# Electronics, radio engineering and telecommunications

# Speech Corpora as Facilities of Creation and Storage of Exemplary Speech Signals

Speech corpora are an important constituent of modern investigators’ toolkit in such areas as speech correction, designing and testing elements of telecommunication systems and systems of automatic speech recognition. In this paper, we search for elements of construction technology of the sound part of noisy Ukrainian speech corpora. To this end, we consider characteristics of the most wiely used modern noisy speech corpora which allow formulating principles of such corpora design.

# Defining Parameters of Quality Mobile Network Technology LTE/MVNO with Tensor Analysis

The paper under scrutiny proposes the sequence of actions for characterizing the quality parameters of the mobile network LTE/MVNO for convenient configuration of network connections of objects. To determine the quality parameters of the network LTE/MVNO tensor decomposition of the network architecture we employ the method for obtaining the optimal configuration of the network connections of objects for preset values of packet delay using the criterion of the maximum capacity.

# Periodical Structure with Transversal Electric Field

In this paper, we solve the problem of electromagnetic wave propagation in a periodic structure with a transverse electric field in the baseband. The period of the structure is divided into two subregions by planes perpendicular to the longitudinal coordinate. We use the method of partial regions. By employing the moments method, the system of functional equations obtained from the boundary conditions and periodicity conditions is reduced to a system of linear algebraic equations (SLAE), whose order is M and N, the number of terms in the fields expansion in the sub-areas.

# The Effect of Packets Length Management Strategies on the Efficiency of the MAC Level Packet in Switched Radio Networks

The paper studies a new method of efficiency enhancement of packet switched radio networks at the radio channel access level. To this end, we consider the known strategies of packet lengths control in such radio networks and reveal incompleteness of a possible set of packet lengths management with channel conditions under carrier sense multiple access (CSMA) protocol. We propose three new strategies to change packet lengths which complete the set. Mathematical simulation is conducted for persistent and nonpersistent CSMA protocols.

# The Research of Instability of the Amplitude Frequency Characteristic of a High-Voltage Potential Divider Caused by Non-Identical Elements of its High-Voltage Shoulder

Based on repeated measurements, we define real distribution of capacity values of condensers of a high-voltage shoulder of a potential divider with the assumed deviation from the nominal equal to ±5%. We show that the given distribution is asymmetric in relation to rating value (22nF). Renormalization of received distribution was done in relation to the average capacity value of condensers. We investigate the influence of real distribution of condensers capacities on instability of the amplitude frequency characteristic (AFC) of a high-voltage potential divider.

# Synthesis of Neural Network System of Automatic Control of Water Level in the Boiler Drum Power Block of Thermal Power Plant

The purpose of this paper is synthesis of intellectual automatic control system (ACS) of the water level of drum boiler unit based on the theory of neural networks. We develop a mathematical model of the research object. Analysis of the transients quality under different operating boiler shows that the traditional ACS has significant drawbacks associated with significant regulation time and the first rejection. To improve the traditional ACS and its efficiency, we propose to use a neural network approach to control.

# Experimental Study of Characteristics of Moving Water Film within Netting

The effects of netting characteristics, sprinkler construction and irrigation density on the moving water film in the net surface is experimentally studied. Netting surface irrigated by water was supplied through some type of sprinkler without the air flow. The film thickness in the netting is determined empirically using the amount of delayed water. The delayed water was collected by clipping. The percent error of the experiment is up to 6 %. Increasing the irrigation density correspond qualitatively to the thickness of water film according to Nusselt’s formula.

# The Tensor Model of Ports Buffering for Digital Switch

The objective of the paper is to develop the tensor model of buffer storage allocation for the input-output ports of digital network switch. To this end the method of segregated lists applied where each external physical port of the switch comprises internal transit buffers for all other external ports. Through experiments performed, we introduce the notion of zero port for the switch that connects external ports with the switch itself as the object of addressing object. The buffering matrix and the quaternion of an arbitrary couple of buffers is provided for the switch ports.

# Research of Characteristics of L-Shaped and Waveguide with Two Corner Cuts by Variational Method

Waveguides with one and two cuts (L-shaped waveguide and waveguide with two corner cuts) are used in microwave devices. Therefore, there is a need for new effective and rapid methods for calculating the characteristics of such waveguides. The variational method is used to calculate the eigenvalues of waves of L-shaped waveguide and waveguide with two corner cuts with arbitrary geometrical parameters. Polynomials orthogonal over the area of considered waveguides are unknown. We consider several types of the field approximation: on the basis of trigonometric and power functions.

# Retransmission Method of Impulse Ultrawideband Signals in Ad-Hoc Networks

This paper describes a new method of data relay in wireless Ad-Hoc networks with impulse ultrawideband radio signals (IR-UWB). Proposed method uses concept of “chipset retransmission” rather than typical store-and-forward scheme. This implies a relay by the intermediate nodes of each particular bit of data, encoded as chipsets, and the use of special markers integrated into that bit transferred in the connection. This provides lower delays and, thus, gives unprecedented advantage in fast retransmission for the multihop environment.