ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

In order to reveal the general characteristics of electromagnetic wave signal transmission in farmland soil and scientifically deploy sensor nodes, taking the farmland soil in Guanzhong region as the research object, adopted the modular design idea, integrated sensor, wireless data transmission, processor and energy supply module into one. Wireless underground sensor networks (WUSN) nodes and sink nodes were designed. The influences of soil moisture content, buried depth of WUSN nodes and horizontal distance between nodes on signal transmission of WUSN nodes were analyzed by single factor test method, and the prediction model of received signal strength and bit error rate was established. The experimental results showed that when the WUSN node signal was transmitted vertically underground, the soil moisture content was increased by 2.5 percentage points, the received signal strength was decreased by 4~6dBm, and the bit error rate was increased by 3~5 percentage points. The buried depth of WUSN node was increased by 5cm, the received signal strength was decreased by 3~5dBm, and the bit error rate was increased by 3~4.5 percentage points. When the WUSN node signal was transmitted in the horizontal direction underground, the soil moisture content was increased by 2.5 percentage points, the received signal strength was decreased by 5~7dBm, and the bit error rate was increased by 4~5 percentage points. When the horizontal distance between nodes was within the range of 10~90cm, the received signal strength was decreased by 6~8dBm when the horizontal distance between nodes was increased by 10cm, and the bit error rate was increased by 6.5~8 percentage points. When the horizontal distance between nodes was within the range of 90~190cm, the received signal strength was decreased by about 1dBm when the horizontal distance between nodes was increased by 10cm. The bit error rate would be increased by 1~1.5 percentage points. The best fit R2 and root mean square error of WUSN node bit error rate and signal receiving strength prediction model in two transmission directions were 0.982 and 1.7%, respectively, and the best fit R2 and root mean square error were 0.942 and 5.136dBm, respectively. In conclusion, the signal transmission of WUSN nodes in soil was seriously affected by soil moisture content, buried depth of WUSN nodes and horizontal distance between nodes. The received signal strength and bit error rate can be accurately calculated by using this prediction model, and then the maximum buried depth and maximum horizontal distance of WUSN nodes can be obtained. At the same time, the general conclusion of WUSN signal transmission in farmland soil was given.