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The article considers various types of statements used in the linguistic description of input factors and regulated parameters of a combine harvester when solving the problem of its technological adjustment. The linguistic description of the environmental conditions, the regulated parameters of the combine and the characteristics of the quality of harvesting operations is presented. The technique of modeling fuzzy statements for the formalization of knowledge in an expert system designed to inform the operator of the combine when choosing the values of adjustable parameters corresponding to the operating conditions of the combine is presented. The technique is illustrated by an example of fuzzy inference.

The task of technological adjustment of the working bodies of a rotary combine harvester is not trivial. The complexity of the task is due to the need to take into account a large number of signs (environmental factors and parameters of the technical condition of the machine), and the level of uncertainty of the values of these signs is quite high. Therefore, when searching for optimal values of the regulated parameters of the combine harvester, ensuring that the values of the work quality indicators do not exceed the permissible ones, it is advisable to use an intelligent information system. The use of this system will allow using various methods and algorithms for finding the desired solutions. In the conditions of uncertainty characteristic of the problem under consideration of adjusting the adjustable parameters of the machine, it is advisable to use a game-theoretic approach when creating an intelligent system for setting up a combine harvester. This approach will provide variability of methods for choosing the optimal strategy for finding a rational solution.Based on the analysis of the subject area, the concepts of performance indicator matrices and the risk of making an ineffective decision are introduced. The choice of a strategy for finding the reason for the deviation of the harvester’s performance indicator is considered based on three criteria: Laplace, mathematical expectation and Savage, widely used in decision-making tasks in the so-called “games with nature”. An example of choosing a strategy for finding the cause of a violation of the technological process of grain harvesting and an adequate response to eliminate it is given. The analysis of the calculation results is carried out, the conditions and scope of the proposed approach are presented.

One of the promising approaches to improve the efficiency and effectiveness of the harvesting process of grain crops using a combine method is the use of an intelligent information system in the form of a decision support system. The expansion of the use of high-performance rotary-type combines in production conditions puts the task of optimal technological adjustment of the working bodies and the entire combine as a whole into the category of topical ones. When performing harvesting work with an axial-rotary threshing and separating device (ARTSD), as a result of continuously changing external harvesting factors, deviations in the values of work quality indicators from acceptable values are possible. For their timely elimination, it is important to know the relationships between the groups of signs: “environmental factors - parameters of the working bodies - indicators of the quality of work.” The lack of knowledge leads to non-optimal decisions on the choice of specific values of the controlled parameters and, as a result, to the loss of grain and other resources. To select the optimal strategy for managing the technological process of harvesting using a rotary harvester, we propose a new approach based on the use of an intelligent information system (expert system), which corresponds to the concept of intellectualization of a new type of machine. The article presents the results of research into the process of technological adjustment of a rotary harvester, as well as an analysis of the empirical knowledge of experts with extensive production experience in operating combines of this type. The concepts of parameters, causes and methods for eliminating violations of the technological process are introduced. As a result of expert analysis, decision trees were formed for the first time, on the basis of which the rules of the knowledge base are formulated. To create a knowledge base, it is proposed to use a production model of knowledge. An example of constructing a decision tree when searching for the cause of the appearance of one of the external signs of a violation of the quality of the work of a rotary harvester is given. A fragment of the system of production rules for solving the problem of adjusting the values of control parameters is presented.

Methods for the field determination of rhenium in plants have been developed. The speciation of rhenium in solutions throughout the process of sample preparation has been investigated. It has been shown that, in the initial ethanol and water-salt extracts, rhenium occurs as perrhenate ions. Perrhenate ions have been established to be partially reduced in time to give Re(VI). Since test methods have been developed for determining rhenium as perrhenate-ions, their partial reduction in the process of sample preparation can lead to an low level of the results. The optimal conditions for preserving rhenium as perrhenate ions have been determined. Two procedures (in four versions) providing the determination of as low as 5 ng of rhenium in a 1-g sample with an error below 23% have been proposed. The developed procedures have been applied in the places of the collection of plant materials for the regional investigation of the occurrence of rhenium in the territories of different ore contents. DOI: 10.1134/S1061934810050163, We have previously found that a rare trace element rhenium, of which the average abundance in the earth's crust is 7 x [10.sup.-8]% (Vinogradov's clark [1]), is efficiently accumulated in [...]

Abstract -- Methods for rhenium extraction from plant materials were studied using model systems and the [.sup.186.Re] isotope. Conditions are described for the quantitative extraction of rhenium with acid and [...]