EPON在住宅小区三网融合中的应用

三网融合背景下,住宅小区的网络连接也要有所变化,打造满足人们需求的新型智能小区。在EPON技术和三网融合理念的基础上提出一种三网融合的住宅小区组网方案,并从EPON技术与其他技术的组合应用方面进行讨论。     

Delay statistics of cooperative automatic repeat request over wireless networks with link adaptation

This paper proposes a method to analyze the delay distribution at the transmitter side for cooperative diversity wireless networks with link adaptation, which uses decode‐and‐forward as a relay strategy. The equivalent end‐to‐end channel model is captured by a finite state Markov channel model representing the multiple states of the Nakagami fading channel, and the delay statistics are obtained by using matrix geometry method. Cooperative diversity wireless network has a better delay performance compared with noncooperation wireless network. Copyright © 2012 John Wiley & Sons, Ltd.     

High efficiency wireless optical links in high transmission speed wireless optical communication networks

Power link budgets are prepared for wireless optical communication systems to illustrate the optical losses that happen during transmission. This paper has presented optical wireless links, which offer ultra multi gigabit per second data rates and low system complexity. For ground space and/or terrestrial communication systems, these links suffer from atmospheric loss mainly due to fog, and scintillation. Optical wireless links provide high bandwidth solution to the last mile access bottleneck. However, an appreciable availability of the link is always a concern. Wireless optical links are highly weather dependent, and fog is the major attenuating factor reducing the link availability. Link margin, received signal power, transmission bit rate, bit rate distance product, signal‐to‐noise ratio, and BER are the major interesting design parameters in the current study. Copyright © 2013 John Wiley & Sons, Ltd.     

基于TS201的松耦合架构处理阵列的自举设计

说明了多DSP并行处理阵列在信息对抗领域中的重要作用,分析了紧耦合与松耦合架构的优缺点,指出松耦合架构是大规模并行处理阵列的发展方向。研究了基于TS201 DSP的松耦合阵列的自举问题,提出了混合自举的方案,并给出详细实施流程。     

基于PON接入与中间件技术的智能社区系统设计

针对智慧城市与社区生活的实际需求,全面构建智能社区系统架构、设计智能业务平台、开发智能业务应用中间件套件、研发PON接入光纤宽带网络社区组网方案以及开发智能社区综合业务应用,为各种智能社区业务应用接入及部署提供快捷便利的方法,逐步建立一个沟通社区内部住户与住户、住户与社区管理服务中心、住户与外部社会的多媒体综合信息交互中心,推动一个安全、舒适、便捷、节能高效的生活环境的实现,推动以社区管理智能和家居智能为主的、可持续发展的现代化智能社区的实现.     

基于社会特征周期演化的机会移动网络路由转发策略

针对分布式k团社区检测引起的超大社区问题,提出了具有节点退出机制的?-window社区检测方法,相应提出了?-window中心性估计。通过实验发现?-window社区和?-window中心性具有周期演化特性,利用该特性,提出TTL(time to live)社区检测和TTL中心性估计,以更准确预测消息生存期上节点的相遇。随后,利用TTL社区和TTL中心性作为转发测度,设计了新的机会移动网络路由算法PerEvo。实验结果表明,与现有的基于社会特征的路由算法比较,PerEvo在保持基本不变的传输开销的同时,有效提高了机会移动网络消息投递的成功率。 关键词：机会移动网络;社区;中心性;周期演化;消息转发     

基于支持向量机的微波链路雨强反演方法

为提高微波链路雨致衰减反演雨强精度, 在Mie散射理论、气体吸收衰减模型以及Gamma雨滴谱分布的基础上, 将支持向量机引入到微波链路测量降水中, 提出了基于支持向量机的微波链路雨强反演方法, 并开展了15–20 GHz频段的视距微波链路与地面雨滴谱仪的同步观测降雨实验. 实验结果表明, 基于支持向量机的微波链路雨强反演模型的反演雨强与实测雨强的相关系数全部高于0.6, 最高达到0.9674; 雨强的均方根误差最小值为0.5780 mm/h, 累积降雨量的绝对最小误差仅为0.0080 mm; 相对偏差大部分在10%以内, 最小偏差为0.7425%. 实验结果验证了基于支持向量机的微波链路雨强反演方法的有效性、准确性和适用性, 对于进一步提高微波链路反演降雨精度、改善降水监测效果具有重要意义.     

Zeros Distribution of the Jones Polynomial for Pretzel Links

In this paper, we deal with basic properties of some pretzel links and properties of the Jones polynomials of some pretzel links. By using these properties, the zero distribution of pretzel links is st...     

An accurate and reliable analysis of trimethylamine using thermal desorption and gas chromatography–time of flight mass spectrometry

Trimethylamine (TMA) is well-known for manifesting the odor of rotting fish and urine. The analysis of TMA in environmental samples generally suffers from low reproducibility and poor sensitivity. In this study, a technique for the quantitative analysis of gas phase TMA was developed using thermal desorption (TD)-gas chromatography (GC)-time of flight mass spectrometry (TOF-MS). This new approach yielded good linearity (R² = 0.9930), precision (RSE = 1.59%), and high sensitivity with the method detection limit (MDL) of 51 pg, i.e., detection of 0.021 ppb of TMA at 1 L sample (limit of detection (LOD): 5.32 pg (0.002 ppb). This method was tested against gas samples collected from two representative sources of TMA: (1) rotten thornback fish and (2) cat urine-soaked clay. The concentration of TMA in these samples, when analyzed after treatment at varying dilution ratios, averaged 293 ± 29.7 ppm (RSE = 3.82%) and 74.1 ± 5.78 ppb (RSE = 3.19%), respectively. The feasibility of this approach, when tested with TD–GC–Quadruple (Q) MS, showed a good compatibility with moderately reduced sensitivity. The results of this study demonstrated that one can achieve highly reliable and reproducible analysis of TMA from environmental samples when using thermal desorption (for pretreatment) and detection (by the TOF or Q-MS system).     

基于链路重构—解构的端到端网络链路时延推测研究简

基于网络时延推测的2个假设、时延推测模型和路径时延数据采集方法,提出了一种基于链路重构—解构的端到端网络链路时延推测方法,应用伪似然估计将原整体问题分解为若干独立子问题分别求解,利用链路重构—解构确定可求解的推测单元,控制平均采样精度和减少推测单元链路数,从而显著降低计算复杂度。通过基于模型的计算和基于NS2的仿真实验研究,验证了推测方法的准确性和有效性。