Reza Jafari is a faculty member of physics complex systems at the Shahid Beheshti University. He started his collaboration with DNDS in the winter of 2016. His research interests are collective behavior and crises in financial and social science, complex networks dynamics, fractional calculus and its application in networks when memory influences the dynamics. Recently he has used fractional calculus to introduce aged networks. Indeed, age is the same as other properties of links such as weight and direction, and it can be considered a new property for a link. Evolution of social networks happens simultaneously with the variation of their links/nodes. However, sometimes it is not easy for some links/nodes to evolve in such a process because of their age. In real networks, some links/nodes can exist that are not happy with any variations. Understanding stability, aged phase transition, information transformation of social networks are some of the challenges of this project. Some other recent projects can be found on his page in ResearchGate (https://www.researchgate.net/profile/G_Jafari).