F irstly\, I will talk about the situation when boun dary conditions are given on many plates and the a ssociated Wiener-Hopf equation. The Wiener-Hopf me thod can be considered as a Riemann-Hilbert method with added analytisity information allowing for f ull power of complex analysis methods to be exploi ted. I will explain the difficulties involved when matrix Wiener-Hopf equations are solved. I will d escribe how recent advances in computation of rati onal approximations and orthogonal polynomials can be used. The corresponding canonical acoustics s cattering problems will be considered.

This i s joint work with Matthew J. Priddin and Lorna J. Ayton.

Secondly\, I will talk about how special functions called Mathieu function can be u sed to solve Helmholz equation with boundary condi tions given on a plate. This allows to produce a fast and stable code for challenging conditions li ke varying elasticity and porosity on a plate. Thi s is joint work with Matthew J. Colbrook. LOCATION:Seminar Room 1\, Newton Institute CONTACT:info@newton.ac.uk END:VEVENT END:VCALENDAR