一种用于激光雷达信号的自适应分段平滑算法

为了抑制米散射大气探测激光雷达回波噪声引起的信号随机波动,采用新设计的自适应分段平滑方法对信号进行平滑处理。根据激光雷达信号特性,信号有效变化幅值大于信号背景噪声波动。以背景噪声标准差的若干倍表示信号的噪声幅度。按照相邻信号幅值差与噪声幅度的对比,可以确定信号发生有效变化的位置,这些位置可以作为信号分段端点,在分段端点内用滑动平均可以实现对信号的自动分段平滑。用实测微脉冲激光雷达信号对方法进行了验证,并与常用固定分段平滑方法进行了对比。结果表明,自适应分段平滑方法可以根据信号变化的剧烈程度自动选择平滑窗口大小,在对噪声进行有效抑制的同时,避免平滑过度造成的信号畸变。     

基于天空约束暗通道先验的图像去雾

针对现有暗通道图像去雾算法存在的天空色彩失真,景物边缘光晕效应等问题,本文提出了基于暗通道理论的改进去雾算法.由于暗原色先验理论不适用于天空区域,本文将引导滤波用于天空区域的细化分割,准确估计包含天空区域图像的大气光照强度,解决了天空色彩失真问题;其次,利用中值滤波得到详细边缘信息,进而得到更为清晰的透射率,有效抑制了景物边缘光晕问题;最后针对去雾后图像偏暗的问题,在HSV空间对亮度分量V通道进行增强处理.实验结果表明,针对带雾图像,本文算法能够有效地去雾,改善天空区域色彩失真以及景物边缘光晕问题.     

Model of 1D charge carrier traps and polyconformism of silicon backbone segments in the polymer poly(di-n-hexylsilane)

Studied an energy spectrum of traps in poly(di-n-hexylsilane) by fractional thermoluminescence. The spectrum is discrete, while the frequency factor is dispersed. It was found that this energies form three oscillatory series. Energy of the oscillatory quantum for each series coincides with the energy corresponding symmetrical Raman mode of the polymer silicon backbone. It is found that each oscillator series corresponds to a specific conformation of the silicon backbone. Model of traps was developed which adequately explain all observed thermoluminescent features of the material.     

Integro-local and integral theorems for sums of random variables with semiexponential distributions

We obtain some integro-local and integral limit theorems for the sums S(n) = ξ(1) + ? + ξ(n) of independent random variables with general semiexponential distribution (i.e., a distribution whose right tail has the form $P(\xi \ge t) = e^{ - t^\beta L(t)} $ , where β ∈ (0, 1) and L(t) is a slowly varying function with some smoothness properties). These theorems describe the asymptotic behavior as x → ∞ of the probabilities P(S(n) ∈ [x, x + Δ)) and P(S(n) ≥ x) in the zone of normal deviations and all zones of large deviations of x: in the Cramér and intermediate zones, and also in the “extreme” zone where the distribution of S(n) is approximated by that of the maximal summand.     

一种基于静态分段补偿的近似乘法器设计北大核心

提出了一种基于静态分段补偿方法的近似乘法器。通过基于静态分段方法的Booth编码方法生成部分积阵列，并对生成的部分积阵列进行误差补偿优化以及近似压缩，以实现硬件性能和精度的折中。仿真结果显示，相比于综合工具生成的全精度乘法器，本设计在保持了较高精度水平的前提下，面积和功耗优化的比例达到了36.96%和35.95%。在图片边缘检测应用中，设计的峰值信噪比和结构相似性指标分别为26.10和98%,可见本设计在降低硬件资源消耗的同时，应用效果接近全精度乘法器。     

SR架构下的软件定义信息中心网络概率路由策略

传统的TCP/IP路由以IP地址为中心,信息传输效率低下,难以满足网络用户需求.信息中心网络(Information-Centric Network,ICN)开始成为研究热点,ICN以内容为中心,可以高效传输信息.为了利用软件定义网络(Software Defined Network,SDN)和分段路由技术的优势,提高...