The practical need for an effective student-centric organisation of active study by Bachelor’s and Master’s students of technical specialties at universities of the course on the fundamentals of optimal control theory determines the relevance of the author’s methodological approach presented in this paper. The approach is associated with the development of a comprehensive individual student assignment on computational multi-criteria nonlinear optimisation modelling of various optimal controls of linear one-dimensional motion of a controlled material point within the framework of the computational visualisation of the sequential nonlinear influence of the algebraic construct of each of the minimized functionals (A1)-(A20). They were mathematically constructed from systems engineering considerations on the completely non-obvious nonlinear dynamic features of each corresponding geometric profile of the desired optimal control signal. Most of the nonlinear formulas for the minimized functionals (A3)-(A20) proposed by the author of this study are original and principally new applied scientific results for the multidisciplinary field of engineering teaching of optimal control. The calculated results of nonlinear optimisation modelling presented in this study were obtained using the computing capabilities of JModelica-{1.17; 2.14} with the Optimica extension. The study can find wide engineering and pedagogical application in teaching university disciplines in automation, cybernetic, mechanical, electromechanical, information technology and computational optimisation cycles.
The problem of effective student learning of a new course within the framework of rational student goal setting is an “eternal” applied problem for the social and technical sciences. Each rational goal setting of the student was formulated in the form of a non-obvious mathematical construct of a nonlinear objective function that determined the minimized functional for the corresponding optimal control problem. Within the framework of the author’s approach to nonlinear modelling of various optimal goal-settings in student study of a new course, 35 optimal control problems for 35 pedagogically-admissible algebraic constructs for minimized functionals were mathematically posed, Optimica-formulated and numerically solved in JModelica-{1.17; 2.14}. As part of further generalization and psychological and pedagogical interpretation of the obtained graphical results of the numerical modelling, the following six strategies for studying a new course by a student were formulated: “Lazy Student” (Strategy A); “Procrastinator” (Strategy B); “Growing Student” (Strategy C); “Steady Student” (Strategy D); “Midterm Hero” or “Halfway Hero” (Strategy E), and “Starting Hero” or “Sprinting Hero” (Strategy F). The six strategies mentioned above for student learning of a new course seem to be a fairly concise summary of the individual educational efforts of both a school student, a university student, and a working professional.
The finite 1-bullet progressive silent duel is considered, in which each of the two duellists shoots with exponentially-concave reward. The duel models a system of one-decision-making competition between two identical intelligent competitors (duellists) through a quantized time span, in which the duellist benefits from shooting as late as possible but only by acting first. The duel is silenced because the duellist does not learn about the action of the other duellist until the very end moment of the duel. Thus, the duel is a symmetric matrix game whose optimal value is 0, and the set of optimal strategies is the same for both duellists, regardless of the duel size and how time is quantized. The duel time quantization is such that time progresses by the geometrical progression pattern, according to which every following time moment is the partial sum of the respective geometric series. In this duel, the duellist has the invariant unique optimal time moment, which is the duel middle, regardless of the number of time moments. Usually, the system manager benefits namely from such a solution, by which the manager latently forces both competitors to act at the invariant optimal moment, maintaining the system more stable and controllable.
Electromagnetic Launcher (EML) systems are classified into two main categories based on their fundamental operating principles: rail guns and coil guns. Rail guns accelerate a conductive projectile using magnetic force by passing a high current between two parallel rails, but they suffer from wear and heat accumulation due to mechanical contact. Coil launchers use electromagnets to accelerate ferromagnetic or conductive projectiles without contact, thus minimising energy losses and wear. Rail guns are preferred in military applications requiring high velocity and kinetic energy, whereas coil guns are more prominent in controlled acceleration applications such as space launch systems and laboratory experiments. Since the velocity of the generated electromagnetic field in coil launchers has no theoretical limit, the accelerated projectile also does not have a predefined velocity limit. However, the use of randomly sized coils and an increased number of sequential coils in coil guns disrupts the linearity of the projectile velocity increase. To address this issue, this study develops a “New Helical Coil Gun”, consisting of four-stage helical coils designed to achieve linear velocity increase. First, the self-inductance coefficient of a coil was simulated based on the time-dependent variations of the current passing through it, and the inductance value that could provide a maximum instantaneous current of 25A (without direction change) under laboratory conditions was determined. Then, the design of the helical coil with a rectangular cross-section to provide this coefficient value was implemented. This design was then transferred to the ANSYS Maxwell magnetic analysis software, where an optimisation process was conducted to determine the ideal projectile size that would maximise the magnetic force exerted on a ferromagnetic projectile when a 25 A current was applied to the coil. Following this stage, a “Helical Coil Gun”, composed of four-stage helical coils, was designed and manufactured based on the determined projectile and coil dimensions. Optical sensors were placed at the initial positions of the coils to measure the projectile’s velocity. An FPGA-based project was developed for data acquisition, processing, and triggering control. This project, designed using the LabVIEW FPGA module, was carried out on the NI myRIO-1950 board containing Xilinx FPGA. After each launch, the collected data was stored on a flash drive connected to myRIO and monitored in real time via a display. What distinguishes this study from literature is its approach to determining the optimal coil geometry by correlating the current variation characteristics with the coil’s self-inductance coefficient and using Genetic Algorithm-based optimisation to identify the ideal projectile size that achieves maximum velocity under maximum force. Experiments with the developed coil gun showed that the projectile velocity change from the beginning of the first coil to the end of the fourth coil was linear.
In fifth generation (5G) wireless networks, radio access techniques and multi-carrier waveforms play a vital role in meeting the diversified demands of ultra-low latency, massive connectivity, and higher throughput. Multi-access schemes used conventionally in 4G system was Orthogonal Multiple Access (OMA) technique. The OMA techniques suffer from inefficient spectrum utilization, high latency, and supports a limited number of users. Next-generation networks, Non-Orthogonal Multiple Access (NOMA), has a great potential, in which multiple users are simultaneously served using the same time, frequency, or code resource increasing the throughput. Code domain-NOMA (CD-NOMA) is the key technique implemented in the system design where multiple users are distinguished based on unique user-specific spreading codes. The NOMA system could significantly benefit from Universal Filtered Multi-Carrier (UFMC) modulation waveform in terms of flexibility, spectral efficiency, compatibility with Multiple Input Multiple Output (MIMO) technique, and relaxed synchronization requirements. The novel integrated system proposed in the paper is CD-NOMA-UFMC with convolutional codes. The major outcome of the paper is that the combination of UFMC air interface modulation technique with CD-NOMA access method can be the most effective way to meet the growing demands of 5G.
