KEYWORDS: Geographic information systems, Internet, Computer simulations, Data processing, Data acquisition, Local area networks, Software development, Data centers, Telecommunications, Distributed computing
This paper firstly introduces the spatial data grid and the CDN (Content Delivery Network) technology. And then it
depicts the significance of integrating grid with CDN. On this basis, this paper proposes a method of constructing the
spatial data grid system by using CDN to support the massive spatial data online service. Finally, the simulation results
by OPNET show that the programme do can improve the system performance, and reduce response time in a greater
extent.
A huge amount of geospatial and temporal data have been collected through various networks of environment
monitoring stations. For instance, daily precipitation and temperature are observed at hundreds of meteorological stations
in Northeastern China. However, these massive raw data from the stations are not fully utilized for meeting the
requirements of human decision-making. In nature, the discovery of geographical data mining is the computation of
multivariate spatio-temporal correlations through the stages of data mining. In this paper, a procedure of mining
association rules in regional climate-changing databases is introduced. The methods of Kriging interpolation, fuzzy cmeans
clustering, and Apriori-based logical rules extraction are employed subsequently. Formally, we define
geographical spatio-temporal transactions and fuzzy association rules. Innovatively, we make fuzzy data
conceptualization by means of fuzzy c-means clustering, and transform fuzzy data items with membership grades into
Boolean data items with weights by means ofλ-cut sets. When the algorithm Apriori is executed on Boolean transactions
with weights, fuzzy association rules are derived. Fuzzy association rules are more nature than crisp association rules for
human cognition about the reality.
Along with the development of earth observation technology, large amounts of geospatial information are accessible.
There are also a lot of geospatial data and services which are shared on the Internet. However they vary in formats and
are stored at various organizations leading to problems of data discovery, data interoperability and usability. The Open
Geospatial Consortium (OGC) has developed standard service called catalogue in order to overcome this problem. The
goal of a geospatial catalogue is to support a wide range of users in discovering relevant geographic data and services
from heterogeneous and distributed repositories. But in most of geospatial catalogue services, the search functionality is
limited to the direct match of keywords from metadata, the OGC catalogues may not return useful results as the used
keywords often do not match with the meta-information stored in the catalogues. In this paper, we propose a geospatial
semantic catalogue services that aims at overcoming this limitation.
Spatial information dissemination is a necessary step to make use of spatial information for which is a bridge between
the acquirement and the application of spatial information. However, conventional methods of spatial information
dissemination cannot cater to users in that not only users' personalized requirements cannot be satisfied, but initiative
dissemination service cannot be provided. In this paper, the idea of intelligent spatial information dissemination (ISD) is
proposed. Combining the ideas of personalized information retrieval, information filtering and recommender systems,
the ISD system employs user profiles and query conditions to provide two implement ways of spatial information
disseminations, namely "pull" and "push". Then, the three layers architecture of intelligent spatial information
dissemination system based on user profile model is given, and the procedure of data in the ISD system is introduced.
Also, the user profile is presented including user profile model and user profile management. Finally, the prototype
system of intelligent spatial information dissemination is presented.
KEYWORDS: Databases, Associative arrays, Buildings, Roads, Geographic information systems, Data modeling, Algorithm development, Information fusion, Nomenclature, Data acquisition
The integration of heterogeneous geospatial data offers possibilities to manually and automatically derive new information, which are not available when using only a single data source. This paper presents a three-level schema integration architecture which consists of local schemas, mapped schemas, and a global schema, for global
heterogeneous geospatial systems. we describe a machine-learning based approach for GIS schema matching. Our approach extends existing machine-learning approaches for (traditional) data mapping but departs from them due to the nature of geographic data. Our solution reduces the complex mappings by identifying different values of a determining property.
Conventional spatial information delivery is system-oriented, and users have to adapt to the system and complete the
delivery of spatial information. Two disadvantages exist in the delivery service mode: (1) users' personalized
requirements cannot be satisfied; (2) Initiative delivery service cannot be provided for users. In this paper, we firstly
classify conventional user profile models into four categories. After analyzing the limitations of these user profile models,
we conclude that conventional user profile models are not suitable for the application of spatial information intelligent
delivery. Then, aiming to the objectives of spatial information intelligent delivery, we propose a user profile model of
spatial information, and give the building method of the model. Also, we put forward a similarity measure method
between spatial information and user profile. In order to verify the availability of the user profile model, we present an
example of spatial information intelligent delivery. The experimental results show that the proposed user profile model
can reflect user profile quite well.
KEYWORDS: Databases, Geographic information systems, Distributed computing, Optimization (mathematics), Analytical research, Data modeling, Remote sensing, Data processing, Signal processing, Information operations
Geographic Information System (GIS) is moving towards distribution and sharing. Distributed Spatial Database Systems
(DSDBS) has attracted the attention of many scholars. This paper introduces the prospects of Distributed GIS (DGIS),
and describes the definition of DSDBS and the existing problems. The researches in related fields are analyzed, including
the research results in the traditional distributed relational database fields, the distributed spatial database fields and the
spatial query optimization aspect. Grid technologies are developing forward, and grid will be turned into the standard
distributed computing platform, therefore the application of DSDBS will be much broader than ever. The present studies
on distributed spatial query focus on spatial join optimization. Researches on query scheduling are rare. In the process of
constructing our test system for distributed spatial query, we find there are some replication nodes after the step of data
localization. These nodes cause redundant computing of query processing. This paper gives a method to solve it based on
the Query Scheduling Tree Model (QSTM). It also gives a detailed scheduling algorithm, and analyzes the effectiveness
of the model and the algorithm.
Nowadays, huge volumes of geospatial data and services are available and accessible to people all over the world.
However, they are searched mostly based on keyword, which is inherently restricted by the ambiguities of natural
language, which can lead to low precision and recall. In this paper, semantic share of geospatial data and services are
studied based on ebXML registry. But ebXML registry specification doesn't take into account the registration of the
semantic information. So we define how OWL DL constructs are mapped to ebXML registry information model
(ebRIM) constructs without causing any changes in the core ebXML registry specification. After that, predefined stored
procedures are provided in the ebXML registry for semantic search, which provide necessary means to exploit the
enhanced semantics stored in the Registry. Then, geospatial ontologies in change detection application of remote sensing
based on Global Change Master Directory, ISO19119 and ISO19115 are established. Finally, a prototype system is
developed based on an open source-ebxmlrr to demonstrate the proposed model and approach.
In the paper brings forward that complexity degree of land use structure can be used as one of quantitative indices to
define the land use/land cover (LU/LC) status expression precision scale. Then by simulating population density spatial
differences in Wuhan district, according to the value of complexity degree of land use structure, divides the experiment
area into a kind of non-uniform and multi-grid structure. Consulting one grid cells' status high or low in the multi-hierarchy
data structure, the LU/LC status expression precision scale rough or fine can be defined in a degree.
Furthermore, the outcome of simulating population density shows that the multi-grids land data structure can integrate
land use data with other social and economic statistics conveniently and neatly to complete some simple land data
mining tasks such as the data computation or analysis effectively, then can reflect the LU/LC status of some region.
The route computation module is one of the most important functional blocks in a dynamic route guidance system.
Although various algorithms exist for finding the shortest path, they are faced with the networks in the local server not
distributed environment. We present an efficient distributed hierarchical routing algorithm that can find a near-optimal
route and evaluate it on a large city road network which is composed of a lot of small networks which are placed on
different servers. Solutions provided by this algorithm are compared with the stand-alone traditional hierarchical routing
solutions to analyze the same and different points. We propose two novel yet simple heuristic to substantially improve
the performance of this hierarchical routing algorithm with acceptable loss of accuracy. The improved distributed
hierarchical routing algorithm has been found to be faster than a local A* algorithm.
This paper proposed a new GIS symbolize process, called virtual machine based symbolize process. It is a new method to create and share map symbol libraries in different GIS platform by using symbol virtual machine, which screened the difference of the concrete GIS platform, and provide a uniform symbol interface for the GIS symbols designer, thus the symbols made by this method can be used in different GIS platforms, and achieve the same representation results.
KEYWORDS: Geographic information systems, Taxonomy, Web services, Data conversion, Composites, Network security, Process modeling, Roads, Data processing, Spatial analysis
The Combination of Geographic Information Services (GIServices) is studied in this paper. First, the way of GIServices combination is analyzed. Based on GIServices combination ways depicted by Service-Oriented Architecture (SOA), OpenGIS (OGC) Web Services Architecture and International Organization for Standardization (ISO) 19119, GIServices combinations are classified into Discrete Service Combination, Chaining Service Combination and Hybrid Service Combination in this paper. Then, the model of GIServices combination is focused. A high-level GIServices combination model based on Petri Net is proposed to improve those proposed by former researchers. The proposed high-level model can represent services combination relationship more clearly and can help to control services combination behavior in an easier way. Since searching GIService that can accomplish certain GIS task is a key step of implementing GIServices combination, GIServices taxonomy is then studied. A multi-level task-oriented GIServices taxonomy is proposed in this paper. Correspondence between GIS tasks and GIServices can be established more easily with the proposed multi-level task-oriented GIServices taxonomy. Finally, a case study is made to support the proposed theories.
KEYWORDS: Geographic information systems, Data storage, Data conversion, Data modeling, Standards development, Databases, Software development, Visualization, Computing systems, Remote sensing
Spatial data sharing among multiple GIS (Geographic Information System) platforms is a fundamental requirement of many GIS applications, yet conventional methods of spatial data interoperability don't adequately consider practical application circumstance, which now becomes a primary barrier to more efficient spatial data sharing among multiple GIS platforms. In this paper, after analyzing the disadvantages of conventional methods and the causation of the disadvantages, and analyzing the principle of spatial data access of ArcGIS, MapInfo and GeoStar based on Oracle Spatial storage, the authors propose a new spatial data interoperability method called Different meta information and Same spatial data Method. This method is based on Oracle Spatial, through which spatial data interoperability for multi-platform of GIS is available. The results of experiments demonstrate that this method is a new simple practical approach adapted for current application circumstance, and it provides us a new idea for spatial data interoperability.
KEYWORDS: Databases, 3D modeling, Geographic information systems, Data modeling, Remote sensing, Visualization, 3D image processing, Multimedia, Statistical analysis, 3D visualizations
The Virescence Separator of Beijing, the capital city of China, is a virescence zone between the central area and the edge group as well as the zone among different edge groups, within irregular shape and the total area of 240 square kilometers. The construction of the Virescence Separator is a big and difficult project, an effective information system for planning and development with satisfactory performance is therefore essential. In this paper, the applications of remote sensing and GIS (Geographical Information System) technologies in BJVSIS (planning and development Information System for Beijing Virescence Separator), including three dimensional (3D) visualization, integrated databases management and multi-media technologies, were presented. The initial pilot project of BJVSIS was finished successfully in 2001, and up to now this information system runs very well and plays a great role in the construction of the Virescence Separator. Just depended on the applications of so many high-tech like GIS, remote sensing, 3D visualization, and databases integration, BJVSIS can manage all kinds of relevant geographic data, such as vector graphics, DEM (Digital Elevation Model), image and multi-media attributes. And BJVSIS also provides many GIS functions, such as spatial query, 2D/3D display, spatial analysis, statistic calculation, form report and map output.
KEYWORDS: Geographic information systems, Java, Data communications, Control systems, Databases, Human-machine interfaces, Data processing, Visualization, Logic, Internet
A systematic plan of building Web Geographic Information System (WebGIS) using ActiveX technology is proposed in this paper. In the proposed plan, ActiveX control technology is adopted in building client-side application, and two different schemas are introduced to implement communication between controls in users¡¯ browser and middle application server. One is based on Distribute Component Object Model (DCOM), the other is based on socket. In the former schema, middle service application is developed as a DCOM object that communicates with ActiveX control through Object Remote Procedure Call (ORPC) and accesses data in GIS Data Server through Open Database Connectivity (ODBC). In the latter, middle service application is developed using Java language. It communicates with ActiveX control through socket based on TCP/IP and accesses data in GIS Data Server through Java Database Connectivity (JDBC). The first one is usually developed using C/C++, and it is difficult to develop and deploy. The second one is relatively easy to develop, but its performance of data transfer relies on Web bandwidth. A sample application is developed using the latter schema. It is proved that the performance of the sample application is better than that of some other WebGIS applications in some degree.
KEYWORDS: Geographic information systems, Internet, Databases, Web services, Data acquisition, Connectors, Data processing, Logic, Associative arrays, Roads
It is the GIS developing direction to integrate GIS with Internet. Internet GIS is not only used to publish distributed geographic information on line, but also to provide on line tools for distributed geographic information real-time analysis and processing. Internet GIS should make use of existing multi-sources and functions for geographic information analysis and processing. The distributed feature is inherent to geographic information, which needs distributed organization and processing approach. Internet GIS (Geographic Information System) is the integration of Internet and GIS, being used to implement publishing on line and distributed real-time analysis of geographic information. The problem of geographic information distributed management and processing should be solved by Internet GIS. This paper provides three approaches to the problem, especially the distributed component and Geo-Connector approach to Internet GIS. The distributed component method includes homogeneous, heterogeneous and conjoint methods, for the problem of distributed geographic information publishing and real - time analysis. With instance, the feasibility and practicability of distributed component method are interpreted in detail. The concept of Geo-connectors in GIS application server side for organization and management of distributed heterogeneous database is presented and a case of heterogeneous geo-data access and interoperability is studied
With the increasing maturity of distributed object technology, CORBA, .NET and EJB are universally used in traditional IT field. However, theories and practices of distributed spatial database need farther improvement in virtue of contradictions between large scale spatial data and limited network bandwidth or between transitory session and long transaction processing. Differences and trends among of CORBA, .NET and EJB are discussed in details, afterwards the concept, architecture and characteristic of distributed large-scale seamless spatial database system based on J2EE is provided, which contains GIS client application, web server, GIS application server and spatial data server. Moreover the design and implementation of components of GIS client application based on JavaBeans, the GIS engine based on servlet, the GIS Application server based on GIS enterprise JavaBeans(contains session bean and entity bean) are explained.Besides, the experiments of relation of spatial data and response time under different conditions are conducted, which proves that distributed spatial database system based on J2EE can be used to manage, distribute and share large scale spatial data on Internet. Lastly, a distributed large-scale seamless image database based on Internet is presented.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.