基于新型地理信息系统的急性心肌梗死空间数据地图建设研究

目的探讨基于新型地理信息系统的急性心肌梗死空间数据地图建设。方法选择2016年1月至2018年5月佛山市南海区发病的胸痛患者2313例作为研究对象,根据佛山市南海区下辖镇街进行分组:桂城街道组、里水镇组、九江镇组、丹灶镇组、大沥镇组、狮山镇组、西樵镇组。所有患者入院后立即进入“急性胸痛绿色通道”,在患者到达急诊科10 min完成初步评估,并完成患者心肌损伤标志物测定与心电图检查,记录患者发病时间,根据患者的住院病历号提取相关信息进行建图、分析,建立AMI发病数据库。结果AMI患者2313例中,男1654例,女659例。其中,桂城街道组380例、里水镇组315例、九江镇组177例、丹灶镇组152例、大沥镇组497例、狮山镇组641例、西樵镇组151例;2016年1月至2018年5月南海区发病的胸痛患者2313例,发病率前3位的分别为:狮山镇、大沥镇、桂城街道,分别占:27.7%、21.5%和16.4%;空间自相关性分析结果表明,南海地区AMI患者发病具有群体聚集性,即在某些村镇AMI发病例数明显增多。结论佛山市南海区心肌梗死发病存在地区分布规律,加强空间数据地图建设能发现急性心肌梗死救治延误高发区,能为临床有效防控提供依据。

基于WebGIS的空间数据更新技术研究

在分析WebGIS环境中空间数据更新内容的基础上,本文首先探讨了在WebGIS中空间数据更新所涉及的关键技术,并研究了空间数据更新主要采用的技术路线,进而探讨了基于地图服务的更新技术,为网络环境下空间数据的更新提供了新的思路。

A CADASTRAL SPATIAL DATA STORAGE STRUCTURE BASED ON RELATIONAL DATABASE

This paper presents a cadastral spatial data storage structure based on relational database,the method and the procedure to realize it.The paper consists of three parts.In the first part,some existing problems in some developed cadastral management systems are discussed.These problems are the following four.1) The security of cadastral spatial data is difficult to be assured.2) It is difficult to varify cadastral data and the integrality of cadastral data is difficult to be kept.3) To transmit and share cadastral data is difficult.4) The efficiency of data access is low.In the second part,the feasibility of using relational database to store spatial data is analyzed and a new cadastral spatial data storage structure is presented.At the same time,the related table structures and field descriptions are given,and then the merits and demerits of this storage structure are analyzed in detail.In the last part,through a real example,the detailed methods to make the new storage structure a reality are given.Moreover,some involving key techniques of the new storage structure are discussed.These techniques are:1) the application of database transaction,2) the application of database trigger,3) and the application of secure recovery of database.

Digital Watermark-based Security Technology for Geo-spatial Graphics Data

The paper presents a set of techniques of digital watermarking by which copyright and user rights messages are hidden into geo-spatial graphics data,as well as techniques of compressing and encrypting the watermarked geo-spatial graphics data.The technology aims at tracing and resisting the illegal distribution and duplication of the geo-spatial graphics data product,so as to effectively protect the data producer＇s rights as well as to facilitate the secure sharing of geo-spatial graphics data.So far in the CIS field throughout the world,few researches have been made on digital watermarking.The research is a novel exploration both in the field of security management of geo-spatial graphics data and in the applications of digital watermarking technique.An application software employing the proposed technology has been developed.A number of experimental tests on the 1：500,000 digital bathymetric chart of the South China Sea and 1：10,000 digital topographic map of Jiangsu Province have been conducted to verify the feasibility of the proposed technology.

Application of RgMap system on digital regional geological survey

Digital geological mapping fundamentally broke through the traditional working pattern,successfully carried out the geological mapping digitalization.By using the RGMAP system to field digital geological mapping,the authors summarized the method of work and the work flow of the RGMAPGIS during the field geological survey.First,we prepared material,set up the PRB gallery,then put the geographic base map under the background maplayer and organizing the field hand map,forming the field factual datum map.At last,the geological space database is formed.

Measurement of Similarity for Spatial Directions Between Areal Objects

Similarity for spatial directions plays an important role in GIS. In this paper, the conventional approaches are analyzed. Based on raster data areal objects, the authors propose two new methods for measuring similarity among spatial directions. One is to measure the similarity among spatial directions based on the features of raster data and the changes of distances between spatial objects, the other is to measure the similarity among spatial directions according to the variation of each raster cell centroid angle. The two methods overcome the complexity of measuring similarity among spatial directions with direction matrix model and solve the limitation of small changes in direction. The two methods are simple and have broader applicability.

A multi-resolution global land cover dataset through multisource data aggregation

Recent developments of 30 m global land characterization datasets （e.g., land cover, vegetation continues field） represent the finest spatial resolution inputs for global scale studies. Here, we present results from further improvement to land cover map- ping and impact analysis of spatial resolution on area estimation for different land cover types. We proposed a set of methods to aggregate two existing 30 m resolution circa 2010 global land cover maps, namely FROM-GLC （Finer Resolution Observa- tion and Monitoring-Global Land Cover） and FROM-GLC-seg （Segmentation）, with two coarser resolution global maps on development, i.e., Nighttime Light Impervious Surface Area （NL-ISA） and MODIS urban extent （MODIS-urban）, to produce an improved 30 m global land cover map-FROM-GLC-agg （Aggregation）. It was pos-processed using additional coarse res- olution datasets （i.e., MCD12Q1, GlobCover2009, MOD44W etc.） to reduce land cover type confusion. Around 98.9% pixels remain 30 m resolution after some post-processing to this dataset. Based on this map, majority aggregation and proportion ag- gregation approaches were employed to create a multi-resolution hierarchy （i.e., 250 m, 500 m, 1 km, 5 km, 10 km, 25 km, 50 km, 100 km） of land cover maps to meet requirements for different resolutions from different applications. Through accuracy assessment, we found that the best overall accuracies for the post-processed base map （at 30 m） and the three maps subse- quently aggregated at 250 m, 500 m, 1 km resolutions are 69.50%, 76.65%, 74.65%, and 73.47%, respectively. Our analysis of area-estimation biases for different land cover types at different resolutions suggests that maps at coarser than 5 km resolution contain at least 5% area estimation error for most land cover types. Proportion layers, which contain precise information on land cover percentage, are suggested for use when coarser resolution land cover data are required.