12.1.4. RDF instance

RDF instance ¶

This is a few lines of a CD list:

Title	Artists	The country	Company	Price	Year
Empire Burlesque	Bob Dylan	USA	Columbia	10.90	1985
Hide your heart	Bonnie Tyler	UK	CBS Records	9.90	1988

Title

Artists

The country

Company

Price

Year

Empire Burlesque

Bob Dylan

USA

Columbia

10.90

1985

Hide your heart

Bonnie Tyler

CBS Records

9.90

1988

These are several lines of an RDF document:

<?xml version="1.0"?>
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:cd="http://www.recshop.fake/cd#">
<rdf:Description
rdf:about="http://www.recshop.fake/cd/Empire Burlesque">
  <cd:artist>Bob Dylan</cd:artist>
  <cd:country>USA</cd:country>
  <cd:company>Columbia</cd:company>
  <cd:price>10.90</cd:price>
  <cd:year>1985</cd:year>
</rdf:Description>
<rdf:Description
rdf:about="http://www.recshop.fake/cd/Hide your heart">
  <cd:artist>Bonnie Tyler</cd:artist>
  <cd:country>UK</cd:country>
  <cd:company>CBS Records</cd:company>
  <cd:price>9.90</cd:price>
  <cd:year>1988</cd:year>
</rdf:Description>
.
.
.
</rdf:RDF>

The first line of this RDF document is the XML declaration. This XML declaration is followed by the root element of the RDF document: <rdf:RDF> .

xmlns:rdf Namespace, which specifies that elements with the prefix rdf come from the namespace “ http://www.w3.org/1999/02/22-rdf-syntax -ns#”.”

xmlns:cd Namespace, which specifies that elements with the prefix cd come from the namespace “ http://www.recshop.fake /cd#”.”

<rdf:Description> The element contains a response to the rdf:about The description of the resource identified by the.

Elements: <cd:artist> 、 <cd:country> 、 <cd:company> And so on are properties of this resource.

RDF online verifier ¶

W3C 的 RDF 验证服务 It is very helpful when you learn RDF. Here you can experiment with RDF files.

The RDF online validator parses your RDF document, checks its syntax, and generates tables and graphical views for your RDF document.

Copy and paste the following example into the W3C RDF validator:

<?xml version="1.0"?>
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:si="http://www.runoob.com/rdf/">
<rdf:Description rdf:about="http://www.runoob.com">
  <si:title>runoob.com</si:title>
  <si:author>Jan Egil Refsnes</si:author>
</rdf:Description>
</rdf:RDF>

After you parse the above example, the result will look something like this.

In recent years, Geographic Information Systems (GIS) have undergone rapid development in both theoretical and practical dimensions. GIS has been widely applied for modeling and decision-making support across various fields such as urban management, regional planning, and environmental remediation, establishing geographic information as a vital component of the information era. The introduction of the “Digital Earth” concept has further accelerated the advancement of GIS, which serves as its technical foundation. Concurrently, scholars have been dedicated to theoretical research in areas like spatial cognition, spatial data uncertainty, and the formalization of spatial relationships. This reflects the dual nature of GIS as both an applied technology and an academic discipline, with the two aspects forming a mutually reinforcing cycle of progress.