The latest outputs from researchers, alumni and friends at the UCL Centre for Advanced Spatial Analysis (CASA).
For a while now, I have been working on the application of the OPTICS clustering, for user generated data in cities. OPTICS is a density-based algorithm that attempts to overcome some of the “weaknesses” of its most famous counterpart: DBSCAN. … Continue reading →
Recently I have been looking into different algorithms for the clustering geospatial data. The problem of finding “similar” regions in space, is a very interesting one, since this type of classification enables a whole range of applications (e.g.: urban development, … Continue reading →
I recently implemented an authentication system, supported by a table on the database. In this table, I store the usernames and passwords. The PostgreSQL “pgcrypto” module supports encryption of specific columns, but I wanted to avoid “bulking” my system with … Continue reading →
A while ago, I wrote a post about multi-master replication using symmetricDS. My scenario consists of a system with multiple nodes, all of them writing in their copies of the database. Sometimes the nodes may be offline, but I would … Continue reading →