计算无圈有向网络ST可靠性的一个新方法

本文考虑计算无圈有向网络的ＳＴ可靠性问题（至少存在一条从源点ｓ到汇点ｔ的正常运行道路的概率）。文章引进了深度优先搜索（Ｄｅｐｔｈ－ＦｉｒｓｔＳｅａｒｃｈ）有序根树的概念并提出一个新的计算无圈有向网络ＳＴ可靠性的拓扑公式。以该公式为基础,我们利用ＤＦＳ方法提出一个新的计算无圈有向网络ＳＴ可靠性算法,它能生成简洁的可靠性表达式,进而有效地计算无圈有向网络的ＳＴ可靠性。两个例子例证了我们的结论     

MC V-BLAST系统的MIMO信道盲估计

本文研究多载波垂直分层空时(MC V-BLAST)系统的下行频率选择性衰落多输入多输出(MIMO)无线信道估计问题.本文首先为MC V-BLAST系统提出了一种新颖的移不变性编码方法.利用上述移不变性性质,本文进一步提出了相应的下行频率选择性衰落MIMO无线信道的盲估计方法.仿真结果表明了本文移不变性编码方法的有效性和信道盲估计方法的性能.     

新型CRZ码的发射器的研究

介绍利用一种新型CRZ编码的发射器,只用一个外部调制器从直流光源获得10Gb/sCRZ编码的机理及实验装置。选用G6.52光纤在放大器跨距为80km、传输距离为3600km的再生环形回路传输系统网进行模拟试验。     

A Channel Sharing Scheme for Cellular Mobile Communications

This paper presents a channel sharing scheme, Neighbor Cell Channel Sharing (NCCS) , based on region partitioning of cell coverage for wireless cellular networks. Each cell is divided into an inner-cell region and an outer-cell region. Cochannel interference is suppressed by limiting the usage of sharing channels in the inner-cell region. The channel sharing scheme achieves a traffic-adaptive channel assignment and does not require any channel locking. Performance analysis shows that using the NCCS scheme leads to a lower call blocking probability and a better channel utilization as compared with other previously proposed channel assignment schemes.     

改进的生成对抗网络的超分辨率方法研究

本文针对基于深度学习的超分辨率重建网络SRGAN中存在的训练不稳定,重建图像信息缺失等问题进行了分析研究,做出相应的改进,提出了一种改良的生成器残差块结构,提高了重建效率,增强了重建图像的质量;引入Wasserstein距离代替JS散度来描述数据分布之间的差异,解决了生成对抗网络训练不稳定的问题,有效避免了梯度消失现象...     

H2对UHV/CVD低温选择性外延生长Si1-xGex的影响

利用超高真空化学气相沉积(UHV/CVD)成功实现了Si1-xGex的低温选择性外延生长,并研究了H2对选择性外延生长的影响及其作用机理.以SiH4和GeH4为反应气源,在开有6mm×6mm窗口氧化硅片上进行Si1-xGex外延层的生长.首先分别以不含H2(纯GeH4)和含H2(90%H2稀释的GeH4)的两种Ge源进行选择性外延生长.通过SEM观察两种情况下氧化硅片表面,发现H2的存在对选择性外延生长有至关重要的作用.接着以90%H2稀释的GeH4为Ge源,变化Si源和Ge源的流量比改变H2分压,以获得SiH4和GeH4(90%H2)的最佳流量比,使外延生长的选择性达到最好.利用SEM观察在不同流量比时,经40min外延生长后各样品的表面形貌,并对其进行比较,分析了H2分压在Si1-xGex选择性外延生长中的作用机理.     

Tunable Optical Mode Ferromagnetic Resonance in FeCoB/Ru/FeCoB Synthetic Antiferromagnetic Trilayers under Uniaxial Magnetic Anisotropy

Ferromagnetic resonance (FMR) is one of the most important characteristics of soft magnetic materials, which practically sets the maximum operation speed of these materials. There are two FMR modes in exchange coupled ferromagnet/nonmagnet/ferromagnet sandwich films. The acoustic mode has relatively lower frequency and is widely used in radio‐frequency/microwave devices, while the optical mode is largely neglected due to its tiny permeability even though it supports much higher frequency. Here, a realistic method is reported to enhance the permeability in the optical mode to an applicable level. FeCoB/Ru/FeCoB trilayers are carefully engineered with both uniaxial magnetic anisotropy and antiferromagnetic interlayer exchange coupling. This special magnetic structure exhibits a high optical mode frequency up to 11.28 GHz and a maximum permeability of 200 at resonance. An abnormally low inverse switch field (<200 Oe, less than 1/5 of the single layer) is observed which can effectively switch the system from optical mode with higher frequency into acoustic mode with lower frequency. The optical mode frequency and inverse switch field can be controlled by tailoring the interlayer coupling strengths and the uniaxial anisotropy fields, respectively. The tunable optical mode resonance thus can increase operation frequency while reduce operation field overhead in FMR based devices.     

基于无线传感网络的瓦斯监控报警系统

该文设计了以CC2430为核心的无线传感网络的瓦斯监控报警系统。该系统通过放置大量的无线传感器网络采集节点,实时进行节点处瓦斯浓度的采集和换算,并通过模糊PID控制实现节点附近的瓦斯浓度的智能化控制。     

基于89C52单片机的遥控电动小车控制系统设计

遥控电动小车系统以89C52单片机为核心控制器,包含了主控制器模块、电机驱动模块、液晶显示模块、键盘模块、测距模块、蓝牙通信模块、电源模块等。进而设计制作出一台具有自动运行的智能小车控制系统。本系统以两个步进电机作为驱动,通过各类传感器件来采集各类信息,通过2．4GHz蓝牙通信模块实现小车在手持无线遥控器的控制下前进、转向、倒退、小车精确转弯、自动定位等功能。智能小车系统具有很高的灵敏度和精确度,操控简单、便捷。