http://ptrinh.com/ 2026-05-14T20:54:05+00:00 http://ptrinh.com/ http://ptrinh.com/ttp://ptrinh.com/lib/tpl/white/images/favicon.ico text/html 2019-03-16T20:02:26+00:00 Anonymous (anonymous@undisclosed.example.com) http://ptrinh.com/blog:15-05-01?rev=1552766546&do=diff May 2015: Two new papers published I'm happy to announce the publication of two new papers. The first paper is published in Nonlinearity and is on the topic of developing exponential asymptotics for problems with coalescing singularities (motivated by the study of ship waves, above left) with Jonathan Chapman (Oxford). The text/html 2019-03-16T20:03:14+00:00 Anonymous (anonymous@undisclosed.example.com) http://ptrinh.com/blog:15-06-01?rev=1552766594&do=diff June 2015: Fluids and elasticity in France _media/:start:elasticposter_1200.png I'll be attending the Fluid and Elasticity 2015 conference, from June 22-24 in Biarritz, France, and presenting some joint work with Stephen K. Wilson (Strathclyde University) and Howard A. Stone (Princeton University). text/html 2019-03-16T20:01:40+00:00 Anonymous (anonymous@undisclosed.example.com) http://ptrinh.com/blog:16-01-01?rev=1552766500&do=diff Jan 2016: Spot patterns on the surface of the sphere _media/:start:spot1200.jpg I'm happy to announce the publication of my paper in the journal Nonlinearity with Michael J. Ward (University of British Columbia) on localized spot patterns on the surface of the sphere. In this paper, we develop the detailed asymptotics that describe the slow dynamics of spot patterns modelled by a system of reaction-diffusion equations. The interesting twist is that when the patterns occur on a surface of non… text/html 2019-03-16T20:01:21+00:00 Anonymous (anonymous@undisclosed.example.com) http://ptrinh.com/blog:16-05-18?rev=1552766481&do=diff 18 May 2016: Jet flows from angled nozzles _media/start:chandler_poster_large.jpg A late congratulations to second-year student Tom Chandler (Lincoln College, Oxford) for successfully presenting his poster [Jet flows from angled nozzles] at the British Applied Mathematics Colloquium 2016 that took place last month in Oxford. Tom's work studies the situation of fluid ejected from an angled nozzle and driven by gravitational forces. It turns out that there are some rather non-trivial issues con… text/html 2019-03-16T20:01:01+00:00 Anonymous (anonymous@undisclosed.example.com) http://ptrinh.com/blog:16-06-01?rev=1552766461&do=diff 01 June 2016: New singularities in Stokes waves I'm happy to announce the publication of a paper in collaboration with Samuel Crew (Lincoln College, Oxford). In this paper, we revisit the classic problem of a periodic wave travelling without change of form, which was first considered by Stokes in the late 19th century. text/html 2019-03-16T20:00:32+00:00 Anonymous (anonymous@undisclosed.example.com) http://ptrinh.com/blog:16-09-08?rev=1552766432&do=diff 8 September 2016: A topological study of gravity free-surface waves generated by bluff bodies using the method of steepest descents This paper, now published in the Proceedings of the Royal Society A (PRSA) has a few interesting distinctions. It's the first paper I've published in PRSA text/html 2019-03-16T20:00:03+00:00 Anonymous (anonymous@undisclosed.example.com) http://ptrinh.com/blog:17-01-30?rev=1552766403&do=diff 30 January 2017: On reduced models for gravity waves generated by moving bodies I'm happy to announce a recent paper published in the Journal of Fluid Mechanics. There is an interesting story behind this paper. (Left) Ernie Tuck (1939--2009) (Right) Marshall Tulin (1926--) Since around 2007--2010, I'd often play with certain reduced models for studying gravity wave generation by two-dimensional bodies. These reduced models you can derive using some more modern techniques in asymptotics, but … text/html 2019-03-16T19:59:28+00:00 Anonymous (anonymous@undisclosed.example.com) http://ptrinh.com/blog:17-05-25?rev=1552766368&do=diff 25 May 2017: A tax on those who can't do maths It's said that playing the lottery is akin to imposing a tax on those who cannot do mathematics. However, there are plenty of real-life situations where it becomes difficult to gauge whether or not you are getting a good deal. Issues of real-estate, investment, and mortgaging is one of those situations. $L = L_0$$r_1 = 2.11\%$$t = n_1$$t = n_e$$r_2 = 3.74\%$$m_1$$m_2$$m_1$$L_n$$0 < n < n_1$\[ L_n = L_{n-1}(1 + r_1/12) - m_1, \]$r_1 = 0.0211$\[ L_n … text/html 2019-03-16T19:58:57+00:00 Anonymous (anonymous@undisclosed.example.com) http://ptrinh.com/blog:17-06-17?rev=1552766337&do=diff 17 June 2017: The Oxford-Cambridge Woolly Owl Yesterday, we sent our team of seven students to compete against Cambridge in the Applied Maths Meeting (aka the Woolly Owl). This is a bienniel competition between Oxford and Cambridge graduate students to claim the prize of the Woolly Owl, a plush toy knitted by a tea-lady in the Maths Institute many years ago. The winner of the competition would be allowed to retain the owl for the next two years until the next clash. text/html 2019-03-16T19:58:00+00:00 Anonymous (anonymous@undisclosed.example.com) http://ptrinh.com/blog:17-09-14?rev=1552766280&do=diff 14 September 2017: Congratulations to graduating and continuing research students This comes a bit late as we are only two weeks away from a new academic term, but I wanted to pause and congratulate the successful research students from the 2016-2017 year.