Cops and Robbers (and Zombies and Humans)
Cops and Robbers is a mathematical game in which pursuers (cops) attempt to capture evaders (robbers). The game is one of many pursuit-evasion games, each of which is governed by a different set of rules. The general goal of these problems is to determine the number of pursuers required to capture a given number of evaders.
The GIFs above show two versions of the game. The first is similar to the standard Cops and Robbers rendition, and the second is best described as “Zombies and Humans”.
In both versions, an evader moves in the direction that gets it furthest away from the pursuers (focusing more on the closer pursuers), and a pursuer moves in the direction that gets it closest to the evaders (focusing more on the closer evaders).
In the first simulation, members of both groups have a constant speed. In the second simulation, members of a group move more quickly the closer they are to members of the opposite group, and slower when further away.Mathematica code posted here.
V: Five Rooms (Part I) PRCZ-3
we see to understand and give so you might show us
PRCZ-3 is the first room, there are five in total.
In this room there is watching, and waiting.
In this room there is nothing to see.
Works comprising the V series are not open in a traditional sense; instead there is an invitation to participate through limited observation. Each work presents its audience with one of the following roles:
an outsider, a view from beyond the work;
a subject, viewing themselves within the work; or
a component of the work, viewing the work from within.
The viewer, in this instance, is invited to observe from outside the gallery.
UbuWeb mourns the passing of the great American composer Robert Ashley. You can listen to his music and invterviews here, watch his films here, read about him here. If you’re unfamiliar with his work, the best place to start is Peter Greenaway’s documentary Four American Composers: Robert Ashley (1983). His most well-known video work is Perfect Lives (1978-83), a television opera in seven parts. He interviewed composers such as Terry Riley, Philip Glass, Alvin Lucier, Pauline Oliveros, David Behrman, and Gordon Mumma in his epic video series, Music With Roots in the Aether, where interviews are followed by performances. He will be missed.
Katydid Nymph (Olcinia or Sathrophyllia sp., Cymatomerini, Pseudophyllinae, Tettigonidae)
by Sinobug (itchydogimages) on Flickr.
Pu’er, Yunnan, China
See more Chinese grasshoppers and crickets on my Flickr site HERE…..
Working interactive tabletop display prototype projects onto mist, allowing to ‘reach into’ the display space and manipulate 3D content with gestures - video embedded below:
MisTable is a tabletop system that combines a conventional horizontal interactive surface with personal screens between the user and the tabletop surface. These personal screens, built using fog, are both see-through and reach-through. Being see-through provides direct line of sight of the personal screen and the elements behind it on the tabletop. Being reach-through allows the user to switch from interacting with the personal screen to reaching through it to interact with the tabletop or the space above it. The personal screen allows a range of customisations and novel interactions such as presenting 2D personal contents on the screen, 3D contents above the tabletop or augmenting and relighting tangible objects differently for each user. Besides, having a personal screen for each user allows us to customise the view of each of them according to their identity or preferences. Finally, the personal screens preserve all well-established tabletop interaction techniques like touch and tangible interactions. We explore the challenges in building such a reach-through system through a proof-of-concept implementation and discuss the possibilities afforded by the system.
More at Bristol Interactive and Graphics here
”…I forgot to ask him how he shot the rocket launch scene, but the space station was an incredibly expensive, very detailed set, made out of thick duralumin. The cold metallic light was gleaming in silver; red, blue, and green beams intricately blinked and twisted from the lights of the various gauges lined up in a row. And above that ran two duralumin rails, from which hung a camera on small wheels, completely free to move about the entire space station set. Tarkovsky took me around, explaining everything to me, beaming with pride like a child showing off the contents of his toy box.”
- Akira Kurosawa
How to catch a satellite
Standard space dockings are difficult enough, but a future ESA mission plans to capture derelict satellites adrift in orbit. Part of an effort to control space debris, the shopping list of new technologies this ambitious mission requires is set for discussion with industry experts.
ESA’s Clean Space initiative is studying the e.DeOrbit mission for removing debris, aiming to reduce the environmental impact of the space industry on Earth and space alike.
Decades of launches have left Earth surrounded by a halo of space junk: more than 17 000 trackable objects larger than a coffee cup, which threaten working missions with catastrophic collision. Even a 1 cm nut could hit with the force of a hand grenade.
The only way to control the debris population across key low orbits is to remove large items such as derelict satellites and launcher upper stages.
Such uncontrolled multi-tonne items are not only collision risks but also time bombs: they risk exploding due to leftover fuel or partially charged batteries heated up by orbital sunlight.
The resulting debris clouds would make these vital orbits much more hazardous and expensive to use, and follow-on collisions may eventually trigger a chain reaction of break-ups.
e.DeOrbit is designed to target debris items in well-trafficked polar orbits, between 800 km to 1000 km altitude. At around 1600 kg, e.DeOrbit will be launched on ESA’s Vega rocket.
The first technical challenge the mission will face is to capture a massive, drifting object left in an uncertain state, which may well be tumbling rapidly. Sophisticated imaging sensors and advanced autonomous control will be essential, first to assess its condition and then approach it.
Making rendezvous and then steady stationkeeping with the target is hard enough but then comes the really difficult part: how to secure it safely ahead of steering the combined satellite and salvage craft down for a controlled burn-up in the atmosphere?
Several capture mechanisms are being studied in parallel to minimise mission risk. Throw-nets have the advantage of scalability – a large enough net can capture anything, no matter its size and attitude. Tentacles, a clamping mechanism that builds on current berthing and docking mechanisms, could allow the capture of launch adapter rings of various different satellites.
Harpoons work no matter the target’s attitude and shape, and do not require close operations. Robotic arms are another option: results from the DLR German space agency’s forthcoming DEOS orbital servicing mission will be studied with interest.
Strong drivers for the platform design are not only the large amount of propellant required, but also the possible rapid tumbling of the target – only so much spin can be absorbed without the catcher craft itself going out of control.
Apart from deorbit options based on flexible and rigid connections, techniques are being considered for raising targets to higher orbits, including tethers and electric propulsion.
TOP IMAGE…One capture concept being explored through ESA’s e.Deorbit system study for Active Debris Removal - capturing the satellite in a net attached to either a flexible tether (as seen here) or a rigid connection. Copyright ESA
CENTRE IMAGE…Simulations of orbital debris show that actively removing large items of debris, such as entire derelict satellites, should help stabilise its population and prevent a collision-based cascade effect. ESA has performed a system study for an Active Debris Removal mission called e.Deorbit. Copyright ESA
LOWER IMAGE…All human-made space objects result from the near-5000 launches since the start of the space age. About 65% of the catalogued objects, however, originate from break-ups in orbit – more than 240 explosions – as well as fewer than 10 known collisions. Scientists estimate the total number of space debris objects in orbit to be around 29 000 for sizes larger than 10 cm, 670 000 larger than 1 cm, and more than 170 million larger than 1 mm.
Any of these objects can cause harm to an operational satellite. For example, a collision with a 10 cm object would entail a catastrophic fragmentation of a typical satellite, a 1 cm object will most likely disable a spacecraft and penetrate the International Space Station shields, and a 1 mm object could destroy subsystems. Scientists generally agree that, for typical satellites, a collision with an energy-to-mass ratio exceeding 40 J/g would be catastrophic. Copyright ESA
Here, you can surely learn to play Go because you can actually play. Enjoy!
Before you begin, please remember just 3 rules below.
- Two players (black and white) take turns, placing one stone on the board at a time.
- A stone must be placed on the intersection of the vertical and horizontal lines.
- Once a stone is placed, you can’t move it, although under some conditions it may be removed.
They are just too easy, aren’t they?
Now, you understand half the rules of Go!
Audiokinetic Jukebox: Program 2 at White Night Festival 2014
NGV Australia: The Ian Potter Centre, 7pm 22nd February to 7am 23rd February
RMIT University’s Audiokinetic Experiments lab presents Darrin Verhagen’s Audiokinetic Jukebox: Program 2, an installation at NGV Australia for White Night Festival 2014.
The Audiokinetic Jukebox is a single participant, immersive artwork integrating sound, movement, vibration and light into a multisensory aesthetic experience, developed by Darrin Verhagen at RMIT’s Audiokinetic Experiments (AkE) Lab.
The project repurposes a motion simulator which tilts a chair on an x-y axis. At its base is a transducer which delivers additional levels of fine vibration. The audience member sits in the chair, in headphones, eyes closed, with abstract visuals (driven by the music) projected directly into their faces. The end result is powerfully immersive, dynamic and stimulating.
The curated works in Program Two range from hypnotic drone through to cinematic sound design, from Noise to K-pop. Darrin Verhagen’s two pieces of Power Electronics transform the abstract assault of an extreme genre into the visceral exhilaration of vehicular travel. Robin Fox’s sinusoidal ambience and intense colourfields explore the theories that light can stimulate the pineal gland into producing DMT. Adam Hunt homages Nine Inch Nails with industrial pop which oscillates between gentle threat and gleeful violence. And James Paul blasts pop music, crafts science fiction and replaces the senses with raw stimuli.
Open one night only at the NGV Australia: The Ian Potter Centre.
The Gladiator Spider can make an expandable sticky web like a net. When an insect passes below it, it stretches out the net, lunges downwards and flings the net over the prey.
Complete Me is an action-packed text-based adventure game in which you control Hair Ghost, a ghost with hair.
Explore strange worlds in an attempt to put the hair back on your corpse, interact with scary ghosts, and do what you have to do to survive
(and so you don’t look like a bald fool at your funeral.)
You can pick up a digital copy at a pay-what-you-want price here.