研究了带未知丢失观测率和传感器偏差的多传感器(Autoregressive,AR)模型融合辨识问题。采用一组伯努利随机变量描述观测丢失现象。选取递推增广最小二乘(Recursive extend least squares,RELS)算法,对未知的AR模型参数和未知的传感器...研究了带未知丢失观测率和传感器偏差的多传感器(Autoregressive,AR)模型融合辨识问题。采用一组伯努利随机变量描述观测丢失现象。选取递推增广最小二乘(Recursive extend least squares,RELS)算法,对未知的AR模型参数和未知的传感器偏差进行在线辨识。应用矩阵加权线性无偏最小方差最优融合估计准则得到AR模型参数的融合估计。通过AR模型与状态空间模型之间的转换和相关函数获得各传感器观测收到率和观测噪声方差估计值。仿真例子验证了此算法的有效性。展开更多
Screen printing is a promising technology because of its simplicity, low-cost, high reproducibility, and efficiency in large-scale production. In this work, a cobalt-based phosphate sensor was successfully fabricated ...Screen printing is a promising technology because of its simplicity, low-cost, high reproducibility, and efficiency in large-scale production. In this work, a cobalt-based phosphate sensor was successfully fabricated using the screen printing technology for the determination of phosphate concentration in the aqueous solution. The disposable sensor consists of a fully integrated cobalt （Co） electrode, which is a layer of carbon conductive ink （C） physically doped with Co powder, and Ag/AgCI reference electrode. The SEM images show that the morphology of the Co electrode changes after exposure to the phosphate solution, indicating that the expendable reaction exists during the measurement. At the Co/C ratio of 1：99, the cobalt-based phosphate sensor shows phosphate-selective potential response in the range of 10-4 to 10-1 mol/L, yielding a detection limit of lxl0-5 mol/L and a slope of over 30 mV/decade in acidic solution （pH 4.5） for HzPO4-. The proposed screen-printed sensor also ex- hibited significant reproducibility with a small repeated sensing deviation （i.e., relative standard deviation （R.S.D.） of 0.5%） on a single sensor and a small electrode-to-electrode deviation （i.e., R.S.D. 〈 3.2%）. The recovery study of HzPO4- in real wastewater samples gave values from 95.4% to 101.8%, confirming its application potential in the measurement of phosphate in real samples. Apart from its high selectivity, sensitivity, and stability comparable with a conventional bulk Co-wire electrode, the proposed phosphate sensor still yields many other advantages, such as low price, compactness, ease of use, and the possibility of integration with other analytical devices such as flow injection analysis.展开更多
文摘研究了带未知丢失观测率和传感器偏差的多传感器(Autoregressive,AR)模型融合辨识问题。采用一组伯努利随机变量描述观测丢失现象。选取递推增广最小二乘(Recursive extend least squares,RELS)算法,对未知的AR模型参数和未知的传感器偏差进行在线辨识。应用矩阵加权线性无偏最小方差最优融合估计准则得到AR模型参数的融合估计。通过AR模型与状态空间模型之间的转换和相关函数获得各传感器观测收到率和观测噪声方差估计值。仿真例子验证了此算法的有效性。
基金supported by the Major Scientific Equipment Development Project of China(2012YQ030111)the Beijing Natural Science Foundation(8132032)
文摘Screen printing is a promising technology because of its simplicity, low-cost, high reproducibility, and efficiency in large-scale production. In this work, a cobalt-based phosphate sensor was successfully fabricated using the screen printing technology for the determination of phosphate concentration in the aqueous solution. The disposable sensor consists of a fully integrated cobalt （Co） electrode, which is a layer of carbon conductive ink （C） physically doped with Co powder, and Ag/AgCI reference electrode. The SEM images show that the morphology of the Co electrode changes after exposure to the phosphate solution, indicating that the expendable reaction exists during the measurement. At the Co/C ratio of 1：99, the cobalt-based phosphate sensor shows phosphate-selective potential response in the range of 10-4 to 10-1 mol/L, yielding a detection limit of lxl0-5 mol/L and a slope of over 30 mV/decade in acidic solution （pH 4.5） for HzPO4-. The proposed screen-printed sensor also ex- hibited significant reproducibility with a small repeated sensing deviation （i.e., relative standard deviation （R.S.D.） of 0.5%） on a single sensor and a small electrode-to-electrode deviation （i.e., R.S.D. 〈 3.2%）. The recovery study of HzPO4- in real wastewater samples gave values from 95.4% to 101.8%, confirming its application potential in the measurement of phosphate in real samples. Apart from its high selectivity, sensitivity, and stability comparable with a conventional bulk Co-wire electrode, the proposed phosphate sensor still yields many other advantages, such as low price, compactness, ease of use, and the possibility of integration with other analytical devices such as flow injection analysis.
