Humboldt-Universität zu Berlin | Wirtschaftswissenschaftliche Fakultät | High Dimensional Nonstationary Time Series | About us | News Feed | News 2017 | Dissertation: L. Fang completes PhD Dissertation: L. Fang completes PhD 07.02.2017. Lei Fang, the former IRTG Manager, successfully finished her doctoral studies on "Mortality Models and Longevity Risk". Congratulations!