Archive for September, 2007

Zotero / Endnote / Bibtex

Zotero is just brilliant for collecting references where you search for them – in your browser. But I’m having issues with conversion to and from Endnote and Bibtex.

Issue#1: When Endnote imports, no matter which format you choose, fields are lost. Some formats seem better than others – RIS at least captures the journal name!

Issue#2: Zotero creates its own labels for its Bibtex export. This is ok in and of itself, but Endnote does not pick these labels up (and Endnote does not have a simple Bibtex import…

I’m working hard at making the full switch to Zotero (and this will include a long session, that I have been putting off, in which I rewrite all my citations to use the Zotero version of the Bibtex label). The only thing that really bugs me at the moment is not being able to edit the Bibtex label.

Leave a Comment

Octave 2.9 for Windows

As always I’m a few months behind the upgrade curve.

Octave 2.9 for Windows has been out for a couple of months. You can’t imagine how frustrating it was working with 2.1 on this windows box at work, while being able to use all the shiny new features at home.

Leave a Comment

Green myths

Dominic Kennedy at Times online has written that Walking to the shops ‘damages planet more than going by car’

The article is centred around the energy cost of food production. I’m increasingly convinced that energy efficiency, and even the development of cleaner energy sources, is just too little, or too much of a long term proposition.

In Climate change and trace gases Hansen et al suggest that due to the possibility of rapid approach to a tipping point (and I would add also the implausibility of stabilising emissions) carbon scrubbing technologies are urgently required.

Comments (2)

On the use of machines

Midnight Notes was an obscure radical publication published int he 70s. One of the pieces that impressed me greatly was title “Prologue: On the use of Machines”.

Its thesis, roughly, was that the development of the steam engine (and its expression in physics, the field of classical thermodynamics) was associated with a redifinition of human labour, by and large, as “work equivalent to the work of a heat engine”. The development of computing machines, and its theoretical expression, Shannon’s information theory, was associated with a defintion of work as “work equivalent to the work of a computing machine”, and linked with the rise of the information work sector (think typists, computer programmers, etc).

Interesting stuff – it’s a while since I read it, from what I remember the maths was light on, but it struck me as a fascinating attempt to link thermodynamics, labour economics, and information theory.

What made me think of it was stumbling across the Amazon Mechanical Turk site. Here you have menial informational work by humans being harnessed as part of a computational engine. I can’t help but think of The Matrix, or comparing it with piecework textile workers stiching hems for 20c each at home.

Related – Farming out work in second life

Leave a Comment

RSA is obsolete

A preprint by White, James, Williams et al (names chosen randomly), some of whom hail from the Centre for Quantum Computing Technology at the Univeristy of Queensland have made groundbreaking progress in the effort to build a quantum computer capable of implementing Shor’s algorithm, and thus defeating the security of the most popular forms of data encryption.

The most common form of public key encryption used today is RSA (Rivest, Shamir, and A…something), which relies on the difficulty of factorising large numbers into their prime factors. More precisely, it is widely believed that the prime factorisation is not possible in polynomial time. RSA is the algorithm behind PGP (Pretty Good Privacy). Modern data security depends on the difficulty of this problem.

Now, Shor’s algorithm is a quantum algorithm for factorisation. It is accepted that, if a quantum computer existed, Shor’s algorithm could factorise numbers into their prime factors in polynomial time.

Willams et al haven’t done this, yet. But they have made significant progress in demonstrating that it is possible. This has major implications for data security. Why else would their work be partially funded by the US Disruptive Technologies office? New Scientist are right when they say that this will have profound implications.

Leave a Comment

Honey keeps rats young


New scientist reports that honey has been shown to decrease anxiety and increase memory in rats

Awesome news. I read a report somewhere last week of honey having antibiotic (antibacterial?) properties, too. I love it when I find evidence that my favourite foods are also good for me.

Leave a Comment

Still intrigued by algae

Tad Patzek says biofuels are simply incapable of supplying current energy usage.

Krassen Dimitrov says algae is simply not commericially viable, and won’t be until oil is over $800 a barrell. I’m not sure how much credibility to give him though – he only talks about Greenfuel, and aside from a few very specific remarks about the Greenfuel patent, his criticisms are economic, not thermodynamic. He is also extremely light on with further sources and references.

A nice overview of research on the issue in the states is A Look Back at the US Department of Energy’s Aquatic Species Program: Biodiesel from Algae by J Sheehan, T Dunahay, J Benemann, P Roessler – Aqua KE Aquaculture Documents Library – Island Press. It’s publicly available via Google Scholar. Their estimate of the best possible price for algae derived fuel was double that of petroleum.

I’m still not convinced algae is not viable, particularly when there are solutions that accomplish multiple goals. See for example this New Zealand example of producing fuel from algae in sewage. We already need to process sewage – is viable to extract fuel, and perhaps sequester the leftover unusable carbon, from shit? How far will my piece of shit car run on a piece of shit anyway?

What if I bring my dogs into the picture – they produce roughly a kilogram or two of faecal matter a day. How awesome would it be if this incredibly nasty urban pollutant became a fuel source. The company doing this is Aquaflow Bionomic.

Andrew Leonard at Salon writes about this topic frequently.

And lastly, the title of this one says it all An in depth look at biofuels from algae.

Leave a Comment

Older Posts »