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In this paper, we design a tracking bracelet device for kids with novel function that can detect in real-time whether the device is still attached or not. The novel function in combined with setting of a safe zone yields an absolute tracking of thekid safety. A prototype is implemented achieving a small size of 60 x 60 x 25 mm. The test results demonstrate that the proposed device works very well with 100 % of exact warning when the kids are assumed in danger. Moreover, thanks to alow power consumption of about 64 mW in average, the device is expected to work continuously at least 18 hours.

INAA, ICP-AES and ICP-MS were used to elementally characterise four environmental reference materials – NIST SRM 1646a (Estuarine Sediment), NIST SRM 1400 (Bone Ash), IAEA-395 (Urban Dust) and IAEA-450 (Algae). An analytical scheme consisting of the three methods was first applied to NIST SRM 1646a to validate the methodology because it has been extensively analysed and has certified values for many elements. With repeated analyses of NIST SRM 1646a, the accuracy and measurement repeatability of the data obtained were evaluated based on two statistical calculations (zeta-score and Horwitz ratio) and were observed to be good enough for the analytical scheme to be applied to similar sorts of environmental/geochemical samples. Applying the same approach to NIST SRM 1400, IAEA-395 and IAEA-450, enabled mass fractions of 29, 38 and 28 elements to be determined, respectively. Among these results, the data for rare earth elements are of particular interest, not only for IAEA-450 but also for the other three reference samples. The data for Pr, Gd, Dy, Ho, Er and Tm in NIST SRM 1646a are newly reported in this study. By using small test portions (