Bit Streaming Processing Algorithms for Intelligent Hardware Converters

The need to transfer the primary data conversions close to the sensors, to the endpoints of monitoring systems, as well as in IoT terminal devices makes the development of new approaches to computing and the design of appropriate algorithms relevant. The article shows stream processing algorithms that provide functional transformations of signals presented in bit stream form (single pulse streams, PWM signal streams) and binary codes at the same time. In such algorithms, the computational process is based on discretization, pulse frequency sweep and pulse-width sweep of codes as well as organization of parallel-serial processing. The suggested principles of algorithm organization are based on the fact that the computation is considered not as an event associated with calculation but as a continuous process of a result formation. The transition to algorithmic representations proposed by the authors makes it possible to obtain universal behavioral descriptions, independently of the specific hardware on which their implementation is performed.

Laser-sound: optoacoustic transduction from digital audio streams

This work presents a novel laser-based optoacoustic transducer capable of reproducing controlled and continuous sound of arbitrary complexity in the air or on solid targets. Light-to-sound transduction is achieved via laser-induced breakdown, leading to the formation of plasma acoustic sources in any desired spatial location. The acoustic signal is encoded into pulse streams via a discrete-time audio modulation and is reproduced by fast consecutive excitation of the target medium with appropriately modulated laser pulses. This results in the signal being directly reconstructed at the desired location of the target medium without the need for a receiver or demodulation device. In this work, the principles and evaluation results of such a novel laser-sound prototype system are presented. The performance of the prototype is evaluated by systematic experimental measurements of audio test signals, from which the basic acoustical response is derived. Moreover, a generic computational model is presented that allows for the simulation of laser-sound reproduction of 1-bit or multibit audio streams. The model evaluations are validated by comparison with the acoustic measurements, whereby a good agreement is found. Finally, the computational model is used to simulate an ideal optoacoustic transducer based on the specifications of state-of-the-art commercially available lasers.

Search for anomalies in pulse flows of acoustic and electromagnetic emissions

Timely warning of disasters caused by earthquakes ensures life safety. Therefore, the search for markers of pre-seismic events preceding earthquakes remains an important research task. The article presents experimental methods for assessing seismic activity in the Kamchatka region based on the results of processing and analysis of geoacoustic and electromagnetic emission signals. The research is aimed at detecting anomalies in quantitative and qualitative indicators that characterize the pulse streams of acoustic emission of near-surface rocks and electromagnetic emission in the surface layer of the atmosphere. Signal processing and analysis are carried out using special algorithms that take into account the structural features of the variety of pulse shapes and their distribution over time.

Interrelation between the number of ectopic foci and the chaoticity degree of ventricular fibrillation

Электрическая активность сердца при фибрилляции желудочков регистрируется на ЭКГ как хаотичное чередование разных по амплитуде и длительности возбуждений. Для количественного анализа этих показателей широко используются методы математического моделирования и теории хаоса. Цель исследования - использование методов математического моделирования для изучения взаимосвязи между степенью хаотичности процесса фибрилляции желудочков и количеством эктопических фокусов, функционирующих в миокарде желудочков. Электрическую активность сердца при фибрилляции желудочков моделировали суммой N-независимых импульсных потоков с различными амплитудно-частотными и фазовыми характеристиками. Степень хаотичности электрической активности сердца оценивали с помощью энтропии и фазовых портретов амплитуд фибриллярных осцилляций. Методом компьютерного моделирования рассчитывали теоретические зависимости степени хаотичности фибриллярных осцилляций от количества импульсных потоков. Результаты теоретических расчетов сопоставляли с результатами физиологических экспериментов, выполненных на крысах и собаках. Показано, что степень хаотичности фибриллярных осцилляций различна у крыс и собак и зависит от числа эктопических фокусов, функционирующих в миокарде желудочков. Для крыс были характерны двухочаговые типы моделей фибрилляции желудочков, для собак - многоочаговые (4-5 фокусов) типы моделей. Cardiac electrical activity during ventricular fibrillation shows on electrocardiogram as chaotic alternation of excitations different in amplitude and duration. Methods of mathematical modeling and the chaos theory are widely used for quantitative analysis of these irregularities. The aim of the present work was using methods of mathematical modeling to study the interrelation between the chaoticity degree of ventricular fibrillation and the number of myocardial ectopic pacemakers. Cardiac electrical activity during ventricular fibrillation was modeled as a sum of N independent pulse streams with various amplitude-frequency and phase characteristics. The chaoticity degree of heart electrical activity was estimated using entropy and phase portraits of fibrillar oscillations. Theoretical dependences between the chaoticity degree of ventricular fibrillation and the number of pulse streams were calculated using computer modeling. Results of computer experiments were compared with those of real physiological experiments on rats and dogs. The chaoticity degree of fibrillar oscillations was shown to be different in rats and dogs and dependent on the number of ectopic pacemakers functioning in the myocardium. Two-focal types of ventricular fibrillation models were characteristic of rats and multifocal (4-5 foci) types we characteristic of dogs.