In this paper, we propose a deep Q-network-based resource allocation method for efficient communication between a base station and multiple Unmanned Aerial Vehicles (UAVs) in environments with limited wireless resources. This method focused on maximizing the throughput of UAV to Infrastructure (U2I) links while ensuring that UAV to UAV (U2U) links could meet their data transmission time constraints, even when U2U links share the wireless resource used by U2I links. The deep Q-network agent uses the Channel State Information (CSI) of both U2U and U2I links, along with the remaining time for data transmission, as state, and determines optimal Resource Block (RB) and transmission power for each UAV. Simulation results demonstrated that the proposed method significantly outperformed both random allocation and CSI-based greedy algorithms in terms of U2I link throughput and the probability of meeting U2U link time constraints.

To accurately assess mechanical properties of micro- and nano-sized specimens, a reliable material testing system is indispensable. However, due to small sizes of these test specimens, in-situ measurement of their mechanical behavior necessitates installing the tester within high-magnification microscopes such as SEM. Traditionally, researchers have used wired methods by placing the tester inside the SEM chamber and connecting it to an external controller via electrical feedthrough. Unfortunately, this approach is cumbersome. In addition, it limits its compatibility with other SEMs. In this study, we developed a compact controller capable of driving 3-axis piezoelectric actuators with nanometer-level displacement control resolution via Bluetooth communication. This innovative setup enables wireless control and data acquisition from outside the closed confines of an SEM chamber. To validate the versatility of our tester, we conducted both a nanoindentation test on a fused silica specimen using a Berkovich indenter in a wired configuration and a copper micropillar compression test wirelessly using a flat punch indenter within an SEM. By installing this tester in various measurement systems, researchers could observe deformation patterns in real time, making it a valuable tool for investigating deformation mechanisms of diverse micro- and nano-sized specimens.

With the increasing use of portable devices, the safety and efficiency of wireless chargers have become significant concerns. Wireless chargers can cause battery damage, deformation, and failure of the charging module due to the high temperatures generated during the charging process. Thus, the importance of thermal management has been increasingly emphasized. In this study, we experimentally confirmed that cooling performance was improved by applying phase change material (PCM) to the heat-generating parts of the wireless charger. The cooling performance of the PCM was analyzed using Ansys Fluent, the component temperature was measured with an infrared camera, and 3D thermal deformation was measured with a DIC measurement device. Electromagnetic field, thermal, fluid, and structural coupled analyses were performed to investigate the impact of thermal deformation caused by wireless charging. The results showed that the temperature and deformation error was within 3% of the coupled analysis results, and the proposed electromagneticthermal-fluid-structural coupled analysis enabled more accurate simulation prediction of the physical coupling process inside the wireless charger.

Most of passive implants belong to medical device are consist of metallic and nonmetallic materials. According to the sort of components, it makes more influence into the human body. In this study, we performed induced-RF (Induced-Radio Frequency) heating evaluation which is part of MRI (Magnetic Resonance Imaging) compatibility and safety test and in-vivo pyrogen test with lumbar stand-alone cage. RF from 3T MRI coil was radiated on medical device, and provided heat nearby stand-alone cage. Thermal change detected areas are distinguished by metallic and nonmetallic part. As followed detection areas, febrility was shown and metallic part was slightly higher than control area, nonmetallic part. Furthermore, stand-alone cage was performed in accordance with in-vivo pyrogen test, and solution injected rabbits had no fever for test period. Through physically and biologically evaluated stand-alone cage, exothemic reaction was observed and we predicted the effect when it would be inserted in patient.