Exam Questions Flashcards
What is closeness and decay centrality based on?
On the shortest distance to all the other nodes
What are examples of the Poisson and scale free distributions in the real world?
Poisson: e.g. coin flips between nodes (since binomial distributed)
Scale free: Rich get richer (i.e. Facebook friends)
What are the three characteristic differences between the scale free and Poisson networks?
- Clustering: The Poisson random network has a small clustering compared to scale free given the same number of links.
- Scale free: fat tails, existence of hubs
- Scale free: Assortativity in degree based on age
How do the Poisson and scale free networks affect the steady state in a SIS model?
Due to the existence of hubs there always is a non-zero steady state of neigh- bor infection in the scale free network. For Poisson random networks it depends on λ
How to determine if a stocachasitic Markov chain converges?
It needs to be aperiodic, this happens when there are selflinks.
How to determine if a network is wise?
Just let the transition matrix for n players go to inf players. Then they should a have 0 impact and thus be wise.
What is meant by mean perserving spread P?
It is just a regular network where all the nodes have the expected degree.
If we change from a partial regular network to a mean perserving network, what happens to 𝜃 in the SIS model?
It increases.
