Loglinear and Multidimensional Scaling Models of Internet Transactions

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GIScience 2002, Boulder, Colorado
An Operational Metadata Framework For
Searching, Indexing, and Retrieving Distributed
GIServices on the Internet
By Ming-Hsiang Tsou Department of Geography,
San Diego State University
E-mail mtsou_at_mail.sdsu.edu
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Why Operational Metadata?
(A Movie Presentation)

• Manipulate huge volume of geospatial data and
  images on the Internet
• Bridge the heterogeneous environments of
  distributed GIS databases and services
• Provide users and computer systems with the
  semantics and syntactic of GIS data objects.

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The Definition of Operational Metadata

• Metadata is the information which can facilitate
  users or computer systems to access, archive, and
  manipulate centralized or distributed information
  services, including data objects, software
  components, and web services.

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An Operational Metadata Scheme
Data 1
Metadata (Descriptive)
Metadata Record 1
Object (Operational)
Metadata Record 2
Metadata Record 3
Data Object, Software components, or Web Map
Services
Data 2
Relational Metadata Scheme
Object-oriented Metadata Scheme

• Flexible metadata format and update
• Protection against metadata loss
• Automatically inherit parent metadata

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The hierarchy of GIServices metadata
GIServices Metadata
UML notations
Generalization
UML Unified Modeling Language
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The Design of Operational Metadata
GeoData Object
Map Browser Java applet
Metadata
GIS-operation requirements
(A, B)
(A, B, C, D, E, F)
System
metadata
Integrating
Metadata describe how the objects should be
represented (color, symbols) and the domain of
the object (vector, line, transportation).
Other
GIS components
Self-describing, Self-managing map layers
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Operational Metadata Example

• Sd_pointofinterest
• Metadata
• Date Type Point
• Predefined Symbols star
• Display color red
• Display Size 7 point for PC, 3 points for PDA.
• Scale threshold 120,000- 110,000

Internet Map Viewer can retrieve the operational
metadata from data objects and apply it on map
display.
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GeoData Object Metadata
How to manipulate and access geodata across
different environments and devices (color scheme,
query languages, access methods for different
bandwidths)
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GIS Software Component Metadata
How to invoke / execute GIS programs across the
networks, and what are the requirements for data
input/output.
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Web Map Services Metadata
How to display web map services on the Internet
and the related GIS analysis capabilities.
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An Union Operation Example
Flood, Boulder
Land use, Boulder
Spatial Operation Metadata
Spatial Operation Metadata
Associated operation overlay, hydrological
modeling Data format Arc Coverage Operation
logs 12-3-2001, clip, Flood areas, USA.
Associated operation overlay, buffer Data
format Shapefiles Operation logs Null
Criterion-A
Spatial Operation Metadata
Associated operation overlay, buffer,
hydrological modeling. Data format Shapefiles.
Operation logs 6-7-2002, union, land use,
Boulder and Flood, Boulder.
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Metadata Framework Implementation

• Digital Library Approach
• A centralized metadata database
• Relational database engine (SQL Server, DB2,
  ACCESS)
• Metadata as records
• Server-side operations. (query and retrievals)
• Data Clearinghouse Approach
• Distributed metadata repositories (multiple
  metadata databases)
• Metadata Search Engine (Z39.50 ISITE)
• Metadata as XML or HTML documents.
• Collaborative operations. (both the clients and
  servers)

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Alexandria/California Digital Library
http//webclient.alexandria.ucsb.edu/

Centralized Databases
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FGDC NSDI Clearinghouse
http//130.11.52.184/FGDCgateway.html
Step 1 Prepare your clearinghouse site and
metadata documents and install the ISITE
software. Step 2 Register your clearinghouse
site to NSDI Step 3 The Gateway Engine will put
the new clearinghouse site on the LIST of NSDI
Clearinghouse. Step 4 People can query the
metadata via the NSDI Gateway.
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Clearinghouse Search Mechanism
Web browser (Users)
Query San Diego
FGDC Entry Point (Z39.50 Gateway)
NOAA Clearinghouse node (ISITE Isearch)
San Diego State University Clearinghouse node
(ISITE Isearch)
ESRI Geo Network (Other search engine)
NOAA Clearinghouse node (ISITE Isearch)
NOAA Clearinghouse node (ISITE Isearch)
Metadata File (SGML)
Metadata File (SGML)
Metadata File (SGML)
Metadata File (SGML)
Metadata File
Metadata File (SGML)
Metadata File (SGML)
Metadata File (SGML)
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NSDI Search Results
Problems all nodes on the same level, lack of
integration
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Alternative FrameworkHierarchical Metadata
Repository
California Atlas Metadata Repository
Register
Los Angeles Atlas Metadata Repository
San Diego Atlas Metadata Repository
Register
Register
Los Angeles Roads (Metadata)
San Diego Land use (Metadata)
San Diego Roads (Metadata)
Similar to the DNS (Domain name systems)
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Hierarchical GIS Component / Web Services
Metadata
Spatial Analysis Tool Box Metadata Repository
Register
Location Analysis Tools Metadata Repository
Hydrological Modeling Tools Metadata Repository
Register
Register
Buffering Function (Metadata)
Contouring Function (Metadata)
TIN Model (Metadata)
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Discussion and Future Development

• Semantic Search Mechanism San Diego Roads ?
  California Roads San Diego is part of the
  State of California. (Metadata ontology).
• Metadata Search vs. Data Attribute Search (San
  Diego International Airport)
• Standardization vs. Flexibility
• New technologies, new frameworks.

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SUMMARY
Traditional Metadata

• Designed for centralized, closed GISystems
• Descriptive
• Too complicated, too many fields
• Not machine readable

Operational Metadata

• More appropriate for on-line GIS applications
• Operational
• Object-oriented and flexible
• Machine readable, self-describing, self-managing