Uzhhorod National University

About: Uzhhorod National University is a education organization based out in Uzhhorod, Ukraine. It is known for research contribution in the topics: Raman spectroscopy & Laser. The organization has 1089 authors who have published 1056 publications receiving 5187 citations. The organization is also known as: State Higher Education Establishment "Uzhhorod National University" & Uzhhorod State University.

Features of occlusal correlations of molars in the dental clinic.

Abstract: OBJECTIVE The aim: To study the odontoglific and odometometric parameters of molar crowns of the upper and lower jaws in males and females. PATIENTS AND METHODS Materials and methods: To achieve the aim of the research was used odontoglyphic, odometometric and statistical methods of research. RESULTS Results: We have found that male molars of the upper jaw are characterized by approximately the same ratio between the vestibular-palatal and mesial-distal diameters of the crown, so the teeth are square-formed. For female large angular teeth of the upper jaw the predominance of vestibular-palatal over mesial-distal diameters of the crown is characteristic, which results in an oval form of the teeth. On having analyzed the forms of the third lower molars, it can be affirmed that for this group of teeth various variational forms of crowns, from three- to five-tuber forms, are characteristic. Vestibular-lingual and mesio-distal sizes also vary according to the type of odontoglific pattern of occlusal crown surface. CONCLUSION Conclusions: We consider it expedient to take into account the abovementioned characteristics of the masticatory surface of molars of the upper and lower jaws of male and female persons for the creation of qualitative orthopedic structures that would fully restore the masticatory function.

Representational Capabilities and Learning of Bithreshold Neural Networks

Abstract: The paper deals with questions related to the ability of real-weighted bithreshold neurons and neural networks to solve the classification tasks. We study how many partitions of a finite set in n-dimensional vector space can be computed by using bithreshold neurons. The upper and lower bounds on the number of bithreshold dichotomies are proved. Our main theoretical result states that there exists \(\mathrm {\Theta }\left( m^{n+1}\right) \) bithreshold dichotomies of the set of m points in general position in n-dimensional space. We also estimate the Vapnik-Chervonenkis dimension of the class of bithreshold neurons. The problem of the synthesis of 2-layer bithreshold neural network for binary classification is considered. We demonstrate that an arbitrary dichotomy of m points in general position in n-dimensional space can be realized by 2-layer neural network containing at most \(\left\lceil m/(2n)\right\rceil \) bithreshold neurons in hidden layer and a single output threshold neuron. The learning algorithm with computational complexity \(O\left( m{{n}^{2}}+{{m}^{2}} \right) \) is proposed for such networks. We give simulation results of the network performance on real data sets and discuss the influence of algorithm parameters on the quality of learning and the representational capabilities of bithreshold networks.

Formation of Ferroelectric Nanostructures in (As2S3)100-x(SbSI)x Glassy Matrix

Abstract: The structure and dielectric properties of (As 2 S 3 ) 100 − x (SbSI) x glasses and their transformation during the heat treatment have been investigated. It has been determined that all glassy alloys have a microgeterogeneous structure. It has been shown that anomalies on the temperature dependences of dielectric permittivity e and tg δ are connected with the transition of glasses into a polar state followed by their crystallization. The crystallization of glasses is accompanied by a sharp increase in dielectric parameters conditioned by the formation of nanocrystalline inclusions in the glassy matrix which have ferroelectric properties. The structure arising in (As 2 S 3 ) 100 − x (SbSI) x (50 < x < 100) glass matrix during its crystallization corresponds to that of crystalline SbSI. The size of crystalline inclusions and dielectric permittivity value of ferroelectric glass-ceramic depend on the heat treatment conditions.

A multiwavelength low-pressure radiation source based on argon and xenon chlorides

Abstract: The characteristics of an excimer radiation source pumped by a subnormal dc glow discharge in an Ar/Xe/Cl2 mixture with the source operating in a spectral range of 160–310 nm were studied. The emission intensities of the 175, 236, 258, and 308 nm bands due to the transitions ArCl (B-X), XeCl (D-X), Cl2 (D′-A′), and XeCl (B-X), respectively, were optimized in relation to the pressure, composition, and discharge current of the mixture.

Regioselectivity of the monohalogenation of 4-allyl-3-allylamino-1,2,4-triazole-5-thione

Abstract: The monohalogenation of 4-allyl-3-allylamino-1,2,4-triazole-5-thione has been studied. It was established that the action of bromine and iodine on 4-allyl-3-allylamino-1,2,4-triazole-5-thione at low temperatures leads to selective closure of a thiazoline ring.