一种改进的机载卫通天线跟踪算法

在圆锥扫描实现过程分析的基础上，提出了一种改进的机载卫通天线跟踪算法。结合天线方位、俯仰方向图及其三维重构法，对该跟踪算法进行了理论推导。运用Matlab曲线拟合仿真，给出了天线跟踪调整方向和角度的计算公式，最后分析了实际应用中需要注意的一些问题。飞行试验表明，该改进的圆锥扫描跟踪技术提高了天线伺服系统的跟踪精度和跟踪速度，很好地满足了机载卫星通信的需求。     

Poverty decompositions with counterfactual income and inequality dynamics

Traditional poverty accounting decomposes changes in a country's poverty headcount ratio into changes in income and inequality. We argue that this approach is unsatisfactory from the perspective of policy analysis because it compares a country in two points of time without taking the country's initial situation, and hence its potential for poverty reduction, into account. We thus suggest comparing traditional poverty decompositions with a counterfactual situation. This counterfactual indicates what a country starting from its initial situation could be expected to achieve in terms of income, inequality, and, hence, poverty developments. We construct those counterfactuals by modeling income and inequality trends characterized by convergence and a “Kuznets” relationship between inequality and development. Parameters in those relationships are estimated using PovcalNet survey data from 144 countries and we construct our counterfactual poverty predictions for 71 developing countries. While there is overall a tight relationship between actual developments and counterfactuals, we identify several cases, where both deviate from each other and discuss the policy implications. We also check for commonalities in differently performing countries and find that those who fell particularly short of expectations often underwent political transition and state fragility.     

铁碳合金相图的计算机处理技术

介绍了“铁碳合金相图ＣＡＩ课件”中的图形处理技术，阐述了拟合曲线的方法、曲线的绘制及其他相关处理技术。