Saturday, January 21, 2012


IBM Research Determines Atomic Limits of Magnetic Memory.
IBM Creates the World’s Smallest Magnetic Memory Bit Using Only 12 Atoms
[01/15/2012 10:05 PM]
by Anton Shilov
Punctuating 30 years of nanotechnology research, scientists from IBM Research have successfully demonstrated the ability to store information in as few as 12 magnetic atoms. This is significantly less than today’s disk drives, which use about one million atoms to store a single bit of information. Until now, it was unknown how many atoms it would take to build a reliable magnetic memory bit.
While silicon transistor technology has become cheaper, denser and more efficient, fundamental physical limitations suggest this path of conventional scaling is unsustainable. Alternative approaches are needed to continue the rapid pace of computing innovation. The ability to manipulate matter by its most basic components – atom by atom – could lead to the vital understanding necessary to build smaller, faster and more energy-efficient devices. By taking a novel approach and beginning at the smallest unit of data storage, the atom, scientists demonstrated magnetic storage that is at least 100 times denser than today’s hard disk drives and solid state memory chips. Future applications of nanostructures built one atom at a time, and that apply an unconventional form of magnetism called antiferromagnetism, could allow people and businesses to store 100 times more information in the same space.
“The chip industry will continue its pursuit of incremental scaling in semiconductor technology but, as components continue to shrink, the march continues to the inevitable end point: the atom. We’re taking the opposite approach and starting with the smallest unit -- single atoms -- to build computing devices one atom at a time.” said Andreas Heinrich, the lead investigator into atomic storage at IBM Research-Almaden, in California.
With properties similar to those of magnets on a refrigerator, ferromagnets use a magnetic interaction between its constituent atoms that align all their spins – the origin of the atoms’ magnetism – in a single direction. Ferromagnets have worked well for magnetic data storage but a major obstacle for miniaturizing this down to atomic dimensions is the interaction of neighboring bits with each other. The magnetization of one magnetic bit can strongly affect that of its neighbor as a result of its magnetic field. Harnessing magnetic bits at the atomic scale to hold information or perform useful computing operations requires precise control of the interactions between the bits.
The scientists at IBM Research used a scanning tunneling microscope (STM) to atomically engineer a grouping of twelve antiferromagnetically coupled atoms that stored a bit of data for hours at low temperatures. Taking advantage of their inherent alternating magnetic spin directions, they demonstrated the ability to pack adjacent magnetic bits much closer together than was previously possible. This greatly increased the magnetic storage density without disrupting the state of neighboring bits.

Writing and reading a magnetic byte: this image shows a magnetic byte imaged 5 times in different magnetic states to store the ASCII code for each letter of the word "think", a corporate mantra used by IBM since 1914. The team achieved this using 96 iron atoms − one bit was stored by 12 atoms and there are eight bits in each byte.


From IBM

Friday, January 20, 2012

Facebook History



 Early 2003, Adam D'Angelo, then a Caltech student who had been Mark Zuckerberg's best friend in high school, had developed the experimental, rudimentary social networking website Buddy Zoo, that was used by hundreds of thousands of people before D'Angelo shut it down. That summer, Zuckerberg and friends who were also computer science students worked coding for the summer in Boston and discussed the implication of D'Angelo's website's success with regard to the future of social networking on the Internet.In the fall, Zuckerberg, returning for his sophomore year at Harvard, wrote CourseMatch, a briefly popular site that helped Harvard students figure out what courses their friends were taking;and then, on October 28, 2003, he wrote Facemash, a site that, according to the Harvard Crimson, represented a Harvard University version of Hot or Not.
That night, Zuckerberg made the following blog entries:

Brain behind facebook
Mark Zuckerberg created Facebook in his Harvard dorm room.

I'm a little intoxicated, not gonna lie. So what if it's not even 10 pm and it's a Tuesday night? What? The Kirkland [dorm] facebook is open on my desktop and some of these people have pretty horrendous facebook pics. I almost want to put some of these faces next to pictures of farm animals and have people vote on which is more attractive.
—9:48 pm
Yea, it's on. I'm not exactly sure how the farm animals are going to fit into this whole thing (you can't really ever be sure with farm animals...), but I like the idea of comparing two people together.
—11:09 pm
Let the hacking begin.
—12:58 am
According to The Harvard Crimson, Facemash "used photos compiled from the online facebooks of nine Houses, placing two next to each other at a time and asking users to choose the 'hotter' person". To accomplish this, Zuckerberg hacked into the protected areas of Harvard's computer network and copied the houses' private dormitory ID images.
Harvard at that time did not have a student directory with photos, and basic information and the initial site generated 450 visitors and 22,000 photo-views in its first four hours online. That the initial site mirrored people’s physical community—with their real identities—represented the key aspects of what later became Facebook.
"Perhaps Harvard will squelch it for legal reasons without realizing its value as a venture that could possibly be expanded to other schools (maybe even ones with good-looking people...)," Zuckerberg wrote in his personal blog. "But one thing is certain, and it’s that I’m a jerk for making this site. Oh well. Someone had to do it eventually..."The site was quickly forwarded to several campus group list-servers but was shut down a few days later by the Harvard administration. Zuckerberg was charged by the administration with breach of security, violating copyrights, and violating individual privacy, and faced expulsion, but ultimately the charges were dropped.
Zuckerberg expanded on this initial project that semester by creating a social study tool ahead of an art history final by uploading 500 Augustan images to a website, with one image per page along with a comment section.He opened the site up to his classmates and people started sharing their notes. "The professor said it had the best grades of any final he’d ever given. This was my first social hack. With Facebook, I wanted to make something that would make Harvard more open," Zuckerberg said in a TechCrunch interview.
On Oct 25, 2010, entrepreneur and banker Rahul Jain auctioned off FaceMash.com to an unknown buyer for $30,201.

thefacebook


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The homepage of Thefacebook on February 12, 2004
In January 2004, the following semester, Zuckerberg began writing code for a new website. He was inspired, he said, by an editorial in The Harvard Crimsonabout the Facemash incident. "It is clear that the technology needed to create a centralized Website is readily available," the paper observed. "The benefits are many." On February 4, 2004, Zuckerberg launched "Thefacebook", originally located at thefacebook.com. "Everyone’s been talking a lot about a universal face book within Harvard," Zuckerberg told The Harvard Crimson. "I think it’s kind of silly that it would take the University a couple of years to get around to it. I can do it better than they can, and I can do it in a week." "When Mark finished the site, he told a couple of friends. And then one of them suggested putting it on the Kirkland House online mailing list, which was...three hundred people," according to roommate Dustin Moskovitz. "And, once they did that, several dozen people joined, and then they were telling people at the other houses. By the end of the night, we were...actively watching the registration process. Within twenty-four hours, we had somewhere between twelve hundred and fifteen hundred registrants."
Just six days after the site launched, three Harvard seniors, Cameron WinklevossTyler Winklevoss, and Divya Narendra, accused Zuckerberg of intentionally misleading them into believing he would help them build a social network called HarvardConnection.com, while he was instead using their ideas to build a competing product.
The three complained to the Harvard Crimson and the newspaper began an investigation. Zuckerberg used his site, TheFacebook.com, to look up members of the site who identified themselves as members of the Crimson. Then he examined a log of failed logins to see if any of the Crimson members had ever entered an incorrect password into TheFacebook.com. In the cases in which they had entered failed logins, Mark tried to use them to access the Crimson members' Harvard email accounts. He successfully accessed two of them.The three later filed a lawsuit against Zuckerberg, later settling.
Membership was initially restricted to students of Harvard College, and within the first month, more than half the undergraduate population at Harvard was registered on the service. Eduardo Saverin(business aspects), Dustin Moskovitz (programmer), Andrew McCollum (graphic artist), and Chris Hughes soon joined Zuckerberg to help promote the website. In March 2004, Facebook expanded toStanfordColumbia, and Yale.This expansion continued when it opened to all Ivy League and Boston area schools, and gradually most universities in Canada and the United States.Facebook incorporated in the summer of 2004 and the entrepreneur Sean Parker, who had been informally advising Zuckerberg, became the company's president In June 2004, Facebook moved its base of operations to Palo Alto, California. The company dropped The from its name after purchasing the domain name facebook.com in 2005 for $200,000.
Face Book

On October 1, 2005, Facebook expanded to twenty-one universities in the United Kingdom, the entire Instituto Tecnologico y de Estudios Superiores de Monterrey (ITESM) system in Mexico, the entire University of Puerto Rico network in Puerto Rico, and the whole University of the Virgin Islands network in the U.S. Virgin Islands. Facebook launched a high school version in September 2005, which Zuckerberg called the next logical step. At that time, high school networks required an invitation to join. Facebook later expanded membership eligibility to employees of several companies, including Apple Inc. andMicrosoft. On December 11, 2005, universities in Australia and New Zealand were added to the Facebook network, bringing its size to 2,000+ colleges and 25,000 + high schools throughout the United States, Canada, Mexico, the United Kingdom, Australia, New Zealand, and Ireland. Facebook was then opened on September 26, 2006, to everyone of ages 13 and older with a valid e-mail address. In October 2008, Facebook announced that it was to set up its international headquarters inDublin, Ireland.
Total active users
Date
Users
(in millions)
Days later
Monthly growth
August 26, 2008
100
1,665
178.38%
April 8, 2009
200
225
13.33%
September 15, 2009
300
160
9.38%
February 5, 2010
400
143
6.99%
July 21, 2010
500
166
4.52%
January 5, 2011
600
168
3.57%
May 30, 2011
700
145
3.45%
September 22, 2011
800
115
3.73%
As of July 2010, Facebook.com was the top social network across eight individual markets in the Southeast Asia/Oceania region (Philippines, Australia, Indonesia, Malaysia, Singapore, New Zealand, Hong Kong and Vietnam), while other brands commanded the top positions in certain markets, including Google-owned Orkut in India and Brazil, Mixi.jp in Japan, RenRen in China (where Facebook is currently inaccessible), CyWorld in South Korea and Yahoo!’s Wretch.cc in Taiwan.[citation needed]Additionally, Facebook has become the largest online photo host, being cited by Facebook application and online photo aggregator Pixable as expecting to have 100 billion photos by summer 2011 
In 2010 Facebook began to pro-actively involve its users in running the website by inviting them to become beta testers after passing a question-and-answer-based selection process, and also by creating a new section known as Facebook Engineering Puzzles where users would solve computational problems and then potentially be hired by Facebook.it
Financials


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Facebook's former headquarters in downtown Palo Alto, California.

Facebook received its first investment of US$500,000 in June 2004 from PayPal co-founder Peter Thiel, in exchange for 7% of the company. This was followed a year later by $12.7 million in venture capital from Accel Partners, and then $27.5 million more from Greylock Partners. A leaked cash flow statement showed that during the 2005 fiscal year, Facebook had a net loss of $3.63 million.
With the sale of social networking website MySpace to News Corp on July 19, 2005, rumors surfaced about the possible sale of Facebook to a larger media company. Zuckerberg had already said he did not want to sell the company, and denied rumors to the contrary. On March 28, 2006, BusinessWeekreported that a potential acquisition of Facebook was under negotiation. Facebook reportedly declined an offer of $750 million from an unknown bidder, and it was rumored the asking price rose as high as $2 billion.
In September 2006, serious talks between Facebook and Yahoo! took place concerning acquisition of Facebook, with prices reaching as high as $1 billion.Thiel, by then a board member of Facebook, indicated that Facebook's internal valuation was around $8 billion based on their projected revenues of $1 billion by 2015, comparable to Viacom's MTV brand, a company with a shared target demographic audience.
On July 17, 2007, Zuckerberg said that selling Facebook was unlikely because he wanted to keep it independent, saying "We're not really looking to sell the company... We're not looking to IPO anytime soon. It's just not the core focus of the company." In September 2007, Microsoft approached Facebook, proposing an investment in return for a 5% stake in the company, offering an estimated $300–500 million. That month, other companies, including Google, expressed interest in buying a portion of Facebook.
On October 24, 2007, Microsoft announced that it had purchased a 1.6% share of Facebook for $240 million, giving Facebook a total implied value of around $15 billion. However, Microsoft boughtpreferred stock that carried special rights, such as "liquidation preferences" that meant Microsoft would get paid before common stockholders if the company is sold. Microsoft's purchase also included rights to place international ads on Facebook. In November 2007, Hong Kong billionaire Li Ka-shing invested $60 million in Facebook.


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Entrance to Facebook's current headquarters in the Stanford Research Park,Palo Alto, California.

In August 2008, BusinessWeek reported that private sales by employees, as well as purchases by venture capital firms, had and were being done at share prices that put the company's total valuation at between $3.75 billion and $5 billion. In October 2008, Zuckerberg said "I don't think social networks can be monetized in the same way that search did... In three years from now we have to figure out what the optimum model is. But that is not our primary focus today."
In August 2009, Facebook acquired social media real-time news aggregator FriendFeed,a startup created by the former Google employee and Gmail's first engineer Paul Buchheit who, while at Google, coined the phrase "Don't be evil". In September 2009, Facebook claimed that it had turned cash flow positive for the first time.In February 2010, Facebook acquired Malaysian contact-importing startup Octazen Solutions.On April 2, 2010, Facebook announced acquisition of photo-sharing service called Divvyshot for an undisclosed amount.In June 2010, an online marketplace for trading private company stock reflected a valuation of $11.5 billion.
At the All Things Digital conference in June 2010, Zuckerberg was asked if he expected to remain CEO if the company went public. Zuckerberg said he did, adding that he doesn't "think about going public ... much." He said he did not have a date in mind for a potential IPO.




Ubiquitous computing

Ubiquitous computing (ubicomp) is a post-desktop model of human-computer interaction in which information processing has been thoroughly integrated into everyday objects and activities. In the course of ordinary activities, someone "using" ubiquitous computing engages many computational devices and systems simultaneously, and may not necessarily even be aware that they are doing so. This model is usually considered an advancement from the desktop paradigm. More formally Ubiquitous computing is defined as "machines that fit the human environment instead of forcing humans to enter theirs."
This paradigm is also described as pervasive computing, ambient intelligence., where each term emphasizes slightly different aspects. When primarily concerning the objects involved, it is alsophysical computing, the Internet of Things, haptic computing,and things that think. Rather than propose a single definition for ubiquitous computing and for these related terms, a taxonomy of properties for ubiquitous computing has been proposed, from which different kinds or flavors of ubiquitous systems and applications can be described

Core concepts

At their core, all models of ubiquitous computing share a vision of small, inexpensive, robust networked processing devices, distributed at all scales throughout everyday life and generally turned to distinctly common-place ends. For example, a domestic ubiquitous computing environment might interconnect lighting and environmental controls with personal biometric monitors woven into clothing so that illumination and heating conditions in a room might be modulated, continuously and imperceptibly. Another common scenario posits refrigerators "aware" of their suitably tagged contents, able to both plan a variety of menus from the food actually on hand, and warn users of stale or spoiled food.
Ubiquitous computing presents challenges across computer science: in systems design and engineering, in systems modelling, and in user interface design. Contemporary human-computer interaction models, whether command-line, menu-driven, or GUI-based, are inappropriate and inadequate to the ubiquitous case. This suggests that the "natural" interaction paradigm appropriate to a fully robust ubiquitous computing has yet to emerge - although there is also recognition in the field that in many ways we are already living in an ubicomp world. Contemporary devices that lend some support to this latter idea include mobile phones, digital audio players, radio-frequency identification tags, GPS, and interactive whiteboards.
Mark Weiser proposed three basic forms for ubiquitous system devices, see also Smart device: tabs, pads and boards.
Tabs: wearable centimetre sized devices
Pads: hand-held decimetre-sized devices
Boards: metre sized interactive display devices.
These three forms proposed by Weiser are characterized by being macro-sized, having a planar form and on incorporating visual output displays. If we relax each of these three characteristics we can expand this range into a much more diverse and potentially more useful range of Ubiquitous Computing devices. Hence, three additional forms for ubiquitous systems have been proposed:
Dust: miniaturized devices can be without visual output displays, e.g., Micro Electro-Mechanical Systems (MEMS), ranging from nanometres through micrometers to millimetres. See also Smart dust.
Skin: fabrics based upon light emitting and conductive polymers, organic computer devices, can be formed into more flexible non-planar display surfaces and products such as clothes and curtains, see OLED display. MEMS device can also be painted onto various surfaces so that a variety of physical world structures can act as networked surfaces of MEMS.
Clay: ensembles of MEMS can be formed into arbitrary three dimensional shapes as artefacts resembling many different kinds of physical object (see also Tangible interface).
In his book The Rise of the Network Society, Manuel Castells suggests that there is an ongoing shift from already-decentralised, stand-alone microcomputers and mainframes towards entirely pervasive computing. In his model of a pervasive computing system, Castells uses the example of the Internet as the start of a pervasive computing system. The logical progression from that paradigm is a system where that networking logic becomes applicable in every realm of daily activity, in every location and every context. Castells envisages a system where billions of miniature, ubiquitous inter-communication devices will be spread worldwide, "like pigment in the wall paint".

History

Mark Weiser coined the phrase "ubiquitous computing" around 1988, during his tenure as Chief Technologist of the Xerox Palo Alto Research Center (PARC). Both alone and with PARC Director and Chief Scientist John Seely Brown, Weiser wrote some of the earliest papers on the subject, largely defining it and sketching out its major concerns.
Recognizing that the extension of processing power into everyday scenarios would necessitate understandings of social, cultural and psychological phenomena beyond its proper ambit, Weiser was influenced by many fields outside computer science, including "philosophy, phenomenology, anthropology, psychology, post-Modernism, sociology of science and feminist criticism." He was explicit about "the humanistic origins of the ‘invisible ideal in post-modernist thought'", referencing as well the ironically dystopian Philip K. Dick novel Ubik.
Dr. Ken Sakamura of University of Tokyo, Japan leads the Ubiquitous Networking Laboratory (UNL), Tokyo as well as the T-Engine Forum. The joint goal of Sakamura's Ubiquitous Networking specification and the T-Engine forum, is to enable any everyday device to broadcast and receive information.
MIT has also contributed significant research in this field, notably Things That Think consortium (directed by Hiroshi Ishii, Joseph A. Paradiso and Rosalind Picard) at the Media Lab and the CSAIL effort known as Project Oxygen.  Other major contributors include Georgia Tech's College of Computing, NYU's Interactive Telecommunications Program, UC Irvine's Department of Informatics,Microsoft Research, Intel Research and Equator,  Ajou University UCRi & CUS.


FROM WIKIPEDIA