Thursday, December 31, 2009

cloud computing is so noughties

now we are in the pre-teen era of the 21st century,
we should concentrate on Blue Sky research...

no more sensor nets (wastes batteries - very unsistainably)

no more MANETs (dont work)

no more opportunistic or p2p networks (capitalism is so much better than anarchy)

no more economics + computing (computing is dismal enough without addign an entire dismal other "science" to it)

no more green computing (the answer is 1 bit - turn it off:)

Friday, November 27, 2009

Digital Communications II Progress by 27.11.2009

QoS, Int-serv, Diff-serv, RSVP, and Traffic Engineering.
Last lecture, monday, 30 nov. wrapup.

Thursday, November 26, 2009

trying to understand the world of 2009

just went through what I read in trying to get a handle on just what is going on in 2009 - see
my 2009 reading list - note this is not compelte - i've only listed things I liked:)

Friday, November 20, 2009

Friday, November 13, 2009 Digital Communications II Progress by 20.11.2009

Switching & Sharing done now

next week - intserv, diffser, traffic

Friday, November 13, 2009

Digital Communications II Progress by 13.11.200

Friday 13th - we havn't got quite as far as I thought - so we've done Scheduling (and Queue Management), and made a start on Switching.

Next week, must finish switching AND do contention networks.

Friday, November 06, 2009

Digital Communications II Progress by 6.11.2009

This week, should have finished
error control (sequence numbers, retransmit/rtt timer estimation)
flow control (at least intro to open&closed loop)

as with last week (routing)
these topics come up in exam questions frequently.

Wednesday, October 28, 2009

Digital Communications II Progress by 1.11.2009

This week I'm doing routing - I've updated the material so please check the new version of slides - DAR + DV/LS is a bit tidier (I hope) but if you spot errata, let me know!

lots of stuff for supervisions and exam questions now.

Friday, October 23, 2009

Digital Communications II Progress by 23.10.2009

We have now covered the material in Section Two of the course

Part 2 - Philosphy/Design

Systems, lecture 5
Layering, lecture 6
Implementation, lecture 7
Alphabet Soup, lecture 8

So I talked about user land and kernel implementations, concurrency and OS problems, and finally about what IP and TCP (and ICMP packets look like

A very nice reference for this last bit is W RIch Steven's fine books
TCP/IP Illustrated volumes 1 (operations of protocols) and 2 (walkthru of code!)

Thursday, October 15, 2009

Digital Communications II Progress by 16.10.2009

By the end of this week, I will have covered the historical review of
telephone nets (circuit switched, voice networks), basic Internet technology (packet switched, datagram networks) reminders, and the comparison with B-ISDN and Asynchronous Transfer Mode (Cell Switched, virtual circuit) Networks.

From Monday 19th, til end of next week, I'll be covering
systems design in general, layered protocol designs, specifically, a quick
overview of different implementation strategies, and then a very quick tour through the immensely thick alphabet soup of protocols - all of Part II (hopefully!) on

Wednesday, September 30, 2009

google wave

bbc article about google wave says "how e-mail would look if it were invented today" - actually it looks how Lotus Notes looked about 20 years ago.

what a lot of people using cr**ppy internet email today don't realize is that early systems for collaboration (Notes, but even Microsoft Exchange) started from a model of sharing documents and sharing editing of documents, and included facilities for managing groups, instant comment/annotation, privacy controls, and multimedia, and predate most of the internet wave of stuff - its amusing that google can rely on the lack of colective memory of the past, and claim they are inventing the future, when really all they've done is re-package an old old old idea (vanevar bush, rip, c.f.)

indeed, the backend for early systems like notes was a database, which meant search/index was optimised already so its even closer to google than you think...

Sunday, September 27, 2009

foundational computer science research "at risk"

we had a visit from the EPSRC's ICT team last week - for those people who don't know, ICT is Information and Communications Technology, wherein CS (including theory and systems and HCI and all the rest) is lumped alongside radio and optical and other low level engineering things, and is a term favoured by eurocrats who don't see why silos are bad, and incorrectly labelled silos are even worse.

Anyhow during the conversation between computer lab academics and EPSRC it was fairly clear that they didn't think it was important that the top ranked computer science department in the UK (and equal top ranked deparment in cambridge, the top ranked university in europe) currently had no EPSRC (i.e. UK government basic research) funding for its theory faculty.

Someone in the EPSRC is either asleep at the wheel, or else they have become slaves to the blairite mantras of industrial relevance. what they don't seem to get is that if the EPSRC only funds short term "industrial relevant" work, why would we need the EPSRC? we could go to the EU.

What is depressing about their taking the moral low-ground like this is that we wil lstart to go to the European Research Council (ERC) to get money first (i.e. the better places will try that) and this wil lstart a vicious cycle of driving EPSRC funded projects ever more short term, making my projection ever more likely...

the rot must be stopped...

Friday, September 25, 2009

new job title for programmers..

I think we should call them
software artistes
and systems analysts could become
computational magicians

Wednesday, September 23, 2009

patents, monopolies and innovation

I'm just reading Heroes of Invention: Technology, Liberalism and British Identity, 1750-1914, by Christine McLeod (CUP), and was thinking about
why we have patents and market failures

[aside: this was because I attended an excellent workshiop run by the
Centre for Intellectual Property and Information Lawin Cambridge earlier in the week, where we were discussing the nature of the invetor, the invention and the inventive step. ]

The market is supposed to deliver the best for consumer and producer (Adam Smith etc)
but it requires efficient (information rich) competition, Market failures are usually indicated by monopoly behaviour (price hiking) which can include cartels.
Markets are claimed to be good for social welfare...
Innovation is supposed to be protected by patents, and a large patent count is supposed to indicate innovation is happening.
Innovation is supposed to be good for social welfare..

What is happening these days (and was happening in the 1600-1700 period) was a lot of patents and a lot of monopolies or near monopolies. In the 17th century, this was regarded very badly and parliament put big changes in, what is happening is big companies are smarter - by analogy with high functioning autistics, who can emulate empathy by running a purely cognitive model of how they should feel, rather than actually feeling it, large companies run a "model" of how a competing company in a market should behave (as close to the line as they can get away with, occasionally overstepping it) - the idea is exemplified by Cisco, whose CEO has allegedly said that they always want to own the middle 50% of the market - i.e. neither be an innovator, nor truly work in the purely marginal business (bottom feeding?) of cheap and cheerful devices - similar observations could probably be made of microsoft and intel - they
tolerate the existence of low end and very high end, but only when its a small part of the market -
they use this to price as high as possible without appearing to have market failure.

they engage in generating as many patents as possible, as close to the line of
obviousness or inaaplicability as can be allowed, to give the appearance of being innovative without the reality.

this also puts a chill on innovation.

innovation often happens in computing related areas in government sponsored labs (same is often true in bio-medical in fact) and then is "absorbed" magically into these large organisations....typically by hiring of PhDs -

what universities should do is charge a LARGE finders fee for PhDs placed in companies.
what patent offices should do is have a revocation on patents that are not exploited with a VERY large revocation fee. the revocation interval should be set according to aggressive norms of the sector. revoked patents are put in the public domain.

Where do you want your Go To to go to, today, sir?

maybe, we should ask what happened to the "Come From" idea? is this google?

Thursday, September 17, 2009

why is #storm >> #planetlab

so if I wanted to develop an internet scale ap, why wouldn't I buy time on storm instead of Amazon EC2 or planetlab? eh? eh?

Wednesday, September 16, 2009

cloud idea for future privacy architecture work

two areas (not unrelated) people want to do better security (both privacy and access control) are
1. social networks
2. cloud computing

I'm going to ignore the (hard) problem of traffic analysis and full on pseudanonymity for this blog for now...

since social nets run (mainly) in the clode, lets see if we can use 1 hammer for both rusty nails:

traditionally, we'd like to have a full subject/object matrix of capabilities - in general, for cntrolling who can see/use/alter what, for n objects, with k attributes and z access styles, we could end up with z*k*n^2 entries.
This doesn't scale for computers, and it doesn't scale for people.

In reality, many systems reduce the problem by two means
a) hierarchy (or multiple hierarchies with domain specific roots) reducing the space to k*z*ln(n) - think unix file systems and r/w/x
b) groups. n.b. with enough groups, you can do the entire s/o matrix of course, but that kind of defeats the purpose (which is simplification by aggregation)....think unix file systems and sudo and r/w/x for u/g/o, and then add newgrp etc etc

People do this sort of thing manually in their online existence by having multiple social net accounts and managing their friend lists differently on each one.

The problem (something Boris Dragovic did his phd on here a few years back) is that a hierarchy doesn't always capture what you want, but an ad hoc collection of exceptions
breaks things and makes things hard to remember for poor old humans again

so lets introduce two new things
1. Dunbar's work on social groups and layers of trust
2. games and BAR-T

In 1, we have a way to express trust relations which auto-magically gives us groups - the layers of trust in a social network are known to decrease as you move out from kinship, through friendship, through colelagues, then acquaintences. But, its dynamic, jim, and not necessarily, dynamic as we know it....
In 2, we have behaviours that are trustworthy (altruism, rational, byzantine) and measureabl, and can be attested to by witnesses....

SO we can build a system that creates defaults and learns and relearns the right settings in the (number of) hierarchy(s), and number of groups and access rights for each layer of the onion, both socially and technically.

We can also incorporate downgrading (or your reputation,creditworthiness, or access rights) forgetting (or un-friending) in the same architecure -

activity keeps friendships alive and rational or altruistic acivity keeps a cloud access right alive at some level.

Now we need a data structure that is an efficient representation of a tree but within a sparse representation of a (easy to update) matrix...that should be easy...

Thursday, September 10, 2009

s/w update process heading for 100% duty cycles

so every time I go away for more than 1 day, i live in fear of coming home or back to my office -no, its not the mountain of email (or spam) - I have the tools for that

its the s/w update on windows, linux, mac (and ditto smart phones) that is queued up waiting to install (and ask me to agree to terms I already agreed to 11 zillion times before for iTunes or Mac Office or foobarbaz antivirus)...

but also it's how **** slow the whole system goes (and there are lots of systems) and how unresponsive it is till all the stuff is done and dusted.....note this is not an anttimicrosoft rant - its just as bad on a Mac and not much better on linux boxen...

there really ought to be a better way (pre-click EULAs and then trickle the updates in is ok, but its not very green or even safe as I have to leave a zillion boxes on in my house - there should be a "sort merge " on the update (I know service packs do this, but perhaps not in enough permutations)...

Tuesday, September 01, 2009

Post docs in Cambridge - could be a whole lotta fun

Horizon Project at Cambridge Computer lab is lookin for 2 researchers (fairly experienced/senior) - it's 5 year
mission, to boldly explore new pervasive computing universes and make them commercially relevant...

this could be a lot of fun...please pass it along!


Thursday, August 27, 2009

android g2 phone....

..we got some for a project (on mobile social nets..) and they are jolly nice (this is the HTC hero) - very very close functionally to the iPhone, plus a lot of cool apps (Doom, can you believe:) - and all this on an open platform....neat...with wifi and GPS on it lasts about most a working day, but with 3G on, wifi and GPS off, about 2 days....with just voice, about not too bad...nice camera...

Wednesday, August 26, 2009

wireless on planes

yesterday we flew back from Crete to London on a nice A320 run by
Monarch Airlines - very pleasant - after the usual safety announcements
about turnign off all wireless (which actually listed wireless
laptops, games, GSM, 3G, SMS and so on), we took off, quickly reached
cruising altitude and then a whole bunch of different kids started
playing on their Nintendo DSs - there's this cute ad hoc wireless
conferencing app that they all started using, and slowly, abut 30 kids
discovered each other and a game evolved which was very like
Nottingham University's "can you see me now", with kids waving arm in
the air and other kids had to tag a person on screen before a hand
went down....very cute

and of cours, entirely based on wireless ethernet......
the game ewnt on most the 3.30 flight and noone from the
flight attendants said a word....

ignorance and creativity...

so cute:)

and prima facie evidence that a WHOLEr LOT Of wifi traffic has abslutely zero impact on the safe flying of a fly-by-wire moden plane.

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 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 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

Tuesday, June 30, 2009

better than zero-copy stacks

conundrum - can you do better than a zero-copy stack?

far as i recall, some folks at Sun Microsystems did the first unix with zero copy
from user space to/from network device way way back (prob. 92?) so that was as good as it gets in some sense....or is it? can you get a packet from the net in less than no time? I think you can in the sense that you could wake up the application before all the packet had finished dma-ing (or for a non blocking read/write application, you could do the copy on write thing 1 bit ahead rather than the whole packet) - of course, you'd need some insanely fine grain lock on the packet buffer somehow (or some fine grain virtual memory hack) which will be Rather Expensive(TM) in Real Life...

Friday, June 19, 2009

quantum networking...

I just got back from madrid where we had a nice dinner in Real Madrid's home stadium restuarant. the event was IMDEA's seminar n qunatum networking and had some seriously interesting talks from

Chip Elliott, BBN Technologies, USA
has a real operational QKD net in Cambridge Mass

Matthieu Legr?, id Quantique, Switzerland
works for a company that sell working QKD kit

Michele Mosca, Inst. of Quantum Computing, Canada
runs this institute in Waterloo which does the whole thing (incl QC algorithmics)

Emina Soljanin, Bell Labs, USA
very clear theorist with clean models of things like quantum multicast

Paolo Villoresi, Univ. of Padova, Italy
QKD over satellite and other free space (i.e. non photonic/fiber) based channels!

i had 4 bad ideas during the meeting
1. have a classical resource model of qunatum resources for the classically challenged
2. QKD satellelites could provide eye in the sky secure control plane
3. QZKP and other interesting zero knowledge or shared secret stuff, homomrphic hashes, quantum watermarks)
4. what's the Qbit rate for a multihop free space qunatum channel?

my proposal is to get the physicists to do this under some bogo-banner (e.g. Quntum Grid)

Monday, June 15, 2009

isps complaints about content companies

so here's th thing
BT, (for example) complain that the bbc's iplayer (for example) causes too much traffic.
well, huhn - now I susbscribe to the internet at a given data rate because that is what is advertised - note this is a _download_ rate - I am already getting a massively erduced uplink speed to prevent me messign up the net as a small customer, and that is fine (and partly due to technology and physics limitations of ADSL on copper).

but when they sold me a service, they should have thought "oh, maybe he'll actually use it" - note I have a solid 8Mbps...

and when the BBC connect a large scale data center to the net (at some large scale price)
maybe the service provider should think "hmm, wonder why they're doing that" and think about who they are (oh, the bbc - maybe they want to let people download programmes later)

so when they service provider complains about the content provider "causing too much traffic", recall AT& complaining about google "causing load" and wanting a slice of the action

whaty is really going on is that company A failed to realise company B was going to be a success, and is now upset it didn't and is trying to remove neutrality as a threat (stick) to get a part of company B's profit. Nevermind that there was nothing whatsoever except lack of imagination stopping company A being in the business company B provided (oh, ok, so in BT's case, there was a long running rule about being a TV company....however this didn't stop them making money out of selling capacity to TV broadcast companies, and now, thanks to Ofcomm, is going away anyhow).

No, sorry, this is getting silly - nonetheleast because they "blame" is the wrong direction - blaming the BBC because the BBC's customers use BT's customers to use BT's network is surreal. You sell some folks a network, (and get a monthly fee, AND a lot of them upgrade as fast as they can pay more to get the upgrade) then complain when they use the network. Doh. what business did you want to be in then, is it?

(BT is a bad example, I admit due to the old no-TV rule) - so add your own.

Now look at Virgin's new "all you can eat" music subscription service proposal , and big stick if you do anything bad (they disconnect you) - this sounds like dubious practice to me...

Thursday, June 11, 2009

a week in cambridge

this week has been bonkers - we had a great talk on monday by Fabio Bustamante about his use of crowdsourcing in bittorrent clients to measure the internet
then we had this stochastic nets workshop which Richard Gibbens organised which was fantastic, with loads of great talks on resource pooling, P2P systems and so on, then we had this workshop on pricing an auctions which Peter Key organised with some great talks on mechanism design and social networks, and now we have this biowire 2009 workshop which has some superb talks on the natural world and its "network" algorithms, and there was a really great semianr by Andrew Birrell on the history of concurrency!

enough for a whole year

Monday, June 08, 2009

Wrong Blog

You have reached the wrong blog. please go back and try again.

Wednesday, May 27, 2009

helping tourists from america

cambridge is famous for science, but that might put off some tourists so I propose that we found some new institutions to attract american investment

we could start with
1. the Darwin Institute of Theology
2. the Isaac Newton Institute of Astrology
and perhaps
3. the Stephen Hawking Economics Laboratory

Thursday, May 21, 2009

twitter users clueless about computing

this survey of happy programmers on twitter just proves what I say about a) twitter users and b) perl....

perl amoongst swine?

Tuesday, May 19, 2009

how useful is pervasive computing....MP expense data analysis

this guardian datastore MP expense visualisation site is a very nice example of how the net + data processing comes togetehr to allow rapid analysis and display of things that matter - this is a lot better than all the headline grabbing and really brings home a lot of interesting facets of the behaviour of our elected representatives...its also a nice example of a distributed collaboration!

Monday, May 18, 2009

matter transmogrifiers & trek tech

so how come in star trek when they beam across to an alien space ship
the enterprise crew don't arrive in the alien transporter
in alien bodies, eh?

answer me that, dearie

Wednesday, May 13, 2009

Tuesday, May 12, 2009

is a research lab useful?

a tech news report on MSR Cambridge open day on zdnet seems to feel that the sort of open ended research they do is not "useful" and is merely a status thing - the report is based on the things seen that day and could be contrasted with the glowing bbc report about google

The contrast is strong - the stuff the zdnet reporter says is useless and the stuff the bbc enthuse about are completely different - they are also selective
a) MSR cambridge has done shedloads of things (more than any other lab) that have made it into products and mainstream products at that (tools and techniques to fix concrrency problems, remove device driver problems, and game AI work, for example) -
b) the pipleline for work to get out of MSR into a products group is around 5 years...
c) the google work, in contrast is much more like Cisco's model (hire or buy some PhDs in whose work is nearly done...and
d) is mostly just development

The lack of context in either report is typical of modern slapdash journalism - IPv6 mobile work came from Lancaster - things like lo-power are on everyone's agenda from home users, EU and US lawmakers to data centers and mobile devices....the idea that apple would exist without the tech transfer from Xerox PARC into Apple research into product lines is laughable - the timeline there was more like 10-15 years - once tat group was done, of course Jobs shut it down but longer term, they will regret not having a constantly refreshed on tap pool of researchers

in the current economic climate, most pundits think it is even more crucial to have a research pipeline to come out of recession with shiny new stuff - hence Telefonica, T-Labs, MSR, etc etc, have ring-fenced the budget for their research labs - governments too have (Obama increased US research budgets, the UK have tried to at least keep EPSRC funding level...)

yes it has status and marketing value none the least amongst tech/geek followers - of course it doesn ,because it is a clueful strategy, not some empty-headed shell purely for windows-dressing (pun intended).

Having recently been part of a review team at Telefonica I&D, the Hamilton Institute, Max Planck Institute for Software Systems, Eurecom (in Sophia Antipolis) and MSR, I can honestly say that these guys are all fantastically useful, and people that can't see this are looking for the wrong thing (I'm not just talking about contributions to fundamental human knowledge, I am talking about contributions to health, entertainment and business (the bottom line)

Friday, May 08, 2009

class hierarchy and facebook

I've just got facebook on my Windows mobile 6 phone

next to my friends who have iPhones, I feel pretty sad

and next to the folks here who haev snazyy android phones, I feel somewhat sad

windows mobile = working class
android = middle class
iPhone = upper class

This is inline with th immortal Cleese, Barker, Corbett class sketch from pre-python years....

Monty-Haskell, anyone?

Friday, May 01, 2009

jolly good project to do with helicopter....

oh, ok it's quite cool - iphone
to run things :-
remotely, in the air

maybe a nintendo wii controller would have been better tho

Friday, April 24, 2009

gay bars at 11am

today I was interviewd by some BBC folks from the Culture Show, about copyright and the internet, in a gay bar (The Friendly Society) behind a sex shop (Ann Summers) in SoHo, london

this was an unnerving experience - all the strip joints in the alley way were just starting to open - it was a glorious sunny day at 11am

Frrrankly, it made a change:)

(What did I say? well you'll have to wait and see:)

meanwhile, Derek Murray continues to update his
Exemplary NSDI Live Blog - this should be a lesson in how to take notes at a conference!

Thursday, April 23, 2009


so i've come across this category of complexity a couple of times, and finally got around to reading it up (page 155 of Garey & Johnson"Computers and Intractability, if you must:-)

its a slightly refined way of looking at a sub class (but a large sub class) at the "harder" end of NP- - basically, instead of just decidability, a Non Deterministic Counting Turing Machine (TM:-) tells you "how many". (hence the #)

so in problems like maximal matching pairs on a bi-partite graph (e.g. call assignment problem in circuit switched net, or route/scedule problem in multihop radio) which can be "reduced" to a set packing problem (and knowing how many makes it a #P equiv to set packing)

Computational Complexity of Loss Networks

Monday, April 20, 2009

debugging in every day life

this easter I had a mixed time debugging things - aside from family (basically a DDoS attack on the fridge&larder from Ireland and France), various things (i.e. stuff) went wrong in interesting (or dull) ways

first, the fridge decided to turn everything to Ice - this turned out to be quite simple - someone had piled Easter Eggs on top of it pushed all the way back to the wall, so the heat exchanger pushing heat out was having to work overtime and the calibration presumably went awry - removing soggy easter eggs from top and putting them in the freezer to reform made that problem go away

second, the very nice, cheap and elegant and easy to use Humax PVR decided to do a few weird recording errors - we'd seen this first when the clocks went forward for "British Summer Time - but I hadn't bothered looking up the full glory that is Digital Broadcast and Electronic Programme Guides (EPG) - this time, we had a couple of truncated recordings and one that overran by 2 hours - so it turns out (thanks to the extremely well documented "hummy" web site and various AV consumer advice sites) that this is largely due to bugs in different implementations of the EPG combined with occasional missing or mis-broadcast EIT (end indication time) signals inband which tell the PVR when a program "really" ends (as opposed to the time set in advance which may not be right any more) .... plus some really strange effects if your multiple tuner PVR decides to use several different broadcast sources (which the Humax 9200T can do apparently - awesome)....anyhow, the overrun problem isn't really a problem but the truncastion is a bit of a pain, so I fiddled around according to various pieces of guidance and may or may not have fixed it...

third, one of the Macs in the house has been deciding that the wireless net isn't there periodically, and has to be told to pick it again (even though it is the ONLY preferred network...) - 4 other Macs in the house all work fine - this turns out to be a WPA re-authentication timer bug in the intel core solo Mac Mini 802.11 security thing - since apple have known this for dokeys years and it ought to just be driver stuff, I really don't know why it isn't fixed- only workaround for now is to go to WEP only security which I don't really care much about coz we only do ssh/ssl any how so there's no real harm, but it is a bit silly (early MacOS was ok, and later is ok - just ones around 10.4.10/10.4.11...i suppose i can roll back or upgrade ....what a palaver)

oh then there was an intermittent audio problem on the playstation 3 on the new LG HD TV - basically it looks like there's an HDMI audio incompatibility (that turned out to be easy - PS3 helpsites abound and advise on how to pick the most liely to work audio codec)...

then there was trying to get 11 and 16 year old to do maths homework/revision (for SATS and GCSEs respectively) - in retrospect, the techie stuff was trivial in comparison

Friday, April 17, 2009

mashing up state of mind and different web page layout

so I am sitting in a programme committee meeting using Eddie Kohler's excellent Hotcrp conference management software - this is used for writing reviews, putting in comments to other PC members and writign discussion notes between PC members during the processs - but it occurs to me that I am blogging it using the same form entry stuff in, and I am posting stuff in facebook using a similar form and in facebook status updates in a similar form - these are all completely different activities yet if one comes to one activity from another, one might mix up the kind of frame of mind one shoudl be in - for example, people posting status update on facebook are very similar in their approach to people tweeting on twitter (lots of bitchin - a bit like youtube comments:) whereas reviewing a paper is a serious activity giving rational for a score/rank and communicating feedbakc to authors (maybe to fix the paper if accepted, or to improve for submissio nelsewhere - and comments to the PC or discussion notes to other PC members are not for publication, but also should be considered at least, rather than subjective/emotive/assertive...

so how would one provide the right "illocutionary act" mindset to an input form (and its display once edit is finished) graphically? fonts, colours, what?

Wednesday, April 15, 2009

.towards the economics of information

today's idea/conjecture

there's an economics of information density and this is why twitter is gibberish and
blogs with google ads makes sense

basically, its some sort of entropic/SNR thing which is to do with the percentage of cognition someone is prepared to spend on stuff that isn't 100% germane (fancy word for relevant)

i think there's two pieces
1. there's a minimum unit's worth which is about 1 web page (8kbytes) - below this (think twitter or SMS), there's no useful semantic content, and its pure deontic/emoticon stuff - above this, the brain can afford some idling time to eyeball some stuff around the edges

so if you can't make money purely from the service (think sms/twitter) for low payload things you are doomed, but once you get into the page (think pagerank) you can build parasitic ways of making money (like advertising) in those cases, you want the _service_ to be free to maximise your chances of reaching the right people with the advert....(the advert could itself just be links to more content of course)

incidentally, this is why the IP MTU should have been 8Kbytes, not 576 (or the de facto 1500) it is today...

Monday, April 13, 2009

Computational thinking

so there's a school of thought that we need to get "commputational thinking" into the early school curriculum - on the other hand, I detect signs that quite a few building blocks of computational style thought are already part of the everyday mindscape - the notional of irony, post-modernism, and narrative tricks like the reverse memory plot in memento, or time travel paradoxes in Dr Who (or easter egg hacks in the famous Blink episode) do not cause the public to go "errrr, wot?" - they are all just part of the norm refs for kids and so i suspect it will be found quite easy (provided one does'nt do something horribly heavyhanded) to capture this in a small number of concepts that can be embedded in lots of other subjects...

on the other hand, everyone should learn to program at the same time as reading, writing and rythmetic and music.

Thursday, April 09, 2009

Bogo cod HCI

I hate those emails from myspace and facebook that purport to be from a person
("from the facebook team")

can't they just say
from the Oort Cloud
from your friendly neighbourhood bot
or something truthful?

Tuesday, April 07, 2009

why havn't we got one of these hackerspace things...

in cambridge?
or do we?

odd types of computer

the occasionally awesome James May on TV this week explained semi-conductors by olding up a spoon (conductor) and a copy of a vinyl record in cardboard record cover of Jeff Wayne's Musical Version of The War of the Worlds (insulator)

this made me think of alternative crazy types of gate that one might propose

historical battles (marathon, poitiers 1&2 etc) aer really gating functions to either populations or cultures moving from one area to another - think of the movement as a large current, and the small armies (relatively speaking ) as a voltage applied - i.e. valve/transistor/switch/gate...

so the whole of history of human migration and population plus landmark battles could be viewed as a computation....what does it compute tho? 42? 23? or does it just deliver a ring pull from a coke can to a stranded tralfamadorian on Titan?

Monday, April 06, 2009

flocking copters...

so i was proposing flocking copters made from commodity (e.g. hobby copters for a 100 quid) - that was 2001 - now we see
cube warriors and war porn is reality.

Tuesday, March 31, 2009

multitouch vnc?

has anyone looked at thin 3G client + cloud computing?

basically ,multitouch VNC and a remote service...

would make the battery life really good and with most the android/t-mobile and iPhone/O2 contracts being unlimited data, one could just win big compared with those platforms...

Friday, March 27, 2009

dasher for cell phone or other consumer electronic config

has anyone looked at using dasher for input for configuration of applications ? It would be quite easy compared to using it for probabilistic text input..

Thursday, March 26, 2009

time to leave facebook?

now they've made it as pointless as twitter!

Monday, March 23, 2009

TINA in Hong Kong

Later today, I'm presenting some work on the
Intelligent Networked Airport project
at a Cambridge Alumni event in Hong Kong at the
Polytechnic University

Aside from the slightly alarming jetlag, its a great place to visit! some more info of my home talks page

I also had a tour of CS in the PolyU and saw some excellent mobile/mesh demos, and a really cool biometric lab (with chinese medicine intergrated in biometric ID!), and a model car/ITS lab, plus of course Henry Chan's new lab for the airport work.

on the way back, i was pleased to be flying Air New Zealand who were not only cheap, but also very good - 30-40 films on a VOD system - including (what I watched)

twilight - kind of like Near Dark, but slightly better

4 xmases - reese withersoon vehicle - basically naff, but likeable - the bloke is very drop dead pan amusing

slumdog millionaire - i prefer the book, but the film doesn't pull many punches - very good

my best friend's girlfriend - great idea fairly well done (bloke messes up dates deliberately for money from ex-s who want their girlfriend back) _ typical hollywood bottleout ending ruins it.

happy-go-lucky - mike leigh movie in a good mood - simply awesome

body of lies - not as good as other recent sensible US movies in the middle east, but not bad at all.

enchanted - fabulous combination of animation and pretty camp live action in NY.

the day the earth caught fire - diabolical remake of classic story.

quantum of solace - bond - better than US government bond, but only just

Saturday, March 21, 2009

grading and reviewing

so in academic life, the one thing I think almost everyone would agree is the most negative experience is grading papers - (or marking exams) - teaching is fun (lecturing, supervising) and research is fun (coming up with ideas, building stuff, writing papers, giving presentations) - even some admin (interviewing, teaching/research admin) is ok

but grading is really de-grading.

so why is it the, that so many academics also volunteer for reviewing (i.e. being on Technical Programme Committees, and on Journal Boards of Editors)??

I suppose the main difference is that at least some of the things one reviews for conferences and journals are new and interesting, whereas most of the things one sees for exam answers are at best correct answers to something we already knew.

But to be honest, the payoff is pretty small, and in exam marking, at least sometimes you get the pleasure of seeing someone do a neat slightly novel answer (or the amusingly awful answers of course)...whereas there's very little amusing about awful paper submissions to conferences... ... ...

Monday, March 16, 2009

this week in european comms research land...

today I am at Pablo's Lab in Barcelona
but then shortly after I'll head off for this unusual workshop in swizzerland, where I may travel under the name of dr necessitor, in the hope of meeting and reconciling Michael Hfuhruhurr and Helen

some pix of barcelona...are at
the usual place

I has ta say any city with an actual Diagon Alley (as Barcelona has) nearly makes me forgive Harry potter.

today's mad idea - virtualise cell phones so you can migrate all the expensive p2p comptutation onto the Cloud, and save battery life in the handset:)

Wednesday, March 11, 2009

ignoble prize alert - the impact on reviewers judgement of being cited in the work under review

so how much is our judgment affected (unfairly) by seeing a citation to our own work in a paper (or book or whatever) we are reviewing?

devising an experiemnt to test this is tricky - there are effects like
a) very bad people who accept a paper because they want to boost their citation count to prepare a bigger H factor
b) there's the simple (correct) effect of being more familiar with the previous and related work (which is why presumably one was picked as a reviewer

to conduct an experiment to test this effect we need to submit some papers with
i) blinded citations for PC members
ii) citations replaced with irrelevant citations
iii) citations with authors names changed
iv) citations replaced by equivalent works (e.g. level of indirection - cite instead a work (survey, similar paper) that cites the original citation)

it should be done:)

Friday, March 06, 2009

facebook minimal age captcha

so its well known that if you break someones legs, the time to heal in weeks is the same as the age of the person.

hence a very big robot controlled mallet connected to the keyboard and remote run by facebook through a browser plugin could deter underage facebook users...

one problem is that the sense of the test is wrong - i am working on that:)

not to muckrake or anything, but... i see they are spreading signage
on the field in front of the vet school
opposite the WGB:)

i'd love to see a picture of a herz rental outlet a donkey and cart with the sign
(Carriage Return, Line Feed) :-)

Friday, February 27, 2009

A Game Called Stop & this years 1b project demos

This is played on a board which is 1 square wide and deep, but 361 squares high. Each player has pieces (koans) made of clear glass.

i thought of this when lookin at the robot ("magic") game board in
this years 2nd year group proejct demos in the lab

idea for a project -seamless integration of pause live program, and download (faster than play - c.f. flash plugin) - so you have a back-to-the-future as well as a beam me forward scotty, button on a PVR combined in one nice package, with a P2P (torrent) delivery and DTN where you need it

Thursday, February 26, 2009

local error, global fault - internet infrastructre critique

so i was talkin to some folks from our national funding agenc about what is interesting net research to do - they were not aware of the set of failures in the internet over recent years caused by "small" errors of configuration leading to global problems -
0. the root DNS zeroing the boot dbase so returning nxdomain for the planet for 6 hours

1. the youtube blackout caused by local BGP config in small asian ISP

2. google mistyping a config rule for listing search result sites as "risk of harm to your computer" and marking 100% of the world as bad

there are others - these represent the problems caused by NOT STAYING WITH THE PROGRAM - the internet is decentralised - organisations that want to own pieces of it horizontally cause problems (there are tools to avoid most of these problems, but they require a modicum of cooperation)...people forget these design philosophy rules (aka architecture) at their peril (and ours:)

Wednesday, February 25, 2009

social networks cause autism

bad science yet again correctly refutes the daft claims in the press, and those behind the stories that social nets cause anti-social behaviour- we have research in social anthropology on people going from school to university, and people retiring, that shows that social networks, just like computer games, increase peoples' social group size and activity in the real world.
This is not published or definitive work yet, but other early work this year also shows this (it ain't hard to do, but it takes time and involves ethics committees since you're seriously treading on peoples' privacy)

Tuesday, February 24, 2009

muggling along

yesterday, I was at St Andrews and had a very nice attendance at a 3 hour seminar I gave on Delay Tolerant and Opportunistic Networks with about 120 students and staff and some very useful questions.

In the pub with Saleem Bhatti and Tristan Henderson, we discussed the new mobile phone game I invented called "muggling" - you juggle 3 cell phones, each with a live in progress call to a different person, while time division multiplexing the 3 conversations

I think this would be quite a skill...

Friday, February 20, 2009

proceeding to a new type of conference....

in the last few years, several conference organisation cttes have experimented with
the idea of Shadow programme cttes - these serve to trai nup new researchers in the process, as well as potentially acting as an error checker for the main conference and providing the paper authors with copious amounts more feedback - sigcomm and conext have both done this a few times...

now here are two proposals for the next step.

1. Run complete shadow conferences as well - instead of just having 1 "main" "real" PC and the shadow PCs just being training ground, let the shadow pcs selerct their actual top n papers and (at the same time in the same place in parallel tracks) have a full set (2, 3 - as many as you like) of conferences - like parallel worlds if you like - clearly if the various PCs select overlapping sets of papers, then they merge for those presentations...

2. two many people invest far too much importance in CS conferences - nowadays grad students in the US think their academic career is over if they don't get their work in SIGCOMM or SOSP, and practically never submit work to Transactions on Networks or TOCS despite those being easier to get into and just as weighty.

The solution is to STOP PRINTING conference proceedings - just have presentations only

3. Even more radical proposal - have a final shadow PC that accepts "all the resr of submissions that weren't accepted by any other PCs, and allow all the authors to present their papers in the "shadow of shadows" parallel track...

Thursday, February 19, 2009


some things you don't normally thing of as pre-owned

1 preowned child
1 pre-owed food - in a coffin - fit for non vegetarian species
1 preowned idea
1 pre-owed joule
1 pre-owned bit - as new, can be set to 0 or 1, true or false, on or off.
some pre-owened order - a little increase in entropy, but still reasonably rare fnd.

Wednesday, February 18, 2009

google map+cal -> travel planner

imagine you had an app where you could click on a set of locations
and then a timeline editor (see below) an then say
get me from here to here in spacetime (with a bike, car, bus, train, plane, sapace elevator, tardis)....(could show constrains like Lorenz space/time/funnel visualiser)

google maps + ical + a web browser plugin/gui and a backend to talk to one of the expedia
type things and game over...

go build - easy:)
mar 1------->apr 2---> apr 4---->apr 7

<< < || > >>

gaussian elimination, revokation, and other CS activities this week

1. Gaussian Elimination

this week I was in Gottingen visiting Xiaoming Fu's group in informatics (for PhD exam and seminar) - I was most impressed with the telekom groups research in multicast (fast recovery), mesh nets, network coding, and security and congestion control - neat stuff. On the other hand, they used to be in the Gauss building but were eliminated from there:-)

While there I saw a BBC World News item on TV where they reported that Fermi Labs claimed they would beat CERN in finding the God Particle (delusion) and that this would explain why matter had mass. The main news reader said this with confidence and then turned to the reporter who was presenting the next item, world economic news. All she had to say is "this is beyond me/over my head" - not surprising then that the world economy is in such a mess if people claiming to be experts don't understand the first thing in simple science. As I've said before, it is insufficient to say "letting allthe banks go broke is unacceptable because it would lead to chaos" - what do we have now if it is not chaos ( is a term in process algebras of course, but few economists would understand those)

2. (Think about the Lavender Hill Mob) Eiffel

Then today I was in an Eiffel meeting talkin about various future internet mad ideas - here's two of mine

1/ run SETI@home on Twitter - see if a) there's any intelligence out there and b) if its not all human

2/ google is not really a program written by humans - its actually a programme written by an AI called Altavista - the worldwide receession was casued by google giving wrong data to share dealers about the future stability of companies products and services and causing them to trade incrrectly - the AI decided that the world war III was necessary to stimulate lots of work on faster AIs and eliminating humans at the same time would be a neat side effect (apologies to samuel delaney - this is a Free Plotware(TM) suggestion). Of course, if this allegation was true, then google would never lead you to sites that when you followed a link said "404" = it would be necessary for it to create the site it understood you to want:)

3. Face-off book:)

facebook think they own and and keep your data, even if you leave and die

well, here's my solution - I already put incorrect facts on my online social net pages to reduce the risk of identity theft - if I close my account (as I have done on some) in UK (and I think EU and US) law I can ask them to correct these facts - I can prove _some_ of the data they have is wrogn (e.g. my birth date, middle name etc) and I can prove it to a third party - but I can also refuse to tell them the right fact. Thus their only recourse to get wrogn data off their system, is to delete the false data.

Game over.

Saturday, February 14, 2009


routing seems quite useful

meanwhile, recent (UK) showings of CSI have revisited their S&M theme - perhaps this could be "re-inventing the wheal" ?:)

to add insult to injury, Nintendo are going to release a Highland Dancing game -
Wii inventing the Reel?

and one could accuse the long now foundation
of re-inventing the while...

thomas hardy spent many novels re-inventing the weald

thats enuff now..

Friday, February 13, 2009

From fleedom to fleadom - 800 years of Cambridge...

ross anderson's
unauthorised history of why Cambridge University has an impact is worth a read - from fleeing religous persecution in oxford, and going on to annoy the government, the story is quite a shaggy dog....

Wednesday, February 11, 2009

digital lives and the wild...

Today I was at the 3rd (last) day of the
Digital Lives conference at the BL in London, and jolly interesting it was too.....

1. very nice talk on Mass Oversation Archive from Sussez - fascinating history on very long running society as observers, and how things changed between 1930s technology and social acceptance/use, and today's near-blogging based approach...

2. Wendy Hall could emember meeting David Beckham n 9/11 but couldn't quite recall the name of the Pleasantville like Jim Carrey vehicle, the Truman Show (neither could I without cyber help) in a relevant talk about M4L

3.Excellent talk from the Centere for Longitudinal Research (no, not Harrington clocks)
and how to keep a project going for > 50 years!

4. Interesting view on the future of scientific publishing from Nature! (see earlier blog entry from yesterday!)

5. Big Ad from Amazon about Cloud computing

6. Really cool talk from Soton/ about fan-generated content - thesis has cool social graphs of the fan/author and interest groups- (thesis from southampton, author now with staff at royal irish academy)

7. me

8. nice talk on vera (virtual field archaeology) - well worth a looksee for people worried about robust kit for adversarial environments for inputting analog data but capturing it in usable digital form...

9 peter bentley standard "here is evolutionary computing and what it is good for" talk

10. fantastic talk about artistic capture (manaual, not computer based) of the writing of Jack Kerouac, with then computer visualisation of structures generated - very crazy in a good way!

then I had to go:)

Tuesday, February 10, 2009

The Origins of Consciousness and the Bicameral Mind by Julian Jaynes

is a rather interesting read....I think the main thing missing from it
is any understanding whatsoever of society

but more interestingly, it seems to be pretty naive about congnition reflection, AI and especially literature.

The basic claim is that sometime between the writing of the Iliad and the Odyssey
humans switched from being a mass of id, with an imaginary friend (the gods, or the voices) and a complex social structure (think the Enki of Loki in Snow Crash) to make sure people didn't just behave chaotically, to having a system of metaphor (actually, confusingly, an analog) called consciousness which each person could apply, which would monitor their behaviour and regulate it (think ego and super-ego).

Two terrible mistakes: 1 the Iliad may just be an example of literary convention - there are lots of weird ways people write - just because there is no "I" in Iliad, doesn't mean that Mycaeneans didn't think like us. There's no "You" in Uysses (James' Joyce's stream of consciousness), and that doesn't mean that early 20th century anglo/irish people didn't have a concept of the "other". Oh, and a third mistake - if every one was guided either by rules, or by delusions, then who wrote the books? (i.e. how do you bootstrap a society out of chaos? who is the author of the enki of loki, or the laws that govern when you plant crops, and when you pray?). no - wont do.

Finally, reading the book did give me one idea:

In the work on social nets, we have this model where human's carry around a set of cognitive structures that represent other human's intentions.

Is this structure:
i) a parameterized model of my model of self?
ii) a set of models (e.g .acquired by observing others)?
iii) a hybrid?

perhaps kinship would (evolutionarily) justify i) where socialisation (i.e. friends, colleagues, acquaitences) would be more ii) or iii)
and does the use of technology (e.g. extending the number of people for which one has a model, albeit, perhaps, at the cost of superficiality) mean that one could study this objectively? perhaps the externalisation of records of interactions means that one can recover the model by looking (at diaries, email traces, web interactions etc) both as an individual (deciding how to interact next time with someone) and as a researcher studying that ineraction.

bicameral: two chambers (commons, lords:)
no "I" in Iliad
but then there's no "U" in Uysses

Monday, February 09, 2009

decentralised anonimity and disreputable algorithm names

If I was to implement the
Cocaine Auction Protocol
using a
Distributed Hash Table
(e.g. to lodge or find bids)
could this be taken as evidence that soft drugs lead to hard?

Friday, February 06, 2009

giving google latitude a wide berth

sp if we found out the home secretaries blackberry number, we could (Instead of just sending her all our emails) we could notify her (and maybe Obama to) Of where we all are - say a few million of us:)

tell jaqui smith where you are now

Sunday, February 01, 2009

Hamiltonian circuit

tuesday I went to Maynooth in Ireland to visit the Hamilton Institute, and then on wednesday I came back again. The institute Is a high power center of mathematicians who apply control theory and other techniques to various problems in communications (my thing) and systems biology (lots of people's thing), and very nice a place it is too

interestingly. as an evolution from the old St Patrick's College (basically a seminary for priests to study) through a national university, and now a place with specialist institutes like the Hamilton, is a very fast upwardly mobile intellectual track, which is most impressive, although if you are familiar with learning in ancient and modern Ireland, perhaps not so surprising...

Saturday, January 31, 2009

This site may harm your computer.

today, google has starting saying this about every site a search result reports.
of course, it is true that any site may - it always was true so maybe this is just an educational move, or maybe google finally got got....

somebody turned on the "E" bit:)

careless typing costs lives - google explains, but doesn't exactly say sorry

liek any critical resource (the DNS) one should do sanity checks on the scale of impact of any configuration change before committing it (ditto BGP as well as DNS) - why do we learn the same mistakes again and again:)

Monday, January 26, 2009

freud versus dali

I'm just finishing this excellent book about the Death of Freud
in which is the delicious description of an encounter between an aging Freud and Salvador Dali
in london - at the time, Freud was dying of cancer and was very deaf
and Dali was almost certainly mad

Dali kept asking Freud about Paranoia
eventually Freud heard him and said
that the thought classical art was interesting for what it revealed about the
subconscious while surrealism only revealed things about the conscious (meaning that it was intellectually contrived)
at which Dali wailed "so surrealism is now definitely dead"

freud remarked in his diary about the meeting that "Dali was the perfect Spaniard"

now put that in your Turing pipe and smoke it!

Thursday, January 22, 2009

quantum computing, pervasive systems and privacy

clearly the qPhone (quantum iPhone) will offer the user unprecedented privacy, because all qPhones will be identical, and so you wont know where the user is - they will have a probability distribution with many nodalities - only if a specific qPhone is moving very fast will you know where it is (so long as you don't measure its speed) - qPhone controlled cars will therefore be immune from speed traps, since, once you know they are breaking the limit, you will no longer know where they are, or what the limit was there, then, anyhow.

I would expect Apple to be shipping the first qPhones in or around q9 2023.

Friday, January 16, 2009

externl examiners and setting and marking standards idea

why not ask the external to take the exams, anonymously, mark her papers
and return the marks to the external

what a great way for an external to cheque the quaility of procedures in the examination process and the department to tell if the external has a clue too.

Monday, January 12, 2009

carbon cost of google dispute

bbc report on google carbon footprint is under debate - i calculated this on the basis that
1. google has to trawl and index the web
2. the web has to be up for google to do this
3. so I count all the machines up in the contribution to the costs

how many thousand searchs are the same
energy consumption as 1 lightbulb for an hour?

This site lists 200 million a day in the USA

so divide by 24 to get searches per hour:
that is about 10million an hour

these guys list US power consumption at
40 billion KWhours per year
(admittedly a couple of years ago)...

so we need to divide that by 360
gives around so 100 million kilowatts (in an hour)
serves 10 million web searches

which means that 10 watts for an hour is needed for 1 web search

i.e. 1 100 watt lightbulb for about 10 minutes for a single search!!!

Google of course (fairly) say that the actual search itself is highly efficient and runs on well engineered eco-friendly data centers....but the pubic understanding
is pribably gonna favour my type of argument over theirs....


race memory for OSs

looking at a bunch of OS resource management papers recently, (as I try to play catch up and be able to do my job on the Eurosys and SOSP PCs properly) it seems to me that if you look across the broad vista of papers over a few years on any resource management aspect of OSs, a lot of what people try to do is what you might call "myopic" schemes for scheduling - there's very litle that carries information over one set of processes running to a later similar mix explicitly.

Implicitly, however, the information is there in the set of benchmark specifications and the results in the sequences of papers - so if we codified the papers, then an OS could boot (and network downloadupdate) a configuration for long-sighted allocation of resources - this ought to be easy-peasy - we just specifiy an XML format for results, and then publish online -

its a bit like traffic engineering for the internet (rather than flow or session based resource allocation) but it also has micro- benefits as well as macro- benefits, snce proceses can be started with the right model of input rather than having to infer it from the usual pile of heuristics run online...

p2p-driven scheduling :-)??

Tuesday, January 06, 2009

grand challeges in Ubiquitous Computing part #17

Yesterday and today I've been attending the latest workshop on grand challenges in Ubicomp at Imperial College - very cool stuff - lots of neat talks

some ideas and pointers while listening

for early computer mediated art in a ubicomp environment, see the Cybernetic Serendipity show at the ICA which I was lucky enough to attend in 1968- I have a copy of the awesome book produced for the exhibition (which featured a very young Nicholas Negroponte amongst others).

On ubicomp sensors for healthcare (great talk by Guang-Zhong Yang - the E-AR sensor is extremely cool way to measure gait etc) - while I am impressed by the creativity of the sensor devices, we are still a LONG way from something that carers or patients will be able to deploy affordably - we cannot scavenge power yet realistically (probably not for 5-10 years) and wires or replacing or recharging batteries every few weeks for a 100 devices is already annoying enough for all the remote controls around a house, let alone life-critical stuff - I suppose if we made the devices provide a useful summary healthcare report for a health visitor (including a reminder of when to replace batteries) that might work - this could work like "Alertme"s home monitoring stuff via GPRS and SMS - reminds me of an idea I had for putting a zigbee beacon inside a battery that would give you a ubicomp location service for all the devices with batteries by default AND would remind you when the battery need recharging (and would let you find missing remote controls under the sofa:)

another cool application of the EAR device would be for monitoring children in "at risk" homes...

Privacy keeps popping its head above the parapet - we design devices and then blame users for misusing them (I think how many people hold strictly private conversatiosn at the top of their voice in public places (the train) on a cell phone - how often you hear stories of people revealing lots of embarassing facts on facebook) - my solution (Tim Kindberg tells me this is called a "privacy mirror") is to show people the "anti-social" network of peopel that can witnes this event _before_ they make this mistake - e.g. as you make a cell phone call, a voice (of someone you don't know) is played back on the phone repeating something you said earlier to remind you who might hear - and as you add a photo to facebook, a list of people more than (say) three hops away in your friends-of-friends-of-friends graph, pops up who could see this photo (preferably people with no common affiliatin, but with common interests, say).

trust is slippery stuff - If a computer A trusts a computer B and B trusts C, then we have GNY/BAN logic to reason about trust (or we can build other trust logics, e.g. interval arithmetic based or bayes based). If a person "trusts" a person, what can we infer about transitivity, associativity etc? not a lot - but social anthropology has things to say on this and we should listen! If my friend Richard thinks Ruth is his friend is Ruth stranger than Richard, to me, as Robert Wyatt once asked?

Jon Bird reminded us that the ludic mode of research (e.g. driven by art) is very valuble in exploring areas of the ubicomp (and other) design space that a purely tech/biz driven approach might not reach (he also had some really cool videos from art from 25 years ago - viz David Rokeby aweome video) and the bit from Monty Python's Life of Brian abut "what did the roman's do for us" which (given situation in Gaza right now) ends with the list of "roads, law, aquaducts, hot baths .... oh, and peace..."

which reminds me of one of my fave XKCD's - see
Alice and Bob etc

maginc new interfaces - see also, dasher:-

and also spoof on
apple spinwheel

On programme properties, what is the relationship between Prism and Microsoft research's (byron cooke et al)'s Terminator programme?

Meanwhile, in Steve Hodge's neat talk, I was reminded that teenagers have telepathy (only 1 bit) that tells them when a friend is about to call or when its a parent so they can turn on (off) their cell phone:)

Steve's key point is that if we do a mindmap of WSN, we find that although a lot of peopel list ad hoc and mobile and multihop/decentralised/self* as key components, the most common applications AND sensor systems are
a) centralised/infrastructure oriented
b) not mobile (particularly)
think remote controls, games and cell phones

i.e the academic obsession with the technically challenging and interesting problems that are roughly grouped under MANET (and maybe DTN) are not relevant to many realworld deployments. (I made this point a while back about most of the projects in the EPSRC WINES programme of research - not only are almost all of them completely diferent (i.e. they are good because they are use-case driven) almost none has a multi-hop radio net or a self-orgnaising system or even any mobility:) Yet they are all good examples of UbiComp.

Day 2 kicked off well with a total power failure at Euston Station. Meanwhile, Wendy Mackay made it from Paris in time to talk about InterLiving - situated UbiComp experiment in everyday life - a lot of the 2nd day talks are more either living or about trust. Tim Kindberg discussed many of th failures of trust in "invisible computing".

Why not put a webcam on the wifi hotspot router and then it could put up a picture of you when it is authorizing your access, and you get to see that it is "physically" actually the router you can see (line of sight:)

Also present in talks was art and politics!

A nice taxonomy of "mobiel art" by Martin Reiser - lots of good gadget ideas here (similar to Jon Bird's and some of the outer scope ideas by Steve Hodges). One work is called the Third WOman and is a mobile installation in Vienna (after the Third Man - graham green/orson welles movie) _ would be neat to add a sound track by Joan as Policewoman and make it the Third Policewoman:)

Next session was two more trust talks:- Palamidessi on Bayesian trust infernecing, and Ian Brown on law.

Last talk I stayed for was Robin Milner, looking at the bigraph work on space/motion in large systems (see his new book! relevant work

Friday, January 02, 2009

smart bricks...

forget about smart dust. what about smart bricks?

these would be devices that can be dropped in any place like a brick, that cost less than a tenner, and can store a few 10s gigabytes of media data and can run computations for a few hours on a battery charge - they have sensor surfaecs (simply light/sound/heat) and they are cheap enough to leave a LOT of them lying around in a city (a bit like velib/free city bikes) and they basically act to hold the city's history. they log what goes on. they can recharge off of intertia or light or ambient heat. they can be your backup server, your neighbourhood watch, your calculator, your e-cache etc etc

much more useful than dust.