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http://gis.pku.edu.cn
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Web Service and Geographical Web Service and Geographical Information IntegrationInformation Integration
—— —— Peking Peking Spatial Applications Integrating Infrastructure, Spatial Applications Integrating Infrastructure, A Research for Spatiality-oriented Web Service ApplicationA Research for Spatiality-oriented Web Service Application
Lab of Spatial Information System@PKULab of Spatial Information System@PKU
http://gis.pku.edu.cn
http://gis.pku.edu.cn
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Syllabus Syllabus
• Introduction of Spatial ApplicationIntroduction of Spatial Application
• Design Intention of Peking Spatial Applications Design Intention of Peking Spatial Applications Integrating Infrastructure(PAI)Integrating Infrastructure(PAI)
• Web Service-Based Distributed Spatial Web Service-Based Distributed Spatial Information Disposition ArchitectureInformation Disposition Architecture
• QoS Strategies in Spatial Information Integration QoS Strategies in Spatial Information Integration & Disposition& Disposition
• An Example for PAI-Organized ApplicationsAn Example for PAI-Organized Applications
http://gis.pku.edu.cn
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Introduction of Spatial ApplicationIntroduction of Spatial Application
• Characteristic of Spatial Information and Manipulation Characteristic of Spatial Information and Manipulation PlatformPlatform Spatial information:
Massive; Long time of data sedimentation; Multiple spatial data models; Adhere to certain GIS platform to be accessible; …
Spatial information manipulation platform: Data stored in heterogeneous GIS(dominated as
MapInfo, ArcInfo) platform or inner spatial module presented by certain manufacturers(Oracle Spatial by Oracle);
Relevant services, product series based on platform self-defined organization;
Single accessible data portal; …
http://gis.pku.edu.cn
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Introduction of Spatial ApplicationIntroduction of Spatial Application
• Characteristic of Conventional Spatiality-oriented Characteristic of Conventional Spatiality-oriented ApplicationApplication Direct development of application based on platform-Direct development of application based on platform-
critical architecture;critical architecture; Spatial information visualization, query, and edition Spatial information visualization, query, and edition
at the front end based on homogeneous data storage at at the front end based on homogeneous data storage at the back end;the back end;
Whenever inter-platform integration is needed, the Whenever inter-platform integration is needed, the writing of application-related adapter software for writing of application-related adapter software for each participating platform is used;each participating platform is used;
…… ……
http://gis.pku.edu.cn
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Introduction of Spatial ApplicationIntroduction of Spatial Application
• Challenges imposed by nowadays spatial data Challenges imposed by nowadays spatial data integration:integration: Participated by processes running on heterogeneous Participated by processes running on heterogeneous
platforms from multiple organizations;platforms from multiple organizations; Integrating existed spatial application systemsIntegrating existed spatial application systems;; Implement of dynamic integrationImplement of dynamic integration accounting for on- accounting for on-
time subsystem scalability;time subsystem scalability; Refining of existing services to present QoS Refining of existing services to present QoS
attributes during integrated service formation;attributes during integrated service formation; Semantic level interoperation to obtain automatic Semantic level interoperation to obtain automatic
service communication and assemblage;service communication and assemblage; …… ……
http://gis.pku.edu.cn
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Introduction of Spatial ApplicationIntroduction of Spatial Application
• Which we are confronted lies in that:Which we are confronted lies in that:
Prevalent large-scaled spatial applications(Digital Prevalent large-scaled spatial applications(Digital City, ECity, E-Government-Government) call for a more ) call for a more flexible, flexible, dynamical, semanticdynamical, semantic integration among existing integration among existing legacy data, system, platform and framework. legacy data, system, platform and framework.
http://gis.pku.edu.cn
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Introduction of Spatial ApplicationIntroduction of Spatial Application
• Work of OGC in Improvement of Spatial Interoperability A common architectural framework for web-based
geospatial services; Concentrating on definition of behavior of functional
components common to all such services and extensible for specific services and service types;
Specification for distributed computing interaction, distributed computing workflow
• Our Emphasis: Above-base integration of Web Services to obtain dynamic interoperation
http://gis.pku.edu.cn
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• Introduction of Spatial ApplicationIntroduction of Spatial Application
• Design Intention of Peking Spatial Applications Design Intention of Peking Spatial Applications Integrating Infrastructure(PAI) Integrating Infrastructure(PAI)
• Web Service-Based Distributed Spatial Web Service-Based Distributed Spatial Information Disposition ArchitectureInformation Disposition Architecture
• QoS Strategies in Spatial Information Integration QoS Strategies in Spatial Information Integration & Disposition& Disposition
• An Example for PAI-Organized ApplicationsAn Example for PAI-Organized Applications
Syllabus Syllabus
http://gis.pku.edu.cn
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Design Intention of PAIDesign Intention of PAI
• The main goal of PAI infrastructure is to provide open
second-time developing platform of spatial information
application integration;
• Provide united sharing mechanism and support
technologies to access and acquire spatial information;
• Solve distributing and heterogeneity of spatial
applications(such as heterogeneity of GIS platforms,
systems, expression and semantic collision);
• Provide interoperation platform for isolated spatial
applications
http://gis.pku.edu.cn
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Design Intention of PAIDesign Intention of PAI
• Reasons for the construction of PAI based on Reasons for the construction of PAI based on Web Service oriented distributed frameworkWeb Service oriented distributed framework Web Service concentrates on fast conformity and Web Service concentrates on fast conformity and
deployment of legacy systems, which facilitates the deployment of legacy systems, which facilitates the integration of existing spatial applications;integration of existing spatial applications;
Web service can separate system implementation and Web service can separate system implementation and function interfaces by function publishing as services, function interfaces by function publishing as services, which permits flexible function replacement in which permits flexible function replacement in implementation aspect;implementation aspect;
Security of sensible data and relevant services inside Security of sensible data and relevant services inside some industries are well protected because of the some industries are well protected because of the separation between interfaces and implementationsseparation between interfaces and implementations
http://gis.pku.edu.cn
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• Introduction of Spatial ApplicationIntroduction of Spatial Application
• Design Intention of Peking Spatial Applications Design Intention of Peking Spatial Applications Integrating Infrastructure(PAI)Integrating Infrastructure(PAI)
• Web Service-Based Distributed Spatial Web Service-Based Distributed Spatial Information Disposition ArchitectureInformation Disposition Architecture
• QoS Strategies in Spatial Information Integration QoS Strategies in Spatial Information Integration & Disposition& Disposition
• An Example for PAI-Organized ApplicationsAn Example for PAI-Organized Applications
Syllabus Syllabus
http://gis.pku.edu.cn
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Web Service-Based Distributed Spatial Web Service-Based Distributed Spatial Information disposition ArchitectureInformation disposition Architecture
http://gis.pku.edu.cn
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• Introduction of Spatial ApplicationIntroduction of Spatial Application
• Design Intention of Peking Spatial Applications Design Intention of Peking Spatial Applications Integrating Infrastructure(PAI)Integrating Infrastructure(PAI)
• Web Service-Based Distributed Spatial Web Service-Based Distributed Spatial Information Disposition ArchitectureInformation Disposition Architecture
• QoS Strategies in Spatial Information Integration QoS Strategies in Spatial Information Integration & Disposition& Disposition
• An Example for PAI-Organized ApplicationsAn Example for PAI-Organized Applications
Syllabus Syllabus
http://gis.pku.edu.cn
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QoS Strategies in Spatial Information QoS Strategies in Spatial Information Integration & DispositionIntegration & Disposition
• Problems deserved consideration in current Problems deserved consideration in current integration:integration: Massive spatial information presented in GML
format in PAI to ease interaction, while GML is pain-text format, which leads to deficiency in transmission;
Frequent map retrieval which calls for data caches to be maintained both in Adapter Service or in Integrating Coordinator(IC) Layer;
Differentiated Services of map to the clients which have different network situations and application requirements;
……
http://gis.pku.edu.cn
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QoS Strategies in Spatial Information QoS Strategies in Spatial Information Integration & DispositionIntegration & Disposition
• Current QoS Strategies in PAICurrent QoS Strategies in PAI
GML data compressionGML data compression
During data transformation & client-end transmission;
Compression editions maintained in caches of IC Layer
Implementation of cache mechanism flexible to multiple Implementation of cache mechanism flexible to multiple
spatial data granularitiesspatial data granularities
Caches by Adapter Service, IC Layer & Web browsers
Elaborate selection of content-equivalent data providersElaborate selection of content-equivalent data providers
Non-function facets, history records & fatal parameters of Web
services
Other QoS-related Differentiated ServicesOther QoS-related Differentiated Services
Vector map clipping, On-line map generation …
http://gis.pku.edu.cn
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QoS Strategies in Spatial Information QoS Strategies in Spatial Information Integration & DispositionIntegration & Disposition
A typical application aided by QoS strategy based on PAI architecture
Geo-UnionDatabase
ArcInfoMap File
MapInfoMap File
Applet
Metadata Requesting
User Requesting
PAIToolkits
MDS
QueryingWebService
Services Requesting
Coordinate Transformer Spatial Analysisor
WebApplication
Using
QoS Interaction Process
Considering
http://gis.pku.edu.cn
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QoS Strategies in Spatial Information QoS Strategies in Spatial Information Integration & DispositionIntegration & Disposition
• Typical Workflows:Typical Workflows:
Sample API in PAI Sample API in PAI ToolkitsToolkits
Invoked Web Service WorkflowInvoked Web Service Workflow
retrieveMapretrieveMap
(MapName)(MapName)
MDS(for layer info & adapter service Info)MDS(for layer info & adapter service Info)
Adapter Service(for corresponding GML data Adapter Service(for corresponding GML data of certain layer)of certain layer)
retrieveMapasJPEGretrieveMapasJPEG
(MapName)(MapName)
QoS Consultation Service(for Cache Info) QoS Consultation Service(for Cache Info) (Uncached) MDS (Uncached) MDS Adapter Service Adapter Service
(Cached)(Cached)
Spatial Analysis Service(for on-line JPEG Spatial Analysis Service(for on-line JPEG transformation)transformation)
http://gis.pku.edu.cn
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• Introduction of Spatial ApplicationIntroduction of Spatial Application
• Design Intention of Peking Spatial Applications Design Intention of Peking Spatial Applications Integrating Infrastructure(PAI)Integrating Infrastructure(PAI)
• Web Service-Based Distributed Spatial Web Service-Based Distributed Spatial Information Disposition ArchitectureInformation Disposition Architecture
• QoS Strategies in Spatial Information Integration QoS Strategies in Spatial Information Integration & Disposition& Disposition
• An Example for PAI-Organized ApplicationsAn Example for PAI-Organized Applications
Syllabus Syllabus
http://gis.pku.edu.cn
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Examples for PAI-Organized ApplicationsExamples for PAI-Organized Applications
• We have implemented the LBS service based on We have implemented the LBS service based on PAI framework PAI framework
• Designed for both mobile terminal and PCDesigned for both mobile terminal and PC
• Provides some location-based services Provides some location-based services
finding the nearest service facilities (for example banks)finding the nearest service facilities (for example banks) getting the nearest services facilitiesgetting the nearest services facilities finding the position of oneself or one’s friendsfinding the position of oneself or one’s friends getting the relevant information about appointed getting the relevant information about appointed
position position …………
http://gis.pku.edu.cn
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Examples for PAI-Organized ApplicationsExamples for PAI-Organized Applications
http://gis.pku.edu.cn
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Components of Layers in LBS
Web Client
Web Application
Integrated Coordinator
Distributed
Services
Distributed Information
PC 、 Mobile phone 、 multimedia message 、 laptop and so on
LBS Server
LBS Worker GML Retriever
Metadata services, Spatial data gateway, GML analyzing services, Format adapt Services
Metadata database, Spatial data file, Database and map layer file on Oracle Spatial, Geo-Union, MapInfo
An Example for PAI-Organized ApplicationsAn Example for PAI-Organized Applications
http://gis.pku.edu.cn
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An Example for PAI-Organized ApplicationsAn Example for PAI-Organized Applications
http://gis.pku.edu.cn
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Another Work in Our LabAnother Work in Our Lab
GMLWeb Resource
GMLWeb Service
GMLApp Service
PKGML Kernel
DataAccessing
DataParsing
Cachingand
Indexing
MemoryData
Pooling
Displayingand
Interacting DataStructure
andAlgorithms
PKGMLApplet
PKGMLPortable
PKGMLComponent
A GML-bases lightweight WebGIS system PKGMLhttp://m
ap.pku.edu.cn
http://gis.pku.edu.cn
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Lab of Spatial Information System@PKULab of Spatial Information System@PKU
http://gis.pku.edu.cn