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Research and simulation of the machining process of difficult-to-cut materials

Heat-resistant and high-alloy steels and alloys are difficult materials to machine. Optimizing the cutting parameters for such materials is a complex and multi-factorial technological process planning task. The paper describes the method of analysis of loading, thermodynamic and stress-strain state of a workpiece while cutting of typical representative of hard-to-cut materials (chromium-nickel alloy IN718) using finite element simulation. Influence of feed rate on cutting force and temperature in the zone of chip formation is given.

A Modeling Study of Operating Conditions and Different Supports on Fe-Co-Ce Nanocatalyst and Optimizing of Light Olefins Selectivity in the Fischer-Tropsch Synthesis

This study demonstrates the effect of operating conditions (Red-GHSV, inlet H2/CO, Oprat-GHSV) and the effect of Fe-Co-Ce nanocatalyst support. A statistical model using the response surface methodology (RSM) was applied with the target of achieving higher olefins selectivity in Fischer-Tropsch synthesis, which indicates the interaction effects of factors. The conditions under which three objectives optimization for maximizing olefins and minimizing paraffins and methane were determined.

Modeling of production processes with regeneration for ensuring enterprise competitiveness

The article presents the research and rationale of theoretical issues and applied decisions regarding the influence of enterprises and the mechanism of managing production processes with regeneration (renovation) on the competitiveness.  Mathematical tools were developed and methods for calculating basic economic indicators were suggested, namely, the starting factors and direct regulatory costs for materials; the economic and mathematical model of production processes with regeneration was designed, which allows comparing the output of production with the cost of its manufacturing and the

Modeling and control of an electromechanical system with a permanent magnet generator and a voltage source converter

In the paper simulation dynamic models for the analysis of characteristics and transients of electromechanical system using a permanent magnet electric generator (PMG) connected to a variable speed fixed pitch wind turbine (WT) and a voltage source converter (VSC) mathematical models are developed. The system supplies a direct current (dc) resistive load through a controlled switch.

Modelling and simulation of pneumatic system operation of mobile robot

Problem statement. Mobile robots are currently of significant interest among researchers and designers all over the world. One of the prospective drives of such robots is equipped by a pneumatically operated orthogonal system. The processes of development and improvement of orthogonal walking robots are significantly constrained because of the lack of an open-access comprehensive scientific and theoretical framework for calculating and designing of the energy-efficient and environmental-friendly pneumatic walking drives.

Design and operational peculiarities of four-degree-of-freedom double-legged robot with pneumatic drive and turning mechanism

Problem statement. Mobile robots are of significant interest among scientists and designers during the last several decades. One of the prospective drives of such robots is based on pneumatically operated walking (stepping) system with no use of electric, heat, magnetic or other types of energy. This allows the use of pneumatically-driven robots in the cases when the use of other energy sources is prohibited (e.g., in some gaseous or fluid mediums).

Implementation of Fpga-based Pseudo-random Words Generator

A hardware implementation of pseudo-random bit generator based on FPGA chips, which use the principle of reconfigurability that allows the modernization of their algorithms and on-line replacement of the internal structure (reconfiguration) in the process of functioning have been considered in the paper. Available DSP blocks embedded into the structure of FPGA chips allow efficient hardware implementation of the pseudorandom bit generator through the implementation of the basic operations of multiplication with accumulation on the gate level.

DEVELOPMENT OF THE BASIC CAPACITIVE ACCELEROMETERS MODELS BASED ON THE VHDL-AMS LANGUAGE FOR THE CIRCUIT LEVEL OF COMPUTER-AIDED DESIGN

In the article, the basic VHDL-AMS models of MEMS-based capacitive accelerometers were developed. The models were designed for two basic types of capacitive accelerometers, namely lamellar and counter-pivotal. The developed models allow us to determine the source of electrical capacitive accelerometers depending on the incoming mechanical and structural parameters and were constructed for MEMS CAD at the circuit level. The circuit level of MEMS development requires an analysis of the total integrated device electric circuits.

Position Controller Design and Implementation of Ball and Beam System with SMC and PD Control Methods

Today, several methods are proposed and tested for controlling many nonlinear and unstable systems. This study employed the sliding mode control (SMC) and proportional-derivative (PD), which are used to control the position and modeling of ball and beam system that is a fundamental system used to test the control methods. Such systems are nonlinear and unstable due to their nature. Therefore, these systems are affected by external disturbances and this leads to a decrease in the control quality.

MODELING THE IMPACT OF GCI COMPONENTS ON UKRAINE COMPETITIVENESS

Global competition is growing not only on a products/firms level, but also among countries. There are many approaches to interpretation of a concept of the “country competitiveness”, which in particular means “the state of the country in the global market due to the international division of labor, national conditions and factors of production and its ability to compete effectively in world markets”.