RESUMEN
This paper deals with the practical application of Radar Cross Section (RCS) reduction technology using plasma. Although various plasma application technologies for RCS reduction have been studied, there are still many issues to be addressed for practical implementation. In order to achieve actual application, the discharge should be sustained regardless of the external environment of the aircraft. It is also important to investigate the actual plasma parameters to determine the expected RCS reduction effect. Building upon previous studies that optimized the electrodes for RCS reduction, this study fabricates a Dielectric Barrier Discharge (DBD) source suitable for dynamic environments and verifies the power consumption during one cycle of plasma generation. The obtained results are expected to contribute to the optimization of DBD electrodes for plasma RCS reduction.
RESUMEN
In this study, the problems encountered in radar cross-section (RCS) measurement experiments utilizing a dielectric barrier discharge (DBD) plasma system are examined and an effective solution is proposed. A DBD plasma system generates heat due to the high bias voltage required for plasma generation. The thermal-induced structural deformation of the DBD structure caused by this high voltage and its impact on RCS measurements are analyzed. In addition, techniques for minimizing the thermal-induced deformation and compensation methods for addressing the minimized deformation are proposed. Furthermore, RCS measurements are conducted on two kinds of DBD structures using the proposed method to experimentally demonstrate the improved agreement between the simulation and measurement results. For both structures, the RCS experimental results are in very good agreement with the simulation results, which enables accurate plasma characterization. In conclusion, it can be expected that the proposed method can be used to provide more accurate RCS measurements on various DBD structures that generate high heat.
RESUMEN
In this study, a method was experimentally verified for further reducing the radar cross-section (RCS) of a two-dimensional planar target by using a dielectric rim in a dielectric barrier discharge (DBD) plasma generator using a frequency selective surface (FSS) as an electrode. By designing the frequency selective surface such that the passbands of the radar signal match, it is possible to minimize the effect of the conductor electrode, in order to maximize the RCS reduction effect due to the plasma. By designing the FSS to be independent of the polarization, the effect of RCS reduction can be insensitive to the polarization of the incoming wave. Furthermore, by introducing a dielectric rim between the FSS electrode and the target, an additional RCS reduction effect is achieved. By fabricating the proposed plasma generator, an RCS reduction effect of up to 6.4 dB in X-band was experimentally verified.
RESUMEN
This research explores different ways to use features of one's own body for interacting with computers. Such "body-based" interfaces may find good uses in wearable computing or virtual reality systems as part of a 3D multi-modal interface in the future, freeing the user from holding interaction devices. Four types of body-based interfaces have been identified: Body-inspired metaphor (BIM); Body-as-interaction-surface (BAIS); Mixed mode (MM); and Object mapping (OM). These four body-based interfaces were applied to a few different applications (and associated tasks) and were tested for their performance and preference. It was generally found that, among the four, the BIM exhibited low error rates, but produced relatively longer task completion times and significant fatigue. The BAIS method had the contrasting character of higher error rates, but shorter task completion times and lower intuitiveness. The OM method exhibited high error rates, longer completion times, and much fatigue. Overall, the MM was superior in terms of both performance and preference as it combined the merits of the above three methods. Thus, it is expected, for applications with many associated tasks, a careful division of tasks among those that have natural semantic links to body parts and those that do not, is necessary to design the most performing body-based interface.