After losing with a rock, for example, a player was more likely to play paper in the next round than the “one in three” rule would predict.
This “win-stay lose-shift” strategy is known in game theory as a conditional response – and it may be hard-wired into the human brain, the researchers say
Category Archives: STEM
What are colored coins?
What exactly are colored coins? I’ve tried understanding, but I don’t quite get it yet . . . Do any examples exist?
via alternatives – What are colored coins? – Bitcoin Stack Exchange.
Colored coins are a method to track the origin of bitcoins, so that a certain set of coins can be set aside and conserved, allowing a party to acknowledge them in various ways. Such coins can be used to represent arbitrary digital tokens, such as stocks, bonds, smart property and so on.
The colored coins protocol is decentralized just like Bitcoin, but the current effort to develop an implementation is done under the BitcoinX project (tentative name), which also aims to provide some related services.
As this is still under development, you will not find any existing examples.
You can read more about it in Overview of colored coins (work in progress).
Lapse-Pi Touch – A Touchscreen Timelapse Controller
Functionality
The User interface allows you to:
- position the dolly on the rail via the motor control buttons
- change the motor pulse duration between shots
- change the delay between shots
- change the number of shots
- see what time is left for the current sequence
- start and stop the time-lapse
And it’s all done using a few simple screens with a simplistic, easy-to-use touchscreen user interface. The following video shows it all in action.
The Hackers Who Recovered NASA’s Lost Lunar Photos
When they learned through a Usenet group that former NASA employee Nancy Evans might have both the tapes and the super-rare Ampex FR-900 drives needed to read them, they jumped into action. They drove to Los Angeles, where the refrigerator-sized drives were being stored in a backyard shed surrounded by chickens. At the same time, they retrieved the tapes from a storage unit in nearby Moorpark, and things gradually began to take shape. Funding the project out of pocket at first, they were consumed with figuring out how to release the images trapped in the tapes.
via The Hackers Who Recovered NASA’s Lost Lunar Photos | Raw File | WIRED.
The resulting framelets had to be individually reassembled in Photoshop. After kluging through countless engineering problems (try finding a chemical substitute for whale oil to lubricate tape heads), the LOIRP team was able to single out and reproduce the famous earthrise image. This proof of concept brought the first NASA funding in 2008, and the team recently completed processing the entire tape collection.
Preventing Heat From Going to Waste
Thermoelectrics are slabs of semiconductor with a strange and useful property: heating them on one side generates an electric voltage that can be used to drive a current and power devices. To obtain that voltage, thermoelectrics must be good electrical conductors but poor conductors of heat, which saps the effect. Unfortunately, because a material’s electrical and heat conductivity tend to go hand in hand, it has proven difficult to create materials that have high thermoelectric efficiency—a property scientists represent with the symbol ZT.
via Preventing Heat From Going to Waste | Science/AAAS | News.
The key to the ultralow thermal conductivity, Kanatzidis says, appears to be the pleated arrangement of tin and selenium atoms in the material, which looks like an accordion. The pattern seems to help the atoms flex when hit by heat-transmitting vibrations called phonons, thus dampening SbSe’s ability to conduct heat. The researchers report the results today in Nature.
BASIC at 50
At 4 a.m. on May 1, 1964, in the basement of College Hall, Professor John Kemeny and a student programmer simultaneously typed RUN on neighboring terminals. When they both got back correct answers to their simple programs, time-sharing and BASIC were born.
via BASIC at 50.
Virtual AGC Home Page
The Apollo spacecraft used for lunar missions in the late 1960’s and early 1970’s was really two different spacecraft, the Command Module (CM) and the Lunar Module (LM). The CM was used to get the three astronauts to the moon, and back again. The LM was used to land two of the astronauts on the moon while the third astronaut remained in the CM, in orbit around the moon.
The Virtual AGC project provides a virtual machine which simulates the AGC, the DSKY, and some other portions of the guidance system. In other words, if the virtual machine—which we call yaAGC—is given the same software which was originally run by the real AGCs, and is fed the same input signals encountered by the real AGCs during Apollo missions, then it will responds in the same way as the real AGCs did. The Virtual AGC software is free of charge, can be obtained for Windows, Mac OS X, Linux, or as open source software source code so that it can be studied or modified.
Software upgrade at 655 million kilometres
Although Rosetta and MIDAS spent 957 days in hibernation, the MIDAS team back on Earth were busy learning how best to use MIDAS with tests on the Flight Spare (the identical twin instrument). As a result we have made a number of tweaks and enhancements to the software ready for our encounter with comet 67P/CG. After the passive checkout we know that we’re in good shape, so the next step is to upload and apply the software patches. The new software was tested both on the Flight Spare and on an instrument/processor simulator developed by the institute.
via Software upgrade at 655 million kilometres | Rosetta – ESA’s comet chaser.
The Mining Algorithm And CPU Mining – All About Bitcoin Mining: Road To Riches Or Fool’s Gold?
One of the most difficult problems in computer science is reversing a secure hash (finding an input text for a given output, the digital signature). Let me explain this problem in simple terms. Let’s assume the wealthy but terminally ill Alice wrote her will and stored it on her computer. Knowing that a computer can be hacked and the will can be altered, Alice digitally signed her will with the secure hash algorithm SHA-256. She then emailed the digital signature to all her friends, allowing them to check the validity of the document. Bob wants to hack into the computer and change Alice’s will so that he becomes the sole beneficiary, but he faces a problem: he needs to change the will in such a way that the widely distributed SHA-256 signature stays the same. Otherwise, everybody realizes that the will has been forged. This is the computationally difficult problem of reversing or brute-forcing SHA-256, or finding an input that matches a predefined output. Satoshi famously decided that in order to find a new block, people all over the world need to compete in reversing SHA-256, turning block creation into a global lottery.
via The Mining Algorithm And CPU Mining – All About Bitcoin Mining: Road To Riches Or Fool’s Gold?.
Once very popular among Bitcoin miners, but now somewhat dated, the Radeon HD 5830 card boasts 1120 stream processing units. But that doesn’t mean it literally has 1120 separate cores. Rather, the GPU employs 224 SIMD cores, each of which sports five ALUs operating in parallel (VLIW5).
How to return to the moon in just four years
In a four-launch scenario, the lander would precede the crew to the moon. The first two launches would be a moon injection stage followed by a lunar lander. These two vehicles would rendezvous in Earth’s orbit before the moon injection stage would send the lander ahead to the moon. The next two Falcon launches would carry a second moon injection stage and then the crew in their capsule/service module. After a similar boost in a moon-injection stage, they would meet up with the lander in lunar orbit.
The rest of the mission would be like the Apollo mission — Americans on the moon, once again taking giant leaps for mankind.
via How to return to the moon in just four years | Fox News.