As discovered from the Twitter open API wwwcsoduedurlewisurbancharacteristics Open Data Gathering Ability to request posts from a region Provide center point and radius 1km Returns 1500 posts up to one week old ID: 239219
Download Presentation The PPT/PDF document "Urban Characteristics" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Urban Characteristics
As discovered from the Twitter open API
www.cs.odu.edu/~rlewis/urban_characteristicsSlide2
Open Data Gathering
Ability to request posts from a regionProvide center point and radius (≤ 1km)Returns ≤ 1,500 posts up to one week old
Contains
User ID
Time
Location
Posted messageSlide3
Socio-Psychological Discoveries
Focus is on the content of the messagePlaces emphasis on link structure of followers (subscribers) of the postGather trends within posted messages to cull tastes/preferencesSlide4
Socio-Migration Discoveries
Focus is on the time and location of the tweetCull regional characteristic patterns from movement histories
Monitor updates from micro-blogging site in relation to geography
Clustering posts as a step to measure movement patterns
Extract characteristic patternsSlide5
Circumventing Twitter Open API Limitation
The naïve wayMethod
Uniformly split a region into 1km grid cells
Call API for each cell
Application
Circular area of 100km radius (124 miles in diameter)
Need ┌100
2
π┐
cells
Results in 31,416 separate calls to the API (current limitation imposed is 150 calls per hour)Slide6
Circumventing Twitter Open API Limitation
Quad-tree splittingMethod
Recursively split the region into four rectangular cells of equal size
Stop splitting when
Cell is larger than the minimum radius permitted by the API (1km)
Number of posts in a cell is < 1,500Slide7
Circumventing Twitter Open API Limitation
Quad-tree splitting (continued)ApplicationSlide8
Quad-Tree SplittingSlide9
Aggregation ModelSlide10
Dispersion Model