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1.
Modeling chronic and infectious diseases entails tracking and describing individuals and their attributes (such as disease status, date of diagnosis, risk factors and so on) as they move and change through space and time. Using Geographic Information Systems, researchers can model, visualize and query spatial data, but their ability to address time has been limited by the lack of temporal referencing in the underlying data structures. In this paper, we discuss issues in designing data structures, indexing, and queries for spatio-temporal data within the context of health surveillance. We describe a space-time object model that treats modeled individuals as a chain of linked observations comprised of an ID, space-time coordinate, and time-referenced attributes. Movement models for these modeled individuals are functions that may be simple (e.g. linear, using vector representation) or more complex. We present several spatial, temporal, spatio-temporal and epidemiological queries emergent from the data model. We demonstrate this approach in a representative application, a simulation of the spread of influenza in a hospital ward.This research was supported by grant R44ES010220 from the National Institute of Environmental Health Sciences (NIEHS) and by grants R01CA092669 and R01CA96002 from the National Cancer Institute (NCI). The content of this paper does not necessarily represent the official views of the NIEHS or the NCI.  相似文献   

2.
This paper deals with the extension of internet-based geographic information systems with functionality for exploratory spatial data analysis (esda). The specific focus is on methods to identify and visualize outliers in maps for rates or proportions. Three sets of methods are included: extreme value maps, smoothed rate maps and the Moran scatterplot. The implementation is carried out by means of a collection of Java classes to extend the Geotools open source mapping software toolkit. The web based spatial analysis tools are illustrated with applications to the study of homicide rates and cancer rates in U.S. counties.This research was supported in part by a number of grants from the US National Science Foundation: NSF Grant SBR-9410612, BCS-9978058, to the Center for Spatially Integrated Social Science (csiss), and a grant from the National Consortium on Violence Research (ncovr is supported under grant SBR-9513040 from the National Science Foundation). In addition, support was provided by grant RO1 CA 95949-01 from the National Cancer Institute. Special thanks to Dr. Eugene J. Lengerich of the Pennsylvania State Cancer Institute for providing the data on colon cancer diagnoses.  相似文献   

3.
A thorough assessment of human exposure to environmental agents should incorporate mobility patterns and temporal changes in human behaviors and concentrations of contaminants; yet the temporal dimension is often under-emphasized in exposure assessment endeavors, due in part to insufficient tools for visualizing and examining temporal datasets. Spatio-temporal visualization tools are valuable for integrating a temporal component, thus allowing for examination of continuous exposure histories in environmental epidemiologic investigations. An application of these tools to a bladder cancer case-control study in Michigan illustrates continuous exposure life-lines and maps that display smooth, continuous changes over time. Preliminary results suggest increased risk of bladder cancer from combined exposure to arsenic in drinking water (>25 g/day) and heavy smoking (>30 cigarettes/day) in the 1970s and 1980s, and a possible cancer cluster around automotive, paint, and organic chemical industries in the early 1970s. These tools have broad application for examining spatially- and temporally-specific relationships between exposures to environmental risk factors and disease.This study was supported by grant R01 CA96002-10, Geographic-Based Research in Cancer Control and Epidemiology, from the National Cancer Institute. Development of the STISTM software was funded by grants R43 ES10220 from the National Institutes of Environmental Health Sciences and R01 CA92669 from the National Cancer Institute. Access to cancer case records was provided by Michigan Cancer Surveillance Program within the Division for Vital Records and Health Statistics, Michigan Department of Community Health. The authors thank Michigan Public Health Institute for conducting the telephone interview and Stacey Fedewa and Lisa Bailey for entering written surveys into a database. The authors thank 3 anonymous reviewers for their helpful comments.  相似文献   

4.
This paper presents the first application of spatially correlated neutral models to the detection of changes in mortality rates across space and time using the local Morans I statistic. Sequential Gaussian simulation is used to generate realizations of the spatial distribution of mortality rates under increasingly stringent conditions: 1) reproduction of the sample histogram, 2) reproduction of the pattern of spatial autocorrelation modeled from the data, 3) incorporation of regional background obtained by geostatistical smoothing of observed mortality rates, and 4) incorporation of smooth regional background observed at a prior time interval. The simulated neutral models are then processed using two new spatio-temporal variants of the Morans I statistic, which allow one to identify significant changes in mortality rates above and beyond past spatial patterns. Last, the results are displayed using an original classification of clusters/outliers tailored to the space-time nature of the data. Using this new methodology the space-time distribution of cervix cancer mortality rates recorded over all US State Economic Areas (SEA) is explored for 9 time periods of 5 years each. Incorporation of spatial autocorrelation leads to fewer significant SEA units than obtained under the traditional assumption of spatial independence, confirming earlier claims that Type I errors may increase when tests using the assumption of independence are applied to spatially correlated data. Integration of regional background into the neutral models yields substantially different spatial clusters and outliers, highlighting local patterns which were blurred when local Morans I was applied under the null hypothesis of constant risk.This research was funded by grants R01 CA92669 and 1R43CA105819-01 from the National Cancer Institute and R43CA92807 under the Innovation in Biomedical Information Science and Technology Initiative at the National Institute of Health. The views stated in this publication are those of the authors and do not necessarily represent the official views of the NCI. The authors also thank three anonymous reviewers for their comments that helped improve the presentation of the methodology.  相似文献   

5.
This article describes the Cancer Atlas Viewer: free, downloadable software for the exploration of United States cancer mortality data. We demonstrate the software by exploring spatio-temporal patterns in colon cancer mortality rates for African-American and white females and males in the southeastern United States over the period 1970–1995. We compare the results of two cluster statistics: the local Moran and the local G*, through time. Overall, the two statistics reach similar conclusions for most locations. Where they disagree reveals functional differences in the kinds of local spatial variation to which the statistics are sensitive and identifies some interesting patterns in the data. There are only two persistent clusters of colon cancer mortality through time, and these are clusters of low values.This project was funded by grant CA92669 from the National Cancer Institute to BioMedware, Inc. The perspectives stated in this article are those of the authors and do not necessarily represent the official views of the National Cancer Institute. Constructive criticism from Heidi Durbeck of BioMedware, Peter Rogerson of SUNY-Buffalo, and three anonymous reviewers helped us improve the interpretation and presentation of these results.  相似文献   

6.
Geographic Information Systems (GIS) technology has had its genesis in the sophisticated computational context of research laboratories and commerical computing. Proprietary packages and a plethora of peripherals present problems in propagating GIS technology, both in developing countries and in conventional classroom settings. GISTARS (Geographic Information STARter System) is a training package developed under the auspices of the Office for Remote Sensing of Earth Resources at Penn State University by the author with support from USAID/India to promte interest in and understanding of GIS technology. It runs on generic PC‐compatible microcomputers having one or more diskette drives and a CGA card. A simple analog overlay device has been developed for converting source maps to digital form, so that training can be conducted without an electric digitizer. Documentation/tutorials are self‐contained. The software in executable form is non‐proprietary and may be freely copied and redistributed. It has served as the basis for a series of introductory GIS workshops given by the author in India.  相似文献   

7.
This paper outlines exploratory research undertaken by the “A New Sense of Place?” Project in Bristol, UK, into the potential new, location sensitive, computing technologies may have for enhancing urban children's socio‐spatial practices. The paper describes a series of workshops held with children in which mapping activities and use of the technologies are supported by the use of a Geographic Information System (GIS). The paper suggests that sound‐enabled GIS could play a major role in the management of such technologies.  相似文献   

8.
When assessing maps consisting of comparable regional values, it is of interest to know whether the peak, or maximum value, is higher than it would likely be by chance alone. Peaks on maps of crime or disease might be attributable to random fluctuation, or they might be due to an important deviation from the baseline process that produces the regional values. This paper addresses the situation where a series of such maps are observed over time, and it is of interest to detect statistically significant deviations between the observed and expected peaks as quickly as possible. The Gumbel distribution is used as a model for the statistical distribution of extreme values; this distribution does not require the underlying distributions of regional values to be either normal, known, or identical. Cumulative sum surveillance methods are used to monitor these Gumbel variates, and these methods are also extended for use when monitoring smoothed regional values (where the quantity monitored is a weighted sum of values in the immediate geographical neighborhood). The new methods are illustrated by using data on breast cancer mortality for the 217 counties of the northeastern United States, and prostate cancer mortality for the entire United States, during the period 1968-1998.The research assistance of Ikuho Yamada is gratefully acknowledged. I also am grateful for the support of Grant 1R01 ES09816-01 from the National Institutes of Health, the support of National Cancer Institute Grant R01 CA92693-0, and the helpful comments made by the referees  相似文献   

9.
1996-2000年中国摄影测量与遥感进展   总被引:9,自引:0,他引:9  
本文总结了从1996年到2000年中国摄影测量与遥感以及地理信息系统等方面的成就,内容涉及,数据获得取与数据管理,航空航天遥感系统及其软硬件,GIS软硬件,摄影测量,遥感及空间信息系统的原理与算法,摄影测量,遥感及空间信息的应用等。  相似文献   

10.
张显峰  崔伟宏 《遥感学报》1997,1(3):231-236
在解决诸如工业选址的空间问题时,空间决策支持系统避免了流行的商用GIS软件在空间信息的分析评价,时空分布,预测和模拟以及决策等模型分析功能的不足,该文提出了建立SDSS的两种基本途径;一是利用现有GIS与分析决策模型进行集成联结生成SDSS;另一种途径是自行开发具有空间数据管理和分析决策模型的一体化SDSS。  相似文献   

11.
地理信息系统是融计算机图形和数据库于一体 ,保存和处理空间信息的高新技术。本文针对市场上出现的几种常用的GIS应用软件进行了比较和分析 ,并阐述了目前GIS软件的瓶颈和发展方向  相似文献   

12.
SARS控制与预警地理信息系统的研制与应用   总被引:14,自引:0,他引:14  
针对中国当前非典型肺炎(SARS)疫情防治工作的迫切需求,作者基于其在地理信息科研领域具有大型国产GIS软件平台(SuperMAP)及其在辅助决策空间信息模型工具等方面的科研优势,紧急研制了“国家SARS疫情控制与预警信息系统”。该系统由5个子系统构成,是一个将空间定位、空间信息管理、空间信息分析技术和通信技术进行有机的整合,形成了前后端一体的SARS疫情实时传输、处理、分析和分布完整的信息系统。在SARS疫情的信息采集、管理、分析及其防治与监控措施的发布等方面发挥了重要的作用。  相似文献   

13.
The image analysis system ASEAN (Advanced System for Environmental ANalysis with Remote Sensing Data) was designed and programmed by a software development group, ImaSOFr, Department of Remote Sensing Technology and GIS, Institute for Geography, National Centre for Natural Science and Technology of Vietnam under technical cooperation with the Remote Sensing Technology Centre of Japan and financial support from the National Space Development Agency of Japan. ASEAN has been in continuous development since 1989, with different versions ranging from the simplest one for MS-DOS with standard VGA 320×200×256 colours, through versions supporting SpeedStar 1.0 and SpeedStar PRO 2.0 true colour graphics cards, up to the latest version named WinASEAN, which is designed for the Windows 3.1 operating system. The most remarkable feature of WinASEAN is the use of algorithms that speed up the image analysis process, even on PC platforms. Today WinASEAN is continuously improved in cooperation with NASDA (National Space Development Agency of Japan), RESTEC (Remote Sensing Technology Center of Japan) and released as public domain software for training, research and education through the Regional Remote Sensing Seminar on Tropical Eco-system Management which is organised by NASDA and ESCAR In this paper, the authors describe the functionality of WinASEAN, some of the relevant analysis algorithms, and discuss its possibilities of computer-assisted teaching and training of remote sensing.  相似文献   

14.
Present methodological research on geographically weighted regression (GWR) focuses primarily on extensions of the basic GWR model, while ignoring well-established diagnostics tests commonly used in standard global regression analysis. This paper investigates multicollinearity issues surrounding the local GWR coefficients at a single location and the overall correlation between GWR coefficients associated with two different exogenous variables. Results indicate that the local regression coefficients are potentially collinear even if the underlying exogenous variables in the data generating process are uncorrelated. Based on these findings, applied GWR research should practice caution in substantively interpreting the spatial patterns of local GWR coefficients. An empirical disease-mapping example is used to motivate the GWR multicollinearity problem. Controlled experiments are performed to systematically explore coefficient dependency issues in GWR. These experiments specify global models that use eigenvectors from a spatial link matrix as exogenous variables.This study was supported by grant number 1 R1 CA95982-01, Geographic-Based Research in Cancer Control and Epidermiology, from the National Cancer Institute. The author thank the anonymous reviewers and the editor for their helpful comments.  相似文献   

15.
The extension of the functional capacity of geographic information systems (GIS) with tools for statistical analysis in general and exploratory spatial data analysis (ESDA) in particular has been an increasingly active area of research in recent years. In this paper, two operational implementations that combine the functionality of spatial data analysis software with a GIS are considered more closely. They consist of linkages between the S-PLUS software for data analysis and two different GIS implementations, the ArcView desktop system, which is mostly vector-oriented, and the primarily raster-based Grassland open GIS environment. We emphasize conceptual and technical issues related to the software implementation of these approaches and suggest future directions for linking spatial statistics and GIS. Received: 14 January 1999 / Accepted: 11 May 1999  相似文献   

16.
Integrating data on health outcomes with methods of disease mapping and spatially explicit models of environmental contaminants are important aspects of environmental health surveillance. In this article, we describe a modular, web‐based spatial analysis system that uses GIS, spatial analysis methods and software services delivered over computer networks to achieve this end. The Environmental Health Surveillance System (EHSS) is a prototype system that is designed to serve three purposes: a secure environment for producing maps of disease outcomes from individual‐level data while preserving privacy; an automated process of linking environmental data, environmental models, and GIS tasks like geocoding for the purposes of estimating individual exposures to environmental contaminants; and mechanisms to visualize the spatial patterns of disease outcomes via Web‐based mapping interfaces and interactive tools like Google Earth.  相似文献   

17.
Spatial data analysis (SDA) tools to efficiently handle and explore spatial data have become readily available. Although these SDA tools have their own strengths and purposes, they suffer from limited support in terms of a development environment offering easy customization and high extensibility, a strength of open source software. This article presents a standalone software package for SDA in a geographic information system (GIS) environment, called Spatial Analysis using ArcGIS Engine and R (SAAR), which provides an integrated GIS and SDA environment. A set of SDA tools in SAAR utilizes functions in R using R.NET, while other tools were developed in .NET independent of R. SAAR provides an efficient working environment for both general and advanced GIS users. For general GIS users with limited programming skills, SAAR furnishes advanced SDA tools in a popular ArcGIS environment with graphical user interfaces. For advanced GIS users, SAAR offers an extensible GIS platform to help them customize and implement SDA functions with relatively little development effort. This article demonstrates some functionalities of SAAR using census data for Texas counties.  相似文献   

18.
Nautical information is one example of spatial data with a strong temporal component. This paper describes the methods of temporal data representation to be used in a National Ocean Service (NOS) Automated Nautical Charting System (ANCS II). The system will be capable of tracing spatial change over time and of tracking cartographic and data-base procedures within the agency. The discussion describes a method of spatiotemporal representation within traditional geographic information systems (GIS) data structures, draws a distinction between information-oriented and production-oriented temporality, and identifies three fundamental elements of temporal metadata.  相似文献   

19.
王艳华  蒋勇军 《测绘科学》2010,35(2):175-177
R数据统计分析软件是Linux平台下的一个优秀的数据统计软件,现在也已提供了在Windows平台下的安装版本并且具有简单的图形用户界面。它使用简单、功能强大且完全免费,因此与SPSS、SAS等较为流行的数据统计分析软件相比具有与一定的经济优势。同时,R语言的灵活性、可扩充性使得R能很容易地应用到GIS领域,在GIS空间数据分析、地统计分析以及图像处理等方面具有很好的应用前景。本文概要介绍了R语言的一些功能特点及其与GIS开源软件GRASS的集成。  相似文献   

20.
基于GIS的区域导游辅助信息系统的建立   总被引:2,自引:0,他引:2  
论述了采用GIS的空间决策分析方法和常用的空间分析方法来帮助游客进行旅游决策,并以湖北省导游辅助信息系统为例,实现了相关的功能。  相似文献   

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