The pozzolanic activity of coal gangue, which is calcining at 500 to 1 000 ℃, differs distinctly. The simplex-centroid design with upper and lower bounds of component proportion is adopted to study the compressive st...The pozzolanic activity of coal gangue, which is calcining at 500 to 1 000 ℃, differs distinctly. The simplex-centroid design with upper and lower bounds of component proportion is adopted to study the compressive strength of mortars made with ternary blends of cement, activated coal gangue and fly ash. Based on the results of a minimum of seven design points, three special cubic polynomial models are used to establish the strength predicating equations at different ages for mortars. Five experimental checkpoints were also designed to verify the precision of the equations. The most frequent errors of the predicted values are within 3%. A simple and practical way is provided for determining the optimal proportion of two admixtures when they are used in concrete.展开更多
为了进一步提高基于物联网的监控系统的可靠性和延长其网络生命周期,设计了一种基于灰色模型GM(1,1)和自回归AR(p)的对物联网监测区域中的数据传输进行控制的有效方法;首先,定义了基于GM(1,1)和自回归AR(p)的预测混合模型并对其运行原...为了进一步提高基于物联网的监控系统的可靠性和延长其网络生命周期,设计了一种基于灰色模型GM(1,1)和自回归AR(p)的对物联网监测区域中的数据传输进行控制的有效方法;首先,定义了基于GM(1,1)和自回归AR(p)的预测混合模型并对其运行原理进行了描述,然后,提出了采用最小二乘法对GM(1,1)的参数进行估计以获得预测模型,以总体最小二乘为评价准则,设计了基于SVD(sigular value decomposition,SVD)的AR(p)参数估计方法,最后将两种预测模型获得的结果进行加权融合作为最终的预测值;仿真实验表明,文中设计的基于GM(1,1)和自回归AR(p)模型的预测方法能较为精确地传感器节点在未来时刻采集的数据进行预测,同时由于节点预测的精确性,避免了其与基站之间的冗余数据传输,延长了网络生命周期,具有很强的可行性。展开更多
基金The National Basic Research Program of China (973Program)(No2000CB610703)
文摘The pozzolanic activity of coal gangue, which is calcining at 500 to 1 000 ℃, differs distinctly. The simplex-centroid design with upper and lower bounds of component proportion is adopted to study the compressive strength of mortars made with ternary blends of cement, activated coal gangue and fly ash. Based on the results of a minimum of seven design points, three special cubic polynomial models are used to establish the strength predicating equations at different ages for mortars. Five experimental checkpoints were also designed to verify the precision of the equations. The most frequent errors of the predicted values are within 3%. A simple and practical way is provided for determining the optimal proportion of two admixtures when they are used in concrete.
文摘为了进一步提高基于物联网的监控系统的可靠性和延长其网络生命周期,设计了一种基于灰色模型GM(1,1)和自回归AR(p)的对物联网监测区域中的数据传输进行控制的有效方法;首先,定义了基于GM(1,1)和自回归AR(p)的预测混合模型并对其运行原理进行了描述,然后,提出了采用最小二乘法对GM(1,1)的参数进行估计以获得预测模型,以总体最小二乘为评价准则,设计了基于SVD(sigular value decomposition,SVD)的AR(p)参数估计方法,最后将两种预测模型获得的结果进行加权融合作为最终的预测值;仿真实验表明,文中设计的基于GM(1,1)和自回归AR(p)模型的预测方法能较为精确地传感器节点在未来时刻采集的数据进行预测,同时由于节点预测的精确性,避免了其与基站之间的冗余数据传输,延长了网络生命周期,具有很强的可行性。
