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171.
<正>To detect the deformation of the tunnel structure based on image sensor networks is the advanced study and application of spatial sensor technology.For the vertical settlement of metro tunnel caused by internal and external stress after its long period operation,the overall scheme and measuring principle of tunnel deformation detection system is introduced. The image data acquisition and processing of detection target are achieved by the cooperative work of image sensor,ARM embedded system.RS485 communication achieves the data transmission between ARM memory and host computer.The database system in station platform analyses the detection data and obtains the deformation state of tunnel inner wall,which makes it possible to early-warn the tunnel deformation and take preventive measures in time. 相似文献
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The cluster global time can change in wireless sensor networks due to leader re-elections and node disabilities between two successive synchronizations,which will affect temporal relationships.This paper analyzes cluster global time continuity,using global time change models for the node dynamics.The results prove that defining the global time using the cluster average time(AGT) is more stable than defining it using a single node’s local time(SGT).With normally distributed clock-parameter assumptions,the AGT change bounds are at most 70.7% of those for the SGT’s.The impacts of the initial phase and frequency skew distributions on the global time continuity are also investigated to show that the initial phase variations may strongly influence the continuity.Simulations show that the AGT is more stable with less disabled nodes or larger clusters.The appropriate cluster size is 20-40 when there are less than 15 disabled nodes. 相似文献
175.
陶秀梅 《辽宁师专学报(自然科学版)》2013,15(2):92-93
研究利用NE555时基电路及人体热释电传感器设计一款遥控开关,利用人体辐射的红外线控制照明灯的亮灭,替代现在的声控开关,满足照明场所临时短时间的照明要求. 相似文献
176.
This paper describes a distributed estimation scheme (DES) for a bandwidth constrained ad hoc sensor network.The DES is universal in the sense that operations on all sensors are identical and independent of noise distribution.The scheme requires each sensor to transmit just a 1-bit message per observation.Simulation results show that the scheme achieves much better mean-squares error (MSE) performance than the simplified isotropic universal DES and even outperforms the isotropic universal DES which requires more than twice the bandwidth of this scheme. 相似文献
177.
本文针对宝钢分公司条钢厂初轧生产线设备耙吊行车和热坯台车交叉作业中出现的故障隐患,提出了采用红外传感器检测两设备交叉作业的状态,并通过DDAA1000无线数据收发模块将交叉作业信号传送入PLC进行程序连锁控制,从而避免交叉作业故障发生的解决方案,并且进行了部分现场试验论证。还针对初轧设备实际提出了各种无线设备在现场的应用展望。 相似文献
178.
在科技高速发展信息瞬息万变的现代社会中,人们在日常生产生活中主要依靠检测技术对信息获取、筛选和传输,实现控制及自动调节。本文主要介绍部分光电传感器的基本检测原理,及其在油泵生产线的应用。 相似文献
179.
以壳聚糖(CTS)、O-羟丙基壳聚糖(HPCHS) 和O-羟丙基-N-辛基壳聚糖(O-HP-N-C8-CTS)为分散剂,采用滴涂法制备3种多壁碳纳米管(MWCNTs)/ CTS衍生物传感器;以铁氰化钾(K3Fe(CN)6)为电化学探针,采用循环伏安法和交流阻抗法作电化学表征.结果表明:K3Fe(CN)6在MWCNTs/... 相似文献
180.
Sensor bias estimation is an inherent problem in multi-sensor data fusion systems. Classical methods such as the Generalized Least Squares (GLS) method can have numerical problems with ill-conditioned sets which are common in practical applications. This paper describes an azimuth-GLS method that provides a solution to the ill-conditioning problem while maintaining reasonable accuracy compared with the classical GLS method. The mean square error is given for both methods as a criterion to determine when to use this azimuth-GLS method. Furthermore, the separation boundary between the azimuth-GLS favorable region and that of the GLS method is explicitly plotted. Extensive simulations show that the azimuth-GLS approach is preferable in most scenarios. 相似文献