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GENERAL INFORMATION
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1. Title of Dataset: SIGNAL : System of Integrated Growth of Networks and Land Use
2. Authors: David Levinson, Feng Xie, Shanjian Zhu
3. Author Contact: dlevinson@umn.edu


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SHARING/ACCESS INFORMATION
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1. Licenses/restrictions placed on the data:

	Attribution-Noncommercial-ShareAlike 3.0 United States (http://creativecommons.org/licenses/by-nc-sa/3.0/us/)
	
2. Links to publications that cite or use the data:

Levinson, David, Feng Xie, and Shanjiang Zhu (2007). The Co-Evolution of Land Use and Road Networks. (839-859) Transportation and Traffic Theory 2007 (ed. Richard 	E. Allsop, Michael G. H. Bell, and Benjamin Heydecker) Emerald Group Pub Ltd. http://hdl.handle.net/11299/179950

3. Recommended citation for the data:

Xie, Feng; Zhu, Shanjiang; Levinson, David M. (2016). SIGNAL : System of Integrated Growth of Networks and Land Use. Retrieved from the University of Minnesota Digital Conservancy, http://hdl.handle.net/11299/181331.


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DATA & FILE OVERVIEW
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This software models the co-evolution of land use and transportation network as a bottom-up process by which re-location of activities and expansion of roads are driven by interdependent decisions of individual businesses, workers, and road owners according to simple decision rules. A Simulator of Integrated Growth of Networks And Land-use (SIGNAL) is developed to implement these decentralized decision making processes, in which the Gini index and equivalent radius were computed to describe and track down the spatial patterns of space and network.

Note: opening and running this program will require an environment that runs Java, such as Eclipse or Dr. Java, which can be downloaded freely.

Instructions to run program:
1. Import all java files in the package into a Java platform, such as Eclipse or Dr. Java
2. Run "Signal.java" as an applet
3. In the bottom-left corner of the applet interface, "signal1.8.0- " will be the default entry into the form field. This is associated with the parameter text files included in the zipped package. Type in a number that matches with one of these file names.
4. Click "load" to load the parameters from the text file.
5. Click "Evolve" to run the scenario.
6. "Batch" runs the simulation in batch mode if you have set up multiple scenarios.
7. Use the controls at the bottom of the applet screen to view the results in different modes or to see results in a specific year.
8. The measurements have also been printed out to the console window.

Files included in the zipped folder

java.policy.applet
Automata$Dimension.class
Automata.class
BooleanStack.class
DijkstrasAlgo.class
DirectedGraph$ReadANumber.class
DirectedGraph.class
FloatStack.class
IntStack.class
Investment.class
MenuFrame.class
NetworkDynamics.class
Signal$DrawArea.class
Signal$DrawPanel.class
Signal$ScrollPanel.class
Signal$VariablesPanel.class
Signal.class
TAssignment$Dimension.class
TAssignment.class
TDistribution.class
TGeneration.class
WindowDestroyer.class

Signal.html

Automata.java
BooleanStack.java
DijkstrasAlgo.java
DirectedGraph.java
FloatStack.java
IntStack.java
Investment.java
MenuFrame.java
NetworkDynamics.java
Signal.java
TAssignment.java
TDistribution.java
TGeneration.java
WindowDestroyer.java

Batch.txt
Coor_Grid03.txt
Coor_Grid10.txt
Coor_Grid20.txt
Coor_Grid3.txt
Coor_Grid50.txt
Grid03U.txt
Grid10.txt
Grid20.txt
Grid20C.txt
Grid20R.txt
Grid20U.txt
Grid3U.txt
Grid50.txt
odcost.txt
River.txt
TAZINFO.txt
LOG

---The following files can be loaded into the program as scenarios---
signal1.8.0-1.txt
signal1.8.0-2.txt
signal1.8.0-214.txt
signal1.8.0-215.txt
signal1.8.0-216.txt
signal1.8.0-217.txt
signal1.8.0-218.txt
signal1.8.0-219.txt
signal1.8.0-3.txt
signal1.8.0-315.txt
signal1.8.0-4.txt
signal1.8.0-414.txt
signal1.8.0-415.txt
signal1.8.0-416.txt
signal1.8.0-417.txt
signal1.8.0-418.txt
signal1.8.0-419.txt
signal1.8.0-515.txt
signal1.8.0-615.txt
signal1.8.0-674.txt
signal1.8.0-715.txt
signal1.8.0-716.txt
signal1.8.0-718.txt
signal1.8.0-719.txt
signal1.8.0-818.txt
signal1.8.0-819.txt
signal1.8.0-915.txt
signal1.8.0-916.txt
signal1.8.0-918.txt
signal1.8.0-919.txt
signal1.8.0-956.txt
signal1.8.0-958.txt
signal1.8.0-959.txt
signal1.8.0-965.txt
signal1.8.0-966.txt
signal1.8.0-971.txt
signal1.8.0-972.txt
signal1.8.0-973.txt
signal1.8.0-974.txt
signal1.8.0-975.txt
signal1.8.0-976.txt
signal1.8.0-977.txt
signal1.8.0-978.txt
signal1.8.0-979.txt
signal1.8.0-980.txt
signal1.8.0-981.txt
signal1.8.0-982.txt
signal1.8.0-983.txt
signal1.8.0-984.txt
signal1.8.0-985.txt



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METHODOLOGICAL INFORMATION
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From page 12 of Levinson, David, Feng Xie, and Shanjiang Zhu (2007). The Co-Evolution of Land Use and Road Networks. (839-859) Transportation and Traffic Theory 2007 (ed. Richard E. Allsop, Michael G. H. Bell, and Benjamin Heydecker) Emerald Group Pub Ltd. http://hdl.handle.net/11299/179950

"Simulation experiments were conducted in a hypothetical metropolitan area where
both the population and employment are distributed over a two-dimensional grid. For
simplicity, the experiments here are conducted over a square planar surface, stretching 20
km in both dimensions, divided into a 20X20 grid lattice of land use cells (400 zones).
Each zone occupies one square kilometer of land. A total of 400,000 people are living in
this city, which is equivalent to an average of 1,000 residents in each zone. Total
employment equals 400,000 as well (and each resident holds a job). Two-way roads
connect the centroids of each pair of adjacent zones, thus forming a 20X20 grid of road
network as well, comprising 400 nodes and 1,520 links.

[...]

The Gini index of land use (employment or population) is computed in this study
to reflect how evenly land uses are distributed on the hypothetical space. The index is a
number from zero to one, which is equal to zero when employment or population is
uniformly located across all zones, while close to one when all employment or population
is located in one zone. The more unevenly land use is distributed, the higher value the
index is."