Physics, mathematics, and technology

This paper is devoted to contemporary the concept of developing a softwa­re module that calculates the radio wave propagation zone for the Global Mar­itime Distress and Safety simulator complex. Adjustments were made to the calculations that optimize the operation of the module. The algorithm is im­plemented on modern cross-platform approach. The main result of the de­veloped module is demonstrated.

The problem of transformation of some elementary closed and non-closed curves by means of successive iterations of conformal mapping is considered. Since the analytical description of the equations of images for some conformal mappings is quite complicated, it is convenient to use the Maple computer algebra system to implement the iterative process.

The method of finding prime numbers without computer calculation is shown. Subsets P1 = {6k1 – 1}, P2 = {6k2 + 1}, Q1 = {6j1 – 1}, Q2 = {6j2 + 1} are considered, where P1 È P2 are all prime numbers p ≥ 5; Qi are all odd composite numbers of such form. Subsets Ai = {ki}, Bi = {ji} (i = 1, 2) are investigated. It is proved that Bi by exploit sequences of natural numbers are lastly defined for ji £ a ⋲ N. Numbers ki are omitted natural numbers in Bi as Ai = N\Bi. For ki £ 200 all numbers of the sets Ai (and therefore all such prime numbers of the sets Pi) are defined.

The authors considered the possibility of using Li-Fi technology using one main emitting LED and several re-emitting LEDs to provide subscriber ac­cess. The use of this method allows achieving a throughput of up to 10 Gbit / s.

The possibility of application coherent time-frequency multiplexing is cosi­dered at construction of free space optical communication lines, which allows to increase the effective communication range and channel capacity for the sub­scriber access network.

The results of simulation modeling of the automated climate control sys­tem for growing plants in closed ground are discussed. Obtained results show the consistent interaction of its all main modules. The presented model is de­signed both for the designing of the new climate-control systems and for the managing of existing software-hardware complexes on the base of commercial­ly available technical devices and software.

The paper presents the results of a study in which laboratory facilities were assembled to measure the probability of receiving erroneous bits for BPSK, QPSK, 8PSK, DBPSK, QAM-4,8,16,64 radio signals for various SNRs in the MATLAB + Simulink simulation environment. The research results and the developed virtual laboratory setup have found application in a comparative assessment of the noise immunity of a ra­dio channel using standard and advanced patented information transmission systems within the marine mobile satellite service when receiving radio sig­nals with various types of shift keying.

The paper considers the development of a simulation model of the valve production process of the electro-pneumatic control unit in AnyLogic envi­ronment. The model is designed to find downtime in production operations. The work of three structures involved in the production of the considered part is simulated: a warehouse, a machine shop and an assembly shop. As a result of the simulation model, downtime was found, which reduced production time by 17 %.

The article is devoted to the development of a transmitting antenna sys­tem, characterized by an increased coefficient of the traveling current wave, realizing one of the ways to create phased antenna arrays of the short wave and ultrashort wave bands, in the conditions of the limited surface of their placement on ships, in order to improve the electromagnetic environment of radio electronic means.

The paper considers the topicality and challenges of the approach for im­proving the quality of diagnosis by modelling of the image of diagnostics med­ical problem as an imitation of integrated combined visual-figurative and ver­bal-sign representations of the diagnostic problem by experts, and also by modelling collective restructuring of the reduced representation of the problem according to the conception of the council using hybrid intelligent systems as diagnostic decision support systems with cognitive visualization of medical diagnostic problems.

A study of the characteristics of high-frequency oscillators on different transistors. The influence of transistor noise on fluctuations is considered. It is noted that in generators with a smaller nonisochronicity and with smaller cut-off angles of the current of the transistor, the fluctuations of self-oscillations are significantly lower. Formulated recommendations on the choice of transistors and their mode of operation for the construction of low-noise oscillators.

It is shown that the Everett worlds act on each other with a force that, in principle, can be measured «with a dynamometer». Hence the conclusion that these worlds really exist. It is shown that, contrary to popular belief, the ma­ny-world (Everett) and «casual» (de Broglie — Bohm) interpretations coin­ci­de. A limited path integral was used to describe coordinate measurement in terms of multiworld interpretation.

We study a dynamic model of a scalar field, the evolution of which leads to SFS-singularities. To estimate the characteristic SFS arrival time, we introduce a simplified model with the δ-function and use the weak anthropic principle. It is shown that our model predicts a rather soon appearance of the SFS-singularity.