基于ZigBee协议的无线传感器网络服务质量的研究

针对于无线传感器网络的发展,以及新型的协议规范ZigBee协议在无线传感器网络中广泛应用,以分析研究基于ZigBee协议的无线传感器网络的服务质量的评价机制为目的。通过对无线传感器网络及ZigBee协议的组成、通信特点的研究,以及结合传统网络的QoS评价机制,最终总结得到可以从5个方面来评价ZigBee协议的无线传感器网络的服务质量。     

基于RFSN的智能停车场管理系统开发

系统采用.NET及RFSN感应式智能卡技术,本着科学、先进、可靠性及经济的原则,在综合考虑诸多因素的基础上开发的,出入口管理设备负责停车场的出入口,使得停车场形成一个相对封闭的场所,车辆进出时系统抓拍入场图像并自动识别车牌号码等,对车辆摄像监控,同时具备收费、经费核算等功能,有效地控制、监测、管理停车场的运作,显著地降低了停车场的营运成本,防止盗车行为,保障了停车场管理人员和车主的利益。     

一种低复杂度的近似最大似然MI~/IO检测算法

为保证无线传感器网络协作式V-BLAST传输中,在较高的检测性能的前提下大大降低算法复杂 度,提出一种低复杂度的近似最大似然检测算法．将传统的V-BLAST算法性能最好一层解的邻域作为候选 判决集合,并以此邻域内每一个符号作为初始值进一步采用传统的V-BLAST算法反馈判决其他层的符号, 采用最大似然准则对候选向量进行判断．该方法有效减小了最大似然检测算法检测向量的数目,降低了算法 的复杂度．仿真结果表明该算法具有良好的综合性能     

智能PID在变频器控制系统中的应用研究

PID控制是风机和水泵变频调速系统控制中应用最广泛的控制方法。但在实际应用中,由于实际系统数学模型的非线性,参数整定未得到很好的解决,使得系统响应慢、精度差低、稳定性差。针对这一问题建立了基于神经网络的智能PID控制系统,利用神经网络可以逼近任意非线性函数的特性,设计一种神经网络自整定PID控制器。仿真结果表明,该控制器具有控制精度高、响应快、运行平稳、节能效果好等特点。     

基于BP神经网络的车削加工刀具变形误差补偿技术

针对目前普通机床加工存在精度不足的问题,提出了一种精度误差补偿方法,使普通机床也能获得较高的加工精度。首先,在分析车床加工误差的基础上,引入了神经网络模型,从结构和方法上进行了详细阐述,并利用MATLAB构建;输入样本对网络进行训练,获取预测值,验证了本方案的正确性和可行性。     

A local dynamic cluster self-organization algorithm in wireless sensor networks for rainfall monitoring

Wireless Sensor Networks for Rainfall Monitoring (RM-WSNs) is a sensor network for the large-scale regional and moving rainfall monitoring, which could be controlled deployment. Delivery delay and cross-cluster calculation leads to information inaccuracy by the existing dynamic collaborative self-organization algorithm in WSNs. In this letter, a Local Dynamic Cluster Self-organization algorithm (LDCS) is proposed for the large-scale regional and moving target monitoring in RM-WSNs. The algorithm utilizes the resource-rich node in WSNs as the cluster head, which processes target information obtained by sensor nodes in cluster. The cluster head shifts with the target moving in chance and re-groups a new cluster. The target information acquisition is limited in the dynamic cluster, which can reduce information across-clusters transfer delay and improve the real-time of information acquisition. The simulation results show that, LDCS can not only relieve the problem of “too frequent leader switches” in IDSQ, also make full use of the history monitoring information of target and continuous monitoring of sensor nodes that failed in DCS.     

三网融合的有线电视接入网选择

三网融合的有线电视接入网,双向HFC有利有弊,光纤到户FTTH是发展方向。     

无线视频监测系统的设计与开发

本系统将3S技术与当前正莲勃发展的3G通信,嵌入式技术等进行创新性的融合,能为用户提供诸如高清视频,各种实时传感器数据,GPS全球定位等功能服务,系统在各种灾害预防与监测、气象地质水文数据采集、远程实时视频监控等诸多领域将具有重大意义     

Development of a computational tool to quantify architectural-design effects on thermal comfort in naturally ventilated rural houses

In the present study, the effect of the opening size and building direction on night hours thermal comfort in a naturally ventilated rural house is investigated. Initially, the airflow in and around the building is simulated using a validated computational fluid dynamics (CFD) model. Local climate night-time data (wind velocity and direction, temperature and relative humidity) are recorded in a weather station and the prevailing conditions are imposed in the CFD model as inlet boundary conditions. The produced airflow patterns are then used to evaluate indoor thermal comfort. For this reason, special thermal comfort indices, i.e. the well-known predicted mean vote (PMV) index and its modifications especially for natural ventilation, are calculated with respect to various residential activities. Mean values of these indices (output variables) within the occupied zone are calculated for different combinations of opening sizes and building directions (input variables), to generate a database of input–output pairs. Finally, the database is used to train and validate Radial Basis Function Artificial Neural Network (RBF ANN) input–output “meta-models”. It is demonstrated that the proposed methodology leads to reliable thermal comfort predictions, while the optimum design variables are easily recognized.     

基于虚拟社会网络挖掘的网络舆情分析

网络舆情是和谐社会的晴雨表,它的变化反映了社会公众对党建设和谐社会的态度和意见,因此对网络舆情进行挖掘、防范负面网络舆情危害社会于未然,显得特别重要。用社会网络分析方法对某一网络参政群体从密度、凝聚子群、结构洞3个角度进行分析,分析结果有利于政府通过互联网去了解民情、汇聚民智。