单中继Wi-Fi网络的MAC协议改进方法研究

Wi-Fi网络由于其诸多优点已受到越来越多人的青睐。为解决无法布线等问题,在原有的网络中引入了中继节点。文中研究了在单中继网络环境中帧的传输过程,用数学形式给出了在此种情况下网络分配矢量的值,并通过与无中继环境帧的比较,得出了二者之间的关系。最后通过实验比较表明,加入中继后的Wi-Fi网络能够切实有效地提高网络边缘用户的通信质量。     

A weighted full-reference image quality assessment based on visual saliency

In full reference image quality assessment (IQA), the images without distortion are usually employed as reference, while the structures in both reference images and distorted images are ignored and all pixels are equally treated. In addition, the role of human visual system (HVS) is not taken account into subjective IQA metric. In this paper, a weighted full-reference image quality metric is proposed, where a weight imposed on each pixel indicates its importance in IQA. Furthermore, the weights can be estimated via visual saliency computation, which can approximate the subjective IQA via exploiting the HVS. In the experiments, the proposed metric is compared with several objective IQA metrics on LIVE release 2 and TID 2008 database. The results demonstrate that SROCC and PLCC of the proposed metric are 0.9647 and 0.9721, respectively,which are higher than other methods and it only takes 427.5 s, which is lower than that of most other methods.     

一种用于融水机油检测的测试装置研究

机油在正常工作时,受温度、湿度的影响,不可避免地会混入水分,长此以往,会使发动机磨损失效。因此,对机油的水融组份进行监测尤为重要。本课题在对国内融水机油检测领域进行相关学习和研究后,设计了一种适用于融水机油检测的平板型电容传感器,利用油水介电常数的巨大差异所引起的电容值的显著变化进行检测,并匹配上后续的检测和调理电路,使其转换成直流电压输出。经调试以后,该电路对电容值的变化能较好地响应,含水量的分辨率较明显。     

基于声表面波传感器的液体运动粘度测量方法

设计了一种用于液体运动粘度在线测量的声表面波传感器.利用液体对水平剪切模式声表面波(SHSAW)传播性质的影响,推导得出液体的密度和动力粘度与SH-SAW的传播速度变化的数学关系式,从而实现液体运动粘度的检测,设计了相应的实验设备.通过实验数据与理论数据的比较证实了该设计的可行性.     

嵌入式Linux下USB主控制器驱动设计

USB(通用串行通信总线)因其自身支持热插拔、高速数据传输和易于扩展的特点,使其成为了当前主流的应用总线。文中介绍了USB的系统总线和Linux系统下USB驱动模块。论述在三星S3C2440芯片上基于OHCI协议的USB主控制器驱动程序的设计方法和实现。     

矩阵嵌入的快速算法

提出了一种矩阵嵌入的快速算法,对随机线性码的奇偶校验矩阵的最后一列取作全1列向量,利用改进后的奇偶校验矩阵可快速地实现对秘密信息的嵌入及提取。分析和实验结果表明,该方法与Fridrich提出的基于随机线性码的矩阵嵌入方法比,在保持其高嵌入效率不变的情况下,有效地减少了计算复杂度。     

电网网架规划智能优化方法的研究与应用

电网网架规划对于电力系统的安全、优质、经济运行有着重大影响,而科学的规划方案则是其基础所在。介绍了传统的规划方法及其不足之处,运用三种智能算法分别设计IEEE-6节点和18节点系统的规划方案并对方案进行建模和仿真,对比结果表明了在电网规划中人工鱼群算法方案具有全局优化功能和良好的适应性,且投资费用最低。具有较广阔的应用前景和明显的经济效果,并能切实提高电网规划水平。     

静态图像中的人体行为分类研究

静态图像中人体行为分类的一般方法是先手动标定出行为对象,再单独对行为对象进行特征提取和分析,不仅费时费力还丢失了场景信息。针对此问题提出了结合场景特征与行为对象特征的图像表示方法,充分利用图像的所有信息。此外为了减小量化误差,在特征编码阶段,采用局部约束线性编码(Locality-constrained Linear Coding,LLC)算法,并将其应用在空间金字塔模型的向量量化中。该算法与传统的矢量量化算法和稀疏编码算法相比,能够降低量化误差。最后在Stanford 40 Action数据集上对文中方法进行实验和验证,结果表明,结合场景特征与行为对象特征并使用LLC编码算法能够获得更好的分类效果。     

Cell vibron polariton resonantly self-confined in the myelin sheath of nerve

Polaritons are arousing tremendous interests in physics and material sciences for their unique and amazing properties,especially including the condensation,lasing without inversion and even room-temperature superfluidity.Herein,we propose a cell vibron polariton(cell-VP):a collectively coherent mode of a photon and all phospholipid molecules in a myelin sheath formed by glial cells.Cell-VP can be resonantly self-confined in the myelin sheath under physiological conditions.The observations benefit from the specifically compact,ordered and polar thin-film structure of the sheath,and the relatively strong coupling of the mid-infrared photon with the vibrons of phospholipid tails in the myelin.The underlying physics is revealed to be the collectively coherent superposition of the photon and vibrons,the polariton induced significant enhancement of myelin permittivity,and the resonance of the polariton with the sheath.The captured cell-VPs in myelin sheaths may provide a promising way for super-efficient consumption of extra-weak bioenergy and even directly serve for quantum information.These findings further the understanding of nervous system operations at cellular level from the view of quantum mechanics.     

一种冲压外圈轴承高度测量装置研究

国内轴承生产厂商主要是采用量规、卡尺对轴承高度进行手动测量,测量效率低,容易造成疲劳操作带来经济损失.现设计了一种基于单片机的无内圈、冲压外圈轴承的高度自动测量装置.该装置采用电感式位移传感器,将高度尺寸的变化值转变为传感器输出电压值,由AT89S52单片机作为控制芯片构成的测量系统,很好地适应了快速的生产节拍需求,并利用VB开发人机界面.该测量装置能精确地测量这种轴承的高度,自动化效率高,满足了生产需求,是一款实用的测量装置.