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Techniques for Information Searching and Retrieval of Web-based Multimedia Digital Library. Presented by: Vincent Cheung Supervisors: Prof. Michael Lyu Prof. K.W. Ng Markers: Prof. K. H. Lee Prof. Y. S. Moon. 3 May 2000. Abstract.
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Techniques for Information Searching and Retrieval of Web-based Multimedia Digital Library Presented by: Vincent Cheung Supervisors: Prof. Michael Lyu Prof. K.W. Ng Markers: Prof. K. H. Lee Prof. Y. S. Moon 3 May 2000
Abstract • Digital Library is getting more and more popular, due to its strength in searching and retrieving information. • Web-based environment provides a better media for information sharing. • The trend that more multimedia information are needed to be stored instead of pure text. • Research on the techniques for multimedia information searching and retrieval in a web-based digital library.
Presentation Outline • XML overview • Data structures for multimedia news archives • for video clips • using graph structures of XML • giving annotation • Architecture and agents of digital library • Research plan and conclusion
Overview of XML • XML - eXtensible Markup Language • Proposed by WWW Consortium, in 1998 • To define a complete, platform-independent and system-independent environment for the authoring and delivery of information resources across the web. • Semistructured
How XML differs from HTML • Extensibility - new tags may be defined at will • Structure - XMLStructures can be nested to arbitrary depth • Validation - An XML document can contain an optional description of its grammar
database news news date title reporter content XML Documents • use elements and attributes to describe your document • <database> • <news> • <date year = “2000” month = “4” day = “15”/> • <title>Press warning appropriate, says Beijing</title> • <reporter>Kong Lai-fan</reporter> • <reporter>Greg Torode</reporter> • <content> • Beijing yesterday defended remarks made by senior • SAR-based official Wang Fengchao that local media • should avoid reporting separatist views. • </content> • </news> • <news> • . . . • </news> • </database>
Document Type Definition • providing the definition of a document type, for member documents to follow • <!DOCTYPE database [ • <!ELEMENT database (news*)> • <!ELEMENT news (date,title,reporter*,content)> • <!ELEMENT date year CDATA #REQUIRED • month CDATA #REQUIRED • day CDATA #REQUIRED> • <!ELEMENT title (#PCDATA)> • <!ELEMENT reporter (#PCDATA)> • <!ELEMENT content (#PCDATA)> • ]>
Data Structure for News Videos • Multimedia presentation • Graph structure property • keyword directory • thesaurus / classification directory • person / place directory • Chinese-English dictionary • Semistructure property • annotation
Indexing a Video • Segment the video hierarchically into scenes. (A video is composed of one or more related scenes.) • Describe the complete news video using bibliographic information (title, source, reporters, and abstract, etc…) plus format, duration, etc. • Describe each scene – id, start frame (time), end frame (time), keyframe, and scripts. • A OCR tools is implemented for indexing the videos in last semester.
Indexing a Video For a news clip: id = 1234 title = N. T. swamped after torrential downpour date = 1999-9-9 source = Hone Kong ATV reporter = Chan Tai Man abstract = Large areas of the northwest New Territories were under water yesterday as torrential rain swept across the SAR. duration = 2:34:56 has_scene = 1234.1, 1234.2, 1234.3 format = MPEG language = Cantonese identifier = http://www.cse.cuhk.edu.hk/1.mpg”
Indexing a Video For a scene: id = 1234.1 belong_to = 1234 next_scene = 1234.2 prev_scene = null start_time = 0:0:00 end_time = 0:30:45 keyframe = 1238 transcrpt = . . .
Sample News Entry In NewsDatabase.XML: <database> <news> <date><year>2000</year><month>4</month><day>15</day> </date> <title>N.T.swamped after torrential downpour</title> <content>Large areas of the northwest New Territories were under water yesterday as torrential rain swept across the SAR. </content> </news> . . . </database>
Keyword Directory • Each news has its own keyword elements • Build a keyword directory containing all keywords • Every keyword points to the news that having the same keyword
Keyword Directory news ID = 0010 title date keyword reporter … N. T. swamped after torrential downpour 15 April, 2000 flood Clifford Lo News Database is a tree structure keyword keyword keyword keyword … flood France fuel gun ID ID ID … Keyword directory would be pointed by news entries, and also point to news entries. 0010 0017 0137 database news news news news … ID = 0010 ID = 0015 ID = 0017 ID = 0043 Keywords point to news database again to for a graph structure
Keyword Directory In NewsDatabase.XML: <database> <news ID=”0010”> <date><year>2000</year><month>4</month><day>15</day> </date> <title>N.T.swamped after torrential downpour</title> <keyword>flood</keyword> <keyword>storm</keyword> <content>Large areas of the northwest New Territories were under water yesterday as torrential rain swept across the SAR. </content> </news> . . . </database>
Keyword Directory In KeywordDirectory.XML: <keyworddirectory> . . . <keyword word=”flood”> <newsid>0010</newsid> <newsid>0017</newsid> <newsid>0137</newsid> . . . </keyword> . . . </keyworddirectory>
Thesaurus/Classification Directory • To search for terms with similar meaning to the keyword • <thesaurus> • <item term = “organisation”> • <spelling>organization</spelling> • <similar>association</similar> • </term> • <item term = “World Trade Organization”> • <spelling>World Trade Organisation • </spelling> • <abbreviation>WTO</abbreviation> • </item> • . . . • <thesaurus>
Thesaurus/Classification Directory • To search for subset terms of the given keyword • <thesaurus> • <item term = “organisation”> • <spelling>organization</spelling> • <similar>association</similar> • </term> • <item term = “disaster”> • <contains>flood</contains> • <contains>earthquake</contains> • <contains>fire</contains> • <contains>storm</contains> • </item> • <item term = “flood”> • <belongs>disaster</belongs> • </item> • . . . • <thesaurus>
Person / Place Directory • Person Directory ( Person ID, name, newsid, …) • <person_directory> • <person id = “wangfengchao”> • <name><first>Fengchao</first><last>Wang</last></name> • <nationality>Chinese</nationality> • <organization> The central Government’s Liaison Office </organization> • <position>deputy director</position> • <newsid>0123</newsid> <newsid>0245</newsid> ... • </person> • . . . • </person_directory>
Person / Place Directory • In news database: • <newsdatabase> • <news id = “0123”> • <date year=“2000” month=“4” day=“15”/> • <title>Press warning appropriate, says Beijing • </title> • <reporter>Kong Lai-fan</reporter> • <content> • Beijing yesterday defended remarks madeby senior • SAR-based official <person id=“wangfengchao”> • Wang Fengchao</person> that local media should • avoid reporting separatist views. • </content> • </news> • . . . • </newsdatabase>
news ID = 0123 title date keyword content … media Presswarning appropriate, says Beijing 15 April, 2000 Person Wang Fengchao person person person person … Wang Fengchao John Tom Robert ID ID ID … Person directory would be pointed by news entries, and also point to news entries. 0123 0246 0369 database news news news news … ID = 0123 ID = 0155 ID = 0246 ID = 0258 Person entries point to news database again to form a graph structure Person / Place Directory
Person / Place Directory Place Directory: category structure <place_directory> <place_id=“china” class=“country”> <name>China</name> <newsid>5839</newsid> . . . <have_places> <place_id>=“hongkong” class=“SAR”> <name>Hong Kong</name> <have_places> <place id=“NT” class=“district”> <name>New Territories</name> </place> . . . </have_places> <newsid>0010</newsid> . . . </place> . . . </have_places> ` </place> </place_directory>
Person / Place Directory • In news database: • <newsdatabase> • <news id = “0010” place=“hongkong”> • <date year=“2000” month=“4” day=“15”/> • <title>N.T.swamped after torrential downpour </title> • <reporter>Clifford Lo</reporter> • <content> • Large areas of the northwest <place id=“NT”> • New Territories</place> were under water yesterday as torrential rain swept across the • <place id=“hongkong”> SAR </place>. • </content> • </news> • . . . • </newsdatabase>
Chinese-English Dictionary • Translate the keywords for searching • We can have English to Chinese dictionary: <e2cdict> <english char = “f”> <english char = “l”> <english char = “o”> <english char = “o”> <english char = “d”> <chinese>氾濫</chinese> <chinese>水災</chinese> <chinese>洪水</chinese> . . . </english> </english> . . . </e2cdict>
Chinese-English Dictionary • We can have Chinese to English dictionary: <c2edict> <chinese term = “世”> <chinese term = “貿”> <english>WTO</english> <english>World Trade Organization </english> </chinese> . . . </chinese> . . . </c2edict>
Annotation • XML is semistructured! • More flexibility in adding tags to contents. • Add our tags to give annotation to the strings to provide “meanings” to it. • Hence, more expressive queries can be supported.
Annotation: example <content> Radioactive coolant water leaked at a nuclear reactor in western Japan yesterday, but the accident had no impact on the environment, the plant director said. "Today when the plant was operating with its usual output, a worker found a small leak of primary coolant water from a pipe of the No 2 reactor," said Katsuhiko Takahashi. </content> • We understand… but the system doesn’t…
Annotation: example <content> <disaster nature=“radioactive” death=“0” injuried=“0”>Radioactive coolant water leaked at a nuclear reactor</disaster> in western <place id=“japan”> Japan </place>yesterday, but the accident had no impact on the environment, the plant director said. "<speech speaker="Katsuhiko Takahashi"> Today when the plant was operating with its usual output, a worker found a small leak of primary coolant water from a pipe of the No 2 reactor </speech>," said <person="Katsuhiko Takahashi">Katsuhiko Takahashi </person>. </content>
Usage of Annotation • So, we can have queries like: • All the speeches from Zhu Rongji in last month • All storms which kill more than 200 people • We can also make some links to give more details to people or places, etc.
Architecture of Digital Library • Designing stores and query processors for semistructured data. • Traditional database systems use a client/server architecture. • Over the distributed environment has given rise to two new architectures, they are data warehouses and mediators. • Video servers will also be integrated to our system to provide video streaming.
Data Warehouse client client client answer query warehouse data update update data data data update server server server data data data
client client client answer query mediator query query answer answer answer query server server server data data data Mediator
Agents Using Structured Data • Larger demands for more structured data than loosely structured HTML. • Using semistructured XML data can provide a very good environment for Web agents. • Our main aim of implementing our agent is to illustrate that our semistructured XML data can provide a better environment for an agent to work.
Research Plan & Conclusion • Design of the structure in XML semistructured format • to support multimedia data, multilingual data, and various kind of retrieval. • Architecture of the system that allows multiple sources of data. • Implementing an agent is to illustrate that our semistructured data can provide a better environment for an agent to work.