农村小学英语课堂教学效益的反思与对策

本文根据对农村地区小学英语课堂教学情况的调查，分析了影响农村小学英语课堂教学效益的问题，并根据分析所得提出重视语篇教学，齐读、个读和默读并进，读写协调发展和培养兴趣与发展认知能力统一等相关对策，旨在为提高农村小学英语课堂教学效益提供参考。

An Improved Satellite Selection Algorithm Based on Optimal Geometry

Satellite selection algorithm is becoming more and more important with the advent of multi-constellation navigation. To obtain real-time processing, it’s essential to limit the number of satellites used for positioning computation among all visible satellites. In this paper, we propose an improved algorithm to select more than four satellites whose geometry is similar to the optimal geometry. Moreover, the computation burden is further lower by limiting the number of times to calculate GDOP value referring to fuzzy comprehensive evaluation method. Simulation shows that the proposed algorithm can get a GDOP value close to the minimal GDOP using traditional optimal algorithm, in spite of a little increase relative to the original algorithm based on optimal geometry, but the number of times to calculate GDOP value is obviously decreased.