546 research outputs found
Hidden attractors in fundamental problems and engineering models
Recently a concept of self-excited and hidden attractors was suggested: an
attractor is called a self-excited attractor if its basin of attraction
overlaps with neighborhood of an equilibrium, otherwise it is called a hidden
attractor. For example, hidden attractors are attractors in systems with no
equilibria or with only one stable equilibrium (a special case of
multistability and coexistence of attractors). While coexisting self-excited
attractors can be found using the standard computational procedure, there is no
standard way of predicting the existence or coexistence of hidden attractors in
a system. In this plenary survey lecture the concept of self-excited and hidden
attractors is discussed, and various corresponding examples of self-excited and
hidden attractors are considered
General Scheme of Risk â Oriented Audit Stages
The article examines the problem of applying risk-oriented approach in audit. A risk-oriented approach on the one hand allows to increase efficiency of auditorsâ activity, the level of compliance with mandatory requirements, and on the other hand, to avoid the excessive inspectionsâ procedures in the formation of a scientifically grounded framework of reasonable sufficiency inherent to each specific audit. At the same time, risk-oriented approach needs to create its own methodological base, develop methodologies and relevant accompanying documents, and, most importantly, train personnel capable of implementing this innovative methodology. For this reason, topic of this paper is extremely relevant.
Keywords: audit, risk-oriented approach, planning, accounting (financial) statement
Rules of Internal Control of the Broker as a Tool for Risk Management of ML/FT
The article analyzes and identifies the features of a brokerage company as an economic entity, identifies the main risks of a broker in the sphere of ML/FT, and examines the rules of internal control and the requirements imposed on them.
Keywords: internal control, broker, risks, economic securit
The Use of Analytical Tools in the Conduct of Internal Control Procedures
The work is devoted to the study of the problems of management, the activities of international companies in solving urgent problems of risk assessment, international cooperation of companies in the development and use of software and the applications of the Business Intelligence class, Data Quality and Business Analytics, the role of SAS in the domestic market. The first part is devoted to the activities of international companies in the field of risk assessment. The second part is devoted to the review of analytical products of SAS.
Keywords: audit, risk assessment, in-depth analytics, business intelligenc
Algorithmic decidability of Engel's property for automaton groups
We consider decidability problems associated with Engel's identity
( for a long enough commutator sequence) in groups
generated by an automaton. We give a partial algorithm that decides, given
, whether an Engel identity is satisfied. It succeeds, importantly, in
proving that Grigorchuk's -group is not Engel. We consider next the problem
of recognizing Engel elements, namely elements such that the map
attracts to . Although this problem seems intractable in
general, we prove that it is decidable for Grigorchuk's group: Engel elements
are precisely those of order at most . Our computations were implemented
using the package FR within the computer algebra system GAP
Charge ordering in the spinels AlVO and LiVO
We develop a microscopic theory for the charge ordering (CO) transitions in
the spinels AlVO and LiVO (under pressure). The high degeneracy
of CO states is lifted by a coupling to the rhombohedral lattice deformations
which favors transition to a CO state with inequivalent V(1) and V(2) sites
forming Kagom\'e and trigonal planes respectively. We construct an extended
Hubbard type model including a deformation potential which is treated in
unrestricted Hartree Fock approximation and describes correctly the observed
first-order CO transition. We also discuss the influence of associated orbital
order. Furthermore we suggest that due to different band fillings AlVO
should remain metallic while LiVO under pressure should become a
semiconductor when charge disproportionation sets in
Optical evidence for symmetry changes above the Neel temperature in KCuF3
We report on optical measurements of the 1D Heisenberg antiferromagnet KCuF3.
The crystal-field excitations of the Cu2+ ions have been observed and their
temperature dependence can be understood in terms of magnetic and
exchange-induced dipole mechanisms and vibronic interactions. Above T_N we
observe a new temperature scale T_S characterized by the emergence of narrow
absorption features that correlate with changes of the orbital ordering as
observed by Paolasini et al. [Phys. Rev. Lett. 88, 106403 (2002)]. The
appearance of these optical transitions provides evidence for a symmetry change
above the Neel temperature that affects the orbital ordering and paves the way
for the antiferromagnetic ordering.Comment: 4 pages, 2 figure
Complex-Orbital Order in Fe_3O_4 and Mechanism of the Verwey Transition
Electronic state and the Verwey transition in magnetite (Fe_3O_4) are studied
using a spinless three-band Hubbard model for 3d electrons on the B sites with
the Hartree-Fock approximation and the exact diagonalisation method.
Complex-orbital, e.g., 1/sqrt(2)[|zx> + i |yz>], ordered (COO) states having
noncollinear orbital moments ~ 0.4 mu_B on the B sites are obtained with the
cubic lattice structure of the high-temperature phase. The COO state is a novel
form of magnetic ordering within the orbital degree of freedom. It arises from
the formation of Hund's second rule states of spinless pseudo-d molecular
orbitals in the Fe_4 tetrahedral units of the B sites and ferromagnetic
alignment of their fictitious orbital moments. A COO state with longer
periodicity is obtained with pseudo-orthorhombic Pmca and Pmc2_1 structures for
the low-temperature phase. The state spontaneously lowers the crystal symmetry
to the monoclinic and explains experimentally observed rhombohedral cell
deformation and Jahn-Teller like distortion. From these findings, we consider
that at the Verwey transition temperature, the COO state remaining to be
short-range order impeded by dynamical lattice distortion in high temperature
is developed into that with long-range order coupled with the monoclinic
lattice distortion.Comment: 16 pages, 13 figures, 6 tables, accepted for publication in J. Phys.
Soc. Jp
A new measurement of the antiproton-to-proton flux ratio up to 100 GeV in the cosmic radiation
A new measurement of the cosmic ray antiproton-to-proton flux ratio between 1
and 100 GeV is presented. The results were obtained with the PAMELA experiment,
which was launched into low-earth orbit on-board the Resurs-DK1 satellite on
June 15th 2006. During 500 days of data collection a total of about 1000
antiprotons have been identified, including 100 above an energy of 20 GeV. The
high-energy results are a ten-fold improvement in statistics with respect to
all previously published data. The data follow the trend expected from
secondary production calculations and significantly constrain contributions
from exotic sources, e.g. dark matter particle annihilations.Comment: 10 pages, 4 figures, 1 tabl
Two years of flight of the Pamela experiment: results and perspectives
PAMELA is a satellite borne experiment designed to study with great accuracy
cosmic rays of galactic, solar, and trapped nature in a wide energy range
(protons: 80 MeV-700 GeV, electrons 50 MeV-400 GeV). Main objective is the
study of the antimatter component: antiprotons (80 MeV-190 GeV), positrons (50
MeV-270 GeV) and search for antinuclei with a precision of the order of
). The experiment, housed on board the Russian Resurs-DK1 satellite,
was launched on June, 2006 in a orbit with an
inclination of 70 degrees. In this work we describe the scientific objectives
and the performance of PAMELA in its first two years of operation. Data on
protons of trapped, secondary and galactic nature - as well as measurements of
the December 2006 Solar Particle Event - are also provided.Comment: To appear on J. Phys. Soc. Jpn. as part of the proceedings of the
International Workshop on Advances in Cosmic Ray Science March, 17-19, 2008
Waseda University, Shinjuku, Tokyo, Japa
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