Use the Magic SysRq Key on Linux to Fix Frozen X Servers, Cleanly Reboot, and Run Other Low-Level Commands – How-To Geek

A useful summary:

Cleanly Restarting Your System

Used in sequence, some of these actions can be used to cleanly end processes, flush data to disk, unmount all file systems, and restart your computer. To perform this process, press and hold the Alt + SysRq key combination and – while holding the Alt and SysRq keys down — type the following keys in order, pausing for several seconds in between each key:

reisub

The mnemonic “Raising Elephants Is So Utterly Boring” is often used to remember this sequence. Here’s what each key does:

r – Puts the keyboard into raw mode, taking control of it away from the X server.
e – Sends the terminate signal to all processes, asking them to end gracefully.
i – Sends the kill signal to all processes, forcing them to end immediately.
s – Flushes data from your cache to disk.
u – Remounts all file systems read-only.
b – Reboots your computer.

More Commands

Here are some other actions you can perform with the magic SysRq key. To perform an action, press and hold the Alt + SysRq keys while typing the letter:

n – Resets the nice level (priority) of all high and realtime priority processes.
f – Calls oom_kill, which will kill a memory-hogging process.
o – Shuts off the computer.

Use the Magic SysRq Key on Linux to Fix Frozen X Servers, Cleanly Reboot, and Run Other Low-Level Commands – How-To Geek.

How Apple has a shitload more profit not on the books and not taxed in the US

Apple’s foreign profits are funneled through different countries to reside in a country where there is no or little tax on profits. They don’t pay taxes in the US untill the money is repatriated to the US, but they do mark a portion of the money as being taxed in the US and take that off their books. This means that there are lower profit figures than they actually have allthough the money is still in foreign accounts.

How Apple's phantom taxes hide billions in profit.

Neuroscience joins cryptography – impant a password into a brain without the person knowing what the password is

Bojinov and colleagues designed a game lasting 30 to 45 minutes in which players intercept falling objects by pressing a key. The objects appear in one of six positions, each corresponding to a different key. Positions of objects were not always random. a hidden sequence of 30 successive positions was repeated over 100 times. Players made fewer errors when they encountered this sequence on successive rounds. This learning persisted when the players were tested two weeks later.

via Neuroscience joins cryptography.

safecopy

safecopy is a data recovery tool which tries to extract as much data as possible from a problematic (i.e. damaged sectors) source – like floppy drives, hard disk partitions, CDs, tape devices, …, where other tools like dd would fail due to I/O errors.

via safecopy.

Using EEG for incredibly rapid human image processing

This is an incredible story of a commercial neuroscience application being used to analyse images at the rate of 20 per second in order to pre screen them by sorting the chaff from the wheat. The brain can regonise and analyse images at that rate and spikes in electrical activity 300 milliseconds after seeing the images (the P300 response) indicate whether the images contain what you’re looking for.

From Bench to Bunker – The Chronicle Review – The Chronicle of Higher Education.

UK proposes to allow Google to digitise all copywriten works with no renumeration

Granted, copyright is a fussy subject which stifles innovation and freedom, but copyright holders are entitled to at least /some/ protection, at least for some time!

The UK government is considering a proposal to allow anyone to digitise anything and use the data for commercial purposes unless the creator of the content ‘opts out’ from this proces somehow. The digitiser only has to pay a ‘nominal fee’ (next to nothing) in order to be able to use the content if there is protest.

A deep critique in the link below.

Hargreaves Review: Extended Collective Licensing and Orphan Works « Action on Authors' Rights.