利用TM图像进行干旱荒漠带牧区土地资源调查

选用TM卫片作为调查基础资料,结合地形图和局部地区大比例尺航片,完成了甘肃河西地域三个牧业县的土地利用现状调查,为遥感技术在干旱荒漠地带牧区进行土地资源调查找出了效果好、经济的方法。     

Linear mixture model applied to Amazonian vegetation classification

Many research projects require accurate delineation of different secondary succession (SS) stages over large regions/subregions of the Amazon basin. However, the complexity of vegetation stand structure, abundant vegetation species, and the smooth transition between different SS stages make vegetation classification difficult when using traditional approaches such as the maximum likelihood classifier (MLC). Most of the time, classification distinguishes only between forest/non-forest. It has been difficult to accurately distinguish stages of SS. In this paper, a linear mixture model (LMM) approach is applied to classify successional and mature forests using Thematic Mapper (TM) imagery in the Rondônia region of the Brazilian Amazon. Three endmembers (i.e., shade, soil, and green vegetation or GV) were identified based on the image itself and a constrained least-squares solution was used to unmix the image. This study indicates that the LMM approach is a promising method for distinguishing successional and mature forests in the Amazon basin using TM data. It improved vegetation classification accuracy over that of the MLC. Initial, intermediate, and advanced successional and mature forests were classified with overall accuracy of 78.2% using a threshold method on the ratio of shade to GV fractions, a 7.4% increase over the MLC. The GV and shade fractions are sensitive to the change of vegetation stand structures and better capture biophysical structure information.     

Improved wetland remote sensing in Yellowstone National Park using classification trees to combine TM imagery and ancillary environmental data

The U.S. Fish and Wildlife Service uses the term palustrine wetland to describe vegetated wetlands traditionally identified as marsh, bog, fen, swamp, or wet meadow. Landsat TM imagery was combined with image texture and ancillary environmental data to model probabilities of palustrine wetland occurrence in Yellowstone National Park using classification trees. Model training and test locations were identified from National Wetlands Inventory maps, and classification trees were built for seven years spanning a range of annual precipitation. At a coarse level, palustrine wetland was separated from upland. At a finer level, five palustrine wetland types were discriminated: aquatic bed (PAB), emergent (PEM), forested (PFO), scrub-shrub (PSS), and unconsolidated shore (PUS). TM-derived variables alone were relatively accurate at separating wetland from upland, but model error rates dropped incrementally as image texture, DEM-derived terrain variables, and other ancillary GIS layers were added. For classification trees making use of all available predictors, average overall test error rates were 7.8% for palustrine wetland/upland models and 17.0% for palustrine wetland type models, with consistent accuracies across years. However, models were prone to wetland over-prediction. While the predominant PEM class was classified with omission and commission error rates less than 14%, we had difficulty identifying the PAB and PSS classes. Ancillary vegetation information greatly improved PSS classification and moderately improved PFO discrimination. Association with geothermal areas distinguished PUS wetlands. Wetland over-prediction was exacerbated by class imbalance in likely combination with spatial and spectral limitations of the TM sensor. Wetland probability surfaces may be more informative than hard classification, and appear to respond to climate-driven wetland variability. The developed method is portable, relatively easy to implement, and should be applicable in other settings and over larger extents.     

Microstructural Modelling of Nb Microalloyed Steels during Thin Slab Direct Rolling Processing

The microstructural evolution during the hot rolling of coarse grain sized austenite has been modeled considering all the microstructural mechanisms (dynamic, static and metadynamic recrystallization, strain induced precipitation) that can take place during an industrial TSDR production of three Nb microalloyed steels. Based on the results obtained from the model, processing maps have been drawn for 0.02%, 0.035% and 0.05% Nb microalloyed steels. Optimum processing conditions to exploit all the benefits of the Nb microalloying have been defined considering a final gauge thickness range between 1.5 and 12.65 mm. In addition, and facing the difficulties present in the production of thick hot strip, several alternative thermomechanical schedules are proposed, which would originate microstructures with a suitable combination of homogeneity and retained strain prior to transformation.     

一种基于Google Maps的土地利用信息发布平台

目前常见的Web地图服务仅支持浏览和查询,不支持矢量数据的发布.文章提出一种基于Google Maps的WebGIS构建方法,支持多种浏览器的矢量数据互操作及空间分析.针对郑州市土地利用信息发布需求,采用B/S架构,借助Google Maps API和AJAX技术,实现了土地利用信息系统化,标准化发布平台.该平台响应速度快,面向多种用户,支持数据共享,能更好的为土地利用变化研究及土地整理决策提供服务.     

基于Android手机的人员定位与管理系统

提出来一种基于Android手机系统和Windows平台的人员定位与管理系统。该系统使用Android手机采集人员的位置和通信信息,通过手机GPRS网络将信息传送给服务器。管理者通过浏览程序访问服务器,获取人员的位置信息及与特定人员进行通信。系统是使用手机移动设备对人员进行管理的初步尝试,并且能建立高效的人员管理程序。     

基于MapXtreme的数字校园房管系统的开发

校园规模在不断地扩大,校园房屋管理规划部门对日益更新和迅速增加的建筑物房屋信息的管理与维护愈感困难,而现有的系统对空间数据与属性数据没有很好集成,更不利于图文信息的相互查询、检索和更新等。针对如上现实问题,应用MapInfo平台中的WebGIS技术,即MapXtreme技术,以及UML统一建模技术和SQL Server数据库等技术,成功地实现了数字校园房屋管理系统设计与开发,解决了房管部门面临的查询搜索更新校园建筑房屋信息时效率低下、管理与维护困难等实际问题。     

基于数据仓库的销售数据可视化分析系统

为了辅助销售管理者充分利用已有的历史销售数据,快速直观地捕获敏感数据,及时准确地把握市场行情,研究了以数据仓库为分析平台,根据销售数据具有的地理特征,结合Google提供的Google Maps API（Application Program Interface）,将OLAP（Online Analytical Processing）的分析操作映射到地图具有的交互操作上的可视化分析系统。并基于实际案例着重设计并优化了数据仓库架构,为系统应用开发奠定了良好的基础。实践证明,系统有效提高了销售管理部门的统筹决策的效率及能力,为企业创造了更大的经济效益。     

基于Krpano的全景校园漫游的设计与实现

在数字校园建设和发展中,以虚拟全景校园漫游为基础的校园信息化平台能够为师生提供全新的沉浸式浏览体验,并提供更集中的信息交互功能。虚拟现实技术能够真实地再现现实环境,通过交互式操作,用户可以获得与真实环境相似的感受和体验,其中全景漫游是虚拟现实技术的一种典型应用。该文以南开大学滨海学院为实践区域,基于Krpano平台,利用Google Maps地图服务,采用全景图制作技术、SQL数据库技术和计算机网络技术搭建了一个虚拟全景校园漫游系统,并可跨系统、跨设备使用。系统实现了2D校园全景和谷歌地图信息服务功能,并提供了搭载陀螺仪传感器的可穿戴式VR设备使用的WebVR全景显示,满足了数字校园分布式、便于使用的需求。实践证明了基于Krpano框架设计能深度定制虚拟全景校园漫游系统的相关功能,能有效开发并拓展系统,并具有重要的实践意义。     

规划专题影像地图的概念重构与视觉融合设计

针对空间规划领域中专题影像地图的制图应用,对影像地图的分类体系、规划专题影像的制图框架及其中影像的功能角色等进行概念重构,并提出以"矢量与栅格、基础与专题"等关系的处理为核心,以色彩配置、符号构形、构图整饰为主体,以视觉变量协调为关键的视觉融合设计策略;示例证明能够有效指导对规划方案概念的系统表达。