UCLA COMM 156 MIDTERM EXAM NEWEST ACTUAL

UCLA COMM 156 MIDTERM EXAM NEWEST ACTUAL /

QUESTIONS WITH 100% CORRECT ANSWERS

VERIFIED/GRADED A+

An epidemic occurs if... - ---Answers---the Infection rate exceeds the Recovery rate

Infectivity (i) - ---Answers---probability that a contact between a Susceptible (S) and Infected individual leads that susceptible person to become infected (ex. probability that you, yourself opens the video and you start sharing it yourself )

Contact Rate (c) - ---Answers---What determines the number of contacts between Susceptible and Infected people?; measured in people per person per day

Infection rate - ---Answers---probability that a random contact is with an infected person

Epidemic Threshold - ---Answers---cid > 1

Duration - ---Answers---how long are you infected before you recover?

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Assumption with Infectivity model - ---Answers---we assume that people interact at random in this equation that any 2 people in the population are equally likely to bump into each other - not true in real life

• ways to increase possibility of epidemic - ---Answers---c —

increase the number of contacts i — increase the "infectivity" d — increase the "duration"

basic reproductive number - ---Answers---R0: average # of

new infections created by each infected person

Average Path Length - ---Answers---For any 2 nodes, find the shortest path between them (called the distance between the nodes) and then take the avg of these lengths over all pairs of nodes

Clustering Coefficient (cliquishness) - ---Answers---For each node, this is the number of connections between neighbors of that node divided by the number of possible connections between those neighbors. For the whole network, the clustering coefficient is the average of the coefficient over all nodes. x / [(n - (n-1))/2]

Clustering Coefficient in the real world - ---Answers---In real world (social) networks, the clustering coefficient

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