group)\nJaehoon Kim (KAIST)\nO-joung Kwon (Hanyang University / IBS Discrete Mathematics Group)\nHong Liu (IBS Extremal Combinatorics and Probability Group)\nJie Ma (University of Science and Technology of China / Tsinghua University)\nShun-ichi Maezawa (Nihon University)\nBoram Park (Seoul National University)\nShohei Satake (Kumamoto University)\nTuan Tran (University of Science and Technology of China)\nShoichi Tsuchiya (Senshu University)\nXuding Zhu (Zhejiang Normal University)\n\nOrganizers\nSeog-Jin Kim\, Sang-il Oum\, Kenta Ozeki\, Hehui Wu \nRegistration\nInvitation Only. https://indico.ibs.re.kr/event/1041/ \nThere is no registration fee and one dinner (banquet) will be provided. \nHistory\n\n4th East Asia Workshop on Extremal and Structural Graph Theory\n\nMar. 27 – Mar. 31\, 2025.\nSchool of Mathematics\, Sun-Yet Sen University\, Guangzhou\, China\nOrganizers: Ping Hu\, Seog-Jin Kim\, Kenta Ozeki\, Hehui Wu.\n\n\n\n\n3rd East Asia Workshop on Extremal and Structural Graph Theory\n\nNov. 1- Nov. 5\, 2023.\nThe Southern Beach Hotel & Resort\, Okinawa\, Japan\nSponsored by the IBS Discrete Mathematics Group\, Korea.\nOrganizers: Seog-Jin Kim\, Sang-il Oum\, Kenta Ozeki\, Hehui Wu.\n\n\n2nd East Asia Workshop on Extremal and Structural Graph Theory\n\nOct. 31-Nov. 4\, 2019.\nHeld at UTOP UBLESS Hotel\, Jeju\, Korea\nSponsored by the IBS Discrete Mathematics Group\, Korea.\nOrganizers: Seog-Jin Kim\, Sang-il Oum\, Kenta Ozeki\, Hehui Wu.\n\n\n1st East Asia Workshop on Extremal and Structural Graph Theory\n\nNov. 30-Dec. 2\, 2018.\nHeld and sponsored by the Shanghai Center for Mathematical Sciences in China\, under the name 2018 SCMS Workshop on Extremal and Structural Graph Theory.\nOrganizers: Ping Hu\, Seog-Jin Kim\, Kenta Ozeki\, Hehui Wu.\n\n\n\n\n\nThursday\nNovember 27\, 2025\n\n\n\n\nTime\nSpeaker\nAffiliation\nTitle\n\n\n\n\n16:00–18:00\n\nRegistration & Discussions\n\n\n\n\n \n\n\nFriday\nNovember 28\, 2025\n\n\n\n\nTime\nSpeaker\nAffiliation\nTitle\n\n\n\n\n09:20–10:00\nJaehoon Kim\nKAIST\nHamilton cycles in pseudorandom graphs: Dirac’s theorem and approximate decompositions\n\n\n10:00–10:30\n\nCoffee Break\n\n\n10:30–11:10\nJie Ma\nUniversity of Science and Technology of China / Tsinghua University\nAn exponential improvement for Ramsey lower bounds\n\n\n11:20–12:00\nShinya Fujita\nYokohama City University\nConnectivity keeping paths containing prescribed vertices in highly connected triangle-free graphs\n\n\n12:00–14:00\n\nLunch Break\n\n\n14:00–14:40\nShun-ichi Maezawa\nNihon University\nTree versus tree of preorder induced by rainbow forbidden subgraphs\n\n\n14:50–15:30\nTony Huynh\nIBS Discrete Mathematics Group\nRainbow triangles and the Erdős–Hajnal problem in projective geometries\n\n\n15:30–15:50\n\nCoffee Break\n\n\n16:30–17:30\n\nProblem Session\n\n\n\n\n \n\n\nSaturday\nNovember 29\, 2025\n\n\n\n\nTime\nSpeaker\nAffiliation\nTitle\n\n\n\n\n09:20–10:00\nXuding Zhu\nZhejiang Normal University\nTBA\n\n\n10:00–10:30\n\nCoffee Break\n\n\n10:30–11:10\nHong Liu\nIBS Extremal Combinatorics and Probability Group\nChromatic\, homomorphism\, blowup thresholds and beyond\n\n\n11:20–12:00\nShohei Satake\nKumamoto University\nTBA\n\n\n12:00–14:00\n\nLunch Break\n\n\n14:00–14:40\nShoichi Tsuchiya\nSenshu University\nOn the number of contractible edges in plane triangulations\n\n\n14:50–15:30\nTuan Tran\nUniversity of Science and Technology of China\nLittlewood-Offord bounds on the symmetric groups and applications\n\n\n15:30–15:50\n\nCoffee Break\n\n\n15:50–16:30\nO-joung Kwon\nHanyang University / IBS Discrete Mathematics Group\nA coarse Erdős–Pósa theorem\n\n\n16:30–17:30\n\nProblem Session\n\n\n18:30–21:00\n\nBanquet\n\n\n\n\n \n\n\nSunday\nNovember 30\, 2025\n\n\n\n\nTime\nSpeaker\nAffiliation\nTitle\n\n\n\n\n10:00–10:40\nJie Han\nBeijing Institute of Technology\nPerturbation of dense graphs\n\n\n10:40–10:50\n\nBreak\n\n\n10:50–11:30\nBoram Park\nSeoul National University\nGraphs avoiding cycles of length 0 modulo 4\n\n\n11:30–12:00\n\nClosing
URL:https://dimag.ibs.re.kr/event/2025-east-asia-graph-theory/
LOCATION:Seoul\, Korea
CATEGORIES:Workshops and Conferences
ORGANIZER;CN="Seog-Jin Kim (%EA%B9%80%EC%84%9D%EC%A7%84)":MAILTO:skim12@konkuk.ac.kr
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20260628
DTEND;VALUE=DATE:20260712
DTSTAMP:20260419T164111
CREATED:20260415T104127Z
LAST-MODIFIED:20260415T104444Z
UID:12537-1782604800-1783814399@dimag.ibs.re.kr
SUMMARY:2026 Workshop on Topological Combinatorics
DESCRIPTION:The 2026 Workshop on Topological Combinatorics will be held from June 28 to July 11\, 2026 at Gwangju Institute of Science and Technology (GIST)\, located in Gwangju in the southwest of Republic of Korea.  \nThe workshop aims to bring together researchers interested in applications of topology to combinatorics and related areas. This will be the fifth workshop in a series initiated by Ron Aharoni (August 2018 in Shantou\, July 2019 in Prague\, July 2020 on Zoom\, and June 2024 in Paris). \nThe first week (June 28 – July 04) will be reserved for presentations\, while the following days (July 05 – July 11) will be for discussion and collaborations.  \nThe campus offers a variety of amenities\, including a guesthouse that can accommodate approximately 20 guests. \nIn addition\, various lodging options are available within a 15–20 minute walking distance. \nWe are planning to provide accommodation for all invited participants\, and we are also considering offering partial travel support for those with limited funding. \n\nWebsite: https://sites.google.com/view/2026topocomb
URL:https://dimag.ibs.re.kr/event/2026-06-28/
LOCATION:GIST
CATEGORIES:Workshops and Conferences
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20260727
DTEND;VALUE=DATE:20260801
DTSTAMP:20260419T164111
CREATED:20260415T104353Z
LAST-MODIFIED:20260415T104353Z
UID:12545-1785110400-1785542399@dimag.ibs.re.kr
SUMMARY:2026 Korean Student Combinatorics Workshop
DESCRIPTION:Website: https://kscw.combinatorics.kr/
URL:https://dimag.ibs.re.kr/event/2026-07-27/
LOCATION:Gongju Hanok Village\, Gongju
CATEGORIES:Workshops and Conferences
END:VEVENT
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