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Links for 2013-04-19

  • Vaccination ‘herd immunity’ demonstration

    ‘Stochastic monte-carlo epidemic SIR model to reveal herd immunity’. Fantastic demo of this important medical concept (via Colin Whittaker)

    (tags: via:colinwh stochastic herd-immunity random sir epidemics health immunity vaccination measles medicine monte-carlo-simulations simulations)

  • Fred’s ImageMagick Scripts: SIMILAR

    compute an image-similarity metric, to discover mostly-identical-but-slightly-tweaked images:

    SIMILAR computes the normalized cross correlation similarity metric between two equal dimensioned images. The normalized cross correlation metric measures how similar two images are, not how different they are. The range of ncc metric values is between 0 (dissimilar) and 1 (similar). If mode=g, then the two images will be converted to grayscale. If mode=rgb, then the two images first will be converted to colorspace=rgb. Next, the ncc similarity metric will be computed for each channel. Finally, they will be combined into an rms value.
    (via Dan O’Neill)

    (tags: image photos pictures similar imagemagick via:dano metrics similarity)

  • A Slower Speed of Light

    a first-person game prototype in which players navigate a 3D space while picking up orbs that reduce the speed of light in increments. Custom-built, open-source relativistic graphics code allows the speed of light in the game to approach the player’s own maximum walking speed. Visual effects of special relativity gradually become apparent to the player, increasing the challenge of gameplay. These effects, rendered in realtime to vertex accuracy, include the Doppler effect (red- and blue-shifting of visible light, and the shifting of infrared and ultraviolet light into the visible spectrum); the searchlight effect (increased brightness in the direction of travel); time dilation (differences in the perceived passage of time from the player and the outside world); Lorentz transformation (warping of space at near-light speeds); and the runtime effect (the ability to see objects as they were in the past, due to the travel time of light). Players can choose to share their mastery and experience of the game through Twitter. A Slower Speed of Light combines accessible gameplay and a fantasy setting with theoretical and computational physics research to deliver an engaging and pedagogically rich experience.

    (tags: games physics mit science light relativity)

  • Eventual Consistency Today: Limitations, Extensions, and Beyond – ACM Queue

    Good overview of the current state of eventually-consistent data store research, covering CALM and CRDTs, from Peter Bailis and Ali Ghodsi

    (tags: eventual-consistency data storage horizontal-scaling research distcomp distributed-systems via:martin-thompson crdts calm acid cap)

  • Latency’s Worst Nightmare: Performance Tuning Tips and Tricks [slides]

    the basics of running a service stack (web, app servers, data stores) on AWS. some good benchmark figures in the final slides

    (tags: benchmarks aws ec2 ebs piops services scaling scalability presentations)

  • Rob “b3ta” Manuel in Dublin next week

    The Bottom Half Of The Internet — “Racism; typos; filth; spam; ignorance; rage – that’s all the bottom half of the internet is good for, right? Rob Manuel wants you to question the internet dictum, most beloved of high-profile columnists, that you should ignore all of the comments all of the time. The ‘war on comments’, he reckons, might just be an echo of a fourth estate that’s having trouble adjusting to the idea of an unwashed public disagreeing with their sacred opinions. Sous les pavés, la plage.” On Tuesday, le cool Dublin & Pilcrow present SPIEL. Rob Manuel is the flashy animator behind B3ta and he’s joined by Ed Melvin, who wants to educate you on ‘The Unreal Engines’ of virtual currencies and economies.

    (tags: rob-manuel b3ta dublin comments internet meetings talks lecool)

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