Tuesday, July 28, 2009

software engineering is really about programming avoidance

just reading the very amusing "Head First Design Patterns" book by Freeman&Freeman (freemen) _ basically, as far as I can tell, all of software engienening is about deferred gratification, or in other words, putting off the real work as long as possible - i.e. avoiding programming if it costs you the earth...

this means that by definition we should never ever ever teach Software Engineeing
becuase no-one learning it would ever do any programming, and so they'd never know why you need software engineering (doh)

maybe we need a new OO paradigm called Manana - the ultimate in late binding...

meanwhile, I am trying out this excellent book on python programming on an 11 year old kid in my house - he's on chapter 3 in 1 day...awesome!

Thursday, July 23, 2009

epidemics....how the swine flu should roll out, and back again

so the beeb reports 100,000 people have h1n1, mainly in under 14s.

Schools finished last friday, i.e. 6 days ago, and in the younger age group, people are infections for 2 days more (7 days), and shed virus thru skin (i.e. touching) - assume most these kids are in families of 4 on average, one would expect all those in the family to be infected during this period too (but not necessarily displaying symptoms just yet), which means an underestimate by *4 - i.e. 400,000. assume most these people are infected last weekend (when kids came home from school and socialised most) and then went to work as normal monday - they would infect (but with lower probability) a fraction of the people they socialise with (on average a person's social group is 150 - this is in physical world, people in family, friends and colleagues) - say per day they infect 1% - i.e 1 person - by end of the week (tomorrow) you'd expect to see the number grow * 7 - ie. 2.8M. This weekend, the rest of the family (except the, curiously, and luckily, mainly immune grannies and grandpas) get it and nex week, those 2.8M infect around 7* more, i.e. 21M

so I'd predict the epidemic peaks with 1/2 the population infected by mid august, but then as everyone who's had i is now immune (we hope) form re-infection, the faction still infectious is decreasing, and the faction not yet infected is decreasing, so the rate should fall fairly fast til september...

that's my 2 cents.

oh, background - i'm using handwavy approcximation to the SIR model (good for pandemics over large numbers) - see
wikipedia entry for SIR for more details

dI = [ beta * I * S ] - [R * I]

where beta is contact rate (we meet that many people a day)
I is number infected so far
and S is susecptability
and R is recover rate

so in discrete terms, with a 1 day step
taking beta as 4 and S as 1/3
and R 1/4 (recovery time as 7 days)
I grows at nearly doubling per day until we hit about 1/2... as per above
and this then starts to fall....

Wednesday, July 15, 2009

3 startup ideas and one visual metaphor

1. using contact graphs (as per haggle project) do a
startup - basically find out what true
hubs and clique, and flow of info between them is
and comapre to company's "pretend" org chart:)

2. pedagogoc virtual machines (aka tinyxen) - so we need to teach people about
multicore and h/w support for virtualising (core/thread, memory, I/O) and OS tasks that use this - so we need a small (like linux was origianly, or xen was or minix or xinu)
system (both a multicore arm and a multucore VM) to teach people from - sort of the henessy&patterson h/w: s/w interface book, but most of that concentrates on what the interface between programming lanagauges (stack/procedure call) and h/w - now we need it for microkernels and OSs etc

3. a business model process for managing the Techncail Intercept window - this is the time that it is best to try spinning an idea out - we were discussing internet food shoping yesterday and remembered a US failed startup a few years back that tried to do an Ocado - just a few years before there were enough broadband accustomed customers to make it make sense...so how tdo you find the ideal window?
(say from inception to boringiness is 20 years and there's roughly a 5 year gap in that 20 years when there might be a 1 ear opportunity to get things first, but not too soon.....optimise!)

FInally, it'd be neat to have a "bad idea crime scene investigations" toolkit - we could carry away the broken ideas in body bags, leaving a chalk outline on the lab floor and pieces of string where the bullets flew....

Sunday, July 12, 2009

greening the internet/computing

is a bit naive - take a look at
gavin schmidt's rather more holistic and complex view of the type of things we need to consider about models and the future in general

Recent CL proposal successes

so we've been sucessful in two EPSRC proposals - one is we are part of the Nottingham run hub in gdigital economy called Horizon - this is mostly about new business models (e.g. advertising) in pervasive computing - the other is an ordinary project in secure by design federating of sensor nets, called Fresnel, collaborating with folks in Oxford (OII and Computing) - each entails 2 post docs and soem PhDs - adverts will appear shortly on the CL normal vacancies page