2,031 research outputs found
Symbolic Abstractions for Quantum Protocol Verification
Quantum protocols such as the BB84 Quantum Key Distribution protocol exchange
qubits to achieve information-theoretic security guarantees. Many variants
thereof were proposed, some of them being already deployed. Existing security
proofs in that field are mostly tedious, error-prone pen-and-paper proofs of
the core protocol only that rarely account for other crucial components such as
authentication. This calls for formal and automated verification techniques
that exhaustively explore all possible intruder behaviors and that scale well.
The symbolic approach offers rigorous, mathematical frameworks and automated
tools to analyze security protocols. Based on well-designed abstractions, it
has allowed for large-scale formal analyses of real-life protocols such as TLS
1.3 and mobile telephony protocols. Hence a natural question is: Can we use
this successful line of work to analyze quantum protocols? This paper proposes
a first positive answer and motivates further research on this unexplored path
A case of left atrial myxoma accompanied by pancytopenia and pathological findings suggestive of pulmonary hypertension
A case of left atrial myxoma accompanied by peculiar
symptoms is reported. A 15-year old boy had progressive congestive heart failure and three episodes of acute attacks of panctyopenia. The anemia was accompanied by helmet-shaped, broken red blood cells, erythroid hyperplasia and elevation of indirect bilirubin. The
thrombocytopenia gave rise to hemorrhagic tendency of the skin and mucous membrane. The leukocytopenia was seen at the same time. The patient also had general constitutional disturbances showing generalized malaise, persistent fever, elevation of erythrocyte sedimentation rate, positive C-reactive protein, pulmonary infection and anginal attacks. Postmortem examinations revealed a left atrial myxoma and intricated pulmonary changes. There was obliterative endarteritis of the left coronary branch and pulmonary arteries. The interstitial pulmonary fibrosis was also prominent. The pancytopenia should have been induced by the mechanical damage of circulating blood cells
by the left atrial myxoma. The pathological findings of the lungs were highly suggestive of pulmonary hypertension, which was assumed to be due to mitral block caused by the atrial myxoma.</p
Motion Planning for Kinematic systems
In this paper, we present a general theory of motion planning for kinematic
systems. This theory has been developed for long by one of the authors in a
previous series of papers. It is mostly based upon concepts from subriemannian
geometry. Here, we summarize the results of the theory, and we improve on, by
developping in details an intricated case: the ball with a trailer, which
corresponds to a distribution with flag of type 2,3,5,6.
This paper is dedicated to Bernard Bonnard for his 60th birthday
An angular momentum approach to quadratic Fourier transform, Hadamard matrices, Gauss sums, mutually unbiased bases, unitary group and Pauli group
The construction of unitary operator bases in a finite-dimensional Hilbert
space is reviewed through a nonstandard approach combinining angular momentum
theory and representation theory of SU(2). A single formula for the bases is
obtained from a polar decomposition of SU(2) and analysed in terms of cyclic
groups, quadratic Fourier transforms, Hadamard matrices and generalized Gauss
sums. Weyl pairs, generalized Pauli operators and their application to the
unitary group and the Pauli group naturally arise in this approach.Comment: Topical review (40 pages). Dedicated to the memory of Yurii
Fedorovich Smirno
The entropic cost to tie a knot
We estimate by Monte Carlo simulations the configurational entropy of
-steps polygons in the cubic lattice with fixed knot type. By collecting a
rich statistics of configurations with very large values of we are able to
analyse the asymptotic behaviour of the partition function of the problem for
different knot types. Our results confirm that, in the large limit, each
prime knot is localized in a small region of the polygon, regardless of the
possible presence of other knots. Each prime knot component may slide along the
unknotted region contributing to the overall configurational entropy with a
term proportional to . Furthermore, we discover that the mere existence
of a knot requires a well defined entropic cost that scales exponentially with
its minimal length. In the case of polygons with composite knots it turns out
that the partition function can be simply factorized in terms that depend only
on prime components with an additional combinatorial factor that takes into
account the statistical property that by interchanging two identical prime knot
components in the polygon the corresponding set of overall configuration
remains unaltered. Finally, the above results allow to conjecture a sequence of
inequalities for the connective constants of polygons whose topology varies
within a given family of composite knot types
Bases for qudits from a nonstandard approach to SU(2)
Bases of finite-dimensional Hilbert spaces (in dimension d) of relevance for
quantum information and quantum computation are constructed from angular
momentum theory and su(2) Lie algebraic methods. We report on a formula for
deriving in one step the (1+p)p qupits (i.e., qudits with d = p a prime
integer) of a complete set of 1+p mutually unbiased bases in C^p. Repeated
application of the formula can be used for generating mutually unbiased bases
in C^d with d = p^e (e > or = 2) a power of a prime integer. A connection
between mutually unbiased bases and the unitary group SU(d) is briefly
discussed in the case d = p^e.Comment: From a talk presented at the 13th International Conference on
Symmetry Methods in Physics (Dubna, Russia, 6-9 July 2009) organized in
memory of Prof. Yurii Fedorovich Smirnov by the Bogoliubov Laboratory of
Theoretical Physics of the JINR and the ICAS at Yerevan State University
Practical inventory routing: A problem definition and an optimization method
The global objective of this work is to provide practical optimization
methods to companies involved in inventory routing problems, taking into
account this new type of data. Also, companies are sometimes not able to deal
with changing plans every period and would like to adopt regular structures for
serving customers
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