
{"id":1677,"date":"2025-10-17T07:58:15","date_gmt":"2025-10-17T07:58:15","guid":{"rendered":"https:\/\/prg.inf.unibe.ch\/?page_id=1677"},"modified":"2025-10-17T07:58:15","modified_gmt":"2025-10-17T07:58:15","slug":"thesis-tangle-based-heuristics-for-subgraph-matching-in-large-networks","status":"publish","type":"page","link":"https:\/\/prg.inf.unibe.ch\/index.php\/education\/thesis-tangle-based-heuristics-for-subgraph-matching-in-large-networks\/","title":{"rendered":"thesis-Tangle-Based Heuristics for Subgraph Matching in Large Networks"},"content":{"rendered":"\n<div style=\"height:150px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<section class=\"wp-block-uagb-columns uagb-columns__wrap uagb-columns__background-none uagb-columns__stack-mobile uagb-columns__valign- uagb-columns__gap-10 align uagb-block-b3397370 uagb-columns__columns-1 uagb-columns__max_width-theme\"><div class=\"uagb-columns__overlay\"><\/div><div class=\"uagb-columns__inner-wrap uagb-columns__columns-1\">\n<div class=\"wp-block-uagb-column uagb-column__wrap uagb-column__background-undefined uagb-block-3e0cbd99\"><div class=\"uagb-column__overlay\"><\/div>\n<h1 class=\"wp-block-heading\">Tangle-Based Heuristics for Subgraph Matching in Large Networks<\/h1>\n\n\n\n<p><strong>Co-Supervised by:<\/strong> Kalvin Dobler<\/p>\n\n\n\n<p>If you are interested in this topic or have further questions, do not hesitate to contact <a href=\"mailto:kalvin.dobler@unibe.ch\">kalvin.dobler@unibe.ch<\/a>.<\/p>\n\n\n\n<p class=\"has-medium-font-size\"><strong>Background \/ Context<\/strong><\/p>\n\n\n\n<p>Traditional subgraph isomorphism methods (e.g., VF2, Ullmann&#8217;s) suffer in large networks due to global combinatorial explosion. Many real-world networks (biological, social, infrastructure) exhibit modularity and local structure, which can be exploited using tangle theory.<\/p>\n\n\n\n<p>Tangle theory, from graph minor theory (developed by Robertson and Seymour), offers a way to capture &#8220;highly connected regions&#8221; of a graph without explicitly identifying the structure \u2014 focusing instead on consistent orientations of low-order separations. This provides a way to reason about complex graph connectivity abstractly.<\/p>\n\n\n\n<p>The idea is to implement a framework for subgraph matching in large and complex networks by leveraging tangle-based decomposition. The core idea is to restrict matching operations to highly connected regions identified via tangles in order to improve both efficiency and interpretability.<\/p>\n\n\n\n<p class=\"has-medium-font-size\"><strong>Research Question(s) \/ Goals<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Goal 1: Literature Review (graph minor theory, tangle theory, algorithmic frameworks)<\/li>\n\n\n\n<li>Goal 2: Implement or adapt existing algorithms (e.g., based on branch decompositions or separators) to compute tangle decompositions of graphs.<\/li>\n\n\n\n<li>Goal 3: Implement or adapt existing for subgraph isomorphisms tools<\/li>\n\n\n\n<li>Goal 4: Integrate the tangle decomposition to restrict matching attempts to meaningful, highly connected regions.<\/li>\n\n\n\n<li>Goal 5: Apply it to large real-world datasets<\/li>\n<\/ul>\n\n\n\n<p class=\"has-medium-font-size\"><strong>Approach \/ Methods<\/strong><\/p>\n\n\n\n<p>Tangle-based decomposition.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Implement or adapt tree or branch decomposition algorithms to approximate tangle structures<\/li>\n\n\n\n<li>Identify high-connectivity regions (\u201cproto-tangles\u201d) by analyzing separator sizes, density, and internal cut resistance.<\/li>\n<\/ul>\n\n\n\n<p>Tangle clustering extraction<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Extract tangle clusters from the decomposition: subgraphs that correspond to dense, hard-to-separate regions.<\/li>\n\n\n\n<li>Allow overlapping clusters to preserve border nodes that participate in multiple regions<\/li>\n\n\n\n<li>Measure intra-cluster and inter-cluster connectivity to guide matching prioritization<\/li>\n<\/ul>\n\n\n\n<p class=\"has-medium-font-size\"><strong>Expected Contributions \/ Outcomes<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Novel framework.<\/li>\n\n\n\n<li>Algorithmic innovation.<\/li>\n\n\n\n<li>Theoretical understanding and contribution.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-medium-font-size\"><strong>Required Skills \/ Prerequisites<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Good programming skills.<\/li>\n\n\n\n<li>Interest in theoretical and applied work.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-medium-font-size\"><strong>Further Reading \/ Starting Literature<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Diestel R. Graph Theory. Springer.<\/li>\n\n\n\n<li>Diestel R. Tangles: A Structural Approach to Artificial Intelligence in the Empirical Sciences. Cambridge University Press; 2024<\/li>\n\n\n\n<li>Klepper et al. Clustering with Tangles: Algorithmic Framework and Theoretical Guarantees<\/li>\n<\/ul>\n<\/div>\n<\/div><\/section>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Tangle-Based Heuristics for Subgraph Matching in Large Networks Co-Supervised by: Kalvin Dobler If you are interested in this topic or have further questions, do not hesitate to contact kalvin.dobler@unibe.ch. Background \/ Context Traditional subgraph isomorphism methods (e.g., VF2, Ullmann&#8217;s) suffer in large networks due to global combinatorial explosion. Many real-world networks (biological, social, infrastructure) exhibit &hellip;<\/p>\n<p class=\"read-more\"> <a class=\"\" href=\"https:\/\/prg.inf.unibe.ch\/index.php\/education\/thesis-tangle-based-heuristics-for-subgraph-matching-in-large-networks\/\"> <span class=\"screen-reader-text\">thesis-Tangle-Based Heuristics for Subgraph Matching in Large Networks<\/span> Read More &raquo;<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":731,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_uag_custom_page_level_css":"","site-sidebar-layout":"no-sidebar","site-content-layout":"plain-container","ast-global-header-display":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"disabled","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"enabled","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","footnotes":""},"class_list":["post-1677","page","type-page","status-publish","hentry"],"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false},"uagb_author_info":{"display_name":"prg-admin","author_link":"https:\/\/prg.inf.unibe.ch\/index.php\/author\/prg-admin\/"},"uagb_comment_info":0,"uagb_excerpt":"Tangle-Based Heuristics for Subgraph Matching in Large Networks Co-Supervised by: Kalvin Dobler If you are interested in this topic or have further questions, do not hesitate to contact kalvin.dobler@unibe.ch. Background \/ Context Traditional subgraph isomorphism methods (e.g., VF2, Ullmann&#8217;s) suffer in large networks due to global combinatorial explosion. Many real-world networks (biological, social, infrastructure) exhibit&hellip;","_links":{"self":[{"href":"https:\/\/prg.inf.unibe.ch\/index.php\/wp-json\/wp\/v2\/pages\/1677","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prg.inf.unibe.ch\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/prg.inf.unibe.ch\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/prg.inf.unibe.ch\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/prg.inf.unibe.ch\/index.php\/wp-json\/wp\/v2\/comments?post=1677"}],"version-history":[{"count":1,"href":"https:\/\/prg.inf.unibe.ch\/index.php\/wp-json\/wp\/v2\/pages\/1677\/revisions"}],"predecessor-version":[{"id":1678,"href":"https:\/\/prg.inf.unibe.ch\/index.php\/wp-json\/wp\/v2\/pages\/1677\/revisions\/1678"}],"up":[{"embeddable":true,"href":"https:\/\/prg.inf.unibe.ch\/index.php\/wp-json\/wp\/v2\/pages\/731"}],"wp:attachment":[{"href":"https:\/\/prg.inf.unibe.ch\/index.php\/wp-json\/wp\/v2\/media?parent=1677"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}