Microsoft Corporation is an American multinational corporation headquartered in Redmond, Washington, that develops, manufactures, licenses, supports and sells computer software, consumer electronics and personal computers and services. Its best known software products are the Microsoft Windows line of operating systems, Microsoft Office office suite, and Internet Explorer web browser. Its flagship hardware products are the Xbox game consoles and the Microsoft Surface tablet lineup. It is the world's largest software maker measured by revenues. It is also one of the world's most valuable companies.Microsoft was founded by Bill Gates and Paul Allen on April 4, 1975, to develop and sell BASIC interpreters for Altair 8800. It rose to dominate the personal computer operating system market with MS-DOS in the mid-1980s, followed by Microsoft Windows. The company's 1986 initial public offering, and subsequent rise in its share price, created three billionaires and an estimated 12,000 millionaires from Microsoft employees. Since the 1990s, it has increasingly diversified from the operating system market and has made a number of corporate acquisitions. In May 2011, Microsoft acquired Skype Technologies for $8.5 billion in its largest acquisition to date.As of 2013, Microsoft is market dominant in both the IBM PC-compatible operating system and office software suite markets . The company also produces a wide range of other software for desktops and servers, and is active in areas including Internet search , the video game industry , the digital services market , and mobile phones . In June 2012, Microsoft entered the personal computer production market for the first time, with the launch of the Microsoft Surface, a line of tablet computers.With the acquisition of Nokia's devices and services division to form Microsoft Mobile Oy, the company re-entered the smartphone hardware market, after its previous attempt, Microsoft Kin, which resulted from their acquisition of Danger Inc. Wikipedia.
Physical Review Letters | Year: 2012
I demonstrate that the wave function for a ν=n+ν∼ quantum Hall state with Landau levels 0,1,...,n-1 filled and a filling fraction ν∼ quantum Hall state with 0<ν∼≤1 in the nth Landau level can be obtained hierarchically from the ν=n state by introducing quasielectrons which are then projected into the (conjugate of the) ν∼ state. In particular, the ν∼=1 case produces the filled Landau level wave functions hierarchically, thus establishing the hierarchical nature of the integer quantum Hall states. It follows that the composite fermion description of fractional quantum Hall states fits within the hierarchy theory of the fractional quantum Hall effect. I also demonstrate this directly by generating the composite fermion ground-state wave functions via application of the hierarchy construction to fractional quantum Hall states, starting from the ν=1/m Laughlin states. © 2012 American Physical Society.
IEEE Journal on Selected Areas in Communications | Year: 2010
In a distributed storage system based on erasure coding, when a storage node fails, repairing the erasure code incurs some network traffic. Previous work has characterized the fundamental tradeoff between storage efficiency and repair network bandwidth. This was done via a cut-based analysis on a graph that models the evolution of information flow in the storage system subject to arbitrary sequences of node failures/repairs. This paper presents techniques for constructing network codes that achieve the optimal tradeoff between storage efficiency and repair network bandwidth. The challenge here is that network coding is applied over an unbounded graph with an unbounded number of receivers. It is shown in this paper that optimal codes can be constructed over a finite field whose size depends only on the maximum number of nodes at any instant, but independent of how many failures/repairs can happen. Key to the code construction is a "path-weaving" procedure that leads to inductive existence proof and code construction. © 2010 IEEE.
Proceedings of the Annual ACM Symposium on Theory of Computing | Year: 2011
We provide the first constant round constructions of non-malleable commitment and zero-knowledge protocols based only on one-way functions. This improves upon several previous (incomparable) works which required either: (a) super-constant number of rounds, or, (b) non-standard or sub-exponential hardness assumptions, or, (c) non-black-box simulation and collision resistant hash functions. These constructions also allow us to obtain the first constant round multi-party computation protocol relying only on the existence of constant round oblivious transfer protocols. Our primary technique can be seen as a means of implementing the previous "two-slot simulation" idea in the area of non-malleability with only black-box simulation. A simple modification of our commitment scheme gives a construction which makes use of the underlying one-way function in a black-box way. The modified construction satisfies the notion of what we call non-malleability w.r.t. replacement. Non-malleability w.r.t. replacement is a slightly weaker yet natural notion of non-malleability which we believe suffices for many application of non-malleable commitments. We show that a commitment scheme which is non-malleable only w.r.t. replacement is sufficient to obtain a (fully) black-box multi-party computation protocol. This allows us to obtain a constant round multi-party computation protocol making only a black-box use of the standard cryptographic primitives with polynomial-time hardness thus directly improving upon the recent work of Wee (FOCS'10). © 2011 ACM.
Communications of the ACM | Year: 2011
In the information realm, loss of privacy is usually associated with failure to control access to information, to control the flow of information, or to control the purposes for which information is employed. Differential privacy arose in a context in which ensuring privacy is a challenge even if all these control problems are solved: privacy-preserving statistical analysis of data. The problem of statistical disclosure control-revealing accurate statistics about a set of respondents while preserving the privacy of individuals-has a venerable history, with an extensive literature spanning statistics, theoretical computer science, security, databases, and cryptography (see, for example, the excellent survey of Adam and Wortmann,1 the discussion of related work in Blum et al.,2 and the Journal of Official Statistics dedicated to confidentiality and disclosure control). © 2011 ACM.
ACM Transactions on Graphics | Year: 2013
In this paper, we propose a general purpose approach to handwriting beautification using online input from a stylus. Given a sample of writings, drawings, or sketches from the same user, our method improves a user's strokes in real-time as they are drawn. Our approach relies on one main insight. The appearance of the average of multiple instances of the same written word or shape is better than most of the individual instances. We utilize this observation using a two-stage approach. First, we propose an efficient real-time method for finding matching sets of stroke samples called tokens in a potentially large database of writings from a user. Second, we refine the user's most recently written strokes by averaging them with the matching tokens. Our approach works without handwriting recognition, and does not require a database of predefined letters, words, or shapes. Our results show improved results for a wide range of writing styles and drawings. Copyright © ACM 2013.