VEGF165基因修饰的神经干细胞对脑外伤大鼠的神经保护作用及机制

目的：探讨移植转染pDsVEGF165Redl-N1质粒的神经干细胞对脑外伤大鼠的神经保护作用及机制。方法：由新生大鼠脑组织分离培养神经干细胞,应用Lipofectamine2000介导pDsVEGF16sRed1-N1质粒转染神经干细胞;分别将PBS（A组）、神经干细胞（B组）、转基因神经干细胞（C组）移植到脑外伤大鼠局部损伤灶边缘;利用ELISA法检测转基因细胞在体内的表达情况,以免疫组化检测移植后局部损伤组织中微血管密度变化,通过NSS评分评价移植后大鼠神经功能的变化。结果：转基因细胞移植后在一定时间内持续表达VEGFl65,C组大鼠NSS评分从移植后第3天开始明显低于A组（P〈0．05）,而B组大鼠NSS评分则从移植后第7天开始明显低于A组（P〈0．05）,C组大鼠微血管密度从移植后第7天开始明显高于其他两组（P〈0．01）。结论：转基因神经干细胞表达的VEGF165既可以通过促进微血管再生和改善微循环发挥保护作用又可以直接作用于神经细胞发挥保护作用。     

Image Independent Driving Power Reduction for High Frame Rate LCD Televisions

In this letter, the constant driving power reduction ratio has been achieved for column drivers regardless of the input image by incorporating a new static power reduction scheme into the previous dynamic power reduction method. The measured power reduction ratio is around 50% for a 120 Hz liquid crystal display panel in such cases of still input video and fallback.     

一种基于串行通信接口的采样速率测试方法

串行接口在工业控制领域得到广泛的应用,而且对串口的功能进行验证具有较为完善的测试设备和方法。另一方面,如何简化并快速进行串口模块的功能验证具有重要的意义。基于此观点,在研究了模块自身的功能特性的基础上,提出一种具有一定通用性的设计思想,即利用通信速率和采样速率之间的关系,将串口收/发送器速率与串口接收器采样速率配置成一定配比关系,从而实现用于测试串口接收器的任意帧结构数据。     

Performance study of hybrid decode–amplify–forward (HDAF) relaying scheme for physical layer security in wireless cooperative network

In this paper, the secrecy performance and power allocation of the signal‐to‐noise ratio‐based hybrid decode–amplify–forward (HDAF) relaying protocol in wireless cooperative network are investigated to get security at physical layer. The performance metrics considered are secrecy rate and intercept probability. The Ergodic secrecy rate is approximated theoretically. The effect of relay and eavesdropper locations on the secrecy performance of the system is analyzed. It is found that maximum secrecy rate is obtained for the relay close‐to‐destination case and minimum for the relay close‐to‐eavesdropper case. Jamming schemes are superior in secrecy rate performance than without jamming schemes. To enhance the secrecy rate further with the optimized relay and jammer powers, invasive weed optimization (IWO) algorithm‐based power allocation is proposed. Here, maximizing the secrecy rate is defined as the cost function for the proposed IWO algorithm‐based power allocation. Comparative study is done over the conventional equal and proposed power allocation schemes for validation. The proposed power allocation scheme proved to be superior. Copyright © 2016 John Wiley & Sons, Ltd.     

基于PSO-LSSVM的过电压识别

为了获得理想的过电压识别结果,提出了粒子群优化算法优化最小二乘支持向量机参数的过电压识别方法。首先采用小波变换对过电压原始信号进行分解,提取过电压信号的特征量,然后将过电压信号的特征量作为最小二乘支持向量机的输入,建立过电压识别分类器,并采用粒子群优化算法估计最小二乘支持向量机的参数,最后采用实测的过电压数据进行仿真实验,测试其可行性。结果表明,本文方法可以对各种类型的过电压信号进行准确分类和识别,识别结果稳定,且过电压识别率要高于其它方法。     

基于双载波随机驻留策略的HSDPA RAB分配成功率优化

通过改变双载波区域UE空闲模式下的驻留策略,提出了双载波随机驻留的方式,有效地提升了HSDPA用户的接入成功率,提升了网络质量,改善用户感知。     

图书馆内空气品质的调查及其灰色关联分析

选择广州某图书馆作为实测对象,从9:00至21:00每隔2 h对图书馆内的空气品质状况进行主、客观实地调查,获得各时段图书馆内的客观指标值及图书馆内人员的空气品质不满意率。利用灰色关联分析方法,计算图书馆内空气品质的客观指标与图书馆内各类人员的空气品质不满意率之间的灰色关联度,以及分析预处理后的客观指标曲线图与空气品质不满意率曲线图关系,最终得出对图书馆内各类人员的空气品质不满意率影响最主要的客观指标是相对湿度、新风量、温度。     

基站天线远场全身暴露人体内SAR计算

采用人体CT数据,重构形成三维模型,并赋予组织器官电磁参数,构成适合电磁计算的人体模型。应用XFDTD软件计算在频率900MHz、1800MHz和2100MHz,功率密度200μW/cm^2、40μW/cm^2、8μW/cm^2和4μW/cm^2的移动通信基站远场全身暴露下,人体模型内比吸收率分布。并与《电磁辐射防护规定（GB8702-1988）》基本限值进行比较,为设计有效的电磁场生物效应实验方案、控制暴露条件提供理论剂量学依据。     

高原地区不同品牌混合动力公交车适应性分析

针对昆明示范运营的混合动力公交客车,依托昆明市新能源汽车示范运行信息化管理与监控平台,采集同一公交线路上不同品牌混合动力公交客车运行数据,并对运行车辆的油耗数据和故障进行对比分析。结果表明:三种不同品牌混合动力公交客车节油效果比纯柴油公交客车明显;高原环境的差异性和技术条件的不成熟导致混合动力公交客车故障率明显高于纯柴油公交客车;不同品牌混合动力公交客车在该公交线路上的性能存在较大差异。     

Depth video spatial and temporal correlation enhancement algorithm based on just noticeable rendering distortion model

Spatial and temporal inconsistency of depth video deteriorates encoding efficiency in three dimensional video systems. A depth video processing algorithm based on human perception is presented. Firstly, a just noticeable rendering distortion (JNRD) model is formulated by combining the analyses of the influence of depth distortion on virtual view rendering with human visual perception characteristics. Then, depth video is processed based on the JNRD model from two aspects, spatial and temporal correlation enhancement. During the process of spatial correlation enhancement, depth video is segmented into edge, foreground, and background regions, and smoothened by Gaussian and mean filters. The operations of the temporal correlation enhancement include temporal–spatial transpose (TST), temporal smoothing filter and inverse TST. Finally, encoding and virtual view rendering experiments are conducted to evaluate the proposed algorithm. Experimental results show that the proposed algorithm can greatly reduce the bit rate while it maintains the quality of virtual view.