495 research outputs found
Elliptic CR-manifolds and shear invariant ODE with additional symmetries
We classify the ODEs that correspond to elliptic CR-manifolds with maximal
isotropy. It follows that the dimension of the isotropy group of an elliptic
CR-manifold can be only 10 (for the quadric), 4 (for the listed examples) or
less. This is in contrast with the situation of hyperbolic CR-manifolds, where
the dimension can be 10 (for the quadric), 6 or 5 (for semi-quadrics) or less
than 4. We also prove that, for all elliptic CR-manifolds with non-linearizable
istropy group, except for two special manifolds, the points with
non-linearizable isotropy form exactly some complex curve on the manifold
Role of interference and entanglement in quantum neural processing
The role of interference and entanglement in quantum neural processing is
discussed. It is argued that on contrast to the quantum computing the problem
of the use of exponential resources as the payment for the absense of
entanglement does not exist for quantum neural processing. This is because of
corresponding systems, as any modern classical artificial neural systems, do
not realize functions precisely, but approximate them by training on small sets
of examples. It can permit to implement quantum neural systems optically,
because in this case there is no need in exponential resources of optical
devices (beam-splitters etc.). On the other hand, the role of entanglement in
quantum neural processing is still very important, because it actually
associates qubit states: this is necessary feature of quantum neural memory
models.Comment: 15 pages, PD
Invariants of elliptic and hyperbolic CR-structures of codimension 2
We reduce CR-structures on smooth elliptic and hyperbolic manifolds of
CR-codimension 2 to parallelisms thus solving the problem of global equivalence
for such manifolds. The parallelism that we construct is defined on a sequence
of two principal bundles over the manifold, takes values in the Lie algebra of
infinitesimal automorphisms of the quadric corresponding to the Levi form of
the manifold, and behaves ``almost'' like a Cartan connection. The construction
is explicit and allows us to study the properties of the parallelism as well as
those of its curvature form. It also leads to a natural class of ``semi-flat''
manifolds for which the two bundles reduce to a single one and the parallelism
turns into a true Cartan connection. In addition, for real-analytic manifolds
we describe certain local normal forms that do not require passing to bundles,
but in many ways agree with the structure of the parallelism.Comment: 42 pages, see also
http://wwwmaths.anu.edu.au/research.reports/97mrr.htm
Neural Replicator Analysis for virus genomes binomial systematics in metagenomics
We have presented some arguments to substantiate the usefulness of neural
replicator analysis (NRA) for constructing variants of the natural binomial
classification of virus genomes based only on knowledge of their complete
genomic sequences, without involving other data on the phenotype, functions,
encoded proteins, etc., and also without the need of genomic sequences
alignment. Perhaps this will make sense when processing metagenomic data. This
makes it possible to construct the binomial classification accepted for the
viruses themselves. We restrict ourselves to three families of viruses having
dsDNA circular genomes (Papillomaviridae, Polyomaviridae and Caulimoviridae)
and partly to the family Geminiviridae having ssDNA genomes though the approach
presented can be also applied to genomes of other dsDNA, ssDNA and ssRNA
viruses, including linear ones (some results for Mitoviridae are also
presented). It is argued that binomial classification of virus genomes which is
difficult to apply in all cases can nevertheless be informative tool of
revealing virus properties, areal of hosts, forms of diseases and can also show
the connections of the viruses belonging to different families and even to
different kingdoms.Comment: 48 pages, 27 figure
Can the natural system of viruses reconcile the current taxonomy with an alternative classification useful to clinicians?
In 2022, a group of basic and clinical virologists, bioinformaticians, and
evolutionary and structural biologists met in Oxford, UK, to develop a
consensus on methodologies used to classify viruses. They concluded that virus
taxonomy, which is hierarchical and based on evolution, is only one of many
possible ways to classify viruses. This taxonomy, while satisfying the four
principles they set out, faces difficulties in coordinating with other
classification systems useful to clinicians, infectious disease specialists,
agronomists, etc. One example discussed is the grouping of different viral
strains that cause different diseases into the species Enterovirus C. Here we
show that the use of a previously proposed variant of a natural virus
classification system based on the use of Neural Replicator Analysis can
resolve this contradiction by establishing the fine structure of the
Enterovirus C species, in which strains that cause different diseases are
placed in several different cells of the binomial table of viruses. A key
element in enabling this is the sophisticated preprocessing of the original
viral genomes using neural replicators.Comment: 11 pages, 4 figures. arXiv admin note: substantial text overlap with
arXiv:2212.0547
Dry Magnetic Separation of Iron Ore of the Bakchar Deposit
Currently, the development of iron ore of the Bakchar deposit (Tomsk region) is considered promising because of the extremely large reserves of iron ore. Ores of this deposit are related to the high-grade type and expected to have a magnetic concentration for iron extraction. The main task of magnetic separation is to increase the total iron content in concentrates to a value which allows its further metallurgical processing. Ferruginous ore particles have a rounded shape that facilitates a separation process. The paper considers the influence of technological parameters on the magnetic concentrate yield and recovery rate of iron-containing fractions
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