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Layout Optimization for greenhouse WSN Based on Path Loss Analysis

Computer Systems Science & Engineering 2021年第4期37卷 89-104页

作者： Huarui Wu Huaji Zhu Xiao Han Wei Xu National Engineering Research Center for Information Technology in Agriculture Beijing100097 China 2 Beijing Research Center for Information Technology in Agriculture Beijing Academy of Agriculture and Forestry SciencesBeijing100097 China 3 Key Laboratory of Agri-informatics Ministry of AgricultureBeijing100097 China 4 Department of Biosystems MechatronicsBiostatistics and SensorsKU LeuvenHeverlee3001Belgium

When wireless sensor networks (WSN) are deployed in the vegetablegreenhouse with dynamic connectivity and interference environment, it is necessary to increase the node transmit power to ensure the communication quality,which leads to serious network interference. To offset the negative impact, thetransmit power of other nodes must also be increased. The result is that the network becomes worse and worse, and node energy is wasted a lot. Taking intoaccount the irregular connection range in the cucumber greenhouse WSN, wemeasured the transmission characteristics of wireless signals under the 2.4 Ghzoperating frequency. For improving network layout in the greenhouse, a semiempirical prediction model of signal loss is then studied based on the measureddata. Compared with other models, the average relative error of this semi-empiricalsignal loss model is only 2.3%. Finally, by combining the improved networktopology algorithm and tabu search, this paper studies a greenhouse WSN layoutthat can reduce path loss, save energy, and ensure communication quality. Giventhe limitation of node-degree constraint in traditional network layout algorithms,the improved algorithm applies the forwarding constraint to balance network energyconsumption and constructs asymmetric network communication links. Experimentalresults show that this research can realize the energy consumption optimization ofWSN layout in the greenhouse.

关键词： Pathloss model vegetable greenhouse networktopology networklayout

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Variations of soil quality from continuously planting greenhouses in North China

引用

International Journal of Agricultural and Biological Engineering 2019年第1期12卷 139-145页

作者： Jing Li Yan Xu Hongguang Liu Key Laboratory of Ecosystem Network Observation and Modelling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100190China Key Laboratory of Modern Water-Saving Irrigation of Xinjiang Production&Construction GroupCollege of Water Conservancy&Architectural EngineeringShihezi UniversityXinjiang 832000China

vegetable greenhouses form a significant land utilisation pattern in China.A case study of the greenhouse soil quality changes and potential risk to humans under a specific long-term environment,which includes high fertilization rates,high temperatures and humidity levels and out-of-season cultivation,is presented in this *** profiles of 72 representative solar greenhouses with various planting years were sampled in Shouguang City,which is the birthplace of winter greenhouse in *** temporal distribution of soil quality changes were quantitatively evaluated through the application of a correlation analysis and soil quality *** soil was highly enriched with phosphorus and potassium and had low organic matter *** organic matter,nitrogen,phosphorus and potassium contents increased with the years planted,reached their peak values after 5-10 a,and declined as the soil layer’s depth *** infiltration rate of nitrate was relatively high,which poses risks to underground water safety.A comprehensive soil quality assessment revealed that in vegetable greenhouses planted for different periods,the soil quality improved at first and then sharply declined after 10 *** greenhouse soil quality changes will aid in implementing nutrient management strategies to improve the soil quality and sustainable development programs for the vegetable industry.

关键词： vegetable greenhouse facility agriculture planting years soil quality microbial activity

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