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The effectiveness of positioning techniques that utilize the receiver signal strength (RSS) is highly dependent on the instability of the received signal strength indicator (RSSI). Up to now, there is no strategy that effectively lowers the influence of such instability on the accuracy of positioning. Moreover, recent studies showed that indoor positioning techniques are vulnerable to noise in RSSI data and cyber-attacks, which make them more expensive. In this study, a new Internet of Things (IoT) paradigm is proposed for the indoor positioning of automated guided vehicles (AGVs) using a deep convolution neural network (CNN). The proposed method handles signal processing by converting the RSSI signal into an image. In which, the 1-D RSSI signal is converted into 2-D image data in order to generate the new features based on continuous wavelet transform (CWT), and then the proposed deep CNN is implemented for the indoor positioning system. The test results show that the proposed model can outperform other state-of-the-art positioning techniques with small position errors. Furthermore, the robustness of the proposed model is validated against various adversarial attacks. In addition, the proposed method can have a lower impact on RSSI change compared with other methods.

The EU demonstration power plant (DEMO) Tokamak will be equipped with an electron cyclotron (EC) system for plasma heating and magnetohydrodynamic (MHD) control. Up to six launchers will be installed into equatorial ports with the aim to inject maximum 130-MW millimeter-wave (mm-wave) power at dedicated positions into the plasma. The mm-waves will be generated in gyrotrons placed in a distinct building at distant location. From this gyrotron hall, a combined transmission line (TL) system of quasi-optical multibeam mirrors and individual waveguides (WGs) will propagate the mm-waves into the tokamak building. That followed, an optical system, composed of miter bends, diamond windows, valves, and microwave bellows, connects the TL through the gallery and the port cell with the EC launchers. This article presents the preconceptual computer-aided design (CAD) of this latter section of the EC system. Based on its general scheme and the given WG trajectories, the model takes into account the available space in the port cell with respect to required clearance for supply systems, assembly, and maintenance. At the preconceptual state, the design includes CAD models of all relevant mm-wave components in realistic dimensions at a level of details, appropriate to demonstrate the feasibility of the concept.

AbstractNuclear fusion power plants require electron cyclotron (EC) heating and current drive (H&CD) systems for plasma heating and stabilization. High-power microwave beams between 1 and 2 MW generated by gyrotrons propagate in a dedicated waveguide transmission system to reach the plasma at specific locations. Key components in this transmission system are the chemical vapor deposition diamond windows on both the torus and gyrotron sides of the reactor as they allow transmission of high-power beams while acting as confinement and/or vacuum boundaries. Diamond windows consist of a polycrystalline diamond disk integrated in a metallic housing. In the conventional configuration, there is one disk perpendicular to the beam propagation direction. A steering mechanism is then used to deploy the fixed frequency beam at different locations in the plasma. This is, for instance, the configuration used in the ITER EC H&CD system. Movable parts close to the plasma will be problematic for the lifetime of launchers in future fusion reactors like the DEMOnstration nuclear fusion reactor (DEMO) because of the higher heat loads and neutron fluxes. Therefore, one of the alternative concepts is to deploy the beams directly at the desired resonant magnetic flux surface by frequency tuning gyrotrons. In this case, diamond windows able to work in a given frequency range, like the diamond Brewster-angle window, are required. It is an elegant and compact broadband window solution with the disk inclined at the Brewster angle with respect to the beam direction. This paper shows the development and the current state of different diamond window concepts including the design, the numerical analyses, and application of standard construction nuclear codes and of a specific qualification program.

Critical problems in Vietnam - such as food safety, traffic management, saltwater intrusion, and wastewater management - require novel Internet of Things (IoT) solutions. Here, the authors analyze current research and developments and propose specific IoT services as solutions.