Variance component ' s estimation in the combined adjustment 联合平差中的方差分量估计问题的探讨
This paper deals with the solution for 200 000 order normal equations in combined adjustment of astro - geodetic and space networks by using conjugate gradient method , puts forward a scheme of adjusting the coefficients and a strategy of separation as well as mergence between the adjustment and inversion 本文研究了用共轭梯度法解算天文大地网与空间网联合平差中20万阶法方程的有关问题,提出了“系数调整策略”和“平差与求逆既分又合的策略” 。
The investigation shows the performance gets quite insensitive to the prewhirl angle of igv as the stagger angle of diffuser vane is reduced to the minimum 7 ; the combination of these two stators enables to greatly improve the compressor efficiency over the entire operating rage , the maximum efficiency with the combined adjustment reaches 86 . 0 % , higher than that in alone adjustment of igv or diffuser vanes by 2 % 研究表明:扩压器进口安装角最小值为7时,压缩机性能对进口导叶预旋角不敏感;采用不同的扩压器进口安装角和不同进口导叶预旋角匹配调节时,压缩机所能达到的最高效率为86 . 0 % ,比单独调节进口导叶预旋角或扩压器进口安装角所能达到的效率高2 % 。