Posts

Showing posts with the label algorithm

Compression Comparison Guide

We used to read about file compression tools eveyrday, back in the days of moving files on floppies. Space was limited, so it made sense. These days, people just copy everything in case they might need it for something or other sometime... So why bother testing file compressors? Because we can! And because technology have evolved.
Check out the Tech ARP - Compression Comparison Guide Rev. 2.0. It still matters which algorithm you use for what, and more time always means better compression!

Google Releases Paper on Disk Reliability

Google has been recording hard disk performance, their life cycle and the individual parameters of their estimated 100,000 hard disks since the beginning. Based on this data, they have analyzed the factors that determine lifespan and disk failure.
Surprisingly, temperatures are not that important. Highly stressed disks are also not more likely to fail, unless the stress occurs in the disk's first 6 months of operation...

PARC natural language patents may form Google rival

After failing to sell PARC, Xerox decided to sell off patents or create licenses for them they appear to have found a gem! Powerset is licensing PARC's "natural language" technology - the art of making computers understand and process languages like English or French. Powerset hopes the technology will be the basis of a new search engine that lets people type queries in plain English, rather than using keywords. Read more on CNET News.com

OpenPGP in Thunderbird

Image
I've recently installed Mozilla Thunderbird 1.5 and I like it very much! It imported all my accounts *(6!), mail folders and address book without a hitch. I really like that you can now detach attachments from mails and set a default folder where to save attachments. I also really like the addition of OpenPGP to Email.
PGP is a system based on trust that adds digital signatures to your Email and/or encrypt Emails. Everyone can generated their own public and private keys and distribute them among your friends. Your friends need your public key to be able to decrypt any encrypted messages to send, and can use it to verify that messages are really from you. Keys can be 2048 bytes, making them very secure and you can set the hash algorithm too, increasing the reliability of the system. A weak point with PGP but also a strength is that normally public keys must be exchanged in real-life, in person. That's the only way you can be sure, the key really belongs to a person. This way, yo…

Google's SiteRanking - How it works

Ever wondered how actually Google uses its Site Ranking algorithm? I mean really, precisely how it works?
Well now you can! Google filled a patent application to protect its idea. Getting a patent means you also have to reveal *exactly* how it's done. In exchange you get 20 years of protection for precisely what you claimed you've invented.
You can read the USPTO patent file or the article on buzzle.com.

Lexar LockTight

If you are a photographer and use a digital camera with CompactFlash cards, do you need to protect your photos from snooping? With the Lexar LockTight you can encrypt the CF card. The images are stored on a slightly modified CF Type I card, using the SHAH-1 algorithm with 160 bit keys. The data is protected and communication is encrypted. The reader is modifed to read the CF cards and decrypt the data. Accidental formatting is avoided by the card itself.
Sadly, the cards only run in Nikon DSLRs so far, the D2X and D2Hs, but they're working on broader camera support.

Bastard Tetris: Tetris Hates You

(From Slashdot) Listen up all you puzzle-loving folks: this one's for you. Some sadist out there has put together a Linux version of Tetris that uses a special algorithm to decide just which tetrad piece you need the least and then sends it in: Tetris Hates You

NSA Announces New Crypto Standards

Image
After all the comotion around SHA and the rumors that it was cracked, it didn't surprise me much to read that the NSA Announces New Crypto Standards. They will now use a system called "Suite B". This suite uses Elliptic Curve Diffie-Hellman (ECDH) and Elliptic Curve Menezes-Qu-Vanstone (ECMQV) for key agreement, and Elliptic Curve Digital Signature Algorithm (ECDSA) for signature generation/verification. So there... now you know.
/me scrambles to read up on specs of Suite B

Dutch government withdraws vote for Software Patents

Yesterday the Dutch government decided to withdraw its vote for Software Patents. :) Cool, that's good. Now let's hope it does some good too. See the FFII Software Patents section for complete coverage.
"This act represents an incisive criticism of the European Council of
Ministers' attempts to introduce broad patentability of software.
Minister Brinkhorst, acting on behalf of the Netherlands, endorsed the
Council's current proposal, which not only reiterated the terms of the
Council's strongly criticized first proposal, but went even further,
directly rebuffing the clear stance assumed by the EU Parliament,
which voted to add numerous amendments which made clear how the
category of logical algorithms would be treated."

Netcraft: Wikis: The Next Frontier for Spammers?

Image
Netcraft reports that spammers have a new tool on their hands. Appearantly, a webmaster has won a search engine optimization (SEO) contest using links in Wiki "sandboxes" - pages where users are urged to test drive the Wiki format and learn how to use it. By doing so, the webmaster made Google see that may "sites" and pages were linking to him, something which raises your importance according to Google because the algorithm thinks you are an important content creator. :)

HP Labs - Photographic memories: Always-on camera captures life's fleeting moments

Image
HP Labs is working on a way to create an always-on digicam so that you'll never loose a precious moment anymore... The biggest problem they have, the cam already exists, "is, can we develop algorithms that will automatically pick out the interesting bits?" Pattern-matching, filtering, motion detection, head tracking, image recognition... this is where it all come together B) Cooool!

Observations on the Adobe Photoshop RAW Plug-in

Observations on the Adobe Photoshop RAW Plug-in is a page with an analysis and comparison of two RAW filters for digital camera images. The original picture came from a Minolta DiMAGE 7i (I believe 6Mpx) and shows that although RAW is a more true and lossless format than JPG, one RAW is not the same as another RAW. Cameras use different algorithms to process the information coming from the CCD and the way they organize this information, makes a big difference! Check the two images on the webpage to see for yourself...
So the next time you think your RAW image is the closest digital approximation of the real world, think again!

Ed Pegg's Math Games - Paterson's Worms Revisited

"Worms eat sediment, delineating some sort of path. The 21 November 1969 issue of Science had computer simulations of worms, side by side with images of actual worm trail fossils. The ancient slimetrails enthralled John Conway and Mike Paterson. Mike started drawing algorithmic doodles for worms eating from an isometric grid (sometimes during lectures). His simple rules led to simple patterns for some worms, but many other doodles wound up being decidedly non-simple."
This problem, worms eating and wondering what their dietary habbits would look like, should they fossile again, kept people busy for 32 years. As of this month, Benjamin Chaffin (co-designer of the Pentium 4 chip and used to optimization problems and challanges), figured out a way to let the little critters roam and feed for long time and was able to solve all but two of the remaining questions. :respect:

First Certified DivX/DVD Player Released

Another cool article (on Slashdot) writes that "According to this piece of Designtechnica News, a company named KiSS Technology announced at CeBit that they are releasing the first fully certified DivX DVD players, the DP-450 and DP-500! They are supposed to be able to playback ALL versions of DivX content and digital rights management. And yes, it plays Ogg Vorbis, too!

That is awesome! DivX is simple and cheap MPEG4 encoding of movies. A DVD movie of 1.5 hrs, that normally takes up 4GB of space, can comfortably fit on one CD! This is still great for viewing on a TV, although if the screen is big (>32"), you might see the well-known digital artifacts that result from the compression algorithm. And Ogg Vorbis is a (relatively) new MP3 audio compression format. It is kinda revolutionary because it needs only half the space of current compression techniques at the same quality setting. One minute of audio generally requires roughly 1 MB of disk space. So now it's only h…