Month: January 2013
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McMillian’s inequality
Kraft’s inequality states that: There is an instantaneous -ary code with word lengths if and only if : But what of codes that are merely uniquely decodable, and not necessarily instantaneous? There number is given to us by McMillian’s inequality and the surprising thing is that, despite the looser bound this is: There is a […]
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Kraft’s inequality
Getting round to re-reading Information and Coding Theory– in physical form after the disappointment of the Kindle edition. Maybe it’s because I’m six months older and wiser, but this time more determined to grasp more of the maths in the book, so came to a basic precept of coding theory – Kraft’s inequality – which […]
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Gamma ray bursts are not that rare
Yesterday it was reported that scientists have suggested that an anomalous peak in radioactive materials discovered in antarctic ice sediments and in ancient Japanese cedar trees could be explained by a gamma ray burst hitting the Earth in the 8th century CE. The BBC radio report I head described gamma ray bursts as “extremely rare” and the […]
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After “comment spam”, comes “like spam”
Maybe if I had a blog that was visited by tens of thousands every day and on which hundreds wanted to comment it would not be so easy, but “comment spam” is not a problem here – anything which the algorithmic spam filter does not pick up can be chucked out by hand. But in […]
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Summing an infinite series
I dare say what I am about to write is no great revelation and indeed I was probably taught this for ‘A’ level maths, but forgot it… Anyway, I was reading about the Fast Fourier Transform (FFT), which, discovered in the 1960s, radically improved the speed of signal analysis. Older algorithms had been able to […]
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I have another blog
Decided I wanted to write about the books I read, even if they are not (computer) science related – so Not Computer Science Related
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We lost more than our record shops because of the MP3
Today HMV, once His Master’s Voice and still one of the UK’s leading retailers of CDs and DVDs, went into administration (one step away from going bust). Hopes are high that at least some of the shops can be saved – not least because the record labels and the DVD manufacturers want something that will […]
cartesian product ... stuff about computing mostly 