8,277 research outputs found
Introduction to Quantum Information Processing
As a result of the capabilities of quantum information, the science of
quantum information processing is now a prospering, interdisciplinary field
focused on better understanding the possibilities and limitations of the
underlying theory, on developing new applications of quantum information and on
physically realizing controllable quantum devices. The purpose of this primer
is to provide an elementary introduction to quantum information processing, and
then to briefly explain how we hope to exploit the advantages of quantum
information. These two sections can be read independently. For reference, we
have included a glossary of the main terms of quantum information.Comment: 48 pages, to appear in LA Science. Hyperlinked PDF at
http://www.c3.lanl.gov/~knill/qip/prhtml/prpdf.pdf, HTML at
http://www.c3.lanl.gov/~knill/qip/prhtm
Bounding Rationality by Discounting Time
Consider a game where Alice generates an integer and Bob wins if he can
factor that integer. Traditional game theory tells us that Bob will always win
this game even though in practice Alice will win given our usual assumptions
about the hardness of factoring.
We define a new notion of bounded rationality, where the payoffs of players
are discounted by the computation time they take to produce their actions. We
use this notion to give a direct correspondence between the existence of
equilibria where Alice has a winning strategy and the hardness of factoring.
Namely, under a natural assumption on the discount rates, there is an
equilibriumwhere Alice has a winning strategy iff there is a linear-time
samplable distribution with respect to which Factoring is hard on average.
We also give general results for discounted games over countable action
spaces, including showing that any game with bounded and computable payoffs has
an equilibrium in our model, even if each player is allowed a countable number
of actions. It follows, for example, that the Largest Integer game has an
equilibrium in our model though it has no Nash equilibria or epsilon-Nash
equilibria.Comment: To appear in Proceedings of The First Symposium on Innovations in
Computer Scienc
Mathematical computer programs: A compilation
Computer programs, routines, and subroutines for aiding engineers, scientists, and mathematicians in direct problem solving are presented. Also included is a group of items that affords the same users greater flexibility in the use of software
Bounding Rationality by Discounting Time
Consider a game where Alice generates an integer and Bob wins if he can factor that integer. Traditional game theory tells us that Bob will always win this game even though in practice Alice will win given our usual assumptions about the hardness of factoring. We define a new notion of bounded rationality, where the payoffs of players are discounted by the computation time they take to produce their actions. We use this notion to give a direct correspondence between the existence of equilibria where Alice has a winning strategy and the hardness of factoring. Namely, under a natural assumption on the discount rates, there is an equilibriumwhere Alice has a winning strategy iff there is a linear-time samplable distribution with respect to which Factoring is hard on average. We also give general results for discounted games over countable action spaces, including showing that any game with bounded and computable payoffs has an equilibrium in our model, even if each player is allowed a countable number of actions. It follows, for example, that the Largest Integer game has an equilibrium in our model though it has no Nash equilibria or E-Nash equilibria.Bounded rationality; Discounting; Uniform equilibria; Factoring game
The Quantum Frontier
The success of the abstract model of computation, in terms of bits, logical
operations, programming language constructs, and the like, makes it easy to
forget that computation is a physical process. Our cherished notions of
computation and information are grounded in classical mechanics, but the
physics underlying our world is quantum. In the early 80s researchers began to
ask how computation would change if we adopted a quantum mechanical, instead of
a classical mechanical, view of computation. Slowly, a new picture of
computation arose, one that gave rise to a variety of faster algorithms, novel
cryptographic mechanisms, and alternative methods of communication. Small
quantum information processing devices have been built, and efforts are
underway to build larger ones. Even apart from the existence of these devices,
the quantum view on information processing has provided significant insight
into the nature of computation and information, and a deeper understanding of
the physics of our universe and its connections with computation.
We start by describing aspects of quantum mechanics that are at the heart of
a quantum view of information processing. We give our own idiosyncratic view of
a number of these topics in the hopes of correcting common misconceptions and
highlighting aspects that are often overlooked. A number of the phenomena
described were initially viewed as oddities of quantum mechanics. It was
quantum information processing, first quantum cryptography and then, more
dramatically, quantum computing, that turned the tables and showed that these
oddities could be put to practical effect. It is these application we describe
next. We conclude with a section describing some of the many questions left for
future work, especially the mysteries surrounding where the power of quantum
information ultimately comes from.Comment: Invited book chapter for Computation for Humanity - Information
Technology to Advance Society to be published by CRC Press. Concepts
clarified and style made more uniform in version 2. Many thanks to the
referees for their suggestions for improvement
The Quantum Tortoise and the Classical Hare: A simple framework for understanding which problems quantum computing will accelerate (and which it will not)
Quantum computing promises transformational gains for solving some problems,
but little to none for others. For anyone hoping to use quantum computers now
or in the future, it is important to know which problems will benefit. In this
paper, we introduce a framework for answering this question both intuitively
and quantitatively. The underlying structure of the framework is a race between
quantum and classical computers, where their relative strengths determine when
each wins. While classical computers operate faster, quantum computers can
sometimes run more efficient algorithms. Whether the speed advantage or the
algorithmic advantage dominates determines whether a problem will benefit from
quantum computing or not. Our analysis reveals that many problems, particularly
those of small to moderate size that can be important for typical businesses,
will not benefit from quantum computing. Conversely, larger problems or those
with particularly big algorithmic gains will benefit from near-term quantum
computing. Since very large algorithmic gains are rare in practice and
theorized to be rare even in principle, our analysis suggests that the benefits
from quantum computing will flow either to users of these rare cases, or
practitioners processing very large data
Adoption of Blockchain Technology in Trade Finance Process
The complexity of trade finance instruments associated with need for many accompanying documents, constant coordination are problems of this process. Successful development of trade finance instruments depend on improvement of software and implement blockchain solutions that enable companies to unite and through partnerships and process automation to accelerate cash flow and documentation throughout supply chain. The paper aims to examine areas and ways of blockchain application in trade finance and to identify key aspects of improving transactions process. We present possible interaction of participants with digital letters of credit and factoring with blockchain application and display its effect on key trade finance instruments. Moreover, we identifies a number of problems, implementation solutions of which will lead to further more efficient application of technology in supply chain finance. The achieving these goals will lead to further more effective application of blockchain in financing of supply chain. Blockchain with a high level of functionality and security in trade finance processes reduces processing time for documents, transaction costs, expanding number of participants and increases level of transparency
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