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Hans Peter Luhn and the Birth of the Hashing Algorithm

The IBM engineer’s hashing algorithm gave computers a way to quickly search documents, DNA, and databases

10 min read
Photo: IBM
Information Scientist: Starting in the 1940s, Luhn devised machines and schemes for parsing information, most notably the now widely used hashing algorithm, which he suggested as a way to sort both numbers and text.
Photo: IBM

In November 1958, at a six-day international conference devoted to scientific information, the inventor Hans Peter Luhn demonstrated a series of his electromechanical machines. They looked rather ordinary. Much like other computing devices of the day, they were boxy and utilitarian, designed to scoop and sort tall stacks of punch cards into slots and bins.

Unlike other computers, however, Luhn’s devices were not designed to work with numbers and calculations but rather with words and sentences. One machine that drew particular attention implemented an algorithm that Luhn called KWIC, for Key Word in Context. Taking in a large number of texts—typically, articles from 500 to 5,000 words in length—the KWIC system could quickly and automatically construct a kind of index.

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This Wearable Neck Patch Can Diagnose Concussions

Self-powered sensors convert neck strain into electrical pulses to detect head trauma in athletes

4 min read
image of back of man's head and shoulders with a patch taped to his lower neck; right image is a time lapse image of a man's head extending far forward and back, simulating a case of whiplash

The prototype patch in this research is shown in (a) on the left; on the right (b) is the kind of head rotation that can yield an electrical response from the patch.

Juan Pastrana

Nelson Sepúlveda was sitting in the stands at Spartan Stadium, watching his hometown Michigan State players bash heads with their cross-state football rivals from the University of Michigan, when he had a scientific epiphany.

Perhaps the nanotechnologies he had been working on for years—paper-thin devices known as ferroelectret nanogenerators that convert mechanical energy into electrical energy—could help save these athletes from the ravages of traumatic brain injury.

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Video Friday: PoKeBo Cubes

Your weekly selection of awesome robot videos

2 min read
A young girl looks at a cluster of three simple robots facing each other on a table

Video Friday is your weekly selection of awesome robotics videos, collected by your friends at IEEE Spectrum robotics. We also post a weekly calendar of upcoming robotics events for the next few months. Please send us your events for inclusion.

RoboCup 2022: 11 July–17 July 2022, BANGKOK
IEEE CASE 2022: 20 August–24 August 2022, MEXICO CITY
CLAWAR 2022: 12 September–14 September 2022, AZORES, PORTUGAL
ANA Avatar XPRIZE Finals: 4 November–5 November 2022, LOS ANGELES
CoRL 2022: 14 December–18 December 2022, AUCKLAND, NEW ZEALAND

Enjoy today’s videos!

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