Web semantics of website construction

Web semantics

What is Web Semantics?

What is semantic? In fact, simply put, the machine can read the content.

• The Beatles are a popular band from Liverpool.
• John Lennon was a member of the Beatles.
• "Hey Jude" is a masterpiece by the Beatles.

We can easily understand the meaning of the sentence above. But how do these statements be understood by computers?

Statements are created by syntax rules. T he syntax of a language defines the rules for creating language statements. But how do you make syntax semantic?

A semantic web is a way for machines to understand data. S emantic web technology, which includes a set of descriptive language and reasoning logic. It is packaged with a number of formats that describe the ontology.

Semantic Web is not a link between Web pages.

Semantic webs describe the associations between things (e.g. A is part of B, Y is a member of Z) and the properties of things (e.g. size, height, age, price, etc.).

The implementation of the Semantic Web is based on the XML (extensible markup language eXtensible Markup Langauge) language and resource description framework (RDF). X ML is a tool for defining markup languages, including XML declarations, DTDs to define language syntax, detailed descriptions of tags, and the document itself. T he document itself contains tags and content. R DF is used to express the content of a web page.

The resource description framework

The Resource Description Framework, the resource description framework, is the language specification recommended by W3C to describe the information resources on the WWW and their relationships.

RDF(S) is an important part of the semantic network, which uses URIs to identify different objects (including resource nodes, property classes, or property values) and to connect different URIs to clearly express relationships between objects.

Realize

Although semantic network is a better network, but the implementation is a complex and huge project. At present, the architecture of semantic network is under construction, which mainly needs the support of the following two aspects:

That is: through a unified set of perfect data standards for network information more thorough and detailed marking, so that the semantic network can accurately identify information, distinguish the role and meaning of information to make semantic web search more accurate and thorough, easier to judge the truth and false information, so as to achieve practical goals, first of all, the standard needs to develop standards, the standard allows users to add metadata to the network content (i.e., explain detailed tags), and allow users to pinpoint what they are looking for; To ensure that different programs can share the content of different websites, and finally, users are required to add additional features, such as adding applications.

The implementation of the Semantic Web is based on the XML (extensible markup language eXtensible Markup Langauge) language and resource description framework (RDF). X ML is a tool for defining markup languages, including XML declarations, DTDs to define language syntax, detailed descriptions of tags, and the document itself. T he document itself contains tags and content. RDF is used to express the content of a web page.

If data networks can be implemented in a short time through hundreds of millions of individuals, then the semantic intelligence of the network must be realized through the efforts of the cutting-edge intelligent groups of human beings. The development of an information search engine with semantic analysis ability will become the most important step of semantic network, which can understand human natural language, and has certain reasoning and judgment ability.

Semantic search engines and semantically analytical search engines are two different things. The former is just the use of semantic network, a way of information search, and semantic analysis ability of search engines is a kind of understanding of natural language, through computer reasoning to further provide more in line with the user's psychological answer.

Prospect

The architecture of semantic network is under construction, the current international research on this architecture has not yet formed a satisfactory and rigorous logical description and theoretical system, Chinese scholars on the architecture is only based on foreign research to make a brief introduction, has not yet formed a systematic elaboration.

The implementation of the Semantic Network requires the support of three key technologies: XML, RDF, and Ontology.

XML (eXtensible Marked Language, which extends the markup language) allows information providers to define tags and property names on their own as needed, making the structure of XML files as complex as necessary.

It has the advantages of good data storage format and scalability, highly structured and easy network transmission, and its unique NS mechanism and XML Schema support a variety of data types and verification mechanisms, making it one of the key technologies of semantic network.

Current discussions about the key technologies of semantic networks have focused on RDF and Ontology.

RDF is a language specification recommended by W3C organizations to describe resources and their relationships, and has the characteristics of simplicity, ease of expansion, openness, ease of exchange and easy synthesis.

It is important to note that RDF defines only how resources are described, but not what data is used to describe resources. RDF consists of three parts: RDF Data Model, RDF Schema, and RDF Syntax.

1. Semantic Network by extending the existing Internet, adding content to the information that expresses its meaning, so that computers can automatically work together with people. I n other words, the resources in the semantic network are no longer just all kinds of connected information, but also the true meaning of their information, thus improving the automation and intelligence of computer processing information. Of course, computers do not have real intelligence, the establishment of semantic networks requires researchers to effectively express information, the development of uniform standards, so that computers can effectively automate the processing of information.

(Source: He Bin Zhang Lihou, "Principles and Methods of Information Management" Tsinghua University Press, July 2007 2nd Edition)

Semantic network architecture

• Tier 1: Unicode and URI are the foundation of the entire architecture.
• The second layer: XML-NS-XML Schema, which is responsible for syntaxally representing the content and structure of data and separating the representation, data structure, and content of network information by using a standard format language.
• Layer 3: RDF-RDF Schema, which provides semantic models to describe information and types on the Web. A mong them, the Resource Description Framework, a resource description framework, is the language specification recommended by W3C to describe the information resources on the WWW and their relationships. RDF(S) is an important part of the semantic network, which uses URIs to identify different objects (including resource nodes, property classes, or property values) and to connect different URIs to clearly express relationships between objects.
• The fourth layer: the ontology vocabulary layer, the ontology is a clear specification of the conceptualization and formalization of domain knowledge. I n semantic network architecture, the role of the ont body is mainly manifested in: (1) conceptual description, that is, through the conceptual description to reveal domain knowledge; Reasoning supports the ontology's certainty in conceptual description and its powerful semantic revealing ability to ensure the validity of reasoning at the data level.
• Layer 5: Logical layer, responsible for providing a sense of reasoning and reasoning principles, to provide the basis for intelligent services. A mong them, Description Logic is a determinable subset of first-order predicate logic based on the formalization of the object's knowledge. I t is different from first-order predicate logic in that describing a logical system can provide a determinable reasoning service. I n addition to knowledge representation, descriptive logic is used in many other areas and is considered to be the most important form of object-centric representation of language. A n important feature of describing logic is its strong expressive power and determinability, which ensures that the reasoning algorithm always stops and returns correct results. Among the many formal methods of knowledge representing, the description logic has received special attention for more than a decade, mainly because they have clear model-theoretical mechanisms, are well suited to represent the application field through conceptual taxonomy, and provide very useful reasoning services.
• The sixth tier of proof and the seventh layer of trust are responsible for providing authentication and trust mechanisms.