人脸识别中基于核的子空间鉴别分析

尽管基于Fisher准则的线性鉴别分析被公认为特征抽取的有效方法之一，并被成功地用于人脸识别，但是由于光照变化、人脸表情和姿势变化，实际上的人脸图像分布是十分复杂的，因此，抽取非线性鉴别特征显得十分必要。为了能利用非线性鉴别特征进行人脸识别，提出了一种基于核的子空间鉴别分析方法。该方法首先利用核函数技术将原始样本隐式地映射到高维（甚至无穷维）特征空间；然后在高维特征空间里，利用再生核理论来建立基于广义Fisher准则的两个等价模型；最后利用正交补空间方法求得最优鉴别矢量来进行人脸识别。在ORL和NUST603两个人脸数据库上，对该方法进行了鉴别性能实验，得到了识别率分别为94％和99．58％的实验结果，这表明该方法与核组合方法的识别结果相当，且明显优于KPCA和Kernel fisherfaces方法的识别结果。     

基于多时相图谱的土地利用变化特征分析

运用地学信息图谱结合多时相遥感数据复合分析方法,对土地利用动态变化过程和空间分布特征进行定量化研究.土地利用变化图谱的构建能够获取土地利用变化的种类、数量和空间分布特征,为探索土地利用变化的成因、过程提供重要的科学依据.本文以分析东莞市近20年来的土地利用变化特征为例.利用多时相遥感分类数据,构建了5个时序单元的(1988～1993、1993～1997、1997～2001、2001～2006、1988～2006年)土地利用变化图谱,并系统地分析了东莞市18年来土地利用的时空演变过程及空间分异规律.研究结果表明,1988年以来,东莞市土地利用急剧变动,其中以大量农田被侵占转化为城市用地最为显著,农业内部结构也发生了调整;从空间格局上看,被侵占的农田主要集中于交通干线两旁.利用GIS空问分析技术对农田流失与道路之间的关系进行定量研究,揭示了农田流失的区位效应.     

尺度分布的Getis统计对遥感图像特征参量空间自相关性的研究

分析了Getis统计中空间尺度设定对于标准Z值的影响，提出用变化的空间尺度设定来进行Gctis空间相关性的计算，直观反映遥感特征参量的空间分布，并用被动微波遥感SSM／I（special sensor microwave／imager）的辐射亮度温度数据进行了验证分析。进一步地，针对Getis标准Z值分布不能评估中值聚类的缺点，提出了多层尺度分布的Getis空间自相关性统计方法，用模拟的图像和主动微波遥感ERS-2SAR（European Remote Sensing-2 Synthetic Aperture Radar）数据进行了验证分析，结果证明多层尺度分布的Getis能够比较全面地反映地表特征参量分布的空间信息。     

山地地貌地表温度的深度学习空间模拟

针对在山地地貌下环境因子与地表温度(land surface temperature, LST)之间存在的空间特征问题,提出利用深度学习方法分析LST在不同植被情景下与环境因子的关系特征。结合山地LST的影响因素和模型特点,构建大青山LST预测模拟模型,利用模型做LST与环境因子变化分析。结果表明：构建的LST深度学习模型预测值与观测值空间分布特征吻合度高(R²为0.89,MAE为0.60℃,MSE为0.65℃);LST随NDVI、海拔和坡度的增加而降低,随平均气温和地表反照率的增加而增加;随NDVI的增大,LST随各环境因子变化的速率变化不同。研究表明,利用深度学习方法预测山地地貌LST的空间分布具有可行性,该方法有助于理解山地环境因子与LST的空间分布关系。     

基于RTI的城市热岛效应变化分析研究-乌鲁木齐市为例

以乌鲁木齐市区为例，利用Landsat TM/ETM+第6波段数据反演地表温度,并计算出其相对温度指数(RTI)。从气温相对性、动态性的角度，对其相对温度指数的变化分布模式进行分析，得出城市热岛的变化特征及其空间分布规律。该方法避免了下垫面复杂性及地-气模型建立的困难性等因素对城市热岛效应变化分析研究的影响。     

中国人口分布及空间相关分析

利用2000年人口普查信息，介绍了在人口地理信息系统中，通过三维模型显示，罗伦斯曲线，人口重心和人口潜力等方法，分析中国人口分布的特征。在此基础上，用空间相关方法对人口分布的现象进行分析，揭示了其空间地理分布的内在联系。     

降水时空关联特征可视分析

目的 降水是影响全球气候变化和系统环境的重要因素,面向降水数据开展时空关联分析,对于区域气候特征探索及异常情况监测具有重要的意义。然而,降水时空关联特征的分析是一个复杂且耗时的过程,与气象站点的空间分布以及降水的时间序列密切相关。本文综合考虑降水的时空变化特征,研究和设计面向降水数据时空关联特征分析的可视化系统工具。方法 利用地图和矩阵图呈现降水数据的空间分布和周期变化特征,设计径向盒须图对降水数据的时空变化异常特征进行捕获;通过局部Moran''s I指数的计算和热力图的呈现表达降水的空间相关性,支持用户交互式地探索空间相关性的时序变化特征;利用普通克里金插值模型获得降水空间插值图,并对插值结果的准确性进行可视化评估。结果 以中国安徽省1971-2014年气象观测站长时间序列月降水数据集为例进行分析,实验结果证明本研究可视化交互系统能够直观高效地探索区域降水长时间序列时空变化特征和极端降水情况;有效探究区域降水空间分布模式、不同站点降水信息间空间依赖性和异质性,并快速发现降水奇异点;分析区域不同时间尺度降水气候特征空间变化。结论 系统工具集成便捷的交互模式,支持用户探索式地分析降水数据的时空关联特征,进而有效地探究区域气候变化规律和特征分布关系。基于真实降水数据的实验结果以及降水领域专家的反馈,进一步验证了本文系统工具的有效性和实用性。     

计算机三维电磁辐射场可视化系统

计算机三维电磁辐射场可视化系统由三维电磁辐射场造型、场强空间向颜色空间的映射、视觉模型的建立、图象合成计算、图象增强处理、等位面提取、磁力线模型求取、辐射源模型立体图生成、场整体分布图象生成、场在任意截面上分布图象生成以及场在特征球面上最大场强的动态采样与在特征球面上分布状况的动态显示、频率－场强特性曲线的生成等模块组成。本文就其系统结构各模块功能及特点作了介绍。     

结合轮廓与姿态的时空融合步态识别方法

现有的大多数步态识别方法是基于轮廓的步态识别方法，然而轮廓容易受到遮挡的影响，从而导致识别准确率下降。在现实的监控场景下，遮挡几乎是不可避免的，提高遮挡情况下的步态识别精度是算法能够“落地”于实际应用的前提。针对此问题，提出了结合轮廓与姿态的时空融合步态识别方法。利用姿态具有抵抗遮挡的能力，设计多模态空间特征融合模块，利用特征重用策略和模态融合策略以提高空间特征的信息容量；设计多尺度时间特征提取模块，利用独立分支提取不同时间尺度下的时间信息，提出一种基于注意力的特征融合策略以自适应地整合时间信息；设计空间特征集合分支，以深监督方式提高时空特征的表达能力。在公开数据集上的实验结果表明了所提方法的有效性，模型在遮挡情况下具有较好的鲁棒性。     

基于智能导向的城市交通空间规划系统设计

针对城市交通空间在规划过程中受到车辆类型的影响,导致其规划效果变差,以提高城市交通空间规划效果为目的,设计了基于智能导向的城市交通空间规划系统.在智能导向的基础上,利用数据采集模块、Web服务器设计及MapObject组件设计,通过预测城市交通空间分布格局变化和城市交通空间的规划流程,实现了城市交通空间的规划.测试结果...     

Positional accuracy, positional uncertainty, and feature change detection in historical maps: Results of an experiment

The measurement and management of positional accuracy and positional uncertainty is especially problematic in historical cartography and Historical GIS applications, for at least two reasons: first, historical sources, and especially historical maps, generally carry a higher degree of positional inaccuracy and uncertainty compared to contemporary geographic databases; second, it is always difficult and often impossible to reliably measure the positional accuracy and positional uncertainty of the spatial attribute of historical data. As an added complication, the terms “inaccuracy” and “uncertainty” are often used as synonyms in the literature, with relatively little attention given to issues of uncertainty.In this article we propose a methodology for detecting the positional inaccuracy and positional uncertainty of measurements of urban change using historical maps at a very high spatial resolution (the building). A widely accepted and routinely employed method for detecting urban change, and spatial change in general, consists in overlaying two or more maps created at different dates, but the technique can lead to the formation of spurious changes—typically, sliver polygons—that are the product of misclassification error or map misalignment rather than actual modifications in land cover. In this paper we develop an algorithm to detect such spurious changes. More in general, we extend the discussion to examine the effects of positional uncertainty and positional inaccuracy in feature change detection analysis. The case-study is the city of Milan, Italy.     

基于3S技术的土地利用/土地覆盖变化野外采样框架设计 ——以东北地区黑龙江省为例

土地利用/土地覆盖变化是全球环境变化的重要组成部分,随着3S技术的不断成熟和发展,运用RS、GPS和GIS技术进行土地利用/土地覆盖变化研究已成为一种越来越成熟的方式和手段。从空间抽样模型理论出发,以我国黑龙江省为例,运用RS、GPS和GIS技术,通过对黑龙江省道路网、土地利用区划、土地利用/土地覆盖类型、土地利用/土地覆盖1 km×1 km格网数据等空间信息分布的综合考虑、分析,设计了土地利用/土地覆盖变化的综合野外采样框架。框架主要包括采样区的布设、采样路线和采样点的选择等。由于以多层空间信息为采样依据,经实践检验,该采样框架具有经济实用等优点。     

Land-use change analysis in Yulin prefecture,northwestern China using remote sensing and GIS

Rapid land-use change has taken place in many arid and semi-arid regions of China such as Yulin prefecture over the last decade due to rehabilitation measures. In this paper, land-use change dynamics were investigated by the combined use of satellite remote sensing and geographical information systems (GIS). Our objectives were to determine land-use transition rates among land-use types in Yulin prefecture over 14 years from 1986-2000 and to quantify the changes of various landscape metrics using FRAGSTATS, the spatial pattern analysis program for Categorical Maps. Using 30-m resolution Landsat Thematic Mapper (TM) data from the Institute of Remote Sensing Application (IRSA) in China, we classified images into six land-use types: cropland, forestland, grassland, water, urban and/or built-up land, and barren land. Significant changes in land-use occurred within the area over the study period. The results show the significant decrease in barren land was mainly due to conversion to grassland. Cropland increased by 3.39%, associated with conversions from grassland and barren land. The landscape has become more continuous, clumped and more homogeneous. The study demonstrates that the integration of satellite remote sensing and GIS was an effective approach for analysing the direction, rate and spatial pattern of land-use change.     

基于城镇居民用地再分类的人口数据空间化方法研究——以长江中游4省为例

基于土地利用数据的人口统计数据空间化方法,在处理过程中会出现同一土地利用类型下人口难以细分的情况,从而影响人口空间数据精度。引入夜间灯光信息并提出了一种基于夜间灯光强度对城镇居民地再分类的人口空间化方法,以改善人口空间数据精度。基于DMSP/OLS夜间灯光及土地利用数据,以长江中游4省为研究区进行方法试验。研究结果显示:利用夜间灯光数据对城镇居民地再分类后,各分区模型的调整R2都提高到了0.8以上,人口空间数据总体平均相对误差较重分类前降低了12.32%。说明该方法在提高传统人口数据空间化模型精度的基础上能够细化城镇居民地人口空间分布。     

Map data processing in geographic information systems

An overview of geographic information systems (GISs) is given, covering data collection, applications, organization, and data models. Recent trends in map data processing are examined, namely, automatic name placement, map generalization, an automatic digitizer and expert system for land-use analysis, a map oriented system for urban planning, and a knowledge-based GIS. Techniques for extracting information from paper-based images are discussed, and some experimental results are given     

A GIS-based approach to spatial allocation of area source solvent emissions

Current area source emission inventories estimate total emissions for various industrial, commercial, and consumer activities at the county or higher levels. The lack of emission estimates at subcounty levels severely limits the modeling and planning capabilities in urban and regional air quality management. This paper extends current area source emission inventory methodology by developing a geographical information system (GIS) based approach for allocating county-level emission estimates to subcounty units. The new methodology uses GIS to develop and integrate spatial data, to analyze spatial variations in emissions, and to derive input to cell-based air pollution models. This approach incorporates statistical models to predict the spatial distribution of emission source activities based on widely available data. The paper presents an application of the proposed approach to emission inventory of the adhesives and sealants category in the Sacramento modeling region, California.     

基于GIS的城市土地利用分析与建模框架研究

本文针对城市土地利用数据的时空特性,依托地理信息系统(GIS)丰富的空间分析工具以及对海量空间数据的高性能计算优势,围绕城市土地利用研究有关数据的处理、分析、建模等方面问题设计了一个基于GIS的城市土地利用分析与建模框架;框架主体结构中有关城市土地利用变化的驱动力机制建模方法选取逻辑回归模型,对地理数据的空间自相关性处理则根据Getis自相关系数构建滤波模型;具体应用则结合深圳市国土资源局的"城市土地利用虚拟政策实验室"项目,取得良好效果     

基于GIS的城市电磁环境仿真平台实现

针对城市电磁环境的特点,根据各种电磁波传播模型的适用环境,选择合适的模型并加以改进,精确地计算出给定条件下的城市电磁场强度分布。通过Visual C++6.0编程并利用GIS控件在城市三维地图绘制电磁场强度分布图,实现了城市电磁环境监测系统仿真平台,为电磁污染的防护和治理提供依据和指导。     

Fine spatial resolution residential land-use data for small-area population mapping: a case study in Riyadh,Saudi Arabia

Rapid growth in the world’s urban population presents many challenges to planning and service provision. Conventional sources of population data often fail to provide spatially and temporally detailed information on changing urban populations. While downscaling methods have helped bridge this gap, use of fine spatial resolution data coupled with object-based image analysis (OBIA) methods is relatively novel, and few studies exist outside the western, developed world. This article presents a study in Riyadh, Saudi Arabia, in which population distribution estimates were obtained by downscaling using detailed residential land-use classes derived from the application of OBIA to fine spatial resolution remotely sensed imagery. To assess the utility of these data for population downscaling, three statistical regression models (using built area, residential built area, and detailed residential built area) and two dasymetric areal interpolation models (using residential built area and detailed residential built area) were applied to downscale the density of dwelling units, prior to estimating the population distribution through a simple transform. The research suggests that, for regression, the proportion of residential land use (Model 2) increased the accuracy over built area proportion (Model 1), and, in a multivariate extension, the proportions of six separate residential land-use classes (Model 3) increased the accuracy further, thereby demonstrating the value of the fine spatial resolution imagery. For example, the actual number of dwelling units was 7771 and the estimated numbers of dwelling units of Models 1 and 3 were 10,598 and 8759, respectively. Moreover, the root mean square error (RMSE) was 5.9 for Model 1 and 2.6 for Model 3. Additionally, six-class dasymetric mapping was evaluated in comparison to the conventional binary dasymetric mapping approach. The six-class dasymetric mapping approach was found to be slightly more accurate than binary dasymetric mapping.     

Monitoring land-use change in the Pearl River Delta using Landsat TM

The Pearl River Delta in the People's Republic of China is experiencing rapid rates of economic growth. Government directives in the late 1970s and early 1980s spurred economic development that has led to widespread land conversion. In this study, we monitor land-use through a nested hierarchy of land-cover. Change vectors of Tasseled Cap brightness, greenness and wetness of Landsat Thematic Mapper (TM) images are combined with the brightness, greenness, wetness values from the initial date of imagery to map four stable classes and five changes classes. Most of the land-use change is conversion from agricultural land to urban areas. Results indicate that urban areas have increased by more than 300% between 1988 and 1996. Field assessments confirm a high overall accuracy of the land-use change map (93.5%) and support the use of change vectors and multidate Landsat TM imagery to monitor land-use change. Results confirm the importance of field-based accuracy assessment to identify problems in a land-use map and to improve area estimates for each class.