Download presentation
Presentation is loading. Please wait.
Published byEthel Summers Modified over 9 years ago
2
REAL WORLD DATA Overall Long Beach Data burglaries: Total number of burglaries (2000-2005)
3
Multiple Robberies distinguished by color
4
LEGEND Blue – 1 Cyan – 2 Red – 3 Yellow – 4 Long Beach Burglaries from the Year 2000, Number of Times Victimized
5
AVERAGE FREQUENCY OF ROBBERIES The following Excel file shows Frequency of the houses burgled with respect to weeks between robberiesExcel file
6
OVERALL DATA ANALYSIS The following Frequency graph plotted using the average data More burglaries occur in rapid succession rather than long intervals.
7
AVERAGE NUMBER OF ROBBERIES The following Excel File shows the Average number of robberies for all five years.Excel File
8
AVERAGE NUMBER OF ROBBERIES PLOT
9
MY MODEL Virtual robbers are placed on a line of length L meant to represent houses robber can do 4 things at each step, essentially: stay put where he/she is, move left or right, or rob the house where he/she is at The probability of moving to a neighboring location is calculated based on the “attractiveness” of the neighbor houses as follows: After all the robbers have robbed and moved, the houses will update their b values according to this formula:
10
COMPARISON OF MY MODEL AND REAL WORLD DATA Robbers=800;Blue Model Houses=13000;Black Data Time=One year; η=.5 =0.5; =.01; b0=.01
11
COMPARISON OF MY MODEL AND REAL WORLD DATA Number of Robberies per site for the same parameters as before Binning number time robbed: 1 2046, 2 296, 3 75, 4 19, 5 2, 6 1
12
What is a Hot Spot?
13
Hot Spot Definition 1: Areas with high percentages of multiple burglaries
14
Hot Spot 1 100x100 grid Each cell is approximately 485x500 ft Each cell represents the number of multiple burglaries divided by the total number of burglaries
15
Hot Spot Definition 2: Clusters of burglaries where one burglary is within 500 ft of another
16
Clustering Algorithm
17
1.Chooses a random point 2.Finds all points within 500 ft
18
Clustering Algorithm
19
1.Chooses a random point NOT already within a cluster 2.Finds all points within 500 ft
20
Clustering Algorithm
21
Eventually, all points are in clustered in some groups
22
Clustering Algorithm Re-checks that points within 500 ft are in the same cluster
23
Clustering Algorithm Some different clusters might be within 500 ft of each other
24
Clustering Algorithm Clusters within 500 ft of each other are combined into one cluster
25
Total of 521 Clusters, top 10 are displayed The biggest cluster consisted of 76 housing units 500 ft is about the size of a block Are these hot spots? Long Beach Burglary Clusters for the year 2000
26
Apologies….
27
Possible Correlations?
28
Possible Correlations: 2000: Total Housing Units
29
Possible Correlations: 2000: Total People
30
Possible Correlations: 2000: Mean Earnings Based on sampling
31
Possible Correlations: 2000: Median Age
32
Possible Correlations: 2000: Percentage of Those 65 and Older
33
Possible Uncorrelations: 2000: Percentage of Households with 1 Person
34
Possible Correlations: 2000: Percentage of those with at most a 9 th grade education level Based on Sampling
35
Possible Correlations: 2000: Percentage of those 25 years or older with at least a Bachelors Based on Sampling
36
Possible Correlations: 2000: Race Percentage of those who are …. ?
37
Possible Correlations: 2000: Race Percentage of those who are Caucasian
38
Possible Correlations: 2000: Race Percentage of those who are African-American
39
Possible Correlations: 2000: Race Percentage of those who are Asian American
40
Possible Correlations: 2000: Race Percentage of those who are Hispanic/Latino
Similar presentations
© 2024 SlidePlayer.com Inc.
All rights reserved.