scholarly journals Statistical properties of derived signal systems

Radiotekhnika ◽  
2020 ◽  
pp. 141-147
Author(s):  
A.A. Zamula ◽  
I.D. Gorbenko ◽  
Ho Tri Luc
Keyword(s):  
Statistical Properties ◽  
Random Sequences ◽  
Signal Systems ◽  
Discrete Signals ◽  
Information Transformation ◽  
Methods Of Synthesis ◽  
Linear Signal ◽  
Correlation Properties ◽  
Derivatives Of ◽  
Structural Ensemble

The search for effective methods of synthesis of discrete signals (sequences) that correspond to the potentially possible limiting characteristics of correlation functions and possess the necessary correlation, structural, ensemble properties remains an urgent problem. The authors have proposed a method for the synthesis of derivatives of signal systems, for which orthogonal signals are used as the initial ones, and nonlinear discrete complex cryptographic signals (CS) are used as generating signals. The synthesis of the latter ones is based on the use of random (pseudo-random) processes, including algorithms for cryptographic information transformation. Derivative signals synthesized in this way have improved (in comparison with linear signal classes) ensemble and correlation properties, while the statistical properties of such signal systems remain unexplored. The paper presents the results of testing derived signal systems using the tests defined in FIPS PUB 140 and NIST 800-22. Analysis of the results obtained allows us to assert that the statistical properties of this class of derived signals satisfy the requirements for pseudo-random sequences: unpredictability, irreversibility, randomness, independence of symbols, etc. In essence, such signals do not differ from random sequences. The use of the proposed class of derived signals will improve the performance of signal reception noise immunity, information security and secrecy of the ICS functioning.

scholarly journals The concept of synthesis of one class of self-synchronizing discrete signals

Radiotekhnika ◽  
2021 ◽  
pp. 24-29
Author(s):  
I.D. Gorbenko ◽  
O.V. Potii ◽  
A.A. Zamula
Keyword(s):  
Structural Properties ◽  
Correlation Functions ◽  
Performance Indicators ◽  
Communication Systems ◽  
Noise Immunity ◽  
Signal Systems ◽  
Discrete Signals ◽  
Information And Communication ◽  
Modern Information ◽  
Correlation Properties

The use of broadband signals (BSS) makes it possible to increase the noise immunity of information and communication systems (ICS) when exposed to structural (mutual) and organized interference. The real noise immunity will be lower than the potential one. The reason for the decrease in noise immunity, when entering synchronism and when distinguishing signals, is the presence of side peaks of the correlation functions. Proceeding from this, the NLS used in ICS should have such correlation properties when the side peaks of the NLS CF are as small as possible, i.e. ideally should tend to zero. In this case, it is necessary to determine the influence of side peaks on the characteristics of signal detection, measure their parameters, distinguish signals, and find the conditions for obtaining small side peaks. The problem of synthesizing a class of signals with given correlation, ensemble and structural properties, as well as properties of "blurring" in correlation characteristics, is formulated and solved in general form. The specified property ("fuzziness") means that increasing or decreasing the length of the discrete signal does not change the correlation properties of the discrete sequence on the basis of which the signal is synthesized. The use of many of these signal systems in modern information and communication systems will improve the performance indicators of such systems, first of all, noise immunity, secrecy, information security, noise immunity of signal reception.

scholarly journals A Bright Entanglement and Squeezing Generated by an External Pumping Radiation in a Correlated Emission Laser

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Chimdessa Gashu
Keyword(s):  
Cavity Mode ◽  
Nonlinear Crystal ◽  
Energy State ◽  
Photon Number ◽  
Statistical Properties ◽  
Intensity Difference ◽  
Normal Ordering ◽  
Cavity Modes ◽  
Correlation Properties ◽  
Correlated Emission

The quantum and statistical properties of light generated by an external classical field in a correlated emission laser with a parametric amplifier and coupled to a squeezed vacuum reservoir are investigated using the combination of the master and stochastic differential equations. First, the solutions of the cavity-mode variables and correlation properties of noise forces associated to the normal ordering are obtained. Next, applying the resulting solutions, the mean photon number of the separate cavity modes and their crosscorrelation, smallest eigenvalue of the symplectic matrix, mean photon number, intensity difference fluctuation, photon number variance, and intensity correlation are derived for the cavity-mode radiation. The entanglement produced is studied employing the logarithmic negativity criterion. It is found that pumping atoms from the lower energy state to excited state, introducing the nonlinear crystal into the cavity and coupling the system to a biased noise fluctuation, generate a bright and strong squeezing and entanglement with enhanced statistical properties although the atoms are initially in the ground state.

scholarly journals The Modification of Polyurethane Foams Using New Boroorganic Polyols: Obtaining of Polyols with the Use of Hydroxypropyl Urea Derivatives

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Iwona Zarzyka
Keyword(s):  
Physical Properties ◽  
Boric Acid ◽  
Propylene Carbonate ◽  
Spectral Characteristics ◽  
Polyurethane Foams ◽  
Thermal Stabilities ◽  
Urea Derivatives ◽  
Methods Of Synthesis ◽  
Derivatives Of ◽  
Substituted Urea

Methods of synthesis of new prospective polyol components for obtaining of polyurethane foams of reduced combustibility using eco-friendly substrates have been presented. With this end in view, N,N′-bis(2-hydroxypropyl)urea was esterified with boric acid and next the hydrogenborate obtained was hydroxyalkylated by the excess of propylene carbonate. The influence of the way of esterification on the hydroxypropyl derivatives of borate substituted urea properties has been investigated. Esterification was run in the presence and in the absence of solvent. According to instrumental analysis, the characteristic of hydrogenborates obtained in both methods was found to be similar. The hydroxypropyl derivatives of borate substituted urea show similar spectral characteristics and thermal stabilities and differ slightly in molar masses, by-product contents, and physical properties, particularly viscosities. The properties of these derivatives were assessed paying special attention to their application as the polyol components of polyurethane foams. Hydroxypropyl urea derivatives, modified by boric acid, show changes in physical properties with temperature, similarly to typical polyols used for obtaining of polyurethane foams.

scholarly journals Synthesis, physico-chemical properties of 3-thio and 3-thio -4-amino derivatives of 1,2,4-triazole

2019 ◽  
pp. 28-44
Author(s):  
V. V. Parchenko
Keyword(s):  
Chemical Properties ◽  
Biological Properties ◽  
Modern Medicine ◽  
Toxic Substances ◽  
Triazole Derivatives ◽  
Synthetic Drugs ◽  
Physico Chemical ◽  
Methods Of Synthesis ◽  
Amino Derivatives ◽  
Derivatives Of

Modern medicine and pharmacy has at its disposal highly efficient synthetic drugs. Large extent of these drugs accounted for derivatives of 1,2,4-triazole. The purpose of the work was an attempt to summarize the literature in recent years related to the methods of synthesis and study of physico-chemical properties 3-thio- and 3-thio-4-amino derivatives of 1,2,4-triazole. Studies national scientists in recent years indicates prospects of the search in this direction, since this class of organic compounds is interest not only to scientists pharmaceutical, medical and veterinary field, but also among researchers of engineering, metallurgical and agricultural areas. 1,2,4-triazole derivatives are also widely used in practice for optical materials, photosensitizers are used as coloring agents, antioxidants, additives for fuels and oils, some of which are widely used as corrosion inhibitors for controlling various pests in agriculture. In addition, 1,2,4-triazole derivatives belong to the class low toxic or essentially non-toxic substances. The presence of a growing number of publications about methods of synthesis, reactions, physico-chemical and biological properties of 1,2,4-triazole, inspires scientists around the world search for perspective molecules of substituted 1,2,4-triazole. It should be noted that in spite of a sufficient amount of information about the derivatives of 1,2,4-triazole, some issues related to the generalization of data in the literature synthesis presented insufficient.

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