基于几何统计的无人机信道模型及硬件模拟

针对无人机(unmanned aerial vehicle, UAV)通信信号三维空间传播特点,提出了基于多圆柱体的非平稳几何统计模型(geometry-based stochastic channel model, GSCM),该模型通过引入天线位置变换矩阵,可支持UAV〖JP2〗和地面移动端(mobile terminal,MT)任意三维移动轨迹。在此基础上,构建了适合硬件模拟实现的离散化模型,并设计实现了模拟时变信道特性的随机簇生灭算法,以及基于线性调频叠加原理的非平稳衰落模拟方法。硬件实测结果表明,本文信道模拟器输出的衰落幅值分布、时延功率谱和多普勒功率谱等统计特性与理论结果比较吻合,有效复现了信道时变衰落、多径时延、多径功率和多普勒频率随着UAV的位置和速度变化而变化的过程。     

斜拉桥索梁锚固结构疲劳试验模型设计优化

为了避免出现斜拉桥索梁锚固结构疲劳试验中辅助部分首先断裂的问题,在以往试验模型设计的基础上,考虑影响疲劳寿命的不同因素,建立了以模型的静力强度、位移、疲劳和断裂性能为模糊约束条件,以模型质量、疲劳和断裂寿命为多个目标的结构多目标优化设计模型.结合苏州南通长江公路大桥钢锚箱式索梁锚固结构足尺疲劳试验,验证了锚箱式索梁锚固结构设计的正确性,经过400万次加载而未破坏,且减少了模型用钢量.模型设计中提出的控制热点应力等措施切实可行.     

基于ADCensus的改进半全局匹配方法

考虑到AD相似性测度对灰度信息及纹理丰富的区域的优势和Census变换对图像辐射差异具有鲁棒性的优势,将AD和Census算法融合替代单一匹配代价来改进半全局密集匹配算法,可有效提高算法的匹配精度和抗干扰性。同时用金字塔分层匹配策略来约束视差的搜索范围,实验结果表明,该方法在保证匹配精度的同时,减少内存消耗和运行时间,适用于无人机影像的密集匹配。     

Cdk5 targets active Src for ubiquitin-dependent degradation by phosphorylating Src(S75)

The non-receptor tyrosine kinase Src is a critical regulator of cytoskeletal contraction, cell adhesion, and migration. In normal cells, Src activity is stringently controlled by Csk-dependent phosphorylation of Src(Y530), and by Cullin-5-dependent ubiquitinylation, which affects active Src(pY419) exclusively, leading to its degradation by the proteosome. Previous work has shown that Src activity is also limited by Cdk5, a proline-directed kinase, which has been shown to phosphorylate Src(S75). Here we show that this phosphorylation promotes the ubiquitin-dependent degradation of Src, thus restricting the availability of active Src. We demonstrate that Src(S75) phosphorylation occurs in vivo in epithelial cells, and like ubiquitinylation, is associated only with active Src. Preventing Cdk5-dependent phosphorylation of Src(S75), by site-specific mutation of S75 or by Cdk5 inhibition or suppression, increases Src(Y419) phosphorylation and kinase activity, resulting in Src-dependent cytoskeletal changes. In transfected cells, ubiquitinylation of Src(S75A) is about 35% that of wild-type Src-V5, and its half-life is approximately 2.5-fold greater. Cdk5 suppression leads to a comparable decrease in the ubiquitinylation of endogenous Src and a similar increase in Src stability. Together, these findings demonstrate that Cdk5-dependent phosphorylation of Src(S75) is a physiologically significant mechanism of regulating intracellular Src activity.     

疏水蛋白rHGFI与rHFBI的发泡能力研究

将巴斯德毕赤酵母异源表达出的疏水蛋白rHGFI和rHFBI修饰硅化玻璃后进行玻璃表面接触角测定.结果显示:蛋白处理的硅化玻璃表面由疏水变为亲水.蛋白溶液表面张力测定结果表明:rHGFI和rHFBI是表面活性非常强的蛋白,均可使表面张力降低.以常用的食品乳化剂酪蛋白酸钠为对照,检测rHGFI和rHFBI蛋白的发泡能力和泡沫稳定性.0.1%的rHGFI和rHFBI蛋白溶液发泡能力明显高于同浓度的酪蛋白酸钠溶液,rHFBI蛋白溶液的泡沫稳定性最佳.     

Fractal characteristics of particle size distribution in dynamic flocculation process

This study selected polyaluminum chloride(PAC) coagulant to remove suspended particles in Kaolin suspension solution and used a turbidimeter and particle counter to monitor the flocculation process online and collected the experiment data. The experiments were conducted to study the dynamic distribution characteristics of suspended particles under different hydrodynamic conditions. The results show the self-similarity and scale invariance of particle size distribution. The study further proposed the concept of fractal dimension of particle size distribution and found out that fractal dimension changed in a similar way as residual turbidity did and could excellently indicate the variation of coagulation effect. Therefore, fractal dimension could be adopted to optimize the addition of coagulants and the quality of outflow could be further improved to reduce production costs.     

钢筋混凝土梁非线性有限元分析在实际工程中的应用

文章利用有限元分析软件ANSYS对实际工程中的梁进行非线性分析,介绍了ANSYS中钢筋混凝土梁建模过程,并对其性能进行评价,对实际工程提出了建议:应对PKPM直接生成的梁配筋进行修正,否则会造减框架结构中梁超强.     

浅析C与C#

C#是微软公司发布的一种面向对象的、运行于.NET Framework环境之上的高级程序设计语言,是微软公司的最新成果.从时间顺序上说,最早出现的是C,然后是C++,最后是C#.C++是为了解决软件危机而引入面向对象的概念,C#是为了实现平台统一和IAVA争夺市场下的产物.最后是C#.C++是为了解决软件危机而引入面向对象的概念,C#是为了实现平台统一和IAVA争夺市场下的产物.C是完全面向过程的程序设计语言,而C++可认为是半个面向对象,JAVA从C++发展而来,吸取了C++精华,C#更是JAVA的超级版,C撑是完全面向对象的.文章对C和C#之间的联系及区别作了简单阐述.     

基于粗糙集理论的仿人控制器设计

针对如何模拟人的控制行为以及提取控制行为特性问题,提出了基于粗糙集理论的仿人控制器的规则提取方法和仿人控制器的设计方法,包括用人控制行为的样本集建立初始决策信息表、信息表离散化、属性约简、规则提取和决策表完备化等。实验结果表明:将所设计的仿人控制器应用到原有的实际系统中,能顺利实现规则校验,提出的仿人控制器的设计方法是可行的。     

新一代交通仿真技术综述

简要回顾了国内外交通仿真技术的发展历程,总结了新世纪以来新一代交通仿真技术的主要特点。然后,比较分析了当前主流交通仿真模型的特性,并对交通仿真应用程序接口、硬件在环和软件在环交通仿真、在线交通仿真等面向智能交通系统应用的高级仿真技术进行了深入解析。最后,根据我国交通仿真研究和应用的现状,在符合我国交通特性的基础仿真模型研究、交通仿真系统的开发模式、在线仿真技术的开发方法等方面提出了改进建议。

Abstract：

The historical course of traffic simulation in China and abroad was briefly reviewed firstly,and some major features of the new generation traffic simulation technology since 21st century were summarized then. Afterwards,the simulation model characteristics of some prevailing traffic simulation models were comparably analyzed,and several advanced traffic simulation techniques for ITS applications were expatiated,including traffic simulation API,hardware-in-the-loop traffic simulation,software-in-the-loop traffic simulation,online traffic simulation. Finally,based on the state-of-the-practice of traffic simulation in China,some suggestions were given on fundamental simulation modeling fitting for Chinese traffic characteristics,development modes of traffic simulation system,development methodologies of online traffic simulation,etc.