XML Schema-RDF Detailed Introduction

Semantic Web (Semantic Web) and Semantic Grid (Semantic Grid) technologies both rely on the Resource Description Framework (Resource Description Framework, RDF). A flexible description language. The RDF format is actually a member of a family of standards. It is used to describe information and resources, making it easy for the system to connect and associate different resources. RDF is another flexible description language that has been developed through WSemantic Web (Semantic Web) and Semantic Grid (Semantic Grid) technologies both rely on the Resource Description Framework (Resource Description Framework, RDF). The RDF format is actually a member of a family of standards. It is used to describe information and resources, making it easy for the system to connect and associate different resources.
RDF is another
W3C-approved standard for defining information and resources. RDF does not require XML, but a serialized format for describing information uses XML. Defining a resource requires specifying an
expression that contains a subject, a predicate and an object. For example, if you describe the content of a website, the subject is the website, the predicate is "contains information", and the object is the type of content. To establish links between this site and other resources, use the Friend of a Friend (FOAF) tag to establish a link between two resources. The purpose of RDF is to transform natural language statements about resources and information into a machine-parsable format. For example, the sentence
The MCSLP.com Website is authored by Martin C Brown can be rewritten into the RDF XML shown in Listing 4.
List 4. Statement of RDF XML format
         

  <rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" 
xmlns:si="http://www.recshop.fake/siteinfo#">
  <rdf:Description rdf:about="http://www.mcslp.com/ ">
    <si:author>Martin C Brown</si:author>
</rdf:Description>
</rdf:RDF>

                              ​

Another example of adopting the RDF standard is the early chain systems provided by news sites and blogs, which used RDF specifications to define feed content and different news. Listing 5 provides an example.

Listing 5. Defining feed content and different news using the RDF specification
           

<?xml version="1.0"?>
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns="http://my.netscape.com/rdf/simple/0.9/">
  <channel>
    <title>MCslp</title>
    <link>http://www.php.cn/;/link>
    <description>MCslp Projects</description>
  </channel>
  <item>
    <title>Voice enabling XMLtitle>
    <link>http://www.php.cn/;
  </item>
...

</rdf:RDF>

                                                               

The RDF standard was originally designed to describe resources on the Web , content and relationships. But RDF has now become a standard for describing general information, resources, and relationships.
Both Semantic Web and Grid technologies require the definition of resources and the relationships between them so that applications can use different information and bundle data together.                                                                                              

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