Category: General

Project GreenFire mentioned on Java Posse

On a recent episode of The Java Posse they mentioned a project I had never heard about before: project GreenFire.

From the project’s website:

GreenFire efficient manages and controls heating control of houses and saves energy. GreenFire is based on Java EE 5 (is tested with Glassfish v2), Scripting, RMI and Shoal. SunSpot integration is planed.

I applaude the effort to create a J2EE-based solution to cheap and efficient home automation. I’ve often felt that home automation was, and still is, the domain of do-it-yourselfers, with its attendant reliability problems. Running a home automation solution on a J2EE stack might solve many of these problems.

In short, kudos to the creator(s) of this project, I’ll definitely keep an eye on what you are doing.

Posted on by David Lindelöf

Enjoying a NO energy home

There’s a nice little article about green energy homes over at Greenprofs.com. The author makes a nice point that home owners have many options when it comes to choosing carbon-neutral energy sources: he mentions solar, wind and even hydroelectric power. I cannot help but submit, respectfully, that this article completely misses the point.

There are, conventionally, five different sources of energy, four of which are carbon-neutral and only three of which can be said to be completely renewable:

But, as Thomas L. Friedman mentioned in his excellent Hot, Flat and Crowded (see my review here), there is a sixth energy source: the energy that we do not use.

And the key challenge we face as a race for the next century or so is to shift our energy consumption patterns more and more towards that sixth source, instead of trying to draw more and more energy from the four carbon-neutral ones.

We have the technology and we have the means, particularly when it comes to the energy needs of homes and buildings; it is only a question of bringing those possibilities to the global awareness, instead of letting people believe they will eventually be able to simple replace all coal-powered plants with wind mills.

Posted on by David Lindelöf

Software Engineering Radio

People often ask me what podcasts I regularly listen to. Well there are many of them and I won’t enumerate them all here, but I wanted to mention one that I listen to almost every day nowadays.

Markus Voelter started Software Engineering Radio in January 2006. As he describes it on the website, this podcast tries to be a lasting educational resource and not a newscast. You won’t find new product announcements, no tech news of any kind. Only tutorials, interviews, and discussions about specific software-engineering topics.

When I discovered this podcast, about one year ago, I quickly downloaded just the episodes that appeared to be the most relevant to my work. But I found that almost all episodes had something in there for me. For example, recently I listened to the episode on real-time systems, a field I do not work in anymore. Well, at one point the interviewee discussed how jobs were scheduled in certain real-time systems, trying to optimize the total value or utility of the work done by choosing which tasks to perform and which to let slip past their deadlines. And that got me thinking about the Scrum planning process, when the Scrumaster selects, for the upcoming sprint, items from the product backlog in decreasing order of importance until the total estimated time fills up the scrum duration.

Now imagine for a minute that we could get the product owner to assign utility values to each product backlog item. Then instead of selecting product backlog items in decreasing order of importance, we could apply the same kind of decision process and optimize the utility created by each sprint.

(Later that day I went to the library to research this topic but all I found was an exercise from the classic Introduction to Algorithms in which the reader is asked to optimize such a job schedule. The chapter in question was the one about Dynamic Programming, in case anyone is interested.)

Anyway, back to SE-Radio. I’ve found the episodes’ quality range from good to very good, covering a broad range of topics. Perhaps they could be slightly improved with a little bit more structure, and also if the interviewer would stop regularly interrupting the guests with their own opinions. Sound quality has been an issue in the early days (ONE episode in particular was literally painful to listen to—I won’t say which one) but now it’s much, much better.

These days I listen to at least one episode a day, my goal being to listen to all of them. I can really recommend it.

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Posted on by David Lindelöf