# z theory

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Midterm (12-19-2014)
Social Network Analysis
Instructor: Dr. Donglei Du
Duration: 80 minutes
Instructions:
You will not get any credit for a single answer without proper process.
2. The exam is closed book and notes.
3. Duration: 80 minutes
4. There are 20 questions in total.
5. The total mark is 40.
Student Name:_______________________
Student ID________
________________
1. (10 points) Explain each of the following comcepts briefly
a. (2 points)
b. (2 points)
c. (2 points)
d. (2 points)
e. (2 points)
2. (2 points) Which node whose deletion would result in the graph below with three connected
components? Find all such nodes.
3. How many strongly connected components are there in the graph below?
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4. (2 points) List all edges in the network below that are local bridge but not bridge?
5.
(2 points) In the figure below (+ means strong tie and – means weak tie), which nodes
violate the Strong Triadic Closure property? (Choose all that apply.)
6. (2 points) Given the first generation of internet below: List all nodes in the shortest path from
UCLA to CASE
7. (2points) Consider the network below. What is the embeddedness of the edge H-I?
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8.
( 2 points) Consider the network above. What is the neighborhood overlap of the edge I-J?
9. ( 2 points) Consider the network below. Find the clustering coefficient of node 2.
10. ( 2 points) Consider the network above. Find the closeness centrality measure of node 2.
11. ( 2 points) Consider the network above. Find the betweenness centrality measure of node 7.
12. (2 points) Recall the concept of pivotal nodes from your assignment: a node X is pivotal for a
pair of distinct nodes Y and Z if X lies on every shortest path between Y and Z (and X is not
equal to either Y or Z). Consider node 4, list all the pairs of nodes such that 4 is pivotal.
13. Recall the concepts of gatekeeper and local gatekeeper from your assignment: (1) a node X is
a gatekeeper if for some other two nodes Y and Z, every path from Y to Z passes through X; (2) a
node X is a local gatekeeper if there are two neighbors of X, say Y and Z, that are not connected
by an edge. Which node in the graph below are local gatekeeper but not gatekeeper?
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14. According to the theory of strong and weak ties, with the strong triadic closure assumption, how
would you expect the edge connecting b and c to be labeled? Give a brief (1-3 sentence)