Multi-channel SAR imaging based on distributed compressive sensing

The rapid development of compressive sensing(CS)shows that it is possible to recover a sparse signal from very limited measurements.Synthetic aperture radar(SAR)imaging based on CS can reconstruct the target scene with a reduced number of collected samples by solving an optimization problem.For multi-channel SAR imaging based on CS,each channel requires sufficient samples for separate imaging and the total number of samples could still be large.We propose an imaging algorithm based on distributed compressive sensing(DCS)that reconstructs scenes jointly under multiple channels.Multi-channel SAR imaging based on DCS not only exploits the sparsity of the target scene,but also exploits the correlation among channels.It requires significantly fewer samples than multi-channel SAR imaging based on CS.If multiple channels offer different sampling rates,DCS joint processing can reconstruct target scenes with a much more flexible allocation of the number of measurements offered by each channel than that used in separate CS processing.     

基于USB电源的智能风扇控制技术

介绍基于计算机USB电源的智能风扇控制技术。     

Negative effects of sufficiently small initial weights on back-propagation neural networks

In the training of feedforward neural networks,it is usually suggested that the initial weights should be small in magnitude in order to prevent premature saturation.The aim of this paper is to point out the other side of the story:In some cases,the gradient of the error functions is zero not only for infinitely large weights but also for zero weights.Slow convergence in the beginning of the training procedure is often the result of sufficiently small initial weights.Therefore,we suggest that,in these cases,the initial values of the weights should be neither too large,nor too small.For instance,a typical range of choices of the initial weights might be something like(0.4,0.1) ∪(0.1,0.4),rather than(0.1,0.1) as suggested by the usual strategy.Our theory that medium size weights should be used has also been extended to a few commonly used transfer functions and error functions.Numerical experiments are carried out to support our theoretical findings.     

无线传感器网络（WSN）在花卉大棚环境监测中的应用研究

针对传统花卉大棚环境参数监测系统的某些缺点,本文对基于Zigbee技术的无线传感器网络在花卉大棚中的应用可行性进行分析和研究,并建立了花卉大棚无线环境监测系统,使得该监测系统的各节点位置、监测范围、节点扩展性、节点间距离都得以改善和提高。     

磁悬浮列车传感器信号传输系统分析

磁悬浮列车传感器系统采用屏蔽双绞线传输数字传感器信号;磁悬浮列车传感器信号传输系统具有典型的传输线系统特点;研究了系统始端内阻抗与终端阻抗对信号传输的影响;分析了在终端为网络变压器时,传输线对信号传输的影响;提出了在有限负载阻抗条件下,阻抗匹配的设计要求;实验证明在有限阻抗负载条件下,并联终端匹配比始端串联匹配具有明显优势。     

基于电子鼻的香蕉储存时间鉴别方法研究

研究了一种基于电子鼻系统的香蕉储存时间鉴别方法。实验检测了不同储存时间的香蕉样品,主成分分析方法可以较好地区分不同储存时间的香蕉样品,同时检验了样品的微生物指标以探讨电子鼻响应与微生物指标之间的关系。随机共振信噪比谱不但可以区分香蕉样品,同时基于信噪比特征值建立的香蕉储存时间鉴别模型具有较高的预测准确率。该方法具有较好的实际应用价值。     

视频会议管理系统的研究及实现

通过对浙江中烟视频会议系统现状、业务流程及业务实际的分析,提出了以软件形式统一管控的会议操作、网络监测和流程管控的管理模式,并对软件架构和实现方式进行了详细阐述。通过该套软件的开发部署,实现了管理与使用分离,达到了简便管理、提高效率、减少故障的目的,取得了良好的效果。     

基于Linux的USB存储设备访问控制机制研究

USB存储设备所造成的数据泄漏问题日益严重。对USB存储设备进行访问控制,可以有效阻止USB存储设备的数据泄漏。文中主要研究基于Linux操作系统的USB存储设备访问控制机制,并且从用户态、内核Lsm框架以及驱动这三个不同层次分别提出了三种可行的USB存储设备访问控制机制。在这基础上,结合这三种访问控制机制各自的特点以及关键技术对它们的有效性、可用性进行了分析。作为验证,在Linux平台上实现了这三种机制。三种方法均可以有效地进行USB存储设备访问控制。     

PTN网络的二次断纤链路规划算法

在PTN（PacketTransportNetwork）网络规划建设中,需要对光纤链路留出备份带宽,以保证部分光纤断开时,受影响业务有足够的容量进行路由重组。这也是提高网络生存性的有效方法之一。文中首先遍历网络双链路的失效状态,然后断开网络中任意两条链路,通过逐次增加链路容量来保证失效业务能够重组路由;最后提出二次断纤链路容量规划算法并进行试验仿真。结果表明,该算法在节约网络带宽、降低建造成本以及故障容错方面有着良好性能,能够很好应用于传送网络的链路规划中。     

构建数据及系统灾备中心的几点考量

概述数据灾备中心的建设规范,从核心基础设施及网络传输架构的设计等方面着手,整合和充分利用灾备中心、生产中心的资源,并以广东惠州社保异地灾备中心的建设为例。阐述构建数据及系统灾备中心需要考量的几个方面。