46bit

Hi! The writing I put here is generally “1.5th-draft quality.”

  1. I've been published!

    March 14, 2017

    In the last month I’ve published twice in our campus newspaper, Nouse:

  2. Security Risk Assessments of
    Semi-Autonomous Vehicles

    March 13, 2017

    I’m in my 4th year at York, the Masters year of my MEng Computer Science degree. This term I’ve taken the Topics in Privacy and Security (PSEC) module, which takes a wide technical swath through privacy and security issues. But the assessment is mostly focused on password cracking and doing a security risk assessment for automated road convoys.

    We’re assessing how to bring an EU-funded project, SARTRE, to market. The concept, “Safe Road Trains for the Environment,” allows an equipped car to automatically follow ~6m behind a Lead Vehicle. You could sit back and watch a movie—er, do productive work.

    SARTRE following drivers doing immersive non-driving tasks […]

  3. Glad I was wearing a cycle helmet

    March 12, 2017

    One of my favourite things about York is how bicyclable it is. I grew up in the countryside but somewhere decidedly not safe to cycle from, so it’s a very welcome change. Aside from a couple of minor things it’s worked fine for the last 5 years. On Friday (2017-03-10) I had a bit of an accident. […]

  4. Recursive Enum expression trees in Rust

    March 3, 2017

    I mused about an implementation of expression trees in Rust two days ago. This is to build a Genetic Programming library in Rust - an biologically-inspired approach to finding robust solutions to difficult problems.

    As discussed elsewhere I’ve become a keen fan of Rust. This language’s limited generics pose interesting problems for expressing and generating equations as described above.

    There are two common ways to represent a tree datastructure: […]

  5. Introduction to Evolutionary Computing

    March 2, 2017

    I took an Evolutionary Computation course last semester, EVCO. This is a family of techniques where you simulate evolution to find good solutions to problems. Let’s watch an evolutionary process evolve vehicles that can get through a course:

    I’d like to thank Dr Daniel Franks for a great course, enthusiastic teaching and many of the examples here.

    Let’s say you want to learn an equation that approximates a function. This is a simple example - one of my evco examples evolves Snake players. We’ll use an evolutionary approach called Genetic Programming, which evolves trees representing expressions. […]

  6. Securing legacy ColdFusion or:
    Why escape spaces against XSS?

    March 1, 2017

    I’m in my Masters year at the moment, which means I have a lot fewer classes but a lot higher expectations in assignments. I’m also undertaking an MEng project (I’ll write about this sometime.) So I have a lot more unreserved time but a bit more work to do. I’ve been filling one day a week doing security and maintainance work on old ColdFusion web applications.

    ColdFusion is an old web technology that Macromedia put out. It’s like you implementated of PHP in HTML tags. For I have been working with it - trying to secure a large number of small webapps built with it in years gone by.

    There’s a bit of a problem with securing these legacy apps. They’re a mess, and ColdFusion is insecure by default. Let’s take some typical Ruby erb markup: […]

  7. Generating expression trees in Rust

    February 28, 2017

    I’ve been writing a lot of Rust. Since @Taneb persuaded me to try it the language has grown phenomenally on me. I’ve always shied away from getting too attached to tools and focused more on systems but for the first time since my early Ruby days I’ve become a language fanboy.

    While building my Genetic Programming library I needed a convenient way to represent and generate syntax trees. More than anything I wanted users to write a minimum of code. I used an interesting but problematic Recursive Enum approach that’s worth discussing.

    enum Equation {
        Add(Box<Equation>, Box<Equation>), // l + r
        Sub(Box<Equation>, Box<Equation>), // l - r
        Mul(Box<Equation>, Box<Equation>), // l × r
        Div(Box<Equation>, Box<Equation>), // l ÷ r
        Float(f64), // n
    }

    This is a very neat representation of a syntax tree for basic mathematics. One can express math quite simply: […]

  8. Engineering as slowly as possible

    February 27, 2017

    I’ve become a fan of developing, “as slowly as possible.” It’s proven hard to crystallise what feelings this sums up, but I relate it to slow, logical, conscious System Two thinking.

    The way you start a project indicates a lot about how it will progress. Something that gets a testsuite early on will probably keep one going; something that is essentially untested is hard to improve. This hill can be climbed over if one is lazy or very disciplined - but sustained effort to undo unforced mistakes is hard.

    So making the right decisions at the right time is important. Ideally we should favour sustained velocity over quickly hacking something together and forgetting about it. We should have good craft in order to still move fast: building things well rather than just building them. […]

  9. UoYBus: bus times for the University of York

    July 7, 2014

    Since November I’ve been quietly running UoYBus, a live bus times webapp focused on the particular whims of the #4 and #44 bus routes serving University of York. Today I released a big improvement. […]

  10. You can't unsell Hospital Records

    February 24, 2014

    The Telegraph reported today that hospital records from 1997-2010 have been sold to insurance companies. They appear to be referring to HSCIC’s Hospital Episode Statistics, a database of NHS hospital records. […]

  11. Going back to College

    October 29, 2013

    It’s been a while since my last post. After living in London for a few months and working out of Shoreditch Works, I chose to head back to York with the new academic year - rather a tough choice given my other, international option. […]

  12. How probable are 3 consecutive birthdays?

    April 1, 2013

    Have you ever wondered what the likelihood is of having three consecutive birthdays in a row? It’s a fun excursion from the classical statisical brain teaser on the birthday problem. […]

  13. Steady state community

    March 29, 2013

    Amazon’s purchase of Goodreads, a social reading community, has reminded me of the difference between building a community and building a business. Goodreads definitely could be a value add for Amazon and the Kindle, yet unless they treat it with a light touch it could become far more of a Goodkindlereads. […]

  14. A first look at Quantum Computers

    February 11, 2013

    The computer in front of you is pretty powerful, but it can’t factor a 600-digit number before Earth gets cooked by the Sun. No supercomputer humanity does or could build could do that either, so it seemed a sure bet to base the security of some encryption schemes on factoring being (exponentially) hard. […]

  15. Train Data Revisited

    February 7, 2013

    I mentioned Network Rail’s feeds briefly last time but hadn’t yet looked into them much. Thanks to Samuel Littley for letting me know a bit more about them. Sign up and your access will be activated within an hour or so. Given that mine was granted at 3am GMT I suspect it’s automated. […]

  16. Trains and East Coast positioning data

    January 26, 2013

    Back in 2011 I built TrainTrackr, a rapidly-built iOS app that worked together with a web interface to track train journeys. It seemed a brilliant way to tracing delays to trains and getting accurate data on their speeds along the route. […]

  17. Remian: a modern virtual machine

    December 19, 2012

    Anyone who follows me on Twitter has probably read that I’m building a virtual machine of my own, named Remian. I’ve reached v0.1.1 and an initial release, so now is the perfect time to talk about why you should try it. […]

  18. Two weeks with Go: an initial review

    November 14, 2012

    As someone who grew up with scripting languages, C and it’s closer brethren always felt incredibly backward. The result of all their decades of history seems to be that obscure compiler flags and awkward syntax are an affectation of the entire community. I don’t care for it, much as I like how fast the code can execute. […]

  19. Building services with iMessage

    November 1, 2012

    Earlier this year, David Kendal and I discovered you can fairly easily send and receive iMessages using Ruby. The key is to interact with OS X’s Messages app, more specifically it’s AppleScript bindings. We built and released iREPL, a Scheme programming environment that you can use on your iPhone/iPad without having to jailbreak. I’ve been using it for months when I fancied hacking some Lisp. […]

  20. On efficiently pairing socks

    May 1, 2012

    Anyone who has done an appreciable amount of laundry has probably noticed the time commonly taken matching up socks of different styles and colours.

    My efforts to optimise the process have led me to the curious practice of un-matching: making pairs of socks so as to deliberately not be a matching pair. It’s much faster, much simpler to compute and yet because there is a process behind it you have a defence against allegations of laziness. […]

  21. iREPL

    April 13, 2012

    A couple of months ago, whilst playing with Messages Beta for Mac, it occured to me that it’d be a lot of fun to programmatically send messages. After I built a basic, insecure Ruby Shell for iMessage, David Kendal decided to rebuild it and switch to Scheme - for which a secure sandboxed version existed in the form of Heist. […]

  22. Development Sparks

    August 29, 2011

    When we encounter a problem as developers, there’s usually 3 ways to solve it. There’s the hacky way with its attendant long-term maintainance costs. There’s a way which works without too much trouble. And there’s the spark of genius that solves all the troubles with the minimum of effort. […]