IJISET - International Journal of Innovative Science, Engineering & Technology, Vol. 3 Issue 2, February 2016. www.ijiset.com ISSN 2348 – 7968 An Introduction To Ontology: Survey Mr. Pranit Chettri Mr. Dhruba Ningombam Dr. C.T. Singh Dr. M.K. Ghose, M.tech,CSE, Assistant Professor, Professor, Dean Academics, Department of CSE, Department of CSE, Department of CSE, Department of CSE, Sikkim Manipal Institute Sikkim Manipal Institute Sikkim Manipal Institute Sikkim Manipal Institue of of Technology, of Technology, of Technology, Technology, Majhitar,Sikkim Majhitar,Sikkim Majhitar,Sikkim Majhitar,Sikkim ABSTRACT- Ontology is the specification of a) Domain Ontology: It represents the concept conceptualization. This paper provides concept about with respect to domain. For example, the the Ontologies and its importance in advancement of word ‘BOW’ has different meaning. An the field of Artificial intelligence. It also focuses on ontology in the domain of place is “a some of the guidelines that should be followed while District in London” and ontology in the implementing it. It also focuses on necessary field domain of weapons is “things to shoot where various ontology can be implemented and projectiles with”. Domain Ontology are proposes a future work on the same. often incompatible since it represents the concept in very specific and often eclectic I.INTRODUCTION ways. Ontology is defines as a set of primitives that is used b) Upper Ontology-It is usually applicable to to design the domain of knowledge. Ontology wide range of domain ontologies. There are language is a formal language that is used to design several standardized upper ontologies ontologies. It allows the encoding of the knowledge available for use, including BFO, BORO about specific domain and often includes reasoning method, Dublin Core, GFO, rule that supports the processing of that knowledge OpenCyc/ResearchCyc, SUMO, the Unified and they are declarative language. The Ontology Foundational Ontology (UFO) and DOLCE. separates the variables that is used for some set of WordNet, while considered an upper computation and also build relationship between ontology by some, is not strictly an them. The Ontology is created to limit the complexity ontology. However, it has been employed as and to organize the information in the field of a linguistic tool for learning domain Artificial Intelligence, the semantic web, System ontologies. engineering, Software Engineering, Biomedical Informatics, Library Science, Enterprise c) Hybrid Ontology-It is combination of both bookmarking and Information architecture. It can be domain and upper ontology. applied to problem solving. Ontology reduces the conceptual or terminological confusion and brings The formal language used to encode the ontology shared understanding that can function in unifying is ontology Languages. There are number of framework for the different viewpoints and serves such languages for ontology. basis for: a) Communication-among the system with I.I.OWL different viewpoints and the needs. Web ontology Language is the family of knowledge representation language authority b) Inter-operability-among systems achieved ontology. It is an international standard for by translating between different modeling encoding and exchanging ontologies and is methods, paradigms, languages and software designed to support the semantic web. The tools. concept of the semantic web is that information should be given explicit meaning, so that machine can process it more intelligently. It is an Ontology can be used as inter-lingua between ontology for the web and is based on the different system. To translate language Li to Lj and description logics. Descriptive logics are a vice versa ontology can be used to support the family of logics that are decidable fragments of translation between different system and first order logics. The logics focus on describing representation. There are three kinds of ontology: classes and roles ,and have a set-theoretic semantics.OWL are build upon a W3C XML 576 IJISET - International Journal of Innovative Science, Engineering & Technology, Vol. 3 Issue 2, February 2016. www.ijiset.com ISSN 2348 – 7968 standard for objects called the Resource The W3C recommendation defines an XML syntaxin Description Framework(RDF).RDF is closely order to exchange the RDF graphs. XML is a related to semantic networks since it has a graph markup language. It uses tags to provide additional based data model with labeled nodes and information about the text. The tags it uses are directed, labeled edges. It is a very flexible denoted by the angle brackets, such as the <p>, model for representing data.It has a fundamental <img> and <a> tags in the Hypertext Markup unit called statement and it corresponds to an Language (HTML). The main syntactic unit in XML edge in the graph.The RDF statement has three is the element, which typically consists of a start tag components: a subject, a predicate, and an (such as <p>), and the end tag (such as </p> and object. some contents enclosed between the tags. If it Subject: It is the source of the edges and must contains other element then it is called subelement. be a resource. Resource can be uniquely Element can have attributes which are name-value identifiable via Uniform Resource Identifier pairs. The attributes are listed inside of the element’s (URI) and it can be anything. Identifier are more start tag. often than not are Uniform Resource Locator (URL),URIs are more general than URLs. < rdf : RDF xmlns:rdf=http://www.w3.org/1999/02/22-rdf- Object: it is the target of the egde. syntax-ns# xmlns:p=http://example.org/pers-schema#> Predicate: It determines the kind of relationship <rdf:Description established between the subject and the object. rdf:about=http://example.org/~dnigombam#dhruba”> <p:teaches rdf:resource=http://example.org/~pchettri#pranit /> <p:name>dhruba nigombam</p:name> <rdf:type Rdf:resource=http://example.org/pers- schema#person” /> </rdf:Description> </rdf : RDF> Fig 2: RDF/XML syntax for the RDF graph in figure 1. In the above figure, the rdf:RDF contains an rdf:Description subelement that is used to identify a resource and to describe some of its properties. All rdf:RDF elements encodes one or more RDF Fig 1: example of RDF graph. statements. As per above example the subject of each of the statements is a resource given by the In the above figure, it shows an example of RDF “rdf:about” attributes and which has the URI graph. It contains three statements. One statement has http://example.org/~dnigombam#dhruba as it value. subject http://example.org/~dnigombam#Dhruba30TU ,U30T The rdf:Description element contains three property predicate p:teaches and object subelement and it encodes three statement.The first http://example.org/~pchettri#pranit30TU .U30T This all subelement is empty element with the qualified name statement altogether represents that “Dhruba teaches p:teaches:based on the namespace declaration at the Pranit”.The statement with predicate p:name is an beginning of the document and this refer to the example of a statement tha has a literal value(i.e, resource http://example.org/pers-schema#teaches and “dhruba nigombam”) as its object. This statement this is the predicate of the statement. The resources denotes that dhruba‘s name is “Dhruba nigombam”. that is used by the predicate is known as property. To Here p:teaches and p:name are the example of specify that “http://example.org/~pchettri#pranit” is qualified names. The third statement declares dhruba the object of the statement we use rdf:resource to be a person. attribute. The second subelement of the rdf:Description encodes such statement which have I.I.I.XML SERIALIZATION SYNTAX FOR RDF literals as objects. This element is a textual content. The statement has predicate “http://example.org/pers- 577 IJISET - International Journal of Innovative Science, Engineering & Technology, Vol. 3 Issue 2, February 2016. www.ijiset.com ISSN 2348 – 7968 schema#name” and object “Dhruba Nigombam”. The domain: propreo:chemical_entity third subelement of the rdf:Description is rdf:type By range: __Description123 using the namespace declaration at the beginning of the document, we can find that it refers to the The above stanza defines the relationship type (the predicate http://www w3.org/1999/02/22-rdf-syntax- OBO equivalent of a property) ns#type.This property in RDF allows to categorize propreo:is_described_by. The terms resources. The rdf:resources attribute is used to propreo:chemical_entity and _Description123 are specify the category such as “http://example.org/pers- used as the domain and range, respectively, of the schema#person”. relationship type being defined. I.I.II.OBO [Instance] The Open Biomedical Ontologies (OBO) is an id: propreo:water_molecule ontology language that is often being used for instance_of: propreo:inorganic_solvent_molecule modeling ontologies is life science. It is an effort to property_value: propreo:is_described_by provide a way to organized knowledge for propreo:CHEBI_1234 subsequent retrieval for shared use across different biological and medical domain. The majority of the Finally, the above stanza defines the instance (the ontologies in that repository are written in OBD Flat OBO equivalent of an individual) File Format. It is an ontology generally design for propreo:water_molecule. The instance is a member of Gene Ontology (GO). The OBO language use simple the term propreo:inorganic_solvent_molecule and has textual syntax. It was designed to be compact, propreo:CHEBI_1234 for the value of the readable by human and easy to parse. The OBO relationship propreo:is_described_by. Ontology is a collection of stanzas. Each stanzas describes one element of the ontology. It is introduced by the line containing a stanza name I.I.III.OntoUML which identifies the type of the element being described. The stanza consists of lines, each of which The OntoUML is an ontology which is well founded has a tag followed by a colon, a value, and an profile of UML for the conceptual modeling of optional comment introduced by “!”.