183 research outputs found
The neural network art which uses the Hamming distance to measure an image similarity score
This study reports a new discrete neural network of Adaptive Resonance Theory (ART-1H) in which the Hamming distance is used for the first time to estimate the measure of binary images (vectors) proximity. For the development of a new neural network of adaptive resonance theory, architectures and operational algorithms of discrete neural networks ART-1 and discrete Hamming neural networks are used. Unlike the discrete neural network adaptive resonance theory ART-1 in which the similarity parameter which takes into account single images components only is used as a measure of images (vectors) proximity in the new network in the Hamming distance all the components of black and white images are taken into account. In contrast to the Hamming network, the new network allows the formation of typical vector classes representatives in the learning process not using information from the teacher which is not always reliable. New neural network can combine the advantages of the Hamming neural network and ART-1 by setting a part of source information in the form of reference images (distinctive feature and advantage of the Hamming neural network) and obtaining some of typical image classes representatives using learning algorithms of the neural network ART-1 (the dignity of the neural network ART-1). The architecture and functional algorithms of the new neural network ART which has the properties of both neural network ART-1 and the Hamming network were proposed and investigated. The network can use three methods to get information about typical image classes representatives: teacher information, neural network learning process, third method uses a combination of first two methods. Property of neural network ART-1 and ART-1H, related to the dependence of network learning outcomes or classification of input information to the order of the vectors (images) can be considered not as a disadvantage of the networks but as a virtue. This property allows to receive various types of input information classification which cannot be obtained using other neural networks
Crystal truncation rods in kinematical and dynamical x-ray diffraction theories
Crystal truncation rods calculated in the kinematical approximation are shown
to quantitatively agree with the sum of the diffracted waves obtained in the
two-beam dynamical calculations for different reflections along the rod. The
choice and the number of these reflections are specified. The agreement extends
down to at least of the peak intensity. For lower intensities,
the accuracy of dynamical calculations is limited by truncation of the electron
density at a mathematically planar surface, arising from the Fourier series
expansion of the crystal polarizability
Neural networks art: solving problems with multiple solutions and new teaching algorithm
A new discrete neural networks adaptive resonance theory (ART), which allows solving problems with multiple solutions, is developed. New algorithms neural networks teaching ART to prevent degradation and reproduction classes at training noisy input data is developed. Proposed learning algorithms discrete ART networks, allowing obtaining different classification methods of input
Dzyaloshinskii--Moriya interaction: How to measure its sign in weak ferromagnetics?
Three experimental techniques sensitive to the sign of the
Dzyaloshinskii--Moriya interaction are discussed: neutron diffraction,
Moessbauer gamma-ray diffraction, and resonant x-ray scattering. Classical
examples of hematite (alpha-Fe2O3) and MnCO3 crystals are considered in detailComment: 5 pages, 1 figure; to be published in JETP Letter
Comment on "X-ray resonant scattering studies of orbital and charge ordering in Pr1-xCaxMnO3"
In a recent published paper [Phys. Rev. B 64, 195133 (2001)], Zimmermann et
al. present a systematic x-ray scattering study of charge and orbital ordering
phenomena in the Pr1-xCaxMnO3 series with x= 0.25, 0.4 and 0.5. They propose
that for Ca concentrations x=0.4 and 0.5, the appearance of (0, k+1/2, 0)
reflections are originated by the orbital ordering of the eg electrons in the
a-b plane while the (0, 2k+1, 0) reflections are due to the charge ordering
among the Mn3+ and Mn4+ ions. Moreover, for small Ca concentrations (x<0.3),
the orbital ordering is only considered and it occurs at (0, k, 0) reflections.
A rigorous analysis of all these resonance reflections will show the inadequacy
of the charge-orbital model proposed to explain the experimental results. In
addition, this charge-orbital model is highly inconsistent with the electronic
balance. On the contrary, these reflections can be easily understood as arising
from the anisotropy of charge distribution induced by the presence of local
distortions, i.e. due to a structural phase transition.Comment: 10 pages, 2 figures.To be published Phys. Rev.
Teeth sizes in their correlation with parameters of dentofacial arches and maxillofacial area based on native cranial preparations examination
The work offers a view on the results obtained from a radiological and morphometric study of native preparations obtained from 43 passported skulls with physiological occlusion and normodontia of permanent teeth under neutral position of the jaws and a neutral type of gnathic facial skull. It was found that in patients with physiological occlusion of permanent teeth, skulls with neutral type of gnathic facial part of the cranium as well as neutral jaw relationships proved to be predominant, while the major parameters of the dentofacial arches are determined through mesial-distal diameters of the teeth
Relative contributions of lattice distortion and orbital ordering to resonant x-ray scattering in manganites
We investigated the origin of the energy splitting observed in the resonant
x-ray scattering (RXS) in manganites. Using thin film samples with controlled
lattice parameters and orbital states at a fixed orbital filling, we estimated
that the contribution of the interatomic Coulomb interaction relative to the
Jahn-Teller mechanism is insignificant and at most 0.27. This indicates that
RXS probes mainly Jahn-Teller distortion in manganites.Comment: 8 pages, 4 figure
Polarization Dependence of Anomalous X-ray Scattering in Orbital Ordered Manganites
In order to determine types of the orbital ordering in manganites, we study
theoretically the polarization dependence of the anomalous X-ray scattering
which is caused by the anisotropy of the scattering factor. The general
formulae of the scattering intensity in the experimental optical system is
derived and the atomic scattering factor is calculated in the microscopic
electronic model. By using the results, the X-ray scattering intensity in
several types of the orbital ordering is numerically calculated as a function
of azimuthal and analyzer angles.Comment: 9 pages, 7 figure
METHODS OF BIOMETRICAL DIAGNOSTICS IN TRANSVERSAL DIRECTION IN PATIENTS WITH MESOGNATHIC TYPE OF DENTAL ARCHES
Aim. A comparative analysis of the horizontal parameters of mesognathic dental arches by the method of Pont and Linder-Harth. Materials and methods. The materials of the research were the results of measurements of diagnostic gypsum models of dental rows of 117 people aged 18-25 with a complete set of permanent teeth, physiological occlusion, mesognathic type of dental arches and various types of dental system. Measurement and calculation of the parameters of the dental arches in the transversal direction were carried out using the methods of Pont and Linder-Harth. Gnathic variants (mesognathy, dolichognathy, brachygnathy) of dental arches (Dmitrienko S.V., 2015) were determined taking into account the dental index calculated as the ratio of the half sum of the width of the crowns of 14 teeth to the width of the dental arch between the second molars. The types of the dental system (normodontia, macrodontia, microdontia) were determined from the summation of the width of the crowns of the upper teeth. Results. Biometric diagnostics of 117 pairs of gypsum models of dentition made it possible to establish that the methods of Pont and Linder-Harth are acceptable for the study of mesognathic dental arches as an estimate of transverse dimensions. There was no significant difference between the calculated indices and actual sizes in patients with mesognathic dental arches and various types of dental system, both in the premolar region and in the molar region. The size of the teeth is of decisive importance for the evaluation of the width of the dental arches of the mesognathic type. Conclusion. Optimization of medical and diagnostic measures in the clinic of orthodontics and orthopedic dentistry in the management of adult patients with dental-jaw pathology provides for the improvement of anthropometric studies, as well as the advisability of reviewing the conventional diagnostic regimens when studying the shape and size of dental arches to predict positive long-term results. Mathematically derived dependences of dental types of dental arches from their transversal parameters are informative, diagnostically significant values that can be used to predict the shape and size of dental arches in the treatment of patients with dentoalveolar anomalies in order to achieve an optimal functional and aesthetic result. The use of the Pont and Linder-Harth method in the analysis of the mesognathic dental arches has no significant errors, and can be used at the stages of diagnosis of shape and size anomalies in the transverse direction
Intraosseous infusion of medicines with autogenous thrombocytose gel in the therapy of chronic parodontal diseases
63 patients with parodontal diseases were divided into two groups. We used standard flap surgery in the first group (32 patients, 50,8%). Complex therapy of the second group (31 patients, 49,2%) were suppelmented with intraosseous infusion of natrium hypochlorite 0,03%. The results of our investigations allow us to speak about enhancement of efficiency in the complex treatment of parodontal disease
- …