基于TV-Anytime规范的PDR多Agent个性化服务

目的研究基于TV-Anytime规范的新一代智能个人数字媒体设备PDR的个性化服务关键技术。方法引入特征表示和相似度度量算法,提出用户个人喜好知识的学习和更新方法,研究了多个Agent之间的通信机制。结果提出PDR智能多Agent个性化服务的关键技术及主要算法和机制,给出验证系统的设计。结论提出的算法和机制为实现PDR智能多Agent个性化服务奠定了基础。     

浅析PDH光端机设备常见故障的处理

对PDH光端机进行了简单介绍,并分析了设备维护中常见的问题。     

玻璃体切割联合视网膜光凝治疗增殖性糖尿病视网膜病变

目的:探讨玻璃体切割联合眼内视网膜光凝治疗增殖性糖尿病视网膜病(PDR)病变疗效。方法:对30例30眼PDR患者进行玻璃体切割联合眼内视网膜光凝,11眼行巩膜环扎术,其中8眼行硅油填充,15眼行白内障摘除。结果:术后三月随访26眼视力都有明显好转,4眼由于视网膜下出血及增殖膜,视力提高不明显。结论:玻璃体切割联合眼内视网膜光凝治疗PDR有明显疗效,同时也是目前治疗PDR最有效的手段。     

iBeacon技术下PDR增强的室内定位方法设计

提出一种利用iBeacon技术辅助PDR的室内定位方法.采用粒子滤波器将PDR和iBeacon技术定位信息融合,从而确定出用户的位置,以此减少PDR随距离增加而产生的累积误差.此外,基于iBeacon在线步长调整模型在一定程度上减少了步长不正确带来的误差.实验结果显示,提出的方法能够有效克服PDR产生的累积误差,有效提升了定位的鲁棒性和精度.     

基于行人航位推算的后向地磁匹配算法

针对行人航位推算(pedestrian dead reckoning,PDR)定位存在误差累积和智能手机内置传感器精度不高的问题,采用PDR结合地磁的方法进行室内定位研究,提出一种改进的基于PDR的后向地磁匹配算法.在构建地磁基准库阶段,使用克里金插值算法有效减少数据采集所耗费的大量时间并构建出双分辨率地磁基准库.在地磁匹配阶段,改进了基于动态时间规整(dynamic time warping,DTW)的后向地磁匹配算法,改进后的算法避免传统DTW地磁匹配需要全局搜索地磁序列的缺点,在保证定位精度的前提下,增强了定位实时性.实验结果表明,本文算法最大定位误差小于1.5m,可以满足普通室内定位需求.     

三维复杂运动模式航迹推算惯性导航室内定位

在微机电惯性测量单元(micro-electro-mechanical system-inertial measurement unit, MEMS-IMU)人体室内定位技术研究领域中,行人航迹推算法(pedestrian dead reckoning, PDR)具有计算简便、对传感器精度要求低的优点,得到了较为广泛的应用,但传统的PDR 研究通常只针对单一的二维前进行走运动模式,这与人体实际的三维复杂运动模式相距甚远. 该文从人体三维室内定位研究角度出发,通过10 轴MEMS 传感器采集人体运动原始信息,提出了三维复杂运动模式航迹推算法. 首先使用双零点交叉区间内的峰值双轴检测法与俯仰角检测法来检测5 类非行走运动模式,排除其对有效跨步检测的干扰;其次使用相位反转法与气压值突变法区分3 类行走运动模式,提取出不同类型的有效跨步;最后针对每一个有效跨步求解出人体位置的三维坐标值,完成人体三维室内定位. 实验表明,所提出的三维复杂运动模式航迹推算法在人体实际室内运动中,相较传统的峰值检测和零点交叉法PDR,水平定位精度提升了99%,并且高度定位精度可以达到92.4%.     

运动分类步频调节的微机电惯性测量单元室内行人航迹推算

行人航迹推算(pedestrian dead reckoning, PDR)作为一种新兴的导航定位方法, 因其不易受外界环境因素影响而受到广泛关注. 针对室内行人航迹推算, 采集并分析了微机电惯性测量单元(micro-electro-mechanical system-inertial measurement unit, MEMS-IMU)数据, 设计了运动分类的区间对称步频检测, 并建立了步频调节的步长估计模型, 最后提出了运动分类步频调节的MEMS-IMU室内行人航迹推算, 从而实现较精准的定位. 针对不同个体, 对步频调节的步长估计模型进行个性化标定, 以进一步提高室内行人航迹推算性能. 验证结果表明: 与传统峰值非线性方法相比, 运动分类步频调节的MEMS-IMU室内行人航迹推算的定位误差降低了32.6%, 使短距离室内行人航迹推算在无其他定位技术支持的情况下具有较高精度.     

基于智能手机传感器的林区行人定位算法

针对林区卫星信号缺失、跟踪定位困难的问题,提出了基于智能手机传感器的林区行人定位算法(forest-pedestrian location,FPL)。算法在行人航位推算算法(pedestrian dead reckoning,PDR)基础上进行改进：采用扩展卡尔曼滤波(extended Kalman filter, EKF)与卡尔曼滤波(Kalman filter, KF)融合算法对磁力计、加速度计及陀螺仪输出进行多次融合,以提高方位角测量精度;随后,使用Savitzky-Golay(S-G)滤波处理方位角测量值,以提高PDR算法中方位角的估计精度;引入K邻近(K-nearest neighbor, KNN)算法估计步长,将拟合显式步长函数问题转化为“懒惰学习”问题;使用差分气压测高法求解行人高程信息,从而获取行人在林区内的3维定位信息。实验结果表明,该算法可以提高方位角及步长的估计精度,同时可以增加精准的高程定位信息,整体误差控制在5%以内,可以满足林区无信号条件下的定位需求。     

Characterization of a PDR type ABC transporter gene from wheat （Triticum aestivum L.）

DON, as a virulence factor, plays an important role in the infection of Fusarium graminearum in wheat. The infection ability of F. graminearum depends on its capacity of producing DON. The production of DON by F. graminearum is significantly decreased in the wheat varieties with scab resistance. In this study, GeneChip analysis indicated that an EST encoding an ATP-binding cassette （ABC） transporter was up-regulated by 45 times in a wheat landrace Wangshuibai, which is resistant to DON accumulation. A pair of EST-derived primers were designed based on the EST sequence, and a clone was then isolated from a wheat genomic DNA TAC library. The TAC clone was sequenced using chromosome walking and gene prediction was conducted using Softberry. A cDNA clone of this gene was subsequently isolated from Wangshuibai induced by DON using gene-specific primers designed according to the untranslated sequence of the gene. The genome size of the gene is 7377 bp, consisting of 19 exons with coding sequences of 4308 bp. It encodes a protein with 1435 amino acid residues and the calculated molecular weight is about 161 kD. BLAST analysis indicated that the gene may belong to pleiotropic drug resistance （PDR） sub-family, and hence designated as TaPDR1 （Triticum aestivum pleiotropic drug resistance）. TaPDR1 was located on chromosome 5A of wheat using nullisomic-tetrasomic lines of Chinese Spring. TaPDR1 was up-regulated by induction of both DON and F. graminearum. Expression patterns of TaPDR1 were different in wild-type Wangshuibai and the fast-neutron induced Wangshuibai mutant lacking FHB1, a major QTL of FHB resistance and DON resistance in chromosome arm 3BS. These results suggested that TaPDR1 might be a candidate gene responsible for DON accumulation resistance. The expression profile showed that TaPDR1 expression was neither induced by hormones typically involved in biotic stress, such as JA and SA, nor by abiotic stresses, such as heat, cold, wounding and NaCI. However, TaPDR1 expression was regulated by Al^3＋ and [Ca^2＋], indicating that [Ca^2＋]1 might mediate the signal of TaPDR1 expression.