基于WSN的油菜生长环境数据采集系统     

李建辉  廖桂平  王访 《湖南农业大学学报(自然科学版)》2013,39(6):675-682

针对传统作物生长环境数据获取手段实时性差、劳动强度大以及部署微型自动气象站和商用Zigbee产品成本高、开放性较差等问题，设计并实现了一种基于WSN的油菜生长环境数据采集系统。提出了轻量级的能量感知路由协议CLFP，并给出了软硬件的相关设计方法。仿真和大田试验结果表明，系统温度采集精度最高可达0.01 ℃，测湿精度达±5%，光强采集范围为1~65 535 lx，可并发的数据传输达到36路，可满足农业现场环境数据的较高测量要求。在标称电源供电情况下，系统实际有效生存周期超过142 d，由于采用AT89C51和nRF2401作为基础硬件平台，成本低廉，有助于大规模部署和应用。  相似文献   

欧盟森林执法、施政与贸易自愿伙伴关系协议国家经验交流会在京召开     

李近 《中国林业产业》2013,(Z3):16

本刊讯10月30日,欧盟森林执法、施政与贸易自愿伙伴关系协议(FLEGT-VPAs)国家经验交流会在北京召开。来自亚洲、非洲、欧洲和美洲等多国的政府官员、专家学者、企业代表、以及国内高校和科研机构人士及企业代表150多人参加了会议。此次会议由多方共同推动举办,旨在贯彻落实2013年举行的中欧森林执法与行政管理双边协调机制  相似文献   

全方位容灾备份构建安全核心网     

傅立杰 《山东饲料》2013,(17)

核心网形成了以软交换端局(关口局)为核心的全IP话务汇接核心网组网模式.TDM端局核心过渡到以IP软交换端局为核心,由3级垂直化网络过渡到IP扁平化网络.采用全方位容灾备份的手段来加强核心网的安全性、抗风险性是非常有必要的.  相似文献   

振弦传感器适配器设计探讨     

李延军  景波云 《中国农村水利水电》2015,(1)

给出了一种基于ATmega16(L)兼容SDI-12总线协议[1]的振弦传感器适配器的设计。该设计通过SDI-12总线、SDI-12总线协议命令扩展和微处理器处理技术进行参数设置和偏差校正,实现了非常规传感器的归一化。工程实践表明该适配器结构简单、设计合理、工作可靠,可现场灵活组态,是解决监测系统中多种数据采集需求的一种有力工具,其设计理念可为其他智能监测装置的设计和应用所借鉴。  相似文献   

对我国建立农作物良种推广补贴制度的思考     

袁国保  张春桂 《中国种业》2003,(6):1-2,4

~~对我国建立农作物良种推广补贴制度的思考@袁国保$湖北省种集团公司!武汉430070 @张春桂$湖北省种集团公司!武汉430070  相似文献   

Performance Analysis of MIPv4 Regional Registration Combined with Low Latency Handoffs     

LIU Hui  LIU Xing-qian  LIU Xiang 《保鲜与加工》2006,(3):76-79

The mechanism of MIPv4 regional registration and the low latency handoff protocols are introduced. Ways and procedure of pre-registration handoff and post-registration handoff are discussed also. The authors analyze the performance of the low latency handoff protocols combined with low latency handoffs over a wireless access based on IEEE 802. 11 standard in a tree-like network topology. The performance of pre-registration and post-registration scheme is given by simulation.  相似文献   

Research on Cooperative Design Network Security Based on IP-VPN     

FU Hong qiao  HE Yu lin  XIAN Zhi ling  WANG Xu xia 《保鲜与加工》2002,(4):32-35

As the important method and instrument of agile manufacture,the technology of distributed collaborative design and manufacturing has become the hotspot of manufacturing. The basic concept and key technologies of IP_VPN are introduced in this paper,and a collaborative design network model based on IP_VPN is presented. Distributed collaborative design is a multi_user,multitask involved system, which is consisted of lots of collaborative processs,so the network security is the key of distributed collaborative design. We research on the security of collaborative design network based on IP_VPN, hence get a conclusion:we can construct an economical?practical and secure collaborative design network system by the application of data encryption,user authentication and access control based on the role,etc.  相似文献   

Study of IP over WDM System Structure     

SHEN Ke  XU Guo  GAN Yu-yu 《保鲜与加工》2001,(3):103-106

WDM technology is the basis of optical network implementation. Due to eliminating SONET/SDH and ATM elements, and allowing direct connection with IP routers, IP over WDM can reduce network cost and simplify network expansion . In this thesis, the structure and protocol layers of IP over WDM are firstly explained. Then the procedures of this network are described briefly. At last, the problems and future of IP over WDM are analyzed  相似文献   

Realizing 3 Layers Transport Model in the Communication Between Embedded System and PC     

CHEN Hua-hong  PANG Tao  ZHOU Sha 《保鲜与加工》2005,(3):65-68

This article puts forward a 3 Layers Model for the communication between embedded system and PC. It is based on the speciality of them and the TCP/IP model. The model defines the communicate process of embedded system to be three layers: Transport Layer, Control Layer and Application Layer. Each layer serves for its higher-up. It can keep the efficiency and credibility of the communicate process and the authors prove and analyse that in the article. the concept of the model is also suitable for Bluetooth, IrDA and other kinds of communication about embedded system.  相似文献   

File Intertransmission Based on WinSock Component     

MA Yong-qin  LI Zheng-wen  WANG Liu-yan 《保鲜与加工》2004,(4):49-52

WinSock is a group of API,which is used to transmit data and exchange information on Internet,the Socket Application programme impoldered by users may communicate with other Socket Application programes by Internet. Delphi provides Socket components,which sustains the TCP/IP protocol and makes the Internet programming acquiring much more flexibility.This paper probes that how to realize transmission of files in any format under nonblocking mode between clients and servers by means of Socket components of Delphi.  相似文献