VMWare Fusion - Reusing Core Ubuntu Install

When testing out new software, Monodevelop this week, I want to keep my daily Ubuntu VMWare guest clean until I decide if I'll use the new tool or not so I use a separate install. I don't want to keep so many Ubuntu installs around so cloning/disk reuse is interesting. I found a good article explaining how to build a core Ubuntu OS and then extend it. Basically, you create a core OS install guest, then share its disk with other testing guests after taking a snapshot in the other testing guest. Taking a snapshot keeps the core disk unwritable.... nice.

Spotify, Airport and Airfoil - Free Web music on my Stereo

Spotify is free in UK now, with ads every few songs but not too bad, or you can pay a bit. It has a great collection of free music - well worth a look.

Combine it with Airfoil and I can stream Web music, or any other audio, to my stereo from my iMac/Airport Extreme.

Active Scaffold and Inheritance

Had a problem getting two cases of single table inheritance to work in ActiveScaffold so thought I'd document it. Package and Classifier are the ActiveRecord classes.

class ExpressSchema 
  has_many :express_entities, :foreign_key => 'package_id'
end

class ExpressEntity 
  belongs_to :express_schema, :class_name => 'ExpressSchema', 
        :foreign_key => 'package_id'
end

YUML Me for Putting UML on Web

Found a very nice little tool called yUML me for putting UML Use Case and Class figures into your blog or other Web pages.

Semantics For and From Information Models

I gave a presentation at the OMG Semantic Information Day on Thursday of last week. My presentation was actually called Semantics For and From Information Models and was about the use of W3C OWL to add semantics to data exchanges using XML and a follow-on project from NIST with a goal of pushing the STEP community towards semantics/ontologies as a core modeling technology.

The presentations will all be made available online and I'll update this post when they're available.

Demos with Rails, Hobo, ActiveScaffold

Continuing to play with doing demos of engineering applications using Ruby on Rails, and in particular the Hobo and ActiveScaffold frameworks that sit on top of Rails. Hobo is nice as long as you have a fairly simple set of concepts to handle. ActiveScaffold is more flexible, but is also a bit more work (e.g. Hobo builds in users/password where you have to add it to ActiveScaffold yourself).

Used ActiveScaffold on one "real" project at for work, which was just a prototype though, with around 30 concepts in the model and it worked out OK. Still some limitations though. It was the front end for a rules engine (jRules from iLog which was recently bought by IBM) so was an interesting architeture. We had to update the data tables from both the Rails GUI and from Hiberbate from the Java accessing jRules. Oracle Express was the database, which poses some problems of its own (e.g. date support is problematic).

INCOSE Activties with SysML and AP233

A bit of work news ...

At INCOSE over the weekend a workshop was held to start mapping the OMG SysML and ISO AP233 standards together. There's an OMG wiki to track progress. Here's an example SysML diagram: