RUDN Journal of Engineering Research

We consider a particular issue of optimal economic planning based on models of intersectoral balance which taxes are additionally introduced as one of the controlling factors. The analysis of describing applications of optimal control methods in economics for various models, as well as an overview of applied software for the development of economic and mathematical models and calculations. The mathematical apparatus used in solving the problem is considered in detail, the formulation of the modeling problem and the rules for calculating the mathematical model using the applied package of numerical and symbolic modeling Maple are described. The mathematical model of the macroeconomic system optimal planning as an optimal task for speed is given, the mathematical apparatus of the optimality conditions is highlighted, the dependence of the planning results on the influence of the taxation factor is established. The degree of economy optimization at its fastest transition from one state and its dependence on certain combinations in the combination of control functions, such as total costs, capital intensity, consumption functions, the amount of taxes collected and production capacity, etc., are investigated.

The results of optimizing the milling process on the Roland MDX-20 machine are presented: the maximum allowable and optimal cutting conditions for parts made of foam, hard and soft modeling plastics, and hardwood are empirically established. At the first stage of the study, a complete list of types of strategies for roughing and finishing, presented in the CAM-system Modela Player 4 (MP4), was studied, as a result of which the optimal one for the intended experiment was chosen (9 virtual tests were carried out), processing time was taken as the analyzed parameter. To understand the specifics of the work on the machine under study and to check the suitability of using the processing parameters and the type of strategy, test processing of the foam was carried out. The main optimization criteria are speed, expressed as processing time, and the quality of the resulting surface. At the second stage of the study - experiment - methods for roughing horizontal surfaces of 20×20 mm models, consisting of a truncated pyramid and a hemisphere, are described on a Roland MDX-20 milling machine using MP4. As cutting tools in both studies, a Hanita 400305002 ∅6 mm cylindrical cutter was used for roughing, and a Hanita 400103002 ∅3 mm spherical cutter was used for finishing. The recommended cutting conditions have been established, which allow reducing the processing time of parts by 40-50 % without deteriorating the quality of the machined surfaces.

This comprehensive study delves deeply into the intricate domain of optimizing Micro-electromechanical Systems (MEMS)-based navigation sensors for aerospace vehicles. It entails a meticulous examination of MEMS sensors, focusing on their role in guidance, navigation, and control, with particular emphasis on MEMS inertial sensors and crucial performance metrics. The study investigates a spectrum of techniques for sensor optimization, including strategies for enhancing fabrication and production through smart structures and mathematical modeling. Additionally, it explores methodologies and mechanisms for improving navigation sensor fabrication, along with the incorporation of optimizer techniques to manage computational complexities effectively. The key findings underscore the challenges tied to material selection and structural intricacies in optimizing these sensors for aerospace applications. Integration of sensors into integrated circuits, development of advanced mathematical models, and harmonization with artificial intelligence algorithms are vital for boosting sensor performance, while calibration and error mitigation during user deployment are essential. Furthermore, the study underscores the imperative for addressing limitations in sensor accuracy and precision through refined calibration mechanisms and error correction processes. The trajectory for future research involves advancing material selection, mathematical models, and innovative calibration techniques to comprehensively enhance sensor performance and reliability in aerospace applications.

A study was undertaken to understand the status of electric power demand, generation and supply in Iraq and the feasibility for adopting gas turbine technology for generating electric power. Based on the climatic and weather data, it was found that Iraq in general experiences a hot and dry climate with cooler nights. Apart from the coastal regions of the country, the relative humidity is generally low. This was found to be an encouraging factor for adopting cost effective evaporative cooling systems for the air entering gas turbine used for power generation (GTPG). The higher frequency dust storms in Iraq can result in operational problems, shorter life span and higher maintenance costs for GTPG, making air filtration mandatory for efficient operation of GTPG. Taking into account the district wise climatic and weather conditions, the district of Nineweh was found to be more suitable for the establishment of gas turbine plant for electric power generation (GTPEG). Among the different cooling systems available taking into to account the cost effectiveness and the simplicity in design, construction, operation and maintenance, it was found that evaporative cooling system was more suitable. Further, it was found that the effectiveness of evaporative cooling system can be enhanced by taking advantage of the low night temperature and cooling the water to be used in the evaporative cooling system. Analysing the performance of the gas turbine, it was found that adopting the cooling system will result in reducing the power loss from 6.68-46.89 % to 2.77 to 21.17 %.