These challenges were specifically studied for a bearingless switched reluctance motor that required both robust and stable operation. In this context, a dynamic sliding mode controller has been proposed to tackle the robustness issue, while a sliding mode observer has been adopted to cope with speed and displacement estimations. It has therefore been demonstrated that the switched reluctance motor can promptly start from any arbitrary initial position without any initial jerk. The speed and displacement measurements were consistently accurate at higher speeds. In [7], [PERSON] et al. proposed analytical models to determine the electromagnetic performance of segmented permanent magnet synchronous machines (without active parts in the stator or the rotor). These unconventional but innovative machines can be used in rim-driven tidal stream turbines or in marine propellers. According to these targeted applications, the proposed models have been adapted for machines with large air gap widths, large diameters, a high number of poles, and large angular gaps. It has been shown that these models allow fast and accurate evaluation of performance and can be used in the systematic design process. Alkaline water electrolysis is also featured in this Special Issue with the contribution of one paper. Indeed, in [8], [PERSON] et al. proposed a strategy to find the best cell design and operating conditions of a diphasic electrochemical cell using an evolutionary algorithm. More specifically, a meta-model was developed to simplify the physics of the void fraction and a genetic algorithm was used to find the optimal design. Global positioning, antennas, and electronics are featured in this Special Issue in three papers. In [9], [PERSON] et al. addressed the issue of poor-quality signals that negatively impact position accuracy in the context of global navigation satellite systems (GNSSs). The improvement of single point positioning accuracy has been proposed by using multi-GNSS data fusion using an extended Kalman filter combined with iterative reweighted least squares and receiver autonomous integrity monitoring. This robust extended Kalman filter method has been applied along with the robust combination of GPS, Galileo, and GLONASS data from ABMF (at the GNSS reception station managed by Meteo France in Guadeloupe). It significantly improves the position accuracy by about 84% compared to the non-robust data combination. Although the robust extended Kalman filter has demonstrated improvements in position accuracy, its outputs might contain errors that are difficult to estimate. For improvement purposes, the authors proposed a long short-term memory method to predetermine the produced error. The fundamental task of designing antennas suitable for generating highly directive electromagnetic signals was studied by [PERSON] et al. in [10]. The motivation of this study was the design of special antennas able to convey electromagnetic signals along patterns characterized by extremely high directivity, which ameliorated in comparison to existing commercial solutions. For this purpose, an extension of the electrodynamics equations was taken into account, where exact solitonic-type solutions were admitted. The achieved results put forward the design of biconic-type antennas that have specific properties. Cones, supplied with an oscillating source, are embedded in a dielectric material of suitable shape to drive the signal in the proper direction. In this context, the targeted applications are point-to-point communications or wireless power transmission. In [11], [PERSON] et al. addressed the issue of current-voltage characteristics' slope control in negative differential resistance (NDR)-based electronic devices. These devices are widely used in electronic and radio engineering systems of the broadest use. In this context, new two-terminal NDR circuits have been proposed based on a combination of a field-effect transistor and multiple-output cascade, Wilson, and improved Wilson bipolar junction transistor current mirrors.