K-means test in Octave

Matlab comes with K-means clustering ‘out of the box’. The GNU Octave work-a-like system doesn’t, and there seem to be quite a few implementations floating around. I picked the first from Google, pretty carelessly, saving as myKmeans.m. These are notes from trying to reproduce this Matlab demo with Octave. Not rocket science but worth writing […]

Querying Linked GeoData with R SPARQL client

Assuming you already have the R statistics toolkit installed, this should be easy. Install Willem van Hage‘s R SPARQL client. I followed the instructions and it worked, although I had to also install the XML library, which was compiled and installed when I typed install.packages(“XML“, repos = “http://www.omegahat.org/R“) ‘ within the R interpreter. Yesterday I set […]

Exploring Linked Data with Gremlin

Gremlin is a free Java/Groovy system for traversing graphs, including but not limited to RDF. This post is based on example code from Marko Rodriguez (@twarko) and the Gremlin wiki and mailing list. The test run below goes pretty slowly when run with 4 or 5 loops, since it uses the Web as its database, via […]

Video Linking: Archives and Encyclopedias

This is a quick visual teaser for some archive.org-related work I’m doing with NoTube colleagues, and a collaboration with Kingsley Idehen on navigating it. In NoTube we are trying to match people and TV content by using rich linked data representations of both. I love Archive.org and with their help have crawled an experimental subset […]

A Penny for your thoughts: New Year wishes from mechanical turkers

I wanted to learn more about Amazon’s Mechanical Turk service (wikipedia), and perhaps also figure out how I feel about it. Named after a historical faked chess-playing machine, it uses the Web to allow people around the world to work on short low-pay ‘micro-tasks’. It’s a disturbing capitalist fantasy come true, echoing Frederick Taylor’s ‘Scientific […]

XMPP untethered – serverless messaging in the core?

In the XMPP session at last february’s FOSDEM I gave a brief demo of some NoTube work on how TV-style remote controls might look with XMPP providing their communication link. For the TV part, I showed Boxee, with a tiny Python script exposing some of its localhost HTTP API to the wider network via XMPP. […]

How to tell you’re living in the future: bacterial computers, HTML and RDF

Clue no.1. Papers like “Solving a Hamiltonian Path Problem with a bacterial computer” barely raise an eyebrow. Clue no.2. Undergraduates did most of the work. And the clincher, … Clue no.3. The paper is shared nicely in the Web, using HTML, Creative Commons document license, and useful RDF can be found nearby. From those-crazy-eggheads dept, […]

‘Republic of Letters’ in R / Custom Widgets for Second Screen TV navigation trails

As ever, I write one post that perhaps should’ve been two. This is about the use and linking of datasets that aid ‘second screen’ (smartphone, tablet) TV remotes, and it takes as a quick example a navigation widget and underlying dataset that show us how we might expect to navigate TV archives, in some future […]

Lonclass and RDF

Lonclass is one of the BBC’s in-house classification systems – the “London classification”. I’ve had the privilege of investigating lonclass within the NoTube project. It’s not currently public, but much of what I say here is also applicable to the Universal Decimal Classification (UDC) system upon which it was based. UDC is also not fully […]

Disambiguating with DBpedia

Sketchy notes. Say you’re looking for an identifier for something, and you know it’s a company/organization, and you have a label “Woolworths”. What can be done to choose amongst the results we find in DBpedia for this crude query? PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> select distinct ?x where { ?x a <http://dbpedia.org/ontology/Organisation>;  rdfs:label ?l . FILTER(REGEX(?l, “Woolworths*”)). […]

Easier in RDFa: multiple types and the influence of syntax on semantics

RDF is defined as an abstract data model, plus a collection of practical notations for exchanging RDF descriptions (eg. RDF/XML, RDFa, Turtle/N3). In theory, your data modelling activities are conducted in splendid isolation from the sleazy details of each syntax. RDF vocabularies define classes of thing, and various types of property/relationship that link those things. […]

Archive.org TV metadata howto

The  following is composed from answers kindly supplied by Hank Bromley, Karen Coyle, George Oates, and Alexis Rossi from the archive.org team. I have mixed together various helpful replies and retro-fitted them to a howto/faq style summary. I asked about APIs and data access for descriptions of the many and varied videos in Archive.org. This guide should […]

Subject classification and Statistics

Subject classification and statistics share some common problems. This post takes a small example discussed at this week’s ODaF event on “Semantic Statistics” in Tilberg, and explores its expression coded in the Universal Decimal Classification (UDC). UDC supports faceted description, providing an abstract grammar allowing sentence-like subject descriptions to be composed from the “raw materials” defined […]

RDFa in Drupal 7: last call for feedback before alpha release

Stéphane has just posted a call for feedback on the Drupal 7 RDFa design, before the first official alpha release. First reaction above all, is that this is great news! Very happy to see this work maturing. I’ve tried to quickly suggest some tweaks to the vocab, by hacking his diagram in photoshop. All it […]