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Geoinformatics, 2009 17th International Conference on

Date 12-14 Aug. 2009

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Displaying Results 1 - 25 of 245
  • Visualization of NASA campaign mission vertical profiles using Google Earth

    Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1253 KB) |  | HTML iconHTML  

    Google Earth, as the pioneer of Virtual Globes, is changing the way in which professionals acquire, assess, organize, manage, share, visualize, and utilize three-dimensional geospatial data in a virtual environment for scientific research. Google Earth is also changing how the public interacts with virtual globes to facilitate their daily life. Keyhole Markup Language (KML) is the key technology making this change possible. NASA campaign missions have collected large volumes of vertical profiles of the atmosphere for various experiments and validation of instruments to be loaded on satellites. This paper describes design and implementation of two solutions to visualizing those vertical profiles in Google Earth for facilitating the validation and testing of the instruments. The first is to read and process the scientific data into images by using Interface Description Language (IDL). Then, collaborative design activity (COLLADA) model is used to process and render these images in the form of three dimension. Finally, KML files are produced-the vertical profiles are visualized in the form of vertical curtains in Google Earth. The second way is to read the data values directly from the vertical profiles and use them to produce KML files that visualize the vertical profiles as vertical curtains in Google Earth. The vertical curtain is composed of a large number of small rectangles. The first way produces a high-resolution curtain quickly, but the positions of the vertical curtain in Google Earth are not accurate. For the second way, the positions of the vertical curtain can be very accurate in Google Earth, but the resolution is low and the speed is slow. Examples are given for both solutions. View full abstract»

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  • A novel feature ranking modelling in GIS context: Addressing complexity and cost issues

    Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (565 KB) |  | HTML iconHTML  

    Nowadays, there is the trend to carry out decisions and analysis on geospatial data by a massive computational approach. The amount of geospatial information available is increasing exponentially as result of the increasing interoperability between informative systems. In a multiplicity of applications and services spatial decision is carried out to pursue business goals, often without involving experts in geography. The informative systems have an increasing autonomous decisional capability on information selection and analysis. The demand is to have systems that require only an input goal, and produces decisions that humans can understand and integrate with their own decisions. In this paper it is proposed an automatic method of feature ranking, which can sort a heterogeneous set of features by their importance in accomplishing an analytical goal. This method produces a rank model that helps to select the minimal set of features needed to pursue a goal with a wanted accuracy or resources involvement. This feature ranking is expected to supports fundamental decisional making in elaborating geospatial data. The method is based on data mining algorithms; the obtained rank model appears to be spatially scalable and fits well to human form of knowledge. View full abstract»

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  • Very high spatial resolution images: Segmenting, modeling and knowledge discovery

    Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (347 KB) |  | HTML iconHTML  

    In this paper we describe the basic functionalities of a system dedicated to process high-resolution satellite images and to handle them through (semi-) structured descriptors. These descriptors enable to manage in a unified representation two families of features extracted from the objects identified by image segmentation: the attributes characterizing each object, and the attributes characterizing relationships between objects. Our aim is to focus on the complement of two approaches, on one hand concerns the remote sensing and the image segmentation, and on the other hand concerns the knowledge discovery and the modeling. The first approach discusses how to apply an auto-adaptive (non-linear) segmentation approach on a collection of such images. This method is based on the morphological transformations of opening and closing to obtain relevant and significant objects. Using this approach, we simplify and conserve the principal features and objects from the image. The second approach proposes to create a set of XML tags to model the main features elicited from the previous objects using their relationships. These tags are then exploited by querying, using topological, directional, or metrical relationships. Using this approach we can extract not only some explicit spatial information like urban areas, wooded areas and linear features such as roads or railways, but some implicit spatial information like urban organization or urban dynamics. View full abstract»

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  • Integration of geospatial information for mobile and services devices

    Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (202 KB) |  | HTML iconHTML  

    The advancement of mobile information systems is going in parallel with Geographical Information Systems where they both meet in providing location-aware services. New systems are providing a new pervasive GIS dimension where access to geographical attributes is being possible at ldquoanytime, anyplace and anyhowrdquo. Having this objective, one of the key problems is the integration of geo-spatial information, which comes from multiple sources completely heterogeneous but has to accomplish all the user tasks. These information sources came mainly from: i) multiple databases, which can contain very different information and different representation method (vector or raster), and ii) useful elements like satellite information (images and GPS). In this article, we propose an approach to integrate all this information. We use XML descriptors to store all different information that the user will need when he is consulting his mobile device. Having this information in XML format has some advantages, for example it can be updated easily and it can be shared with other services and users. We also propose an approach that provides mobile users with a service that corresponds not only to their requests but also to their preferences, location and querying time. View full abstract»

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  • Towards building a geo-service broker

    Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (184 KB) |  | HTML iconHTML  

    Most national spatial data infrastructures (SDI) were built based on a clearinghouse concept. The concept requires all of the service providers to maintain a Web (map) service recourse which leads to duplication of efforts from data collectors. The objectives of developing a geo service broker are to make data services and other services within an SDI centrally organized, available and accessible to consumers. A geo service broker offers a centralized and harmonized view on resources. The objective of this research is to investigate how a geo service broker is built as a tool for intelligent search and information retrieval in the semantic Web for better service delivery of geo services over the Internet. View full abstract»

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  • GML parsing technology service and its sharing platform

    Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (409 KB)  

    GML (geography mark-up language) has been adopted by ISO as standard for the transport and storage of geographic information, and it has been generally recognized by GIS researchers owing to its obvious advantages in these fields. However, most studies about GML are concentrated on its data description, exchange and representation etc. As GML is used in GIS application systems complexly and extensively, and related software tools and products are developed more and more, interoperation between GML applications technologies are becoming an outstanding obstacle that restricts their developments. As to the same application such as GML parsing, different users or GIS software can describe it differently when transferring their applications request through the web, which will result in semantic discrepancy and obstacle GML application technologies to share.Based on the previous work, this paper will analyze the problems of GML parsing, and propose GML Parsing Technology Service (GPTS) on precondition of full studies on GML parsing referring to OGC specification implementation related to GML. In web server, service requests are generated from fragments by parsing module, which will invoke the specified interfaces from GML Parsing Processing Server (GPPS). Applying related services to the requests, the parsing result will return to clients. Via the GPTS, various clients will conform to certain convenient rules when posting their parsing requests, so one target will request XML files to parse GML geodata from different sources by invoking the same operations on geographic features and elements. The experiment results which are carried out by different clients in this paper demonstrate GPTS's feasibility, availability and rationality. This research on GPTS will provide an interoperable parsing way on the web to eliminate obstacles between GML parsing application technologies sharing and interoperability. View full abstract»

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  • Quantitative visualizations of hierarchically organized data in a geographic context

    Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1502 KB) |  | HTML iconHTML  

    Here we introduce a novel quantitative technique for visualizing hierarchically organized data in a geographic context. In contrast to existing techniques, our visualization emphasizes the hierarchical relationships in the data by depicting them in a standard tree format that takes advantage of many fundamental perceptual properties. Our technique allows users to define a geographic axis and visualize how well a tree correlates with the ordering of geographical locations along this axis. This is accomplished by finding the ordering of leaf nodes, subject to the constraints of the tree topology, which minimizes the number of crossings that occur between lines that connect leaf nodes to their associated geographic locations. In this optimal layout, any crossings that occur between these lines indicate discordance between the topology of the tree and the user defined geographic axis. We have developed a branch-and-bound algorithm that allows optimal leaf orderings to be determined quickly enough to support interactive exploration of different geographic axes even for large multifurcating hierarchies. The quantitative nature of our visualization has allowed us to specify a permutation test for determining if the relationship between a tree topology and a geographic axis is statistically significant. In this paper, the utility of our visualization is demonstrated on biological data sets, but our method is applicable to any hierarchical data where geographic structure may be of interest. View full abstract»

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  • A SOA based debris flow monitoring system

    Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (667 KB) |  | HTML iconHTML  

    Taiwan is located at the collision boundary of the Philippine sea plate and the Eurasian plate. The mountain terrain is precipitous and the region, on the whole, is characterized by fragile rocks and frequent seismic activity. In addition, the concentrated torrential rainfall brought by typhoons cause extensive disasters, debris flow, the most serious disaster caused by torrential rainfall, lead to very heavy casualties in recent years. There are 17 fixed debris flow monitoring stations and 2 mobile stations deployed in Taiwan. However, the whole architecture was designed in late 2000 and implemented by traditional and proprietary methodologies. Hence, several interoperability issues have been unveiled in the recent years when the needs of interoperability increased. In this study, we propose a whole new and open standards based debris flow monitoring architecture following the service oriented architecture (SOA) paradigm. Relevant open geospatial consortium (OGC) standards (for example Web processing service, WPS specification and sensor web enablement, SWE technologies) and advancements from grid computing where lead into the proposed architecture. The use of open standards and distributed computing technologies in the proposed architecture enables heterogeneous resources (data, processing and computing power) interoperability. This study also implements an OGC WPS grid processing profile that was developed in the OGC Web services, Phase 6 (OWS-6) initiative of the OGC interoperability program. View full abstract»

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  • Geospatial Information semantic retrieval algorithm Research based on geo-ontology

    Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (824 KB) |  | HTML iconHTML  

    Spatial information retrieval which is mainly catalog service based on metadata is the foundation of spatial information sharing. Today's information retrieval methods in catalog service are typically limited to keyword searches or matches of sub-strings, which do not meet user's retrieval demand. This paper presents a semantic similarity degree algorithm, in which geo-ontology is compared from concept of the hierarchical structure similarity degree and property similarity degree to adjust the relations of concept. Firstly, overall evaluating the geo-ontology concept hierarchical structure similarity degree and attribute similarity degree; secondly, the semantic similarity degree was calculated as the basis for spatial information retrieval; In the end, the retrieval algorithm was applied in the ldquoOcean Grid Portalrdquo, the retrieval results demonstrate the feasibility and effectiveness of the semantic similarity degree retrieval algorithm. View full abstract»

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  • GeoProfiling

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (322 KB) |  | HTML iconHTML  

    Northrop Grumman has developed a GeoProfiling analysis algorithm which creates a probabilistic spread of where a criminal might live or work based on crime locations. Also known as geographic profiling, the analysis is based on the concept that criminals commit crimes within a certain radius of where they live or work but not too close to these locations. Northrop Grumman has developed a GeoProfiling Web service and integrated it within various geospatial visualization tools to allow users to analyze and predict criminal where abouts using the tool of their choice. The service takes a set of crime points and statistical information, such as the mean and standard deviation of historical criminal data, as input parameters for basis of analysis. The paper explores the development of the GeoProfiling tool and the use of the GeoProfiling algorithm as applied to real world data and situations. View full abstract»

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  • Persistent Surveillance

    Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (678 KB) |  | HTML iconHTML  

    Effective persistent surveillance (PS) involves integrating and utilizing data from a variety of assets including sea, land, air, and space-based sensors as well as humans spanning all intelligence disciplines. The data from these assets range from simple observations that are small in size to enormous images and full motion video (FMV) streams, all with varying degrees of metadata. PS missions need to access and analyze both archived and real-time data from these assets and fuse the data to gain a better understanding of the time, location, and activity under surveillance. Given the dynamic nature of PS missions and the assets and data involved, there is a clear need for innovative ways of storing, accessing, and fusing PS data. Northrop Grumman is developing state-of-the-art capabilities for handling PS data including: Storage of FMV and imagery in an efficient manner; geospatial, temporal, and activity based indexing of all of the persistent surveillance data; innovative methods for visualizing and controlling the amount of geospatial and temporal data for retrieval, processing and dissemination; in-synch visualization of the various types of persistent surveillance data. View full abstract»

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  • Urban forest inventory using open access web mapping services and photogrammetric solution

    Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (465 KB) |  | HTML iconHTML  

    Community-based data collection is a new trend that can empower and diversify our data collection methods and increase our understanding of the environment. As citizens are becoming more interested and involved in ecological matters utilizing their manpower and knowledge can be a new valuable resource for researchers and urban managers. Utilizing web mapping services to assist in collecting spatially related data can provide data that previously required dedicated personnel. National or regional programs for urban forest inventories that utilize trained crews, such as the UFORE program, were previously used exclusively. Much of the information collected by crews can be collected by interested community volunteers if combined with proper education and other resources such as high resolution aerial images and ground images. Our research tested the idea of utilizing a web application built around Google Mapstrade web-based service that allows users to actually select and input information about their backyard vegetation. We extended this idea by extracting metric information such as crown diameter, tree heights and diameters by solving close-range photogrammetric models for images captured using consumer-grade digital cameras and uploaded by participating citizens. The images were processed using one of the commercial photogrammetric software. Ground survey measurements made using survey equipment were collected and analyzed to test the accuracy of the photogrammetric model. We compared the results of the photogrammetric solutions with the higher-accuracy survey-quality measurements. The preliminarily results of this research demonstrated the potential for photogrammetry to provide valuable data for urban forest inventory programs. View full abstract»

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  • Research on shared platform of water environment information services based on GeoGlobe

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1236 KB) |  | HTML iconHTML  

    GIS is widely used in many fields and various industries, which makes sharing and interoperability of geographic information become urgent requirements of all departments in network environment. In the application field of water environment, some analysis systems of water environment have appeared. However, these systems often work in single computer, and their characters of common sharing are poor, besides, the maintenance and update for them is more difficult; Also, occurred some analysis services of water environment based on web services, but usually these services are dispersed and have less function, so it has much more difficulties to find and use them. This causes the contradiction of information asymmetry between the providers and the users of the services. Because single service barely satisfies the complex requirements of the users, it is a problem to be solved that how to integrate these single service into service chains which will meet the needs of broad users; At the same time, after constructing the service chains, it is also a problem needed to be solved that how to make users find the chains simply and show the results of the calls of these service chains. Aiming at these problems, this paper presents the shared platform model of water environment information service based on GeoGlobe (hereinafter service platform of water environment). This platform is put up on the basis of GeoGlobe, as a sub module of GeoGlobe. This platform provides a better solution for the above problems. The service platform of water environment is just like a store whose commodities are various information services of water environment. If we say that the appearance of stores satisfy the needs of everyday life, well then, we can say that the occurrence of the service platform of water environment satisfies people's work needs in the area of water environment. This paper can be mainly divided into two parts: One is the building of the service platform of water environment, - which contains the constructing of service chains, the registry of the chains, visual displays of information and so on; The other is to show the validity and feasibility of this paper's work, combined with the practical work item (namely ldquowater evaluation servicerdquo), which is built using the service platform of water environment. View full abstract»

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  • Automatic farmland extraction from multi-temporal landsat TM data based on artificial neural network

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (389 KB) |  | HTML iconHTML  

    It is an important method of the land use change dynamic monitoring to withdraw the land utilization information using remote sensing image accurately and quickly. However, most of them seemed to be immature enough. This paper aims to use the prior knowledge which is established from one land cover map and remote sensing imagery to realize the automatic extraction of specific land cove class from other remote sensing imagery. The TM satellite imageries in Changyang District of Beijing are taken as an example, and the automatic extraction procession introduce various key technology including relative radiometric correction, feature selection and ANN. The results show that the classification accuracies between the mentioned approach and conventional statistical method (MLC) for individual remote sensing image are very close. View full abstract»

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  • Urban expansion simulation based on constrained Artificial Neural Network cellular automata model

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2327 KB) |  | HTML iconHTML  

    With development of metropolis, it has been widely accepted the urgent need to simulate and forecast urban growth. In this paper, we proposed a constrained-CA-Urban-model relies on remote sensing (RS) techniques, geospatial process of geographic information systems (GIS) and artifical neural network (ANN). A three-layer back-propagation (BPNN) is set up for acquisition of transition rules in terms of urbanization probabilities for CA model. As an example, urban expansion maps are extracted from three TM satellite imageries (1991, 2001, and 2007) in Chaoyang District at Beijing. Neighborhood, distance, and constrain variables are considered. Evaluation of results indicates this model is effective in simulation for urban expansion. The experiment results in study area demonstrated this model is feasible and convenient for CA simulation and forecast for urban system. View full abstract»

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  • Effects of mining on the ecosystems integrating GIS and hydrological model

    Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (454 KB)  

    Natural and anthropogenic (e.g. land cover/land use change) processes can lead to ecosystems change dramatically on timescales from years to decades. Especially, land cover/land use changes by mining can have drastic impacts on ecosystems and basin-wide water budgets. Phosphate rock is an important strategic resource. China and U.S. are two major phosphate reserves counties in the world and both facing the same problem of reclamation for post-mining. In this study, the current conditions and status of phosphate mining in China and U.S. are reviewed. And, the advanced methods using an interdisciplinary approach integrated 3S (RS, GIS and GPS) high-tech means to extract hydro-ecological environment, and coupling of hydrological model to simulate the land cover/land use changes by phosphate mining behavior (e.g., flow and water table) are introduced. The various impacts of land use changes on the domain ecosystems can be evaluated by comparing pre-mining and post-mining conditions using GIS and RS coupled with HSPF hydrologic model. As the rehabilitation and reconstruction of ecological environment in abandoned mining area, it has a positive meaning for regional eco-environment, also to improve the living conditions of local residents in an effective way. View full abstract»

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  • Simulation on the effects of non-point source pollution in Qingjiang River basin based on SWAT model and GIS

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (537 KB) |  | HTML iconHTML  

    Assessment of the pollution of water bodies from non-point sources (NPS) is a complex data-requiring and time-consuming task. The accuracy of NPS pollution models depends to a great extent on how well model input parameters describe the relevant characteristics of the watershed. It is assumed that promoting the precision of input parameters affects the simulation results of runoff, sediment and nutrients yield from the entire watershed. An integration of simulating model with GIS technique is one of the most efficient methods to NPS pollution quantified research at present. In this study, the basic database, which includes DEM, soil and landuse map, climate data, and land management data, were established for the study purpose using GIS. The generation and formation of non-point source pollution involves great uncertainty, and this uncertainty makes monitoring and controlling pollution very difficult. Understanding the main parameters that affect NPS pollution uncertainty is necessary to provide the basis for the planning and design of control measures. Based on the results of parameter sensitivity analysis, the sensitive parameters of Soil and Water Assessment Tool (SWAT) model were identified, and then model parameters related to stream flow and nutrient loadings were calibrated and validated by the observed value, and the simulation showed that the simulated values were reasonably comparable to the observed data, suggesting the validity of SWAT model. The spatial-temporal distribution features of NPS pollution in the Qingjiang River basin (a case study of this paper which is one main branch of Yangtze River basin in Three Gorges Project area) were revealed. NPS pollution mainly takes place in flood season. The critical risk areas of soil erosion were identified. Stream flow and nutrient loadings (including total nitrogen (TN) and total phosphorus (TP)) in Qingjiang River Basin were simulated. The surface runoff and nutrient yield results indicated that the averag- e annual runoff and output of TN and TP provides better understanding on stream flow and nutrient loadings responding to variations of land use conditions, agricultural tillage operation and natural rainfall etc. View full abstract»

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  • New spatial measures of terrain dynamics derived from time series of lidar data

    Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2031 KB) |  | HTML iconHTML  

    We anticipate that multiyear lidar surveys, currently focused on vulnerable coastal areas, will soon become a common resource for monitoring and analysis of various aspects of regional terrain change. We propose raster based measures for mapping and quantification of discrete and continuous terrain changes by introducing novel concepts, such as core and envelope surfaces, contour evolution band, and evolution regression slope map that can provide insights into the spatial aspects of terrain dynamics and changes in structures. The methodology is applied to a section of North Carolina coast where multiyear time series of lidar data is already available. Dynamics of bare dune and beach systems, changes in structures and vegetation growth are mapped and quantified to evaluate the proposed approach. View full abstract»

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  • Temporal and spatial variation of urban airborne inhalable particle and it's influence factor analysis using GIS & RS

    Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (478 KB) |  | HTML iconHTML  

    To identify the inhalable particle matter (IPM) sources and to estimate the variability in their contributions to inhalable particle concentrations across the Beijing city, the spatial distribution of PM0.3, PM1.0 and PM3.0 concentration are simulated by monitoring data obtained from 93 air sampling stations in Beijing urban city and Kriging techniques. Inhalable particles in this study had aerodynamic size between 0.3 and 3.0 mum. By taking streets and towns as the basic spatial analysis unit, some factors are mapped influencing urban airborne inhalable particulates pollutions such as urban ground surface types based on GIS and RS. The correlation between PM0.3, PM1.0 and PM3.0 and their influencing factors are quantitatively evaluated by using GIS multifactor integrated analysis and GIS overlay of ranked data layers. The results show that spherical models with nuggets could fit the variograms of PM0.3, PM1.0 and PM3.0. The IPM concentration had significant decreasing trend from 2007 to 2008. Meanwhile, the pollution center has transferred from north and northeast district to southwest and northwest. The spatial relativity between three air particles and their impact factors have spatial heterogeneity in the north, southwest and downtown. Among the three pollutions, the spatial distribution of PM1.0 is firstly influenced by the influence factors; PM3 is secondly, PM0.3 is thirdly. View full abstract»

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  • Spatial data access control in grid environment

    Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (580 KB) |  | HTML iconHTML  

    A spatial data access control model in grid environment was proposed base on Globus Security Infrastructure (GSI). Firstly, A spatial datasets sharing framework was built up by Monitor and Discover Service (MDS), and then a common control model was proposed to realize spatial data access control. In this model, every user was mapped to a given role, and every role had a unique digital certificate to distinguish its identification, then every role had the given permission to access the resources. Moreover, a further designed model was proposed to control the role's accessibility of rectangle in given spatial datasets. Two scenarios were put forward to control spatial data access between different organizations. The first was that all of the organizations shared the same roles, and then the organization realized self-control by enduing different roles with different rights. While the second was that every organization had its own users, roles and resource controls, and then the self-control was enhanced. The model was implemented by Globus Toolkits (GT), and experiment results illustrated that the proposed model could control the spatial data access effectively in a grid environment. View full abstract»

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  • Integer Programming (IP) formulation for minimizing sediment delivery in a watershed by reforestation of optimal sites

    Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (356 KB) |  | HTML iconHTML  

    Several approaches exist to model the production, transport and delivery of water and sediment flows in watersheds but none of these are dealing with spatial optimality requirements. However, policy and decision makers dealing with environmental conservation and land use planning often require identifying potential sites for contributing to minimize sediment flow reaching riverbeds. This is the case of reforestation initiatives, which can have sediment flow minimization among their objectives. This paper proposes an Integer Programming (IP) formulation for selecting a predefined number of locations to minimize sediment load at a watershed outlet. Although the core structure of the IP model can be applied for different sorts of flow, the formulation is targeted to minimization of sediment delivery. Several experiments are performed for two watersheds in South Dakota in the USA. The results are in agreement with expert assessments of erosion levels, slopes and distances to the riverbeds, which in turn allows concluding that this approach is suitable for minimizing sediment flow. View full abstract»

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  • Discovery of spatial links between individuals on the Geospatial Semantic Web

    Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (543 KB) |  | HTML iconHTML  

    In 2002, Egenhofer described his conceptual vision of the future geospatial semantic Web. As a contribution towards the concretization of this approach, we propose here a spatial ontology that can be used to attach spatial characteristics to Web resources, coupled with a spatial reasoner, called ONTOAST. Our work is applied to the field of semantic analysis, a new search paradigm for the Semantic Web, that answers queries like "Is instance x in any way connected to instance y". However, semantic analysis has been defined for RDF(S) graphs only, and has, in this context, a limited power of expression. We propose here the adaptation of this search paradigm to OWL 2 ontologies, with the objective of gaining more expressivity and activating more powerful inferences. We also investigate several ways of exploiting spatial information in the process of semantic association discovery. The purpose is to infer new and possibly interesting ontology paths between target instances, based on spatial relations existing between individuals. Then we show how spatial contexts are handled in order to limit the search space to a given spatial region. View full abstract»

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  • Organization and schedule of multi-resolution pyramid based on wavelet transform

    Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (395 KB) |  | HTML iconHTML  

    The technology of multi-resolution pyramid is widely used in raster data (image and DEM) processing. However, the main weakness of such implementation is that redundant store exists among different resolution levels. To overcome this problem, we propose a novel organization for multi-resolution pyramid, called wavelet pyramid, which combines the strength of pyramid structure and wavelet transform. To integrate wavelet pyramid into Geoglobe (a Google Earth like system), we build the relationship between wavelet subbands and Geoglobe tiles. We also discuss the network transmission of wavelet pyramid in Geoglobe, and propose an incremental and progressive schedule method. Compared to tile pyramid, wavelet pyramid occupies less storage size, and its network schedule is more effective. View full abstract»

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  • The design of intelligent expert classifier for featured crop mapping combining spectral library

    Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (235 KB) |  | HTML iconHTML  

    In the study, a module was designed which was used to estimate yield of crop (such as lychee, banana and sugarcane etc) using spectral library of featured crops of South China. An approach combining spectral library with expert system classification methods by spatial data mining techniques is present. Being one of spatial data mining techniques, inductive learning algorithm is used to discover knowledge of spectral library for the expert system and is designed specially for monitoring featured crops of South China. So the intelligent expert classifier can make use of spectral data, attribute data and spatial data of spectral library to extract information of South China's featured crops. The study pre-defined some attributes of inductive learning algorithm which are in favor of featured crops mapping, for improving the efficiency of algorithm and ensuring the usability of rules. The estimation of lychee planting area of Shenzhen city in 2005 was presented as a case study. The following classification rules of lychee were acquired by running inductive learning algorithm: for example, 0.062< reflectance of TM2 <0.071, 0.47<NDVI<0.54, 20<DEM<90, special rules of lychee planting in Guangdong province, 40<area of lychee orchard (pixel number) <5000 and the result of classification was presented by figure 2. Compared with traditional unsupervised classification, it improves classification accuracy greatly, and the rate of accuracy reaches 93.5% with KAPPA coefficient of 0.85. The result indicates that intelligent expert classifier is a better classification method for extracting of lychee planting area and is able to meet the need in agriculture application for quick crop area monitoring in South China. View full abstract»

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  • A framework of spatio-temporal data adaptive visualizations for mobile environment

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    Developing spatiotemporal data adaptive visualization methods for spatial information services is an essential and complex issue, particularly on the small display devices. It is becoming ever more important with the progress in the fields of mobile Internet and positing methods, as well as the widely use of mobile devices. However, the limitations in devices and the changes in user's demands make the traditional methods difficult to fit this situation in mobile environment. In this paper, we present a conceptual framework to handle spatial information representation on mobile devices based on vehicle navigation systems, and discuss related key techniques including the spatial information filtering using the geographic relevance theory, modeling the typical context and designing the adaptive visualization methods. Finally, a case application in the vehicle navigation services was discussed and the results prove this proposed framework is feasible. View full abstract»

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