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An Overview: Ontology Concepts, Tools, Sample CEOP Ontology And Perspectives Rama Suresh NASA/MTECH CEOS WGISS Joint Subgroup.

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Presentation on theme: "An Overview: Ontology Concepts, Tools, Sample CEOP Ontology And Perspectives Rama Suresh NASA/MTECH CEOS WGISS Joint Subgroup."— Presentation transcript:

1 An Overview: Ontology Concepts, Tools, Sample CEOP Ontology And Perspectives Rama Suresh NASA/MTECH CEOS WGISS Joint Subgroup Meeting Tromso Norway, May 11, 2004

2 Background Ontology Concepts Ontology tools and Protégé CEOP background and Sample Ontology Perspectives EO Projects Outline

3 Background Current Web is a powerful means for collaboration between people, broadcasting and publishing information worldwide The next generation web will extend collaborations between to computers... Machines become capable of analyzing all the data on the Web – the content, links, and transactions between people and computers… When it arrives, the day-to-day mechanisms of trade, bureaucracy, and our daily lives will be handled by machines talking to machines, leaving humans to provide the inspiration and intuition… The intelligent "agents" people have touted for ages will finally materialize… This machine-understandable Web will come about through the implementation of a series of technical advancements and social agreements that are now beginning… Weaving the Web, Tim Berners-Lee, with Mark Fischetti. Harper San Francisco, October 1999

4 Formula for computer conversation Meaning = Ontology + representation + constraints Conclusions = Inference engine (new knowledge, experience, context) Rama Bot Must find low priced 3star hotel in Tromso, accurate 3 day Weather forecast for Tromso from May

5 Discovering the new semantic worlds Future – ubiquitous, machine-to-machine collaboration Today – increasing consistency of metadata management for some localized uses cite

6 What Is An Ontology An ontology is an explicit description of a domain: Concepts properties and attributes of concepts constraints on properties and attributes Individuals (often, but not always) An ontology defines a common vocabulary a shared understanding

7 Why Develop an Ontology? To share common understanding of the structure of information –among people –among software agents To enable reuse of domain knowledge –to avoid re-inventing the wheel –to introduce standards to allow interoperability

8 Building Ontology 1.Acquire domain knowledge - Assemble appropriate information resources and expertise in the domain of interest - These definitions must be collected so that they can be expressed in a common language selected for the ontology 2.Organize the ontology - Design the overall conceptual structure of the domain. - Identify the domain's principal concrete concepts and their properties, and their relationships among the concepts 3. Flesh out the ontology - Add concepts, relations, and individuals to the level of detail necessary to satisfy the purposes of the ontology.

9 4. Check your work - Reconcile syntactic, logical, and semantic inconsistencies among the ontology elements. - Consistency checking may also involve automatic classification that defines new concepts based on individual properties and class relationships. 5. Commit the ontology - Incumbent on any ontology development effort is a final verification of the ontology by domain experts - Subsequent commitment of the ontology by publishing it within its intended deployment environment. Building Ontology

10 Ontology building today is a fragmented practice. Proliferation of logic languages Information models that have combined to yield even more ontology forms and editing environments These tools and methodologies, along with the ontologies built with them, generally exist without proven interoperability Challenges for establishing methods to integrate ontology components with enterprise information systems and standards Ontology Issues

11 Software tools are available to accomplish most aspects of ontology development. While ontology editors are useful during each step outlined above, other types of ontology building tools are also needed along the way. More than 50 tools have been identified for building and integrating ontologies: Commercial, public domain and Academic projects Protégé is one of the tools described in the survey. Ontology Tools Survey

12 Protégé-2000 An extensible and customizable toolset for constructing knowledge bases (KBs) and for developing applications that use these KBs Outstanding features –Automatic generation of graphical-user interfaces, based on user-defined models, for acquiring domain instances –Extensible knowledge model and architecture –Scalability to very large knowledge bases

13 Protégé-2000 Java based graphical ontology-development tool Supports a rich knowledge model Open-source and freely available Large user base Easy to use Some other available tools: Ontolingua and Chimaera OntoEdit OilEd OWL plug in

14 Protégé system development methodology Protégé-2000 support determine scope consider reuse enumerate terms define classes define properties define constraints create instances In reality - an iterative process: determine scope consider reuse enumerate terms define classes consider reuse enumerate terms define classes define properties create instances define classes define properties define constraints create instances define classes consider reuse define properties define constraints create instances

15 GUI Components Tabs partition different work areas –Classes tab for defining and editing classes –Forms tab for custom-tailoring GUI forms for defining and editing instances –Instances tab for defining and editing instances –Classes & Instances tab for working with both classes and instances Widgets for creating, editing, and viewing values of a slot (or a group of slots) –Text-field or text-area widget for a slot with string value type –Diagram widget for set of slots defining a graph –Slot widgets check facet constraint violations (red rectangles) Buttons and menus for performing operations

16 Classes, slots, facets and instance are all frames

17 Protégé Information Protégé web site: –Documentation –Users Guide –Tutorial –protege-discussion mailing list –Ontology library Contributed ontologies and plugins

18 A Sample Ontology for CEOP In Situ Data Why CEOP In Situ data? Global level significant involvement and commitment In situ data is relatively simple What will it do? Will improve resource discovery and create an open interface based on standards that will include large number of users. What are the next steps? Build an ontology for CEOP involving CEOP and CEOS community that could potentially lead to a EO semantic web

19 The Coordinated Enhanced Observing Period (CEOP) was originally envisioned as a major step towards bringing together the research activities in the GEWEX Hydrometeorology Panel (GHP) and is being developed and implemented within the Global Energy and Water Cycle Experiment (GEWEX) of the World Climate Research Program (WCRP) CEOP Data sets Satellite Data TERRA, AQUA, ENVISAT and ADEOS-II), in addition to TRMM, LANDSAT, NOAA-K series and other operational satellites Observation Data (In Situ Data) Model Output Data CEOP

20 Worldwide Reference Sites

21 Primary and ancillary data sets Each Reference site has four data sets for each station that is a part of the Reference Site Surface Meteorological and Radiation Data set Flux Data Set Soil Temperature and Soil Moisture Data Set Meteorological Tower Data Set Source JAXA Metadata paper – Ben Burford CEOP In Situ Data

22 ParameterFormatMissing Value Final Units, Equations, Notes UTC Nominal Date/Tim e 16 charsN/A yyyy/mm/dd HH:MM, where MM is 00 or 30, only UTC Actual Date/Tim e 16 charsN/Ayyyy/mm/dd HH:MM CSE Identifier10 charsN/A Fill name with underscores, not spaces. Reference Site Identifier 15 charsN/A Fill name with underscores, not spaces. Station Identifier 15 charsN/A Fill name with underscores, not spaces. Latitudef decimal degrees. South is negative. Longitudef decimal degrees. West is negative. Elevationf meters CEOPS Surface Meteorological and Radiation Data

23 Station Pressuref hPa (mb). Station Pressure Flag1 charMSee Flag values Air Temperaturef Celsius. Air Temperature Flag1 charMSee Flag values Dew Point Temperature f Celsius. See Equations Dew Point Temperature Flag 1 charMSee Flag values Relative Humidityf percent. See Equations Relative Humidity Flag 1 charMSee Flag values Specific Humidityf g/kg. See Equations Specific Humidity Flag1 charMSee Flag values Wind Speedf m/s. See Equations Wind Speed Flag1 charMSee Flag values Wind Directionf degrees. See Equations Wind Direction Flag1 charMSee Flag values U Wind Componentf m/s. See Equations U Wind Component Flag 1 charMSee Flag values V Wind Componentf m/s. See Equations V Wind Component Flag 1 charMSee Flag values CEOPS Surface Meteorological and Radiation Data

24 Precipitationf millimeters. Incremental precipitation over the previous 30 minutes. Precipitation Flag1 charMSee Flag values Snow Depthf centimeters. Snow Depth Flag1 charMSee Flag values Incoming Shortwavef W/m 2. Incoming Shortwave Flag 1 charMSee Flag values Outgoing Shortwavef W/m 2 Outgoing Shortwave Flag 1 charMSee Flag values Incoming Longwavef W/m 2. Incoming Longwave Flag 1 charMSee Flag values Outgoing Longwavef W/m 2. Outgoing Longwave Flag 1 charMSee Flag values Net Radiationf W/m 2. See Equations Net Radiation Flag1 charMSee Flag values CEOPS Surface Meteorological and Radiation Data

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28 What can we do with it? We can build autonomous agents or software to fetch information Bring sites collecting data for certain period of time Bring data sets with values for temperature ranging from degree Celsius to….. Bring sites that have data parameters…….

29 CEOS 17 th Plenary Recommendation CEOS space agency members need to develop information systems with more integrated catalog, search, ordering and retrieval mechanism. It is recommended that the CEOS WGISS study how to develop this incrementally for particular application fields- building on experience gained in developing such capabilities with CEOP – and to report on its findings to the 2004 Plenary Building an Ontology for CEOP and Earth observation data is one step in this direction. This could potentially lead to EO Semantic web that will help Users in faster and efficient resource discovery Effective use of these technologies could potentially lead to an integrated catalog, search, ordering and retrieval mechanism Perspectives

30 SWEET – NASA JPL GEON – University of San Diego UK Met Office GCMD, ECHO and ESML Other Earth Science Ontology Projects


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