Distributed L1-state-and-fault estimation for Multi-agent systems

In this paper, we propose a distributed state-and-fault estimation scheme for multi-agent systems. The proposed estimator is based on an $\ell_1$-norm optimization problem, which is inspired by sparse signal recovery in the field of compressive sampling. Two theoretical results are given to analyze the correctness of the proposed approach. First, we provide a necessary and sufficient condition such that state and fault signals are correctly estimated. The result presents a fundamental limitation of the algorithm, which shows how many faulty nodes are allowed to ensure a correct estimation. Second, we provide a sufficient condition for the estimation error of fault signals when numerical errors of solving the optimization problem are present. An illustrative example is given to validate the effectiveness of the proposed approach

Superconductivity and Magnetism in REFeAsO1-xFx (RE=Rare Earth Elements)

Fluoride-doped iron-based oxypnictides containing rare-earth gadolinium (GdFeAsO0.8F0.2) and co-doping with yttrium (Gd0.8Y0.2FeAsO0.8F0.2) have been prepared via conventional solid state reaction at ambient pressure. The non-yttrium substituted oxypnictide show superconducting transition as high as 43.9 K from temperature dependent resistance measurements with the Meissner effect observed at a lower temperature of 40.8 K from temperature dependent magnetization measurements. By replacing a small amount of gadolinium with yttrium Tc was observed to be lowered by 10 K which might be caused by a change in the electronic or magnetic structures since the crystal structure was not altered.Comment: 4 pages, 4 figures, Journal of Physics: Conference Series (Proceedings in the LT25 Low Temperature Physics Conference) Submitte

Forecasting U.S. Trade in Services

This paper provides a set of forecasts of United States international trade in services, both at the aggregate level and for four subcategories. These sectors are: travel, which is mostly tourist expenditures; passenger fares, which is mostly passenger air transportation; transportation, other than passenger transportation; and other private services, including education, financial services, insurance, telecommunications, and business, professional and technical services. A forecasting model is constructed and estimated, based on conventional economic forces of supply and demand, dependent on cost variables and income variables as well as relative prices. For forecasting purposes, these variables are taken from the Michigan Quarterly Econometric Model of the U.S. Economy, a macroeconomic forecasting model with forecasts provided regularly by the University of Michigan Research Seminar in Quantitative Economics. The equations of the services trade model are reported and discussed, and the performance of the estimated equations is evaluated. The quarterly forecast paths are provided for both aggregate and sectoral services trade, including exports and imports, through the end of 2001. Results indicate that imports will continue to rise over the forecast period, while exports, after remaining nearly stationary for several quarters in some sectors in 1999, will resume their rise thereafter. This forecasting work is to be continued, and it is suggested, in addition, that future research would be useful to explore the determinants of the production and sales of foreign services affiliates of U.S. parent companies.Services, International Trade

Associated production of a neutral top-Higgs with a heavy-quark pair in the \gamma\gamma collisions at ILC

We have studied the associated production processes of a neutral top-Higgs in the topcolor assisted technicolor model with a pair of heavy quarks in \gamma\gamma collisions at the International Linear Collider (ILC). We find that the cross section for t\bar{t}h_t in \gamma\gamma collisions is at the level of a few fb with the c.m. energy \sqrt{s}=1000 GeV, which is consistent with the results of the cross section of t\bar{t}H in the standard model and the cross section of t\bar{t}h in the minimal supersymmetric standard modeland the little Higgs models. It should be distinct that hundreds of to thousands of h_t per year can be produced at the ILC, this process of \gamma\gamma \to t\bar{t}h_t is really interesting in testing the standard model and searching the signs of technicolor.Comment: 4 pages, 4 figures, some references are adde