A MultiModel XML MMX Framework for Digital Video Library DVL Systems

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A Multi-Model XML (MMX) FrameworkforDigital
Video Library (DVL) Systems

• Presented by Jacky Ma
• Date 11 Dec 2001

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Presentation Outline

• Introduction
• Background
• An Example
• The Problem
• The MMX Framework
• Models
• Syntax
• Behaviors
• Conclusion
• Contribution
• Difficulties

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Introduction
4
Background

• Previous Research
• Digital Video Library (DVL)
• Extensible Markup Language (XML)
• Motivation
• Facilitate searching in DVL with XML
• Search XML in specialized and customizable way

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An XML Example
ltkey N"7" S"3" E"16" W"1"/gt ltnode
id"1"gt ltkey N"7" S"3" E"6" W"1"/gt ltnode
id"1"gt ltkey N"7" S"5" E"2" W"1"/gt ltdata
x"1" y"5"gtitemAlt/datagt ltdata x"2"
y"7"gtitemBlt/datagt lt/nodegt ltnode id"2"gt ltkey
N"4" S"3" E"6" W"4"/gt ltdata x"4"
y"3"gtitemAlt/datagt ltdata x"6"
y"4"gtitemClt/datagt lt/nodegt lt/nodegt ltnode
id"2"gt ltkey N"6" S"4" E"16" W"8"/gt ltnode
id"1"gt ltkey N"5" S"4" E"8" W"9"/gt ltdata
x"8" y"4"gtitemGlt/datagt ltdata x"9"
y"5"gtitemDlt/datagt lt/nodegt ltnode id"2"gt ltkey
N"6" S"5" E"11" W"16"/gt ltdata x"11"
y"5"gtitemFlt/datagt ltdata x"16"
y"6"gtitemElt/datagt lt/nodegt lt/nodegt
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Queried by XPath

• Based on the XML structure and the data
• Retrieve the node data containing attribute
  x8
• //data_at_x8
• Can also retrieve the parent-node, sibling-node,
  etc.
• /node1/node1/key/following-sibling
• Useful in XSLT

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Queried by RDBMS

• Based on the data
• Classical select from clause
• Can retrieve any item based on its attributes

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Queried by R-Tree

• How about if I told you it is a R-Tree?
• Spatial Queries
• Give me the point at (2,7)
• Give me the point nearest to (4,4)
• Nearest Neighbor Search
• Give me the point nearest to itemB

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What makes the difference?

• Make use of knowledge we have on the data given.
• We can do the spatial query ONLY if we know the
  data segment is representing a R-Tree, and
  understand what are the attributes (id, N, S, E,
  W, etc.) representing.

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Problem

• There are a lot of different data structures,
  different data manipulations, and different query
  methods.
• How could we model them with XML?

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The MMX Framework
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The MMX Framework

• To solve the previous problem
• A framework allowing various data structures to
  be implemented upon
• Knowledge on knowledge
• Describe the structural information of XML
  Document
• Empirical knowledge
• Analogeous to RDF
• Manipulation of information with structural
  information
• Queries
• Updates
• Exchanging information

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Model the Models

• The kinds of Models is unlimited
• They may looks similar, all of them can be
  represented by graphs or XML tree
• But the underlying structures, constraints and
  algorithms are different
• No generic descriptive syntax
• Use a label and procedural approach
• Label known structures, and
• Program the new structures

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Major Labeled Models

• Generic
• Object
• Vector
• Relational
• Document
• Tree

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Basic Model

• Abstract Data Object (ADO)
• Encapsulate the information about a package of
  structured data
• Accessible at Root
• Pointing out at Child Node
• Includes
• Model Name
• Properties
• Behaviors
• Data

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Syntax

• Serialization Syntax
• Embedded in XML Document
• Defines elements like ltadogt, ltpropertygt, etc.
• Easy to use
• Change the document instance
• Schema Syntax
• Embedded in XML Document Schema
• Associate element names with structural
  information
• More complicated
• Do not need to change the document
• Favors reusability, scalability and
  interoperability

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Behaviors

• Behaviors
• The program to manipulate the data
• Default Behaviors allow operations on any
  standard ADOs
• Properties
• Persistent variables
• Keeping the state of the ADO
• Data
• User data
• Appear as DOM Tree to the Behavior program

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Conclusion
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Contribution

• Propose a representation to encapsulate data
  structures
• A procedural model to manipulate the data
• Promote the use of interoperable data structure
  format
• Describe how will typical Models functions
• Describe the Tree model which features spatial
  queries, and particularly suitable for searching
  in DVL

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Difficulties

• No general syntax can precisely describe all
  kinds of data structures
• Not possible to include all data structures
  one-by-one

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Research Direction

• Develop the full specification for the MMX
  Framework
• Develop various structures that tailored for
  content-based searching in DVL

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QA