The Centre for Mathematical Sciences research seminars and events are listed below.
The four main seminar series are in applied mathematics, pure mathematics, statistics and theoretical physics. Visit the centre's webpages for the latest seminar updates and information.
8 March (13:30-14:30): Rigidity and global rigidity of graphs
- Speaker: Bernd Schulze (Lancaster)
Rigidity theory is concerned with the rigidity and flexibility analysis of bar-joint frameworks and related constraint systems of geometric objects. This area has a rich history which can be traced back to classical work of Euler, Cauchy and Maxwell on the rigidity of polyhedra and skeletal frames. Since Laman’s celebrated result from 1970 (which provided the first combinatorial characterisation of generic rigid bar-joint frameworks in the plane), rigidity theory has received steadily increasing attention and it is now a highly diverse and thriving research area with many practical applications. Bernd will give an introduction to rigidity theory, concentrating on results and problems for bar-joint frameworks, but also describing how these have been extended to some other types of frameworks. Moreover, Bernd will summarise some recent progress in the rigidity analysis of symmetric frameworks.
21 March (14:00-15:00): Multi-state models for observed and latent cognitive function in the older population
- Speaker: Ardo van den Hout, Department of Statistical Science, University College London.
Due to the ageing population there is a growing interest in the statistical modelling of cognitive function in old age. When analysing longitudinal data on ageing, lost to follow-up because of death cannot be ignored. One option is to model survival and change of cognitive function jointly by specifying submodels for the two processes and linking these models by individual-specific random effects.
Another option – and the topic of this seminar – is to use a continuous-time multi-state survival model where a series of living states is defined by the level of cognitive function and an additional dead state is included. This multi-state approach is quite general and can be used in many other applications in biostatistics, social statistics, and demography.
The seminar will start with introducing the continuous-time multi-state survival model by discussing model specification and maximum likelihood estimation. The second part will present an extension of current methods: a hidden Markov model for modelling bivariate cognitive function. The methods will be illustrated by using longitudinal data from a UK survey of the older population.
21 March (15:00-16:00): Accuracy and Stability of Virtual Source Method for Numerical Simulations of Nonlinear Water Waves
Speaker: Omar Al-Tameemi (Plymouth)
The Virtual Source Method (VSM) is based upon the integral equations derived by using Green’s identity with Laplace’s equation for the velocity potential. The velocity potential within the fluid domain is completely determined by the potential on a virtual boundary located above the fluid, avoiding the need to evaluate the singular integrals normally associated with integral equation methods. This talk will present numerical simulations of non-linear standing waves and sloshing problems using VSM. We will discuss stability and convergence of the method as well as looking at global and energy and volume conservation.