Study On Semantic Web And Search Engines Computer Science Essay

By fiting the NL question footings or seeking keywords to the footings that express the constructs or techniques of a SWD which is normally known as the ontology construct. When this technique is applied in the semantic hunt engines as it is in found in the SWOOGLE hunt engine, the matching algorithm used in this hunt engine does non use the semantics of the SWD. Matching procedure is done on the footing of the lexical techniques i.e the searching of the keywords with that of the uttered constructs of the ontology.

The basic construct of semantic matching is based on the extension to the word that expresses the construct i.e the lexical one and the syntatctic similarity between the keyword term and duplicate term are non considered. Here the similarity of the significance of two footings is found as really of import when compared to keyword hunt. Sing the undermentioned instance, the duplicate term or the searching keyword ‘book ‘ and the document term ‘reserve ‘ executed. Here it identifies the significance of the duplicate term book as the reserve of a ticket. In another instance, it is falsely identified as the significance of the book denotes the publication which was used in a question and while in the document term the significance of book is taken as the reserve ( lexical ambiguity ) .

Searching of query term or keyword in semantic matching is done by adding description or semantics about the papers and the question term which is to be searched. This query term and its corresponding semantics must be good known and uncovered prior their matching. The query term can be specified officially or informally. When the question or keyword is officially specified, its matching description of each term is explicitly defined. Therefore in order to stand for the question as a ontology ( query ontology ) , the semantic dealingss between this construct and the other assorted constructs of the ontology construction of its vicinity reveals the account of each term that expresses the ontology construct. Such semantic dealingss are know as the equivalent word or significance to the query term that is been searched by the semantic matching.

The query term can besides be specified informally, which is another type of stand foring a question as a ontology. Though the semantics of the question is non known, it should be some how exposed. Here the biggest challenge is to recover the papers harmonizing query term searched since the act of thinking the exact or relevant significance of the question term which is been specified informally. Natural linguistic communication processing techniques or Pr & A ; eacute ; cising the query term with interested users is used to manage the challenge of recovering the relevant papers as it is used in the intelligent hunt engines for illustration AskJeeves ( Teoma engineering ) .

Using the two techniques such as vector infinite indexing techniques ( eg: LSI ) ( Deerwester et al, 1990 ) and a vocabulary ( eg: Wordnet ) ( Miller, 1995 ) is combined together in order to map the query term to the intended significance.

Knowledge direction:

Geting the needed information about a subject, and accessing it and keeping ( modifying, canceling and adding ) the information is known as the cognition direction. This cognition direction has become an of import factor for all degree of concern in this competitory universe. In order to prolong, great productiveness is drawn and new values are created by holding the closer expression on the internal cognition. Particularly in larger and international concerns, this has become a major procedure with geographically assorted sections.

Largely the information ‘s available in the web are weakly structured. Some of the weakly structured signifiers are text, audio and picture. The current web engineering is non efficaciously applied since there are more restrictions in the undermentioned countries:

Searching information – Most of the companies uses the keyword hunt engines, where I have already listed the jobs of it.

Extracting information – The available intelligent agents are non able to pull out the relevant information from the consequences produced in a satisfactory manner.

Keeping information – Outdated and inconsistent information are failed to take.

Uncovering information – Extraction of new cognition from the corporate databases are done utilizing the information excavation. But its non really effectual in the distributed weakly structured paperss.

Sing information – It is hard to happen the restricted information over an intranet or the web whereas it is know from the database country.

Purposes of the Semantic Web in knowledge direction systems are the undermentioned:

Knowledge is maintained harmonizing to the significance in conceptual infinites.

Knowledge is besides efficaciously maintained by utilizing the machine-controlled tools in happening the incompatibilities and acquiring new cognition.

The requested information or cognition are searched by the question answering and the requested cognition is retrieved, extracted and presented user friendly.

Restrictions to see the cognition over the web, intranet and besides over the corporate databases.

Semantic Web Technologies:

The procedure of leting machines to understand the significance of query term is done by adding semantics to the papers in the World Wide Web. This procedure is done by utilizing group of methods and engineerings. It is called as the Semantic Web.

For the semantic matching, it is really effectual to add the semantics of the papers which are specified officially and explicitly in ontology. Where as in the unstructured paperss, it is necessary to utilize the advanced ontology larning techniques to infer their intended semantics and utilize them as the remarks or guidelines to the related paperss.

In the instance of known construction of SWD for the formal questions in priory which is called as the semantic homogeneousness, Semantic Web query linguistic communication like OWL-QL ( Fikes et al, 2003 ) and RQL ( karvounarakis, 2003 ) are used by the Querying Semantic Web paperss to question the semantic portals. In the another instance of unknown construction of SWD which is called as the semantic heterogeneousness, questioning procedure is done by utilizing the planetary scheme which is know as the shared common ontology or utilizing the horizontal function techniques across local scheme in distributed scene utilizing the attack called p2p.


The typical ontological committedness is the abstract categories depend on the belongingss that are shared from the combined specific objects.

Nowadays, most of the concerns are started utilizing ontologies for the usage pilotage between different web sites. Most of the web sites are started exposing the top degrees of a conceptual hierarchy of footings on the left-hand side of web pages. The user are besides allowed to snap on one of the hierarchal constructs of term and allowed to see the subcategories of it.

The chief advantage of utilizing ontologies is to better the quality of the web hunts by bring forthing accurate consequences relevant to the hunt value. By utilizing ontologies, the hunt engines look for the exact pages by mentioning to the precise construct in the ontology instead than roll uping all pages and showing to the user utilizing the keywords that occur.

The another usage of ontology is that if the question fails find the relevant papers for the user, the hunt engine may interact or motivate to the user for a more general question. In the instance of recovering more pages as a consequence, once more the hunt engine may propose the user for some specialisation ( eg. Advanced Search ) .

Making belongingss for the single nowadays in the ontology will depict the dealingss between different persons. So when compared to the current web engineering, in Semantic Web, utilizing these types of ontologies for developing web application is a long tradition of Artificial intelligence. In the current existent universe, the most of import ontology linguistic communications for the Web are the undermentioned:

RDF is one of the Ontology linguistic communications for developing a information theoretical account for objects. Here the relation between those objects can besides be specified. Simple semantics for this information theoretical account are provided by utilizing RDF. XML sentence structure is the representation of these informations theoretical accounts.

Another Ontology linguistic communication is the RDF Schema. It is known as a vocabulary description linguistic communication for depicting the belongingss of RDF resources. It besides describes the categories of RDF resources. These descriptions are given with semantics for generalisation hierarchies.

Among RDF and RDF Schema, OWL ontology linguistic communication is a richer vocabulary description linguistic communication for depicting belongingss and categories. It besides used in stipulating many dealingss between categories ( e.g. , disjointness ) , cardinality ( e.g. , precisely one ) , equality, richer typewriting of belongingss, features of belongingss ( e.g. , symmetricalness ) and enumerated categories.


It is a survey made by the machine about the rules of concluding. Once the machine surveies about the grounds we have created so it is said to be logic is understood by the machine and it is used for the procedure of recovering information harmonizing toand for the procedure of pulling decisions. This logic will besides supply accounts about the decisions to the agents.


It is a piece of package which works freely and be givening to originate alteration instead than responding to the events. Agent was developed organize the constructs of Object oriented programming and component-based package development. The function of the agent is to roll up the information and forming it. Semantic Web agents will do usage of the engineerings like Metadata, ontologies and logic. Using these engineerings will assist the agent to pull out relevant information from the web beginnings, helps in pass oning with the other agents and compare the relevant information harmonizing to the user question and doing determination the showing the desired end product to the user.

A Layered Approach:

The development of the semantic web application is done in sequence of stairss. A separate bed is being construct for each measure on top of another. The superimposed attack to the Semantic Web diagram describes the of import cardinal beds of the Semantic Web design and vision.

In this superimposed attack, we find XML in the underside most layer. XML is linguistic communication that helps the coder to compose the structured paperss with the vocabulary that are user defined. This linguistic communication is chiefly appropriate for reassigning paperss across the web.

The following top bed contains RDF which is found over the top of the XML bed. RDF is a basic information theoretical account, for adding simple statements about the objects similar to the entity-relationship theoretical account. Here the object denotes the resources where those simple statements are written. RDF information theoretical account has XML based sentence structure but it does non depend on XML.

RDF Schema organizes the Web objects into hierarchies. The provided modeling primitives of the RDF Schema aid in organisation. Here cardinal primitives are categories and belongingss, subclass and subproperty relationships, sphere and scope limitations. This RDF Schemas is based on the RDF.

A crude linguistic communication helps in composing the ontologies. In the superimposed attack of the Semantic Web, RDF Schema is viewed as a crude linguistic communication. But RDF Schema is quiet efficient is stand foring the more complex relationships between objects. Therefore alternatively of RDF Schema, there is a demand for stronger ontology linguistic communications which extends the RDF Schema.

Following is the current criterion Web ontology linguistic communication which is been instantiated with two option from the Ontology bed. The options of the Ontology beds are OWL and ruler-based linguistic communication. These options lead to the development of the Semantic Web appears.

DLP is another option to the Ontology bed which is the intersection of OWL and Horn logic, and serves a widespread footing.

The Ontology linguistic communication is improved farther by saying the application-specific declaratory cognition by the usage of logic bed.

From lower degree to the higher degree, all the cogent evidence are validated in the cogent evidence bed. The cogent evidence bed besides performs the concrete deductive procedure and besides the presentation of the cogent evidence in the web languages.

Trusting of informations is done in the trust bed. Use of digital signatures, recommendations of sure agents or evaluation given by the consumer organic structures makes the usage of Semantic Web information trustable in WWW. This will accomplish its full potency merely when the users trust the quality of operations performed.

Protege OWL API

API- Application scheduling interface is a interface which is been applied by a package plan. It is used as an interface for the interactions between the other package plans. The API is designed and it is used for the development of constituents. These developed constituents are executed inside of the Protege-OWL editor ‘s user interface. The API is besides designed and it is used for the development of base alone application. Some of the base entirely applications are Swinging applications, Servlets or Eclipse circuit boards.

The protege – OWL API is an open-source Java library. It is used as the Web Ontology Language ( OWL ) and RDF ( S ) for the development of Semantic Web. The API allows the categories and the methods to lade and salvage OWL files, seeking and commanding of OWL information theoretical accounts is performed by the API. This API besides provides logical thinking of OWL informations theoretical accounts that are created based on Description Logic engines. In order to implement the graphical user interfaces, the API in Owl is optimized.