Abstract: As location-aware applications and location-based services continue to increase in popularity, data sources describing a range of dynamic processes occurring in near real-time over multiple spatial and temporal scales are becoming the norm. At the same time, existing frame- works useful for understanding these dynamic spatio-temporal data, such as time geography, are unable to scale to the high volume, velocity, and variety of these emerging data sources. In this paper, we introduce a com- putational framework that turns time geography into a scalable analysis tool that can handle large and rapidly changing datasets. The Hierar- chical Prism Tree (HPT) is a dynamic data structure for fast queries on spatio-temporal objects based on time geographic principles and theories, which takes advantage of recent advances in moving object databases and computer graphics. We demonstrate the utility of our proposed HPT us- ing two common time geography tasks (finding similar trajectories and mapping potential space-time interactions), taking advantage of open data on space-time vehicle emissions from the EnviroCar platform.
I knew that Uber drivers do not make a terrible lot of money, but this breakdown shows how bad the situation really is for them. If you factor in all costs, drivers are getting ripped off to the point where they are actually losing money when they drive for Uber. So much for the ethics of the self-proclaimed sharing economy.
I just hope the old school taxi cab companies will eventually get their act together and make it as easy to order a cab as Uber does.
Our proposal for the next (6th!) Linked Science workshop at ISWC has been accepted. Our theme this year is “Supporting collaboration and learning in e-research infrastructures” to help diminish the knowledge gap between technologists and those less tech-savvy. Here’s the gist of it, head over to linkedscience.org for the full announcement:
This film was made mining the Thomas Jefferson’s Grid in Google Earth. By superimposing a rectangular grid on the earth surface, a grid built from exact square miles, the spherical deviations have to be fixed. After all, the grid has only two dimensions. The north-south boundaries in the grid are on the lines of longitude, which converge to the north. The roads that follow these boundaries must dogleg every twenty-four miles to counter the diminishing distances: Grid Corrections
Interesting read about what can happen if you use a technology – IP addresses in this case – for something completely different than it was meant to:
For the last decade, Taylor and her renters have been visited by all kinds of mysterious trouble. They’ve been accused of being identity thieves, spammers, scammers and fraudsters. They’ve gotten visited by FBI agents, federal marshals, IRS collectors, ambulances searching for suicidal veterans, and police officers searching for runaway children. They’ve found people scrounging around in their barn. The renters have been doxxed, their names and addresses posted on the internet by vigilantes. Once, someone left a broken toilet in the driveway as a strange, indefinite threat.
The title is a little bit misleading – it’s not really a mapping glitch, but I can see how using IP-based geocoding in the title would turn most readers away without even reading the first sentence of the article.
The successful candidate must have a strong commitment to both undergraduate and graduate teaching and be prepared to teach graduate level Introduction to Geographic Information Systems and Introduction to Geographic Information Science; combined graduate and undergraduate level Advanced GeoInformatics and a special topics course in the candidate’s area of focus (for a total of 3 courses per semester). It is expected that the successful candidate will also mentor a small group of undergraduate and graduate students over the course of the academic year. Candidates must have a PhD in Geography or a related discipline. The Department of Geography has a suite of geospatial software and dedicated lab facilities, and approximately 150 undergraduate majors and 50 MA/GIS Certificate students.
Applicants should submit via email a cover letter, curriculum vitae, statement of teaching interests, copies of or links to up to three publications, contact information for three references, and any questions to firstname.lastname@example.org. Review of applications will begin March 18, 2016 and continue until the position is filled.
CUNY encourages people with disabilities, minorities, veterans and women to apply. At CUNY, Italian Americans are also included among our protected groups. Applicants and employees will not be discriminated against on the basis of any legally protected category, including sexual orientation or gender identity. EEO/AA/Vet/Disability Employer.
I’ll be offering the one-week professional training course on Open Source GIS again through Hunter College Continuing Education. It will be running from January 25–29, 2016. We have changed the content of the course a bit, so that each day is a self-contained unit, and participants can book individual days if they are only interested in specific topics – or book the full week to get the full FOSS GIS treatment. This is the schedule:
Monday: QGIS. Hands-on introduction to the most popular FOSS desktop GIS, covering setup, data management, spatial analysis, map design, digitizing, the plugin ecosystem, and integration with other FOSS GIS software.
Tuesday: PostGIS. Introduction to the spatial extension to the popular PostgreSQL database. Participants will learn how to set up and use PostGIS as the central data storage in their GIS software stack, how to connect it to other software, and how to query the database using SQL.
Wednesday: Geospatial Python. General introduction to the Python programming language with a specific focus on its capabilities for processing and analyzing geographic information, including automating GIS workflows, raster and vector data processing, and geocoding.
Friday: Web Services. Introduction to Geospatial web services including OGC services such as the Web Map Service and the Web Feature Service, as well as tile services that deliver base maps for interactive web maps. Participants will learn how these different kinds of web services work and practice how to set up and configure different kinds of web services.