{"id":75,"date":"2025-10-25T06:07:14","date_gmt":"2025-10-25T06:07:14","guid":{"rendered":"https:\/\/sites.massey.ac.nz\/djws\/?page_id=75"},"modified":"2026-03-12T02:12:26","modified_gmt":"2026-03-12T02:12:26","slug":"profile","status":"publish","type":"page","link":"https:\/\/sites.massey.ac.nz\/djws\/","title":{"rendered":"Research"},"content":{"rendered":"<p><span style=\"color: red\">New<\/span>: <a href=\"https:\/\/sites.massey.ac.nz\/djws\/phd-scholarship\/\">PhD scholarships<\/a> available now!<\/p>\n<p>I study mathematical models of dynamical systems.  Mainly I deal with low-dimensional ODEs and maps and analyse critical parameter values (bifurcations) where the dynamical behaviour changes in a fundamental way.<\/p>\n<p>My research focuses on models that involve a switch or discontinuity.  Such models have novel bifurcations and readily exhibit chaotic dynamics.  Refer to my <a href=\"https:\/\/sites.massey.ac.nz\/djws\/publications\/\">publication list<\/a> or <a href=\"https:\/\/scholar.google.com\/citations?user=Dxy-PkkAAAAJ&amp;hl=en\">Google Scholar profile<\/a>.<\/p>\n<p>I hope to soon publish a <a href=\"https:\/\/sites.massey.ac.nz\/djws\/book\/\">book<\/a> on piecewise-smooth bifurcations, so watch this space!<\/p>\n<p>Former PhD students:<\/p>\n<ul>\n<li> <a href=\"https:\/\/indrag49.github.io\/\">Indranil Ghosh<\/a> (2021&#8211;2024)<\/li>\n<li> <a href=\"https:\/\/scholar.google.com\/citations?user=HqDJFc0AAAAJ&amp;hl=en\">Sishu Muni<\/a> (2018&#8211;2021)<\/li>\n<\/ul>\n<p><a href=\"http:\/\/sites.massey.ac.nz\/djws\/wp-content\/uploads\/sites\/177\/2025\/10\/PWLMaps_Thailand_v3.pdf\">Slides<\/a> on piecewise-linear maps from a keynote talk at the 28th International Conference on Difference Equations and Applications, Phitsanulok, Thailand, July 2023.<\/p>\n<p><a href=\"http:\/\/sites.massey.ac.nz\/djws\/wp-content\/uploads\/sites\/177\/2025\/10\/BangaloreHandout.pdf\">Lecture notes<\/a> on piecewise-smooth ODEs from the Dynamics of Complex Systems Summer School at the International Centre for Theoretical Sciences, Bengaluru, India, June 2018.<\/p>\n\n\n<h2 class=\"wp-block-heading\">Other things of mine on the web<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/dsweb.siam.org\/Media-Gallery\/basins-of-infinitely-many-attractors\" data-type=\"URL\" data-id=\"https:\/\/dsweb.siam.org\/Media-Gallery\/basins-of-infinitely-many-attractors\">DSWeb Media Gallery<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/www.xwordinfo.com\/Crossword?date=4\/29\/2010\" data-type=\"URL\" data-id=\"https:\/\/www.xwordinfo.com\/Crossword?date=4\/29\/2010\">NYT Crossword<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/www.myminifactory.com\/object\/3d-print-self-locking-8-piece-puzzle-cube-112927\" data-type=\"URL\" data-id=\"https:\/\/www.myminifactory.com\/object\/3d-print-self-locking-8-piece-puzzle-cube-112927\">3D-Printable Self-Locking Cube Puzzle<\/a><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Contact<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>email: <a href=\"mailto:d.j.w.simpson@massey.ac.nz\">d.j.w.simpson@massey.ac.nz<\/a><\/li>\n\n\n\n<li>phone: 06 951 7618 (or 84618 within Massey)<\/li>\n\n\n\n<li>office: ScB3.07<\/li>\n\n\n\n<li>postal: School of Mathematical and Computational Sciences, Massey University, Palmerston North 4410, New Zealand<\/li>\n<\/ul>\n\n\n\n<p><em>Last modified: March 12, 2026<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>New: PhD scholarships available now! I study mathematical models of dynamical systems. Mainly I deal with low-dimensional ODEs and maps and analyse critical parameter values (bifurcations) where the dynamical behaviour changes in a fundamental way. My research focuses on models &hellip; <a href=\"https:\/\/sites.massey.ac.nz\/djws\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":314,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-75","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/sites.massey.ac.nz\/djws\/wp-json\/wp\/v2\/pages\/75","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sites.massey.ac.nz\/djws\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sites.massey.ac.nz\/djws\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sites.massey.ac.nz\/djws\/wp-json\/wp\/v2\/users\/314"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.massey.ac.nz\/djws\/wp-json\/wp\/v2\/comments?post=75"}],"version-history":[{"count":22,"href":"https:\/\/sites.massey.ac.nz\/djws\/wp-json\/wp\/v2\/pages\/75\/revisions"}],"predecessor-version":[{"id":152,"href":"https:\/\/sites.massey.ac.nz\/djws\/wp-json\/wp\/v2\/pages\/75\/revisions\/152"}],"wp:attachment":[{"href":"https:\/\/sites.massey.ac.nz\/djws\/wp-json\/wp\/v2\/media?parent=75"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}