A 1MV AMS was installed in KIGAM (Korea Institute of Geoscience and Mineral Resources). After 4 months of installation, the AMS started normal operation from January 2008. This multi-element AMS was developed by HVEE to measure 14C, 10Be, and 26Al. The results of an acceptance test demonstrate that this machine is capable of routine 14C age dating and of measurements of other radioisotopes in terms of accuracy and precision as well as the background level. After installation, an investigation aimed at determining the stable operating conditions was conducted, and background levels were determined to be as low as 10–15 for 14C and 10–14 for 10Be and 26Al.

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In literature it is conjectured that the states of the generalized Lorenz system with an unknown parameter can not be estimated by adaptive observers. In this paper we show that this unknown parameter and the states can actually be estimated simultaneously by some kind of adaptive observer. The proof is obtained by constructing some exponential observer to achieve chaotic synchronization for the generalized Lorenz system. The result implies that more work needs to be done to apply generalized Lorenz system in secure communication.

In this letter, we propose a new H∞ synchronization method, called a delayed feedback fuzzy H∞ synchronization (DFFHS) method, for time-delayed chaotic systems with external disturbance. Based on Lyapunov-Krasovskii theory, T-S fuzzy model, and delayed feedback control scheme, the DFFHS controller is presented to not only guarantee aymptotical synchronization but also reduce the effect of external disturbance to an H∞ norm constraint. The proposed controller can be obtained by solving the linear matrix inequality (LMI) problem. A numerical example for time-delayed Lorenz system is presented to demonstrate the validity of the proposed DFFHS method.

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