Hybrid location determination technology within urban and indoor environment based on Cell-ID and path loss

The location determination technology based on simple delay evaluations or GPS is not accurate enough or even impossible in urban and indoor environments due to the multi-path propagation. To enhance the location accuracy and reduce the operation cost within these environments, this paper proposes a novel hybrid location determination technology which combines CELL-ID with the database correlation method. The proposed method generate the prediction database of path loss according to CELL-ID, and after the computation the smallest squared error of measured path loss and the prediction path loss,the location of the mobile terminal is decided by the coordinates of the best matching matrix entry.     

基于并行模式挖掘和路径匹配的用户位置预测

为了提高移动用户位置预测的精度,提出了基于并行模式挖掘和路径匹配的移动用户位置预测方法,对传统的FP-GROWTH算法作了并行化处理,优化了节点负载分配方法,在Spark平台下挖掘用户移动频繁模式.改进了基于索引的路径相似度算法,提出基于路径最短距离的相斥度算法,提高了对轨迹数据缺失的适用性.在真实的用户轨迹数据集上实验表明,提出的基于轨迹相斥度预测方法相比马尔可夫模型和卡尔曼滤波模型拥有更高的预测精度,预测精确度平均提升7%左右.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location, because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.     

3.5 GHz频段城市环境路径损耗特性研究

应用一种基于入射和反弹射线法(shooting-and-bouncing ray, SBR)以及一致性绕射理论(uniform theory of diffraction,UTD)的射线跟踪方法,主要研究了在3.5 GHz频段上发射天线的高度、位置等对城市环境中路径损耗特性的影响。应用SBR实现从发射天线到接收点的射线查找,然后应用UTD计算与每条射线相关的复电场,研究发现,在3.5 GHz频段上,路径损耗特性对发射天线的高度不敏感,而在这一频段改变发射天线的位置会引起路径损耗特性产生很大的改变。对实测值和仿真值进行了比较,比较显示实测值和仿真值吻合得较好,这说明应用基于SBR/UTD的射线跟踪法可以有效预测城市环境中的路径损耗特性。     

基于改进YOLO的虹膜快速定位检测算法

虹膜定位是虹膜识别系统中不可或缺的环节,针对传统的虹膜定位方法对镜面反射、眨眼等复杂环境下质量差的虹膜图像定位准确率低、计算复杂度高和鲁棒性差等问题,提出了一种基于改进YOLOv3模型的虹膜快速定位方法。针对眼周图像中虹膜内、外圆尺寸变化不大,将YOLOv3网络的多尺度结构改进为双尺度检测;引入了轻量级网络Mobilev3中bneck块来改进特征提取网络,减小模型复杂度;利用kmeans++算法对虹膜数据集进行类聚,获得更优的锚点框;模型边框损失函数采用改进的损失函数代替原均方差(MSE)损失函数;利用虹膜特有几何特征,将模型矩形预测框更改为圆形预测框。在CASIA-IrisV4数据集验证表明,改进模型定位准确率为96.32%,mAP为99.37%,检测速度为49.4帧/s,模型参数减少到4.13M。结果表明改进后的模型较小,并且能够快速精准对虹膜区域定位,具有较高鲁棒性,能够满足虹膜实时定位的场景。     

超宽带体域网信道测量及传输特性分析

随着通信技术的发展,高速的近距离超宽带无线体域网受到越来越多的重视。该文采用基于频域的无线信道测量平台,对3～5GHz频率范围的人体范围无线宽带信道进行测量,其中测量环境分为办公室和静室环境,人体模型包括3种不同体型;获得的测量数据通过统计建模,得到了路径损耗模型和功率群延迟模型。对标准模型与本文模型的仿真结果进行比较表明:该模型在平均附加时延、均方根时延扩展、峰值20dB内多径数目等方面更加符合实测数据。     

基于GPS轨迹数据的混合多步Markov位置预测

随着移动设备和定位技术的广泛应用,基于位置服务成为研究热点,位置预测是其重要研究内容.基于GPS轨迹数据,对位置预测方法进行研究.Markov模型可以较好地表示时序数据,因此可较好地用于位置建模和预测.在基于Markov建模的位置预测中,1阶Markov模型存在轨迹信息利用不充分、预测准确率低的问题;而多阶Markov模型存在状态空间急剧膨胀的问题.针对这些问题,提出了基于混合多步Markov模型的位置预测方法,在将原始GPS轨迹转化为区域轨迹的基础上,对各多步模型进行融合,提出了基于Adaboost框架的各多步模型影响系数的生成方法,在保证状态空间不变的情况下提高了预测准确性.真实数据集上的实验验证了所提位置预测方法的有效性.     

两维编码光电检测与识别技术

提出了一种基于光电检测与识别的平面位置检测方法,以此为基础完成了一种新型计算机手写输入系统设计.给出了位置编码算法以及基于图像采集与图像处理的编码识别方法,讨论了光电检测系统的结构及其光路设计,给出了坐标转化及笔的起落检测方法,可以完成书写和绘画等传统鼠标难以完成的功能.     

从Lotus Notes数据库到关系型数据库的数据转换

不同结构的数据环境是一个普遍存在的问题,Windows常用开放数据库互连标准ODBC进行数据交换与操作,而作为目前办公自动化系统的主流开发平台之一的LotusNotesR6使用的是文档型数据库.先从几个方面对文档数据库与关系型数据库进行了比较,指出各自特点,然后给出了一种将文档数据库中信息向关系型数据库中转换的方法.     

基于遗传算法优化的支持向量回归的室内定位算法

基于zigbee接收信号强度指标的室内定位由于成本低,硬件功耗低,易于实现而受到越来越多的关注。为了提高zigbee技术的室内定位精度,减少环境因素的不利影响,本文提出了一种遗传算法优化支持向量回归的室内定位方法。该算法分为离线采集和在线预测两个阶段,离线采集进行指纹数据库的建立,在线预测则根据训练模型进行位置预测。首先所有的采集数据通过卡尔曼滤波进行处理,然后通过遗传算法优化支持向量回归(GA-SVR)的惩罚参数 、RBF核宽度 和损失函数变量 ,从而使支持向量回归达到最好的位置预测性能。在实际场景中的实验结果表明,与PSO-SVR, GS-SVR, SVR和WKNN算法相比,该算法具有较好的定位性能。     

The RCT approach for cell coverage prediction (I): Principles

A new method for the coverage prediction of Cellular Mobile Radio (CMR) system is developed and its basic principle is presented. Unlike the Statistical Prediction Model (SPM) that estimates propagation loss by empirical formulas or the Deterministic Prediction Model (DPM) that reckons propagation loss with analytical expressions, the Radio Computerized Tomography (RCT) method does not seek to express the propagation loss explicitly. The 2-D distribution of propagation loss factor is computed using CT technique, based on measured data collected through drive test under appropriate geometric constraint. The total propagation loss can be obtained by integral of propagation loss factor along the equivalent, ray path. The advantages and limitations of the technique, as well as its implementation are discussed. Biography: Yu Sheng-bing (1974-), male, Ph. D. candidate, research interest: theory analysis and application development of radio propagation in wireless communication systems.     

空区激光探测系统在我国的研究与应用

阐明了空区激光探测系统(CMS)的基本构成和工作原理,分析了井下环境温度、湿度、目标反射率及探测位置等环境因素对CMS探测结果的影响,并提出了相应的解决措施;紧密结合国内各矿山的自身特点,阐述了目前CMS在我国的研究现状,分别从空区信息动态监测、露天塌陷坑探测、采场边界对比分析、顶板安全管理、采场回采贫化损失精确测定、复杂边界矿柱回采爆破设计及实测采空区稳定性数值模拟分析等主要方面对CMS的应用进行了深入研究。研究结果表明,CMS的成功应用为我国矿山空区动态监测及安全预警等相关研究开辟了一条新的有效途径。     

基于地形信息的平流层通信系统传播衰减预测

给出了一种基于地形信息的预测平流层通信系统大尺度衰落的算法，包括地形重建和传播衰减计算，及编程实现的方法，计算出了平流层空中平台到某一区域的大尺度传播衰减，并根据该算法针对地形变化对传播衰减的影响进行了仿真，结果表明，平流层通信系统的传播衰减受地形变化的影响比地面通信系统小得多，在没有平流层通信实测数据的情况下，上述预测算法对仿真通信系统性能具有重要意义。     

H.264/AVC帧内预测器的VLSI实现

提出了一种帧内预测电路的实现方法,在舍弃了平面预测模式情况下,通过多路选择器选择不同加法路径,和大量共用加法器,以较小代价实现了帧内预测所有剩余的预测模式。在基于SMIC CMOS 0.18 μm最坏工艺条件下,电路规模仅为4000门,关键路径延迟为5.7 ns。     

蓝牙4.0标准规范下的模糊指纹定位算法

蓝牙技术的普及以及蓝牙4.0标准规范的提出, 使得利用蓝牙技术实现室内定位具有极其广阔的应用前景.把模糊理论应用于蓝牙室内定位系统, 提出一种模糊指纹定位算法. 基于该算法的定位过程分为离线和在线两个阶段: 离线阶段建立模糊指纹库; 在线阶段对手机客户端进行实时模糊决策定位. 仿真实验结果表明, 该算法的平均定位误差为1.36 m, 相比于传统的指纹标定法, 其定位精度提高约49%, 而计算量缩减至原来的1/c, 其中c为模糊聚类类别数.     

矿井UWB路径损耗模型的构建及仿真

采用射线反射模型预测电波传播损耗,建立了矿井超宽带路径损耗模型,并进行了仿真验证。首先对适合窄带信道的射线反射模型进行了分析和仿真,然后结合超宽带信道的频率依赖特点,对射线反射模型进行了修正,建立了矿井UWB路径损耗预测的镜像法反射模型,并对实际UWB测量矿井环境进行了传播损耗预测,将预测结果进行了最小二乘法参量拟合,得到了与测量结果相符的路径损耗指数,验证了预测结果的正确性。     

In-vehicle GPS/DR navigation system development and test results in Singapore

This paper introduces the in-car navigation system prototype development and test results under the context of Singapore. In the system, integrated GPS/DR is used for continuous vehicle positioning. A digital road network map database is built for the whole Singapore. The database is designed to support map matching, route determination, and route guidance functions. The prototype system demonstrates GPS positioning of the vehicle in real-time, tracking the vehicle onto a digital map with fix updates every one or two seconds.With the map matched vehicle location on the map, voice and/or text guidance is provide to the driver. The vehicle position can also be transferred to control centre through communication data link for the purpose of fleet management.     

对深井冻结凿井中水文孔不溢水问题的分析

通过工程实例,对目前深井冻结工程中的水文孔不溢水原因进行了较详细的分析,提出了应该从水文孔报道层位的设计、水文孔的结构、冻结管的偏斜控制、钻孔的施工质量控制、地下水流速度控制和根据不同工程和地质条件对水文孔溢水时间的预测以及加强冻结信息化监测和分析等方面采取措施,来保证水文孔的正常溢水和冻结井筒按时开挖。     

基于丢包率预测的多路径网络负载均衡策略

为了弥补传统多路径网络负载均衡策略在网络状态改变前无法预先提供相应预测信息的不足,提出了一种基于预测多路径丢包率的负载均衡策略.该策略以主动测量获取的每条路径的丢包率为观察值,采用确定型时间序列预测为预测手段,利用预测的丢包率作为负载分配的依据.此外,在负载均衡的调节中,提出了利用丢包率作为每条路径流量分配比例的惩罚函数,将流量引入丢包率低的路径.分析及仿真结果证明,该策略能有效地均衡负载,减少网络的丢包率.