非正弦波通信的发展与关键技术

为了正确把握非正弦波通信的发展方向,从脉冲无线电技术和正交函数两个角度分 析了非正弦波通信的发展历程,并对研究现状、待解决难点问题进行深入剖析;从信号设计 、谐振理论、辐射理论和信号产生4个方面分析了非正弦波通信的关键技术,以此探索发展 高能效、高频谱利用率的非正弦波通信体制的有效途径。     

基于nRF905的嵌入式多点数据采集系统设计

设计了以MSP430单片机和nRF905无线收发模块为核心的嵌入式数据集中器和数据采集器。介绍了MSP430的SPI驱动、nRF905的SPI驱动及其接口实现,阐述了链路控制方案和实际应用中应注意的问题。实现了数据采集器与数据集中器之间高效而稳定的无线数据传输,具有应用灵活、成本低廉、工程建设周期短等优点,可广泛应用于多种场合。     

THERE IS NO SUCH THING AS A FREE WINE TASTING: THE EFFECT OF A TASTING FEE ON OBLIGATION TO BUY

Building on reciprocity theory, the current study suggests that, at least to some extent, consumers purchase goods and services in response to sampling due to a perceived need to reciprocate for trying the products/services. In addition, the study explores the effect of charging for sampling (i.e., wine tasting) on tourist behavior. The sample (N = 357) was drawn from visitors to six wineries in an emerging wine region. Three of the sampled wineries charged a small fee for tasting, while the other three wineries offered complimentary wine tasting. The study examined whether differences exist in a perceived need to buy wine between visitors who paid a tasting fee and those who tasted wine for free. The results indicated that visitors who had complimentary wine tasting spent significantly more money at the wineries than visitors who paid a fee for tasting. Furthermore, visitors who tasted wine for free felt significantly more appreciative of the personnel than did visitors who paid a tasting fee. Also, visitors who had complimentary wine tasting reported significantly higher levels of obligation to make a purchase at the end of their visits to the wineries. Managerial implications are discussed.     

Hotel Information Technology Security: Do Hoteliers Understand the Risks?

During the past decade, information technology (IT) has significantly changed the way the hotel industry controls and manages operations. While many technologies have been utilized, some newer technologies have emerged in the literature and in practice, and many of them impact the hotel's security. The purpose of this study is to understand how hotels with different service levels are currently using these technologies, and if having an internal IT department and sufficient IT budget impacts the use of these technologies. Among the results, this study identified a gap between hoteliers’ understanding of IT budget adequacy and the adequacy of installed IT security systems. The results also showed that luxury properties were significantly more likely to employ adequate IT security systems than other service levels.     

基于改进克隆算法的WSN的QoS路由研究

为解决在无线传感器网络QoS约束下的最优路由选择问题,在优化网络拓扑结构的基础上,提出利用克隆选择算法和蚁群算法结合求解WSN组播路由的方法．该算法利用克隆选择算法对原始路由种群进行优化改善,避免搜索过程陷入早熟收敛问题,然后利用蚁群算法快速搜索．该算法在保证能力最优的前提下,提高了路由搜索速度,在保证最优路径选择基础上,节约了通信成本,仿真结果证明了其可行性和有效性．     

无人机搜索救援系统中机载探测器设计

针对现有的搜索救援系统存在的搜救效率低下和容易发生二次灾害等不足,研究了一种以无线通信技术为核心的无人机搜索救援系统,主要讨论了机载探测器的设计。系统以MSP430微处理器为控制单元,机载探测器通过无线收发模块RFC33A与救援信标机通信,激活信标机并接收信标机获取的遇险人员地理位置信息,通过数传电台XTend将信息实时地传回地面站以及接收地面站的控制指令。实验测试表明,机载探测器对信标机的有效探测距离达到2 km,与地面站的通信距离大约为10 km,工作时间超过3 h,实现了搜索的目的。     

抗突发误码的双重交织Turbo码设计

为了解决无线通信中常见的突发误码问题,提出了一种新的抗突发误码的Turbo码设计方案。该设计方案通过采用双重交织结构,极大地降低了突发误码对接收信息序列连续删除的风险,在不引入额外延迟的前提下,显著地提升了Turbo码抗突发误码的性能。仿真结果表明,当通信中存在较长突发误码时,双重交织Turbo码比一般Turbo码的纠错性能更好,其误比特率甚至可达到10-6数量级。     

基于网络编码的无线体域网多中继协作节能策略

针对无线体域网中传输链路存在中断情况从而消耗额外能量的问题,在多源多中继系统模型中引入网络编码,提出一种基于网络编码多中继协作算法,并分析了该算法下系统的网络能耗,推导出系统的每比特网络整体能耗公式。仿真结果表明：该算法与传统的多路径多中继转发算法相比,可以较大程度的减少网络的整体能耗,适当地增加信源节点或者减少中继节点的数目对降低网络的整体能耗也有一定的作用。该算法能减少多源多中继网络的整体能耗,延长网络的生命周期。     

基于FPGA的超声波无线透传模块的设计与实现

文章阐述了超声波无线透传模块的工作原理及设计思路,从系统的角度给出了利用超声波来实现无线点对点通讯的整体方案。该声波通讯系统可实现由串口到超声波无线再到串口的单双工数据透传。实验结果表明本设计扩展性灵活,可在一定距离内实现稳定无线声波通讯。     

提高无线传感器网络的运行寿命方法

针对无线传感器网络的节点一般体积小,携带能量低,运算能力弱,能量一旦耗尽不可再生这一特点,本文提出提高网络运行寿命的方法。一方面,在网络节点运行时间上,将基站作为主控中心,根据系统的需求,采用有效的调度算法,来唤醒需要传输的无线传感器节点进行数据采集,然后将传输信息发送给簇头进行网络内传输,直至到达基站,从而获得传感器节点最小运行时间。另一方面,在网络内多跳通信时,靠近基站的簇头节点由于转发大量数据导致节点过早失效问题,本文提出一种不均匀分簇多跳算法,根据节点与基站距离调整簇首概率,能量优先为原则选择簇首,使据基站近的区域簇头多于据基站远的区域。