210,634 research outputs found
DRA method: Powerful tool for the calculation of the loop integrals
We review the method of the calculation of multiloop integrals suggested in
Ref.\cite{Lee2010}.Comment: 6 pages, contribution to ACAT2011 proceedings, Uxbridge, London,
September 5-9, 2011, typos are correcte
Relativistic Coulomb Green's function in -dimensions
Using the operator method, the Green's functions of the Dirac and
Klein-Gordon equations in the Coulomb potential are derived for
the arbitrary space dimensionality . Nonrelativistic and quasiclassical
asymptotics of these Green's functions are considered in detail.Comment: 9 page
Temporal Aspects of Smart Contracts for Financial Derivatives
Implementing smart contracts to automate the performance of high-value
over-the-counter (OTC) financial derivatives is a formidable challenge. Due to
the regulatory framework and the scale of financial risk if a contract were to
go wrong, the performance of these contracts must be enforceable in law and
there is an absolute requirement that the smart contract will be faithful to
the intentions of the parties as expressed in the original legal documentation.
Formal methods provide an attractive route for validation and assurance, and
here we present early results from an investigation of the semantics of
industry-standard legal documentation for OTC derivatives. We explain the need
for a formal representation that combines temporal, deontic and operational
aspects, and focus on the requirements for the temporal aspects as derived from
the legal text. The relevance of this work extends beyond OTC derivatives and
is applicable to understanding the temporal semantics of a wide range of legal
documentation
Nonlinear dynamic intertwining of rods with self-contact
Twisted marine cables on the sea floor can form highly contorted
three-dimensional loops that resemble tangles. Such tangles or hockles are
topologically equivalent to the plectomenes that form in supercoiled DNA
molecules. The dynamic evolution of these intertwined loops is studied herein
using a computational rod model that explicitly accounts for dynamic
self-contact. Numerical solutions are presented for an illustrative example of
a long rod subjected to increasing twist at one end. The solutions reveal the
dynamic evolution of the rod from an initially straight state, through a
buckled state in the approximate form of a helix, through the dynamic collapse
of this helix into a near-planar loop with one site of self-contact, and the
subsequent intertwining of this loop with multiple sites of self-contact. This
evolution is controlled by the dynamic conversion of torsional strain energy to
bending strain energy or, alternatively by the dynamic conversion of twist (Tw)
to writhe (Wr).
KEY WORDS Rod Dynamics, Self-contact, Intertwining, DNA Supercoiling, Cable
HocklingComment: 35 pages, 9 figures, submitted to Proceedings of the Royal Society A:
Mathematical, Physical and Engineering Science
Similarity-Based Models of Word Cooccurrence Probabilities
In many applications of natural language processing (NLP) it is necessary to
determine the likelihood of a given word combination. For example, a speech
recognizer may need to determine which of the two word combinations ``eat a
peach'' and ``eat a beach'' is more likely. Statistical NLP methods determine
the likelihood of a word combination from its frequency in a training corpus.
However, the nature of language is such that many word combinations are
infrequent and do not occur in any given corpus. In this work we propose a
method for estimating the probability of such previously unseen word
combinations using available information on ``most similar'' words.
We describe probabilistic word association models based on distributional
word similarity, and apply them to two tasks, language modeling and pseudo-word
disambiguation. In the language modeling task, a similarity-based model is used
to improve probability estimates for unseen bigrams in a back-off language
model. The similarity-based method yields a 20% perplexity improvement in the
prediction of unseen bigrams and statistically significant reductions in
speech-recognition error.
We also compare four similarity-based estimation methods against back-off and
maximum-likelihood estimation methods on a pseudo-word sense disambiguation
task in which we controlled for both unigram and bigram frequency to avoid
giving too much weight to easy-to-disambiguate high-frequency configurations.
The similarity-based methods perform up to 40% better on this particular task.Comment: 26 pages, 5 figure
Talon cusp affecting primary dentition in two siblings: a case report
The term talon cusp refers to a rare developmental dental anomaly characterized by a cusp-like structure projecting from the cingulum area or cement-enamel junction. This condition can occur in the maxillary and mandibular arches of the primary and permanent dentitions. The purpose of this paper is to report on the presence of talon cusps in the primary dentition of two southern Chinese siblings. The 4 years and 2 months old girl had a talon cusp on her maxillary right primary central incisor, while her 2 years and 9 months old brother had bilateral talon cusps on the maxillary primary central incisors. The presence of this rare dental anomaly in two siblings has scarcely been reported in the literature and this may provide further evidence of a hereditary etiology.Article Link:
http://www.rjme.ro/RJME/resources/files/540113211213.pd
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