An approach for determining the correlation functions of the noise modulation function under the influence of modulating (or more often multiplicative) noise is described. Both stationary and slow noise is considered as influencing multiplicative noise. Correlation functions of noise modulation and fluctuations of the latter can be found by the four-dimensional characteristic function of phase and amplitude distortions. We have derived expressions for the abovementioned correlation functions affected by static multiplicative noise for the normal law of variation of amplitude and phase distortions in the case of their uncorrelation and cross-correlation. The correlation functions of noise modulation and noise modulation function fluctuations under the influence of slow modulating noise were determined for the case when the phase and distortion amplitude variations are independent. The expressions of the correlation functions of noise modulation and its fluctuations for correlated and normal distribution of phase and amplitude distortions under the influence of slow modulating noise are obtained.
The operation of anomaly detection systems in modern computer networks, as a rule, is associated with the processing of large amounts of traffic. With the increase in the scale of computer networks and the growing complexity of network attacks, it becomes necessary to detect multi-stage attacks in real time. This paper presents the architecture of a multi-stage anomaly detection system. The features of the system are the use of generative adversarial neural networks and the minimization of processed traffic using an attacker’s behavior model. The described architecture has a multilevel structure and allows monitoring in distributed computer networks.
The study presents an analysis of universal JFET and CMOS differential stages (DS) circuits. Such cascades provide a smaller range of transistor currents (10-100 $\mu$A) compared to classical cascades. The described DSs are implemented on combined process technologies, and therefore can be designed on JFET, BJT or CMOS chips. In addition, gallium arsenide, diamond gallium nitride, thin-film TFT and silicon carbide transistors. A computer simulation of the static modes of the developed DSs and their current dependences is presented. The results of GaAs DS modeling and its frequency dependence are presented.
This article presents the research results of JDE algorithm for detection and tracking athletes in video data. The developed convolutional neural network was trained and tested on the NVIDIA DGX-1 supercomputer. To analyze the quality of the model, MOTA metric was used, which is related to how the human eyes track targets in the video stream. The detection and tracking people on video data is relevant to many tasks of computer vision, in particular, in sport to collect statistics about players. The quality of JDE algorithm was assessed by the video fragments of basketball games filmed in the sports halls at P.G. Demidov Yaroslavl State University.
The article presents the results of extracting the envelope of radio impulse signals using the digital processing methods. Three methods of extracting the envelope are studied in the work: correlation function; the Hilbert transform; and the new approach in which the combination of correlation function and Hilbert transform are used. For the research we used the measured reflectograms of the multilayer liquid. As a result of processing and comparing a variety of experimental characteristics the accuracy of determination of Hilbertcorrelation combination sequence was better than standard methods of processing. The resulting waveform is easier to analyze and process, but the processing need more time to calculate.
In this article, we are talking about improving the accuracy of distance measurement as a way of reducing instrumental error by using the approximation of data obtained from an active-pulse television measuring system (AP TMS) as a distance measurement device using the least squares method (LSM).
The paper substantiates the need to create a Integrated management model of distributed information systems in conditions of destructive impact, as the basis of an information decision support system in the field of information security, analyzes the requirements of regulatory documents in this area, justifies the requirements for the functionality of the model, modeling methods are selected, ontological structural and functional models of information modules of distributed information systems are developed, interrelations of scenarios for the implementation of UBI and vulnerabilities, destructive impact and protective measures that allow determining the objects of impact at various levels of information modules, their vulnerabilities and current scenarios for the implementation of information security threats, a neuro-Bayesian model has been developed that allows calculating probabilistic indicators of the joint probability distribution of protective and destructive events, a model of operational management of distributed information network in conditions of destructive impact has been developed.
A method for embedding a visually imperceptible message into an object of a digital image for transmission through a noisy communication channel is proposed. The embedding method is based on inverting some of the pixels of the secret image according to a certain rule and adding them to the selected positions of the bit plane of the least significant bit according to the mask generated by the pseudo-random number generator (PRNG). The authors use a two-dimensional nonlinear filtering algorithm in order to ensure the integrity of the data transmitted over the communication channel at low signal-to-noise ratios. The article presents the results of experimental estimates of the invisibility of the embedded image and the integrity of the original and secret images after transmission over a noisy communication channel for signal-to-noise ratios up to -6dB.
The article presents the results of simulation of pulse DC-DC step-down converter with different types of diodes. Simulations have shown that the use of a silicon carbide diode instead of convenient silicon diode gives the best performance. It also shown, the parasitic inductances in the circuit significantly increase the power losses when the diode is switched-off and reduce the losses when the transistor is switched-on.
Non-orthogonal multiple access (NOMA) methods are a promising technology that can be the basis of the next generation communication networks and ensure their high throughput. One of the most effective NOMA methods is sparse code multiple access (SCMA). SCMA allows providing better noise immunity and connecting a larger number of subscribers compared to classical solutions used in modern networks. Together with modulation and multiple access, it is reasonable to consider noise-resistant coding procedures that equally affect communication characteristics. One of the most efficient types of noise-resistant codes is low density parity check (LDPC) codes. Now LDPC is used in a number of communication systems, including 5G NR. In this paper, we propose the concept of a communication system with the joint use of LDPC and SCMA. We introduce a sequence of algorithms for the generation and processing of signals. The dependencies of bit error rate (BER) performance on SNR are given: they show the efficiency of the proposed solutions and the ability of the considered communication system to work in various conditions. The results obtained can be used to form a modulation and code scheme (MCS) table for next-generation communication systems.
The use of flexible wearable electronics in robotics, industry, agriculture, clothing, medicine, etc. is caused by an ever-increasing need. Various sensors and devices for reading and transmitting information based on environmentally friendly, flexible and durable materials can be securely mounted in the shell structure of the robot or attached to the surface of human skin, which will allow extracting and analyze a number of important technical and medical indicators. Important parameters include temperature, pressure, load values, air composition, environmental parameters, medical indicators, etc. The paper proposes an approach to describing the types of wearable electronics for monitoring information about the state of robotic objects involved in production, or a person, about his health, environmental monitoring, pressure sensors, various types of deformation, force sensors that can be combined with temperature sensors, physiological and biochemical sensors, and can also be included in multifunctional sensors. A network of sensors is necessary to determine the parameters of the shell structure during its operation, to monitor the state of a robot or a person. The technical parameters of the multilayer protective shell can be local values of the distributed load on the shell, pressure, tensile or bending deformation, etc. The general principles of operation of sensors and transmitters embedded in a flexible multilayer protective shell structure are considered, and structural innovations are also proposed. The paper considers functional modules that will make wearable electronics more adequate to real technical objects and for humans. A number of problems that arise in the development of wearable electronics and its application for modeling flexible intelligent shell structures are described.
This article presents a technology of the acoustic frequency response equalization. It is based on the usage of the modified x-filtered adaptive algorithms in the equalizers. Comparing to the traditional x-filtered algorithms, the modified ones allow to accelerate the equalizer convergence if the computationally simple LMS or the NLMS adaptive algorithms based on the gradient search strategy are used for the equalizer weights computation. Besides, the modification allows to use the computationally complex but simultaneously efficient RLS adaptive algorithms in the x-filtered mode because the algorithms cannot be used in the traditional x-filtered mode. The proposed equalizer architectures and the computational procedures of the traditional and modified adaptive filtering algorithms are presented. Simulation demonstrates a better performance of the modified algorithms comparing to the traditional ones in the following terms: the equalized frequency response ripple value, the proximity of the PSD curves of the undistorted speech signal and the signal passed through the equalizer and acoustic medium, the initial duration of the transient response of the error signal and the response steady-state value.
Modern IIoT systems include a huge number of sensors and actuators designed to control the processes of technological production. Trusted interaction, which involves the guaranteed transmission of data within such systems, is a key aspect in the operation of such systems. However, the currently available industrial protocols contain a certain number of vulnerabilities, which can destabilize the operations of IIoT systems. That’swhy, when designing such systems, additional attention should be paid to the protection of transmitted data. The current article presents the modeling of computer attacks on the IIoT system, using the industrial Modbus TCP protocol. This protocol is widely used in the design of IIoT systems, also has a number of vulnerabilities
The applicability of the previously proposed method for determining the imaginary part of the complex permittivity for weakly absorbing liquids in the 25-40 GHz frequency band is considered. Based on the results of 3200 measurements with the data obtained by the open waveguide method were compared. The obtained values are in good agreement with each other.
The paper presents the schemes for manufacturing a microoptoelectromechanical (MOEM) accelerometer for measuring small accelerations. MOEM-accelerometer includes three subsystems: mechanical, optical and electronic. The mechanical subsystem includes an inertial body, mounted on a spring suspension in a case. The optical subsystem includes a laser, moving and fixed waveguides. The electrical subsystem includes a photodiode and electronic components. To measure microdisplacements that correspond to measured microaccelerations, an optical system based on the optical tunnel effect was used. The work considers the schemes of the optical transducer for linear and angular displacements of the mechanical subsystem. The moving waveguide together with the inertial body are combined into the mechanical sensing element that diverges in the case of acceleration. A technological process for manufacturing a MOEM accelerometer based on the “silicon on insulator” technology with additional layers of nitride and silicon oxide for optical functional elements is presented. Depending on the character of the movement of the sensing element, the functional schemes of the MOEM-accelerometer were developed with various changeable parameters: optical coupling length, gap, overlapping area between the moving and fixed waveguides. The article analyzes the advantages and drawbacks of the proposed schemes of accelerometers from the perspective of their manufacturing feasibility and the predicted accuracy. The highest sensitivity $(6.25 \times10^{6} \text{m} ^{\text{-1}}$) belongs to schemes with changeable gap between the waveguides. The dynamic displacement ranges of them is ± 80 nm. Lower sensitivity $(1.25 \times10^{6} \text{m} ^{\text{-1}}$) belongs to schemes with changeable overlapping area. The dynamic displacement range may reach ± 300 nm. Schemes with changeable optical coupling length possess the highest dynamic range which directly depends on a chosen optical coupling length and amounts to dozens of microns. The sensitivity of the last scheme also depends on the optical coupling length and amounts to $11.25 \times10^{3} \text{m}^{-1}$ for an optical coupling length of 44 $\mu$m and to $30 \times10^{3} \text{m} ^{-1}$ for an optical coupling length of 15 $\mu $m.
This paper delves into the problem of designing a buck converter, serving as the key element for testing sets, also known as load simulators. These simulators impose varying electric load onto power supplies that may be employed in harsh environments and under temperatures below 0 0 C. This provides ground testing for such supplies over a wide range of electric loads as well as creating the proper voltage waveform on the supply terminals. For this purpose, we implement a subordinate control system containing an internal inductor current loop and main output voltage feedback of the buck converter topology. Within the present research frameworks, a methodology of the control system designing, have been outlined. The resulting voltage and current waveforms confirm the correctness of the presented methodology and applicability of the buck converter with subordinate control system as a functional component of load simulators.
Despite the fact that electronics over the past decades has been developing with great intensity. Modern industry needs to master new high-tech solutions to create efficient power-supply systems and energy storage devices for high reliability equipment. Various fields of science and technology are increasingly faced with tasks that require the use of accurate and stable devices. In this regard, there is a problem of assessing the quality and performance of electronic components in real operating conditions. The main purpose of this article is to assess the feasibility of incoming quality control of chemical current sources using the example of supercapacitors. The article presents an experimental method for determining the main characteristics of storage devices by conducting controlled charge-discharge cycles. Seven different supercapacitor fabricators participated in the experiment The studies were carried out using a specially designed hardware-software complex. The results obtained in the course of measurements and calculations show the importance of quality control of supercapacitors.
It is important to separate a useful signal from noise in measuring small voltage deviations of about 1 $\mu$ V and lower. This problem is relevant to eddy-current testing method in non-destructive testing metal constructions, thermal nondestructive testing, etc. The identification accuracy of a useful signal directly depends on the common-mode rejection ratio of subtraction circuit. The paper presents the circuit solutions concerning the increase in the common-mode rejection ratio using the power tracking with the phase error compensation of the voltage follower transfer factor and proposes a schematic circuit diagram of the phase compensated power tracking. The circuit was proposed for the phase compensated power tracking. The subtraction of two similar voltages of10 V on the PGA207 instrumentation amplifier could provide a 10 nV resolution at a frequency band up to 20 kHz.
this work is devoted to the transfer training of a model for automatic detection of children. The main goal of the work was to increase the accuracy of detecting children in comparison with the MobileNet V1 model taken as a basis, with which a comparative analysis will be carried out in the future. Our own data set was used for transfer training. The training itself was carried out in the free cloud service Google Colab. Both models were launched and tested on a single-board NVIDIA Jetson Nano microcomputer.
The GPR method is being used more and more widely in diagnostics, engineering surveys and inspection of highways, as well as in quality control of road construction works. In this case, different designs of ground penetrating radar and methods of work, as well as various software are used. The ground penetrating radar method is uncontested, since it allows you to continuously explore the internal structure of the pavement structure. This article presents the design of the existing ground penetrating radar and the method of processing the received geodata using this ground penetrating radar.
