2014年11月に電気学会の「電気システムセキュリティ特別技術委員会」において，E部門から「社会インフラ用センサシステムセキュリティ特別調査専門委員会」が設置され，3年と5ヶ月間，社会インフラに関わるセンサ・セキュリティ技術の調査および講演会やシンポジウムの開催に

We have prepared a magnetic flux transformer that is operable at 77K by using commercially available RE123 High-T_c superconducting (HTS) tape. HTS seamless loop used in this study has been prepared by “Cut-and-wind” method, which enables to fabricate not only the large bore loop but also the multi-turn structure without jointing. The seamless loops constituting the transformer have diameter above 10 cm in this report. We have confirmed induction of superconducting shielding current in the loop for static field applying and magnetic field transferring by the flux transformer at 77K.

The human error prevention system is realized by 3-point collation using a barcode reader. A new optical device consisting of Littrow prism and cylindrical lens, which are optically aligned with a built-in camera and an LED in a smartphone, has realized the smartphone with the same usability as the conventional barcode reader.

Serious flood disasters have escalated because of climate variation by global warming. For early alert of flood disasters, it is necessary to employ multipoint and wide-area water level monitoring throughout river basins, including headwaters. However, cost issue of the conventional sensing system has prohibited the progress of installation in small rivers. In this work, we propose the low-cost and contactless sensing system for water level in the river using a millimeter-wave radar and LPWA network. The prototype sensor can detect distance with average error rate of 2.56% and monitor water level in the actual river even during stormy weather. Furthermore, it is demonstrated that water level can be monitored by this sensor in various river conditions.

In this paper we describe a secret sharing technology (e-Tally), which is a secure scheme, where we show how to make the e-Tallies and how secure they are. This technique enables the construction of the secure social infrastructure to protect the data from the disaster or hacker and to prevent the sensitive personal data from leakage. This secure social infrastructure also can be used to construct secure Internet of Things (IoT) networks by connecting to the sensor system of IoT networks.

NH₃ gas is a poisonous substance that adversely affects the environment and humans. A low level NH₃ is created by human bodies and emitted as a component of urine and exhaled breath. Therefore, the detection of NH₃ gas is important to monitor human health conditions. A novel WO₃ multiple-layered thin film NH₃ sensor using Pt catalyst has been developed in this study. WO₃ thin film coated with Pt nanoparticles successfully improves the sensitivity to NH₃ gas. Furthermore, WO₃ multiple-layered thin film with an interspace has the effect of enhancing the sensitivity and lowering the optimum operating temperature. The developed sensor can detect as low as 1 ppm NH₃ gas.

There has been so far few odor sensors with an array of the biosensor elements. However, an odor sensor constructed in this fashion is expected to have high performance in terms of the ability to discriminate between odorants. In this study, a parallel lock-in measurement circuit was developed to acquire the fluorescent image of the cells even under an ambient light. Since that circuit can extract only the responses of the cells from the fluorescent image, its output represents a specific pattern corresponding to the odorant. Therefore, principal component analysis was applied to that output in order to confirm the availability of the odorant discrimination by using a fluorescent image. It was found that the output pattern from the developed circuit included information enough to discriminate between at least two types of odorants.

Au-Au-bonding-based wafer-level vacuum packaging technology using in-plane feedthrough of thick Au signal lines was developed for RF MEMS. Compared with conventional technology based on glass frit bonding, the developed technology is advantageous in terms of smaller width of sealing frames, lower process temperature and smaller amount of degas. To guarantee the hermetic sealing, the adhesion between the thick Au lines and a SiO_x dielectric frame is improved by an Al₂O₃ interlayer by ALD (Atomic Layer Deposition). The steps of the dielectric frame above the thick Au lines are absorbed by an electroplated Au seal ring planarized by fly cutting. The thermocompression bonding of the Au seal rings of 20∼100 µm width was done at 300ºC. A cavity pressure of about 500 Pa or lower was measured by “zero balance method” using Si diaphragms. Vacuum sealing was maintained for more than 19 months, and the leak rate is less than 8×10^-16 Pa m³/s. The isolation of open signal lines was measured up to 10 GHz for different designs of the sealing ring and SiO_x dielectric frame. The influence of the in-plane feed through to the isolation is as low as 2∼3 dB, if the width of the sealing ring is 20 µm and the thickness of SiO_x dielectric frame is larger than 10 µm. The developed wafer-level packaging technology is ready for applications to an RF MEMS switch.