Question

Difficulty: MediumTransportation Modes and Network Connectivity

In transport network analysis, a geographic planner models a regional planar road network connecting 66 primary market towns (v=6v = 6) via 99 direct road links (e=9e = 9). What is the Gamma index (γ\gamma) of connectivity for this transportation network?

  1. 0.750.75Answer
  2. B
    1.501.50
  3. C
    0.500.50
  4. D
    0.600.60

Answer

The Gamma index (\(\gamma\)) of connectivity for the transportation network is 0.750.75 (or 75%75\%).
The Gamma index (\(\gamma\)) represents the relationship between the actual number of edges (ee) in a network and the maximum possible number of edges (emaxe_{\text{max}}) for a planar graph, expressed by the formula γ=e3(v2)\gamma = \frac{e}{3(v - 2)}. Given v=6v = 6 nodes and e=9e = 9 edges, substituting these values yields 93(62)=912=0.75\frac{9}{3(6 - 2)} = \frac{9}{12} = 0.75.

Step-by-Step Solution

1
Identify the given network graph parameters
Number of vertices (vv) = 66, number of edges (ee) = 99.
Topological indices require the count of nodes and links in the network.
2
Apply the planar Gamma index formula
γ=eemax=e3(v2)\gamma = \frac{e}{e_{\text{max}}} = \frac{e}{3(v - 2)}
The Gamma index measures the ratio of actual edges to the maximum possible number of edges in a planar graph.
3
Substitute values into the formula and solve
γ=93(62)=93×4=912=0.75\gamma = \frac{9}{3(6 - 2)} = \frac{9}{3 \times 4} = \frac{9}{12} = 0.75
Simplifying the numerical expression gives the fractional connectivity score.

Key Concept

Gamma Index of Network Connectivity
Estimated Time:1m 15s
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