Numerical investigation of the effect of spiral curvature on the flow field in a spiral channel viscous micropump

This paper investigates the effect of spiral curvature on the flow field within a newly introduced spiral channel viscous micropump. Increasing the spiral curvature increases the angle between the channel axis and the direction of upper plate motion, and more fluid is dragged normal to the axis of the channel, which changes the flow characteristics. A number of 3D models for the pump geometry with different design parameters are built and analyzed using the finite volume method. Numerical visualization of the flow field contours through the spiral channel is presented. It has been found numerically that the flow rate varies linearly with both the pressure difference and boundary velocity for a wide range of design parameters, which supports the validity of the linear lubrication model for this problem for the full range of spiral curvatures studied. Further, it is found that the error resulting from ignoring the spiral curvature exceeds 5% for spiral curvature ratio above 2. Obtained results depict a complete representation of the effect of spiral channel width, height, length and curvature on the flow field through a spiral-grooved micropump.     

基于分布式编码的多描述视频编解码器

为了解决多描述视频编码器在丢包信道下的漂移问题,本文提出了一种新的基于分布式视频算法的多描述视频编码方案。实验结果表明,借助于分布式编码的稳健性,这一新方案能有效地避免漂移问题。为了解决多描述视频编码器在丢包信道下的漂移问题,提出了一种新的基于分布式视频算法的多描述视频编码方案。实验结果表明,借助于分布式编码的稳健性,这一新方案能有效地避免漂移问题。     

一种低复杂度的MIMO—OFDM信道估计阈值算法

本文分析了现有的基于导频的MIMO—OFDM信道估计技术，提出了一种低复杂度的信道估计闽值算法，这种算法与采用维纳滤波器的估计技术相比较，具有计算复杂度低，适应性好的特点。在“B3G”系统仿真平台上进行了仿真验证，仿真曲线充分表明该算法具有良好的跟踪信道变化的能力。     

多业务通信系统中切换方案的研究

在无线移动通信系统中要想获得连续的通信就必须有切换技术的支撑,切换方案是否优良决定着信号的业务流量以及服务质量。因此,本文主要讨论在多业务系统中,非强占优先切换方案和抢占优先的切换方案。     

基于INT5200的低压电力线通信模块设计

本文通过分析低压电力线信道模型,结合美国Intellon公司的电力线MAC/PHY/AFE集成收发器INT5200的主要功能和结构特点,详细阐述了以电力载波芯片INT5200为核心的通信模块设计,实现了数据在低压电力线上的高速传输。     

钢铁企业发展钢材直供的思考与对策

分析了钢铁企业目前营销渠道现状及发展趋势，总结钢材直供的形式、特点、合作方式，为钢铁企业发展直供提供了一些问题关注点及相应的对策。     

SAN存储系统的性能分析模型

存储区域网(SAN)作为一种新的网络存储体系结构，已成为存储领域重要的研究方向。性能研究是网络存储研究中的一个重点内容。该文通过对SAN数据传输流程的分析，建立了存储区域网系统的排队网络模型，并求得了基于光纤通道的模型性能参数的定量结果。通过仿真实验发现，模型的理论结果和仿真实验性能测试结果十分接近。     

A channel equalizer using reduced decision feedback Chebyshev functional link artificial neural networks

In this paper, a reduced decision feedback Chebyshev functional link artificial neural network (RDF-CFLANN) is proposed for the design of a nonlinear channel equalizer. An RDF-CFLANN structure uses functional expansion utilities to nonlinearly transform its input signals into the output space. In most MLP structures, one or more hidden layers are needed to nonlinearly map the input signals to the output signal space. Therefore, the complexity of the RDF-CFLANN structure is generally much lower than that of an MLP structure. In addition, the required amount of computing at the training mode can also be reduced. The comparisons of the mean squared error (MSE) and the average transmission bit error rate (BER) among RDF-CFLANN, DF-CFLANN and CFLANN are presented in this paper. Simulation results demonstrate that RDF-CFLANN presents the best performance among the three structures.     

水平矩形窄缝通道内水沸腾换热的实验研究

以去离子水为工质,在1.0～6.0MPa压力范围内,对大宽高比(1.0×60mm、1.8×60mm、2.5×60mm)矩形狭窄通道内两相沸腾的换热特性进行了实验研究.分析了压力、窄缝间隙、热流密度、质量流量、含汽率等参数对矩形窄缝通道内水的沸腾换热的影响,得到了矩形窄缝通道内沸腾换热经验关系式,与实验数据符合良好.     

一种基于混合模型的离子单通道信号重构算法研究

细胞膜离子单通道信号是皮安级的随机离子电流,膜片钳技术记录中单通道电流往往被淹没在强背景噪声中.本文提出了一种隐马尔可夫模型(HMM)和径向基函数(RBF)神经网络相结合的混合模型,用于白噪声背景下细胞膜离子单通道电流的统计重构.该方法首先采用RBF网络强大的模式分类能力,确定离子单通道信号的电流幅值水平;然后利用HMM模型强时序信号处理能力,估计通道的动力学参数.在此基础上,从强噪声污染的膜片钳记录中统计重构理想化的通道电流信号.理论和仿真实验结果表明,在低信噪比情况下(SNR＜5.0),该混合模型重构信号精度高,且具有较强的噪声鲁棒性.