Question 1

Link impedance for network applications can be measured by:
A) physical length
B) travel time
C) both of these are correct

Accepted Answer

Link impedance in network applications refers to the resistance or opposition that a circuit presents to the passage of a current or to the flow of an electromagnetic wave. It can be characterized by both the physical length of the link and the travel time of signals across it. The physical length affects the impedance due to the resistance, inductance, and capacitance of the materials, while the travel time relates to how quickly signals can propagate through the medium, which also affects impedance characteristics.

Question 2

What is the main objective of the "vehicle routing problem"?

Accepted Answer

The main objective of the "Vehicle Routing Problem" (VRP) is to optimize the routes of a fleet of vehicles that must visit a set of locations (customers, delivery points, etc.) to perform services or deliver goods. The optimization is typically aimed at minimizing the total distance traveled, the total time spent, or the overall costs associated with the routes, while also satisfying a set of constraints. These constraints can include factors such as:

1. Vehicle capacity: Each vehicle can carry a limited amount of goods or number of passengers.
2. Time windows: Deliveries or pickups may need to occur within specific time frames.
3. Service time: The time required to serve each location.
4. Fleet size and composition: The number and types of vehicles available.
5. Customer demands: The quantity of goods required at each location.
6. Driver regulations: Rules regarding driver working hours and mandatory breaks.

By addressing the VRP, businesses and organizations aim to improve operational efficiency, reduce transportation costs, enhance customer service, and decrease environmental impact through reduced fuel consumption and emissions. The VRP is a complex combinatorial optimization problem and is often solved using various mathematical and computational techniques, including exact algorithms, heuristics, and metaheuristics.

Question 3

Explain the difference between a network and a line shapefile.

Accepted Answer

A network shapefile is a type of geographic information system (GIS) file that represents a network of interconnected features, such as roads, rivers, or utility lines. It contains information about the connectivity and relationships between these features, allowing for analysis of routes, flow, and connectivity within the network.

On the other hand, a line shapefile is a more general type of GIS file that represents linear features, such as roads, rivers, or boundaries. It does not contain information about connectivity or relationships between the features, and is typically used for visualizing and analyzing the spatial distribution and characteristics of linear features.

In summary, the main difference between a network and a line shapefile is that a network shapefile represents interconnected features with information about connectivity and relationships, while a line shapefile represents individual linear features without such connectivity information.

Question 4

A shortest-path analysis can include intermediate stops between the origin and destination.

Accepted Answer

A shortest-path analysis can include intermediate stops (also known as waypoints) between the origin and destination to determine the most efficient route through all specified points.

Question 5

A ____ link connects a cell to one of its immediate neighbors, and a ____ link connects the cell to one of its corner neighbors.
A) lateral, diagonal
B) diagonal, lateral

Accepted Answer

A lateral link connects a cell to one of its immediate neighbors (up, down, left, right), while a diagonal link connects a cell to one of its corner neighbors (top-right, top-left, bottom-right, bottom-left).

Question 6

The diagram below represents a cost raster, with the origin at the upper left corner. (1) What is the cost for moving from (col. 1, row. 1) to (col. 2, row 1)? (2) What is the cost for moving from (col. 1, row. 1) to (col. 2, row 2)? (3) What is the least accumulative cost from (col. 1, row. 1) to (col. 2, row 3)?

Accepted Answer

The answer of The diagram below represents a cost raster,...

Question 7

Least-cost path analysis is _____based, and network analysis is _____based.
A) vector, vector
B) raster, raster
C) vector, raster
D) raster, vector

Accepted Answer

Least-cost path analysis is typically raster-based, as it involves analyzing a grid of cells to determine the path of least resistance or cost across a landscape. Network analysis, on the other hand, is vector-based because it deals with points, lines, and polygons to model and analyze pathways and connections within a network, such as roads or rivers.

Question 8

Explain the role of a source raster in least cost path analysis.

Accepted Answer

The answer of Explain the role of a source raster...

Question 9

How does the surface distance differ from the regular (planimetric) cost distance?

Accepted Answer

The answer of How does the surface distance differ from...

Question 10

Explain the difference between the minimum impedance model and the maximum coverage model for location-allocation analysis.

Accepted Answer

The answer of Explain the difference between the minimum impedance...

Question 11

The surface distance measure is calculated from a(n):
A) path raster
B) allocation raster
C) elevation raster
D) cost raster

Accepted Answer

The surface distance measure is calculated from an elevation raster, which provides the necessary data to account for changes in elevation when measuring distances across a surface.

Question 12

In ArcGIS a network dataset can be built from:
A) a shapefile
B) a geodatabase
C) both of these are correct

Accepted Answer

A network dataset can be built from both a shapefile and a geodatabase in ArcGIS, allowing for flexibility in the source data format.

Question 13

A raster that assigns each cell to its closest source cell on the basis of cost distance measures is called a(n):
A) allocation raster
B) none of these are correct
C) direction raster
D) shortest path raster

Accepted Answer

An allocation raster assigns each cell in the raster to the closest source based on cost distance measures, effectively allocating areas to the nearest source based on the criteria defined (e.g., distance, time, or other cost factors).

Question 14

Define "allocation analysis."

Accepted Answer

The answer of Define "allocation analysis."...

Question 15

In an allocation analysis, the service area of a fire station will _____ if the response time increases:
A) increase
B) decrease

Accepted Answer

If the response time increases, the fire station can cover a larger area within the allowable time, thus increasing its service area.

Question 16

Explain the difference between the physical distance and the cost distance in distance measure operations.

Accepted Answer

The answer of Explain the difference between the physical distance...

Question 17

One-way streets are treated as ______in network analysis:
A) link impedance
B) turn impedance
C) none of these is correct
D) restriction

Accepted Answer

One-way streets are treated as restrictions in network analysis because they limit the direction of travel on a road segment.

Question 18

The surface distance _______ when the elevation difference between two cells _______.
A) increases, decreases
B) increases, increases

Accepted Answer

The surface distance increases when the elevation difference between two cells increases because the terrain becomes steeper, making the actual distance one would have to travel over the surface longer compared to a flatter terrain.

Question 19

The cost in a cost raster usually represents the sum of a number of cost factors.

Accepted Answer

A cost raster typically aggregates multiple cost factors, such as distance, time, energy, or financial expenses, to represent the total cost of moving through or utilizing each cell in the raster.

Question 20

If the speed limits are lowered (e.g., from 30 miles/hour to 20 miles/hour) on a network, then the service areas of a fire station will ________ in an allocation analysis:
A) decrease
B) increase

Accepted Answer

When speed limits are lowered, the distance that can be covered in a given amount of time decreases, leading to a reduction in the service area of a fire station in an allocation analysis.

Quiz 17: Least Cost Path and Network Analysis

Link impedance for network applications can be measured by:

What is the main objective of the "vehicle routing problem"?

Explain the difference between a network and a line shapefile.

A shortest-path analysis can include intermediate stops between the origin and destination.

A link connects a cell to one of its immediate neighbors, and a link connects the cell to one of its corner neighbors.

Least-cost path analysis is _based, and network analysis is _based.

Explain the role of a source raster in least cost path analysis.

How does the surface distance differ from the regular (planimetric) cost distance?

Explain the difference between the minimum impedance model and the maximum coverage model for location-allocation analysis.

The surface distance measure is calculated from a(n) :

In ArcGIS a network dataset can be built from:

A raster that assigns each cell to its closest source cell on the basis of cost distance measures is called a(n) :

Define "allocation analysis."

In an allocation analysis, the service area of a fire station will _____ if the response time increases:

Explain the difference between the physical distance and the cost distance in distance measure operations.

One-way streets are treated as ______in network analysis:

The surface distance _ when the elevation difference between two cells _.

The cost in a cost raster usually represents the sum of a number of cost factors.

If the speed limits are lowered (e.g., from 30 miles/hour to 20 miles/hour) on a network, then the service areas of a fire station will ________ in an allocation analysis: