Error correcting codes (by alaric)

I've just finished reading A Commonsense Approach to the Theory of Error-Correcting Codes. The book does exactly what it says on the tin; it explains error correcting codes in terms of linear modulo-2 algebra, only getting into Galois fields and all that in an appendix.

And, as such, it does little more than scratch the surface. It only goes into Reed-Solomon codes that can correct single word errors, for example. But hey, I'm not complaining - it's done a great job of giving me an intuitive understanding of Hamming codes, cyclic codes (such as CRCs), the single-word-correcting RS codes, and so on. And I've learnt a lot about Linear feedback shift registers.

But it strikes me that the whole field of error correcting code is a bit insular. The maths required to really grasp it are really complex. Finite fields are bizarre things. While lots of people can experiment with things like data compression or basic encryption, error correction codes, the third cornerstone of low-level coding technology, is quite inscrutable.

This sucks.

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Derren Brown at Southend (by sarah)

Tuesaday saw numero-uno of my friend Clares Birthday celebrations and so we headed off to South end (of all places) to see Derren Brown. We saw him in London about two years ago when I was still on the crutches - I got hit by a monky that time so Clare got to go up on stage and win £50 off of him which was fantasmigorical as you can imagine.

This time none of us made it onto the stage but the show was fantastic! What with gorrilaz and a truelly spectacular Oricle show that had me wowing - he does he do it? Clare almost took out half the threater with her egerness to put a question in his pot! We really enjoyed the show 🙂

However the pre-show meal was a bit of a disastor, they just took too long to bring it out and got the order wronge and in one case brought out something that was inedible ie Lianes cake could smash plates! They are the resturant in the theatre so you'd have thought they would have been better but no we had to leave half our desserts and had no coffee (which was all part of the set meal) and we only just got in for the beginning of the show.

Also poor Al had to do a bit of a marathon to get to us for the meal which he should have been late for but becuase of how they where being we had bearly ordered! Still us girls had a nice wonder around the place and as me and Lianne are obessed with taking photos and neither of us had a camera Clares new camera was getting a good old try out. I'm hoping to see them soon so I can post them up on here 🙂

Tonight sees round two of the celebrations - Karyoky mucho mucho fun 🙂

The Castle – The Return of Sarah (by sarah)

Yesturday I went to the Castle climbing centre I was cery nervous as I didn't know if I would even be able to get up onto the bouldering walls from the floor, nor how the pelvis would react to such an activity.

I haven't attempted climbing since the day after our wedding, sure we've taken the scouts climbing a few times but with Jean being there and time constraints etc... we have never managed to have a little climb at such events. I was excited and worried and then too my suprise my body sort of remebered things though I was still pretty dreadful!

First off I refused to try things until we found a stretch of relatively flattish wall with like no one else around using it. I pulled myself onto it and intially had the problem that I always want to go up but once I realised I was supposed to go along thats what I did. Being me though I got a bit confused as there where too many hand holds and foots holds so the first time I went along the wall I just used what ever was handy then Al showed me that the different colours where different hardnesses of route so I did the 4a holds which are basically the easiest and then had a little go at the black holds later on but had to give up with trying them as pelvis had gone click.

My pelvis actually with stood me falling off onto crash matts whilst trying to navagate a tricky corner - Al tended to fall off at this point too. This was in the bit behind the protrusions they've called envy and lust. I did alot of trying to climb round the pink one of those too, again just using any old hand holds! Al said lots of girls tend to climb on that one becuase it is pink - I thumped him. He on the other hand was obessed with getting around using the wooden hand and foot holds on Envy which are apparently 4a's aswell though he had to stretch to do them so I don't know how I could manage them.

I managed another horizontal stretch of boldering wall but alas I tried to do a specific route and basically stretched too wide with my legs resulting in pelvis click. It didn't hurt but I know from bitter experience that once it has clicked it is very easy to make to properlly mobile and therefore painfull once more so I did the thing I find the hardest to do and stopped.

We had a sandwitch in the cafe place and then went back - I was sort of optomistically hoping the pelvis would have settled down but it hadn't so I just helped Al for our second half showing him where the holds where and sorting out the slight issue of why he was getting so breathless whilst climbing - to wit - he was concentrating so hard he was holding his breath and trying to wizz around the bolder before oxygen deprivation got him!

The after math today is that I have slightly acted up the pelvis but my disc (which I acted up on Wednesday probably as I didn't do my normal amount of daily wallking as I had acted up my knee on Monday by us walking from Angel to Highgate) feels alot better and my shoulder has so far really behaved itself much to my joy :). This makes me really happy as I really miss doing all the climbing and stuff and it makes me feel more like me 🙂

Hyper = non-linear (by sarah)

I have decided that html which conforms to those standard thingies is the equivolent to the plasmids or little circular bits of DNA that bacteria and microorangisms in general expell which can be taken up and incorporated into other organisms either of the some or different species, phylum and some times even kingdoms.

I'm getting a little confused with URLs here and feel that they should somehow fit into this analogy but that might involve re-reading the chapter I've just read again and I dont really want to do that - oh the folly of reading a book on HTML and CSS straight after finishing on on early life and the evolution of life. I think I might have been thinking about links as well and exactly how they are hyper - websites etc... are non-linear and organisms can share DNA across Kingdoms and even take it up from things that have died leading to non-linear evolution - erm.... my heads hurting now.

This post is complete waffle please ignore it.

My Favourite Film (by sarah)

I saw a film a long time ago when I was in my early teens that had me tingling and longing to watch it again, I have always mantained that it was my favourite film but have been unable to track it down and no one has ever heard of it. I had begin to think that I had imagined its existance and yet it seemed quiet odd and seemed like it should be known. In researching wikipedia links for yesturdays posts I think I have found it!

I remebered it as being called Angel Eggs Apocolypse, what I remebered of it was that it was about a girl who has an egg that is really human dreams and that she was gaurding it and wasn't allowed to sleep, her older brother appears but she doesnt realise that thats what he is and he tries to guide her through her task. She has to learn to become an angel like him.

But he tells her a story about these sky whales that used to swim in the sky of a world but their song was so buetiful and lovely that they where hunted to extinction and then their world was sad. The girl falls asleep and then her brother smashes her egg.

She awakes and is disturbed by its distruction but the brother is the angel of second chances so she falls into our world, the world where she will be a propper angel and eggs appear as he is the angel of second chances.

Now this isnt exactly what wikipedia says on this, what I was doing was I was looking up surrealism after linking it to the Bruge post when I spotted Angel's Egg amoungst the writting. I have been hunting for reference to this film outside of my head for so long now that it just sort of jumped off the page. So I looked at it and its so similiar that maybe I just remembered it wronge - it was along time ago - it turns out to be symbolic of apocolypse and re-birth which is interesting but they say she dies at the end where I though she was falling into a new world - not sure why I should have thought that. But still it does mean I can now track it down and watch it again.