Vol. 4 Issue 4
September 2009

Azavea Journal

Next time you drop by our Philadelphia offices to say hi, don't be surprised to find us wearing mustaches, trench coats,  and conversing with our good friend Dr. Watson.  For the past several months we've been sleuthing, exploring, and solving spatial mysteries.  We've developed new ways to search Japanese Gardens, have traversed the entire Philadelphia map to determine the most 'walkable' neighborhoods in the city, and have added heat map 'hunch' visualizations to our HunchLab software.   Our newly exercised sleuthing skills enabled us to find ourselves among the ranks of the 2009  Inc. Magazine 500|5000 list of the nation's fastest growing companies!  Welcome to another edition of the Azavea Journal.

Azavea Makes the 2009 Inc. Magazine 500 | 5000 List

After ranking 13 on the 2009 Inner City 100 List, we are thrilled to announce that, in August, we were named one of the nation’s fastest-growing companies on the 2009 Inc. Magazine’s 500|5000 List at number 1,741 and ranked 52 in the Greater Philadelphia region, based on our 182.4 percent revenue growth over the past three years.

The 2009 Inc. 500|5000 serves as a unique report card on the U.S. economy.  Despite the current gloomy economic situation, the aggregate revenue among the companies on the 2009 Inc. 5000 List increased to $214 billion, up $29 billion from last year, with a median three-year growth rate of 126 percent. The Inc. 5000 are responsible for creating more than 1 million jobs since their founding, making the list perhaps the best example of the impact private, fast-growing companies can have on the economy.

Read more about the 2009 Inc. 500|5000, here.

HunchLab: Heat Map and Kernel Density Calculation for Crime Analysis

Hunchlab_heatmap_timeday

Results for a “Hunch” set by a user with crime points overlaid on a heat map that shows crime density in a geographic area of interest. The Time-of-Day/Day-of-Week chart below shows crime density at various points in time at that location.

The purpose of HunchLab, Azavea’s geographic early warning system, is not only to identify changes in the geographic patterns in crime and alert users about detected crime spikes, but also to help users analyze and make sense of information about those spikes.

The “Hunch Detail” section of the application provides several tools geared for exactly that purpose. For the past several months we have made significant changes to it.  In addition to thematic mapping and Time-of-Day/Day-of-Week graphs, the latest upgrade provides a heat map layer.  This feature provides a visualization of crime density in a hunch’s geographic area during a specific timeframe.

When designing this new feature, we faced the question of how to best determine density. One way would be to divide an area into square cells and take a simple count of crimes per cell, but these results may not give a clear indication of actual crime density.  If there are two different cells, neither of which contains any crime points, then the density values for both will be zero.  But if one is in the middle of an area with no crime, while the other is adjacent to a cluster of crimes, this difference should really be reflected.  So HunchLab makes use of a more sophisticated process known as “kernel density estimation” which overcomes this problem

“What is kernel density analysis?” you may ask.  Well, rather than treating each crime event as if it only impacted the exact point where it occurred, the effect of each event is spread over the surrounding area.  The distance over which the effect is spread can vary and is specified by a parameter known as the “search radius”.  A “kernel” defines the pattern to use for distributing the event’s impact.  Several kernels are available, each with a different pattern.  The simplest kernel distributes the impact uniformly over the surrounding area, but most use mathematical formulas to give a greater weight closer to the crime event itself.

We’ve not only added this new density calculation feature to HunchLab but also made it into a reusable library that we can add to other applications.  The new library leverages the Azavea Raster Grid (ARG) format already developed for Azavea’s DecisionTree product as well as other investments from previous projects.  In HunchLab, users can adjust several parameters, such as the search radius to use during analysis and the rendering approach to use for displaying the results (equal interval or quantile).  The heat map layer is just one of several tools available to help users analyze the crime spikes that HunchLab detects, with even more on the way!

Philadelphia Walkshed: An Innovative Application to Calculate and Map Walkability

Last December I wrote an article describing my Azavea research project to better calculate and map walkability using friction-based distance calculations to determine a location’s walkable access to a variety of amenities.  As I had hoped, that research has matured and become the building blocks of a sophisticated, soon-to-be-released walkability calculator – Philadelphia Walkshed.

A screenshot of the walkshed application, showing the walkability and amenities of the area around 20th and Walnut.

Philadelphia Walkshed shows the walkability and amenities of the area around 20th and Walnut Sts.

Currently in testing, Walkshed enables users to make very precise and personal walkability calculations.  First, every distance we measure is an actual walking distance, rather than a distance calculated “as the crow flies”.  For example, we do not assume that you can walk on I-76 or the Delaware River.  Second, we give you enough data to make intelligent choices.  Walkability is not only proximity to basic amenities but also crime density, tree cover, and more.  Finally, we understand that walkability is very personal in many ways.  Some people may prefer access to parks and libraries while others prefer shopping and nightlife.  Since Walkshed is built on DecisionTree, Azavea’s planning and geographic prioritization tool, users have the ability to set their priorities and create a walkshed that is tailored to his or her preferences.

Don’t miss my walkability research presentation at this year’s Global Creative Economy Convergence Summit on October 5 in Philadelphia.  I hope to see you there!

‘Redistricting The Nation’ (and the Philadelphia Region): Upcoming Release of Citizen Education and Engagement Websites

redistricting_logoSome of you may remember our Gerrymandering Index white paper, which we released in October 2006. In the report we assessed the ‘compactness’ of both congressional and local legislative districts.  Our findings — PA congressional districts rated #2 most gerrymandered in the country and local City Council districts 7 and 5 were among the most gerrymandered in the country — contributed to conversations locally and nationally regarding how the redistricting process might be changed and made fairer.

Now, three years later we have decided to take another crack at our study, this time in the context of the 2010 Census and subsequent 2011 national redistricting process.  How does the new white paper differ from the 2006 Gerrymandering White Paper?  We’ve added more cities, included upper and lower state legislatures, and added several new compactness metrics.  Last but not least, we will make the whole study available as two interactive websites called ‘Redistricting the Nation‘ and ‘Redistricting the Philadelphia Region’.

Redistricting the Nation search page

Redistricting the Nation search page enables users to enter their address and check how compact the legislative districts they live in are (Congress, State and Local).

First, on October 14 Azavea and The Committee of Seventy (a local political watchdog organization whose mission is “to fight for clean and effective government, fair elections and a better informed citizenry in Philadelphia and the region”) will be releasing a regionally-focused website, ‘Redistricting the Philadelphia Region’. A week later, on October 21, Azavea will release its nationally-focused parent site, ‘Redistricting the Nation’.  Both websites are aimed at educating and engaging the public around redistricting issues in the runup to the 2010 Census and the 2011 national redistricting process.

While we are a for-profit company, no one paid us to do this.  So why do it?  The partial answer is “because we can”.  Our Cicero web service plus our experience with geographic analysis mean that we have both the legislative boundary data and the experience to do this kind of analysis.  But we also have a broader, social reason.  Azavea believes that a confluence of the internet, geographic data, and tools for online collaboration have the potential to transform the redistricting process by enabling citizens to participate directly in the effort.  Rather than meetings behind closed doors where incumbent legislators parcel out blocks of voters in order to guarantee they remain in office (the usual process in many cities and states), it should be possible for citizens and community groups to:

  • Create their own redistricting plans
  • Share those plans with each other
  • Assess the fairness of plans
  • Vote on their favorites plans
  • Submit the best plans to their local and state legislatures
  • Have fun doing it!

These two websites are the first step in our effort to promote this idea of public engagement in the redistricting process.

So mark your calendars:

  • October 14:  ‘Redistricting the Philadelphia Region” site goes live with lots of valuable information and wacky stories about Philadelphia’s history of redistricting (both good and not so good)!
  • October 21: ‘Redistricting the Nation’ site with a new version of the white paper as well as national data on districts, compactness and redistricting.  Find out how your legislative districts measure up to the rest of the country.  You’ll also be able to see a preview of our online, geospatial software tools that enable a collaborative redistricting process.

New Map View Search Available on Sajara

sajara_logoThroughout its development, Sajara has focused on enabling users to search for digital assets based on geographic criteria such as address, intersection, and neighborhood or by navigating around a map. While our standard search page with its many thumbnails remains a  powerful window to retrieve digital assets, we recently decided to create a new search page that expanded the map to full-screen size and put an even greater emphasis on Sajara’s geographic search capabilities.

Sajara_Map_Search

The new Sajara geographic search page is available in Japanese Gardens of the World, a sample application that demonstrates Sajara's capabilities.

In order to try out our idea for another geographic-based search page, we turned to Japanese Gardens of the World, our sample application powered by Sajara. To create the map, we utilized the same technology that drives our thumbnail search page, OpenLayers and ExtJS. These upgrades offered us increases in loading speed and better compatibility with new browser versions.

While the map-based search page focuses more on geographically displaying the results of a search, it still contains all the original search functionality. A drop-down ‘Search By’ menu contains fields allowing users to search by address, keyword, topics, collections, time period, and a variety of advanced search options. In order to help users keep track of their search criteria, we also implemented a new search feature called ‘Active Filters’, which provides a quick reminder of the selected criteria.

'Fisheye' thumbnail view of photographs found on the current map view.

'Fisheye' thumbnail view of photographs in the current map view.

The results of a search are displayed as a row of thumbnails across the bottom of the map with flags on the thumbnails corresponding to flags on the map. The thumbnails expand as you mouse over them. We used some simple math and javascript to implement this fish-eye effect, allowing users to quickly view basic data about an asset without requiring them to load a new page. A larger, more detailed page with additional information and photographs of the garden is available by clicking on the thumbnail.

The map-based search provides users with another option for searching through and browsing assets in their digital collection, but the thumbnail search is also still available as a way to view search results. Using the ‘Search’ menu, users can select whether they would like to search the database using the map or thumbnail view.  They can also switch between the two pages thanks to the ‘Map/Thumbnail’ button in the upper right corner of the page.

Make sure you visit our Japanese Gardens of the World sample application and let us know what you think!

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Conference Report: 10th Crime Mapping Research Conference (CMRC)

CrimeMappingConferenceLogoThe 10th Crime Mapping Research Conference was held August 19 – 22, 2009 in New Orleans.  The CMRC is organized every one to two years by the Mapping and Analysis for Public Safety (MAPS) office in the National Institute of Justice.  The CMRC brings together academic researchers, crime analysts and command staff to review the state of the art in geographic analysis and visualization of crime.  This was a lively group with a number of high quality talks and workshops, and a strong series of research-oriented presentations.  While sponsored by the NIJ in the U.S. Dept. of Justice, attendees included folks from Japan, Turkey, Canada, and the UK.

While there were several interesting presentations, I would like to highlight four that I particularly enjoyed:

I attended two presentations by Dr. Elizabeth Groff, a Professor of Criminal Justice at Temple University.  In her keynote address, she suggested that while our ability to visualize crime patterns has steadily improved, there is a difference between information and “actionable” information, and, as a community, we need to be creating more tools that are aimed at generating actionable intelligence.  She set out several examples of what this might look like in different operational contexts.  I was very proud that one of her examples was Azavea’s prototype for HunchLab, the Crime Spike Detector currently in use at the Philadelphia Police Department.  Dr. Groff also did a fascinating presentation introducing the use of Agent-based Modeling and how this simulation technique can be applied to modeling geographic patterns of criminal behavior.

Hunchlab_points_heatmap

Dr. Wilpen Gorr, from Carnegie Mellon University, presented a paper on Receiver Operating Characteristics (ROC) for Hot Spot Analysis.  ROC was a technique originally developed for analyzing radar signals and has since been used in medical imaging, but crime analysis is a novel application.  He has been working with the technique to calibrate kernel density smoothing as well as to use leading indicators to create predictive analytics for particular classes of crime.

Jerry Ratcliffe, a colleague of Liz Goff at Temple University, also did multiple presentations.  The one I attended was on a pattern his team has been researching, called the “near repeat” effect.  He has demonstrated that for some crimes, like burglary, there is a “contagion” effect that raises the likelihood of a repeat crime occurring near the original crime within a short period of time after the event.  His work does not end with a research paper – he has built some helpful software tools to help calculate the extent of the effect.

In summary, this was a terrific event, and I have to commend the Director of MAPS, Ron Wilson, and his colleagues for creating an excellent forum for exchanging ideas.

Meet Our New Staff: Jeremy Heffner

Jeremy Heffner, Marketing Associate

Jeremy Heffner, Business Development Associate

Jeremy Heffner joins Azavea as a Business Development Associate.  Coming to us from the nonprofit technology sector, he will be supporting the marketing and business development teams with writing content for our marketing pieces, managing our web presence, developing product campaigns, and researching trends in the technologies impacting our work.  He most recently worked at NPower Pennsylvania where he helped local nonprofits to better utilize technology by producing educational seminars and implementing constituent relationship management databases.  When he’s not tweaking settings on our two blogs (Atlas and Labs),  fiddling with our Google Analytics account, writing press releases or trying to persuade Robert to upgrade our CRM to SalesForce, he’s enjoying life in South Philadelphia writing content for his own blog on his Mac and reading about the latest tech fad.  Did we mention he’s obsessed with technology?

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From Our Blogs

ArcGIS Explorer – 5 Favorite Things

Mappa Mundi: Mapping the Medieval World

Google Fusion Tables – First Look

Geolocation: Followed, Not Just on Twitter

OpenLayers Map Centering and the International Date Line

Have a Kindle?  Our two blogs are available via the Amazon Kindle store: Azavea Atlas and Azavea Labs

Conference Schedule

URISA Annual Conference, 2009
Anaheim, CA – September 29 – October 2
Megan Heckert presenting on Muralfarm, LandStat

Community Indicators Consortium 2009 International Conference
Bellevue, WA – October 1 – 2
Robert Cheetham attending and exhibiting Kaleidocade Indicators Framework (KIF)

IACP 2009 Annual Conference
Denver, CO – October 3 – 7
Robert Cheetham and Sean McGinnis exhibiting HunchLab at the ESRI Pavilion

International Economic Development Council 2009 Annual Conference
Reno, NV – October 4 – 7
Rachel Cheetham-Richard and Tamara Manik-Perlman exhibiting DecisionTree at the ESRI Pavilion

Global Creative Economy Convergence Summit
Philadelphia, PA – October 5
Aaron Ogle presenting Walkshed in a pecha kucha session.

ESRI Mid-Atlantic User Conference
Philadelphia, PA – December 9
We’ve submitted some abstracts, but aren’t sure what we’re presenting.  It’ll be good, though.