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排序方式: 共有532条查询结果,搜索用时 31 毫秒
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基于ZigBee和GPRS网络的温室大棚无线监测系统设计 总被引:1,自引:0,他引:1
为了监测温室大棚的温湿度、CO2浓度、土壤PH值及光照强度等参数,设计了一套基于ZigBee和GPRS网络的温室大棚无线监控系统;多个传感器网络节点采集温室大棚的环境参数,并通过ZigBee网络传给协调器节点,最后利用GPRS网络将数据发送到监控终端,以便农业人员调节温室大棚的环境;介绍了系统的总体设计方案,详细讲述了系统的硬件设计、网络协议的建立及软件的实现,经过现场实际运行测试,该系统长时问工作稳定可靠,具有一定的市场价值和很好的发展前景. 相似文献
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An interval type-2 fuzzy weighted support vector machine (IT2FW-SVM) is proposed to address the problem of high energy consumption for biped walking robots. Different from the traditional machine learning method of ‘copy learning’, the proposed IT2FW-SVM obtains lower energy cost and larger zero moment point (ZMP) stability margin using a novel strategy of ‘selective learning’, which is similar to human selections based on experience. To handle the uncertainty of the experience, the learning weights in the IT2FW-SVM are deduced using an interval type-2 fuzzy logic system (IT2FLS), which is an extension of the previous weighted SVM. Simulation studies show that the existing biped walking which generates the original walking samples is improved remarkably in terms of both energy efficiency and biped dynamic balance using the proposed IT2FW-SVM. 相似文献
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Yunhai Zhang Yongsheng Liu Yejie Cao Liyang Cao Jing Wang Yu Pan Ning Wang 《Journal of the American Ceramic Society》2021,104(1):645-653
C/SiC composites prepared by chemical vapor infiltration technique (CVI) have been regarded as thermal structural materials widely. However, these composites still suffer from poor functional properties like low thermal conductivity, especially in thickness direction of the composites, limiting their large-scale applications. Herein, mesophase pitch based carbon fiber (MPCF) and continuous wave laser machining were utilized to construct highly effective heat conductive micro-pipelines within CVI C/SiC composite. The effect of initial density on the final density and thermal conductivity of the as-obtained MPCF-C/SiC composites were investigated. The results revealed that higher initial density would directly enhance the thermal conductivity and reduce the negative impact of the bottle-neck effect. At temperatures between 100°C and 500°C, MPCF-C/SiC composites preserved more than threefold of the thermal conductivity (340%) when compared to reference C/SiC composites. This work provides a highly effective route for enhancing the thermal conductivity of C/SiC, which would broaden their future applications. 相似文献
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低成本MEMS陀螺实时滤波方法 总被引:1,自引:0,他引:1
为找到一种普遍适合低成本MEMS陀螺仪的随机误差实时处理方法,利用Allan方差分析法首先对MEMS陀螺仪进行分析,根据其误差特性进而设计了平均滤波算法以剔除粗大误差,然后使用最小二乘法,通过拟合前一段历史结果得到下一时刻输出的预测值,基于以上工作最终设计出Kalman滤波器对所输出进行滤波。由于将最小二乘法的推测作为预测过程,避免了系统状态模型难以准确建立的问题。该方法动态性能好,具有普适性。实验结果证明,该方法在静态和动态下均能有效工作,滤波后常值漂移被有效补偿,角度随机游走不再占误差的主要成分,均方差小于滤波前的十分之一。 相似文献
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Hongli YANG Chao CAI Liyang PENG Xiangpeng ZHAO Zongyan QIU Shengchao QIN 《Frontiers of Computer Science in China》2013,(5):710-728
Web service choreography describes global mod- els of service interactions among a set of participants. For an interaction to be executed, the participants must know the required channel(s) used in the interaction, otherwise the ex- ecution will get stuck. Since channels are composed dynami- cally, the initial channel set of each participant is often insuf- ficient to meet the requirements. It is the responsibility of the participants to pass required channels owned (known) by one to others. Since service choreography may involve many par- ticipants and complex channel constraints, it is hard for de- signers to specify channel passing in a choreography exactly as required. We address the problem of checking whether a service choreography lacks channels or has redundant chan- nels, and how to automatically generate channel passing based on interaction flows of the service choreography in the case of channel absence. Concretely, we propose a sim- ple language Chorc, a channel interaction sub-language for modeling the channel passing aspect of service choreography. Based on the formal operational semantics of Chore, the algo- rithms for static checking of service choreography and gen- erating channel passing are also studied, and the complexity results of algorithms are discussed. Moreover, some illus- trated service choreography examples are presented to show how to formalize and analyze service choreography with channel passing in Chorc. 相似文献
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CIMS环境下车间级集成质量系统研究 总被引:3,自引:0,他引:3
文章分析了基于功能管理和基于过程管理两种模式的计算机辅助质量管理系统的集成结构模型,提出了车间级集成质量管理系统的功能模型。在此基础上,利用软件组件和Web技术,详细设计和实现了该系统的各个软件模块。该软件应用于实际,与CIMS其它子系统集成运行,提高了制造企业的车间整体质量水平。 相似文献
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The issue of information loss in the process of system reliability modeling through conventional load–strength interference analysis is discussed first, and the reason why it is impossible to construct dependent system reliability model simply by means of component reliability index is demonstrated. Then, an approach to modeling the reliability of dependent system with common cause failure (CCF) is presented. The approach is based on system-level load–strength interference analysis and a concept of ‘conditional failure probability of component’ as well. With the opinion that load randomness is the direct cause of failure dependence, a discrete type system reliability model is developed via the conditional component failure probability concept. At last, the model's capabilities to estimate system reliability with CCF effect and to predict high multiplicity failure probability based on low multiplicity failure event data are proved. 相似文献