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NICT REPORT 7oped a solar flare prediction model that uses deep learning to predict the occur-rence of large solar flares that can have a large effect on our satellites and communi-cation/broadcasting infrastructure. This work has now reached the stage of putting this model into actual operation.When a large solar flare was detected in September 2017, the NICT issued a press release and held a press conference to warn of its possible effects on society, re-sulting in widespread media coverage (271 newspaper articles, 60 television pro-grams, and 779 Web news items) (Fig.2). The NICT Space Weather Forecast web-site received 1.8 million hits in two days.R&D of ultra-precise atomic clocksThe transition frequencies of the stron-tium optical lattice clock and the indium ion clock were accurately measured in NICT, leading to the adoption of these technologies in the Consultative Commit-tee for Time and Frequency at the Interna-tional Committee for Weights and Mea-sures. The committee was held in June 2016, and we made a large contribution to the revision of recommended frequencies.Our success in generating a time scale using a strontium lattice clock was pub-lished not only in an original paper but also in a press release (Research Highlight p.44).For chip-scale atomic clocks that we hope will be installed in mobile phones or IoT devices, we have developed a 3.4 GHz oscillator using a film bulk acoustic reso-nator (FBAR) (Fig.3), resulting in an atomic clock with better short-term frequency sta-bility than commercial products.R&D of electromagnetic com-patibility (EMC)Regarding calibration techniques for high-frequency power measuring instru-ments up to the terahertz band, we have developed a calorimeter for the 220-330 GHz band in collaboration with the Na-tional Institute of Advanced Industrial Sci-ence and Technology. By establishing the traceability to the national standard and assessing the uncertainty of the results, we started a calibration service from FY2018.The results of a study that accurately evaluated human exposure based on mea-surements of the dielectric constants of biological tissues up to the terahertz band was published by the UK Institute of Phys-ics in the journal Physics in Medicine and Biology (Fig.4), and was adopted as the basis of the next revision to the interna-tional guidelines on RF safety that the In-ternational Commission on Non-Ionizing Radiation Protection (ICNIRP) and the IEEE have been developing and will pub-lish in the near future.Various social advances in elec-tromagnetic wave technologyWe are actively involved in various ef-forts to utilize electromagnetic wave in real society. For example, we are collaborating with a general conductor to develop short-distance positioning technology for the use in construction sites. It is based on wireless two-way time comparison (WiWi) technique. We are also contributing at an international level by working with foreign museums on the use of electromagnetic waves in non-destructive sensing technol-ogy for the study of social infrastructure and cultural properties (Fig.5). Further-more, our wavefront printing technique is expected to be used in various applica-tions such as automotive or in-vehicle dis-play devices, because it enables the fabri-cation of very complex optical components on a lightweight holographic film.Fig.5: Analysis of the mortar condition beneath The Annunciation — a typical renaissance-era fresco, painted by Fra AngelicoFig.4 : Measurements of the dielectric constants of biological tissues in the millimeter-wave frequency band (left), and the results of a numerical analysis of the increase in temperature at the surface of the body due to exposure to electromagnetic waves up to the terahertz band (right)Fig.3 : 3.4 GHz FBAR oscillator for use in chip-scale atomic clocks Research and Development