Reengineering the refractive index profile of inhomogeneous coatings is a troublesome task. Multiplicity of solutions may significantly reduced by providing additional information. For this reason an in-situ broadband...Reengineering the refractive index profile of inhomogeneous coatings is a troublesome task. Multiplicity of solutions may significantly reduced by providing additional information. For this reason an in-situ broadband monitoring system was developed to measure the transmittance of the growing film directly at the rotating substrate. For characterization of these coatings, a new model was developed, which significantly reduces the number of parameters. The refractive index profile may be described by a proper number of equally spaced volume fraction values using the Bruggeman effective media approach. A good initial approximation of the refractive index profile can be generated based on deposition rates for both materials recorded with quartz crystal monitor during manufacturing. During the optimization process, a second order minimization algorithm was used to vary the refractive index profile of the whole coating and film thickness of the intermediate stages. Finally, a significantly improved accuracy of the modelled transmittance was achieved.展开更多
基于接收信号强度指示(Received Signal Strength Index,RSSI)的测距技术因其低成本及低复杂度被广泛用于无线传感网络(WSN)定位技术中。由于RSSI值易受环境的影响,即使在同一位置采集到的RSSI值也会出现波动、突变,从而导致测距结果误...基于接收信号强度指示(Received Signal Strength Index,RSSI)的测距技术因其低成本及低复杂度被广泛用于无线传感网络(WSN)定位技术中。由于RSSI值易受环境的影响,即使在同一位置采集到的RSSI值也会出现波动、突变,从而导致测距结果误差较大。在分析RSSI测距原理和当前常见的滤波算法的基础上,通过实验比较单一滤波的效果,综合单一滤波的优势,提出了一种基于狄克逊检验法滤波、中位值滤波及高斯滤波的混合滤波算法。实验首先利用线性回归算法优化RSSI测距模型的参数,再通过混合滤波过滤异常RSSI值来获得最优值,以实现准确测距。实验结果显示,与单一的滤波算法相比,混合滤波算法能明显减小RSSI值的波动,更为有效地剔除异常RSSI值,且滤波后的RSSI值更接近理想值,测距误差更小,证明了混合滤波算法是有效且可行的。展开更多
文摘Reengineering the refractive index profile of inhomogeneous coatings is a troublesome task. Multiplicity of solutions may significantly reduced by providing additional information. For this reason an in-situ broadband monitoring system was developed to measure the transmittance of the growing film directly at the rotating substrate. For characterization of these coatings, a new model was developed, which significantly reduces the number of parameters. The refractive index profile may be described by a proper number of equally spaced volume fraction values using the Bruggeman effective media approach. A good initial approximation of the refractive index profile can be generated based on deposition rates for both materials recorded with quartz crystal monitor during manufacturing. During the optimization process, a second order minimization algorithm was used to vary the refractive index profile of the whole coating and film thickness of the intermediate stages. Finally, a significantly improved accuracy of the modelled transmittance was achieved.
文摘基于接收信号强度指示(Received Signal Strength Index,RSSI)的测距技术因其低成本及低复杂度被广泛用于无线传感网络(WSN)定位技术中。由于RSSI值易受环境的影响,即使在同一位置采集到的RSSI值也会出现波动、突变,从而导致测距结果误差较大。在分析RSSI测距原理和当前常见的滤波算法的基础上,通过实验比较单一滤波的效果,综合单一滤波的优势,提出了一种基于狄克逊检验法滤波、中位值滤波及高斯滤波的混合滤波算法。实验首先利用线性回归算法优化RSSI测距模型的参数,再通过混合滤波过滤异常RSSI值来获得最优值,以实现准确测距。实验结果显示,与单一的滤波算法相比,混合滤波算法能明显减小RSSI值的波动,更为有效地剔除异常RSSI值,且滤波后的RSSI值更接近理想值,测距误差更小,证明了混合滤波算法是有效且可行的。
