Aim. To explore the peculiarities of nitrogen transformation in sod-podzolic soils with corn growing under dif- ferent fertilizer types and the effect of bacterization. Methods. Agrochemical, fi eld and lyzimetric, chromato- graphic determination of nitrogen fi xation activity and emission of N 2 O. Results. The highest losses of nitrogen from the soil occurred in the variants with manure application and use of mineral fertilizers N 90 P 90 K 90 . The processes of nitrogen transformation in soil and corn yield were optimized using the combination of mineral fertilizers with green manure and microbial agent. Conclusions. The application of fertilizers for corn grow- ing on sod-podzolic soils of Polissya region should be accompanied with the use of green manures. The use of microbial preparations is recommended.

Random sequences are used in various applications in construction of cryptographic systems or formations of noise-type signals. For these tasks there is used the program generator of random sequences which is the determined device. Such a generator, as a rule, has special requirements concerning the quality of the numbers formation sequence. In cryptographic systems, the most often used are linearly – congruent generators, the main disadvantage of which is the short period of formation of pseudo-random number sequences. For this reason, in the article there is proposed the use of chaos generators as the period of the formed selection in this case depends on the size of digit net of the used computing system. It is obvious that the quality of the chaos generator has to be estimated through a system of the NIST tests. Therefore, detailed assessment of their statistical characteristics is necessary for practical application of chaos generators in cryptographic systems. In the article there are considered various generators and there is also given the qualitative assessment of the formation based on the binary random sequence. Considered are also the features of testing random number generators using the system. It is determined that not all chaos generators meet the requirements of the NIST tests. The article proposed the methods for improving statistical properties of chaos generators. The method of comparative analysis of random number generators based on NIST statistical tests is proposed, which allows to select generators with the best statistical properties. Proposed are also methods for improving the statistical characteristics of binary sequences, which are formed on the basis of various chaos generators.

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Context. The task of increasing the secrecy of information transmission based on combined random coding is considered. The object of research is the integration processes of stochastic, block and timer coding. Objective. The aim of the article is to develop a method of increasing the secrecy transmission based on combined random coding. Method. The method of increasing the secrecy of information transmission based on combined random coding with three steps of code converters: internal, intermediate and external is proposed. The internal converter is implemented based on stochastic coding with various numbers of random code combinations. The number of random combinations depends on the probability of the character of the symbol in the message text. The information secrecy of the transmission is ensured by equalizing the probabilities of the occurrence of code combinations from the output of the statistical coder. Intermediate coding is implemented using a noise immunity block code. Information secrecy and noise immunity leads to the increasing the length of the code block at each stage of coding, which reduces the code rate. To solve this problem, an external converter based on timer coding is used. At this stage, binary combinations are converted into timer signal structures, which allows for the implementation of a structural transmission secrecy, increase the code rate and improve noise immunity. When the stochastic encoding and a timer used codebooks. Results. The developed method of combined random coding allows to increase the main indicators of noise immunity: interference protection, information and structural secrecy. Conclusions. The proposed method of combined random coding allows to eliminate the main disadvantages of stochastic coding, in which the choice of the number of random code combinations does not take into account the entropy of the discrete source of information. For solving this problem, it was proposed to use different number of random combinations, in view of the probability of an alphabet symbol appearing in the text. From the theoretical point of view, this will allow the output of the statistical coder to form a stream of combinations with equal probabilities of occurrence. Due to the usage of timer signal constructions, the problem of redundancy compensation is solved, which appears during stochastic and noise-immune coding.

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