Database and Metadata Support of a Web-based. based Multimedia Digital Library for Medical Education

Transcription

1 Database and Metadata Support of a Web-based based Multimedia Digital Library for Medical Education Jianting Zhang, Le Gruenwald, Chris Candler, Gary McNutt, Wei Shung Chung School of Computer Science College of Medicine The University of Oklahoma 1

2 Introduction Outline Proposed Architecture Metadata and Database Design Conceptual Design of Metadata Management Mapping Conceptual Design to RDBMS Implementation Mapping RDBMS Table Structure to IEEE/IMS Metadata Specifications Metadata and Database Supported Applications Building an Online Metadata Searching Engine Content Packaging Conclusion and Future Work Directions 2

3 Introduction Hippocrates [ ] Online curriculum website of the College of Medicine at the University of Oklahoma Thousands of images, videos, animations and numerous web pages: 1.5 Gigabytes of space Web-enabled file system (IIS/ColdFusion) No metadata support Only support full-text search using standard text search engine Can not search through multimedia data 3

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5 Project Goals Multimedia Resource Repository with Full Database Support Metadata based on IMS (Instructional Management System) Specification and MeSH (Medical Subject Headings) Standard Content-Based and Semantic Searching Based on Metadata Improving Exchangeability of Online Courses by Using XML Data Mining on Learning Patterns Using Tracking/Logging data 5

6 Related Work The National SMETE Library program (NSDL) Domain specific education digital library systems Biology (Futrelle, 2001) Earth System (Marlino, 2000) 6

7 Metadata Standards General purposed and simplified Dublin Core metadata (DC) XML related metadata standard DTD/XML Scheme/RDF MPEG-7 for multimedia IEEE Learning Object Metadata (LOM) IMS (Instructional Management System) Global Learning Consortium standards 7

8 Unified Medical Language System (UMLS) One of the most prevalent systems in representing medical knowledge Includes Metathesaurus, Specialist Lexicon and Semantic Network MeSH (Medical Subject Heading) is one of the Metathesaurus We use MeSH controlled vocabulary as the source of the taxopath specified in the LOM 8

9 Proposed Architecture Tracking, Logging & Data Mining Packaging & Export Tier 1: Web Browser HTTP Content Model Metadata Model Tier 2: ColdFusion Application Server Session Management Authorization ODBC Tier 3: SQL Server Interface Development Searching Engine 9

10 Techniques involved Multimedia Medical Information Database SQL Server, ColdFusion, Java/VB Script, HTML, XML, IMS, MeSH, Education Web Metadata 10

11 Hierarchy of Learning Objects -Course (Biochemistry) -Subheading (Metabolic Pathway Animations) -Resource (Interactive Slide Atlas) -Section (Cytology) -Multimedia File (Slide91.jpg) 11

12 Generic LO Hierarchy Mapped to ER Model 12

13 Common Metadata Attributes Mapped to ER Model 13

14 Multimedia LOs and their Metadata 14

15 Mapping Conceptual Design to RDBMS Implementation RDBMS v.s. XML Technology maturity Storage overhead Vertical Segmentation of Metadata Elements Put the metadata elements common to all LOs into one table and metadata elements specific to a particular type of LO into a separate table Relation Table: (ParentID, ParentType, ChildID, ChildType) Advantages Conceptual Simplicity Coding Simplicity Flexible Extensibility 15

16 Mapping RDBMS Table Structure to IMS Metadata Specifications 16

17 Building an Online Metadata Searching Engine 1. Divide the searchable metadata attributes into several logical groups 2. Select on the metadata attributes among the groups 3. Specify metadata values for each selected metadata attribute MeSH keywords will be mapped to MeSH IDs String based attributes: specify sub-string to be contained Number and date based attributes: specify lower and upper bound limits 4. Dynamic SQL query string generation and query result rendering 17

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19 Searching Engine Snapshots (1) 19

20 Searching Engine Snapshots (2) 20

21 Searching Engine Snapshots (3) Search Results 21

22 Content Packaging Compliance with IMS Content Packaging Specification Extract related explicit or implicit information from the database tables and generate a Manifest in XML The Manifest together with the related learning object content are added to a Zip file by calling a server-side Java class Memory Variable Single file Whole directory (recursively) 22

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24 Conclusion Summarized our work in transferring a file repository into a multimedia digital library on top of a database system for medical education Presented our design and implementation of database schemas, metadata management, metadata-based searching engine and IMS compliant content packaging 24

25 Future Work Directions Add more semantic-based metadata attributes, such as incorporating UMLS semantic networks, to LOs Use standardized multimedia description scheme, such as MPEG-7, as multimedia metadata Provide better GUI and web-content authoring tools 25