Solving problem of semantic terminology in digital library

A Digital library is is a special library with a focused collection of digital objects that can include text, visual material, audio material, video material, stored as electronic media formats , along with means for organizing, storing, and retrieving the files and media contained in the library collection. Digital libraries [1]–[4] can vary immensely in size and scope, and can be maintained by individuals, organizations, or affiliated with established physical library buildings or institutions, or with academic institutions. The digital content may be stored locally, or accessed remotely via computer networks. An electronic library is a type of information retrieval system [5]. Nowadays many digital library are already move to convensional search to semantic search. As is done by University of Strathclyde (uk). They using an RDF-XML [6] , JASON, N-Triple for suppporting a semantic searching process (Fig. 1 and Fig. 2).


II. Methontology Methodology
Methontology is among the more comprehensive ontology engineering methodologies as it is one for building ontologies either from scratch, reusing other ontologies as they are, or by a process of re-engineering them. The framework enables the construction of ontologies at the knowledge level, i.e., the conceptual level, as opposed to the implementation level. The framework consists of: identification of the ontology development process with the identification of the main activities, such as, (1) Evaluation, (2) configuration, (3) management, (4) conceptualization, (5) integration implementation; (6) a life cycle based on evolving prototypes; and (7) the methodology itself specifying the steps for performing the activities, the techniques used, the outcomes and their evaluation. Methontology methodology identifies three main types of activities: Project management activities; development-oriented activities; and support activities. [12]   Planning identifies which tasks are to be performed, how they will be arranged, how much time and what resources are needed for their completion. This activity is essential for ontologies that need to use ontologies which have already been built or ontologies that require levels of abstraction and generality;  Control guarantees that planned tasks are completed in the manner that they were intended to be performed;  Quality assurance assures that the quality of each and every product outputted (ontology, software and documentation) is satisfactory, describing how these activities are performed.
Development-oriented related activities include [12]: Methontology methodology describe very detailed the process to build an ontology for centralized ontology based systems. Methontology ontology includes : the identification of the ontology development process, a life cycle based on evolving prototypes, and particular techniques for carrying out each activity, and on the other hand 101 methodology underlines that the methodology should reflect reality. We are trying to build the proposed model describes the process in detail, and also reflects the reality.

III. Implementation
A digital library [2] is a repository of digital documents of different files formats like.pdf, .doc, .ppt or even plain .txt which can be any journal, newspaper, books, magazines, instruction manuals, presentations and others publications. Nowadays Ontology is very important for making an efficient searching in digital library. Ontology based digital library should have the additional features of semantic based accessing querying and searching the library using a reference ontology to reform the user query and extract only appropriate content from the library. In this section we will present a future face of digital library, it will work for different ontology support. In summary, our works requires available collections in one library [13] associated with each collection in another library [14]. Ontology 1 (Fig. 4a)  A. Properties and Individual in Ontology 1 and Ontology 2 OWL Properties represent relationships. There are two main types of properties, Object properties and Data type properties. Object properties are relationships between two individuals. In this section we will focus on Object properties; data type properties are described in next section. Object properties link an individual to an individual. OWL also has a third type of property -Annotation properties. Annotation properties can be used to add information (metadatadata about data) to classes, individuals and object/data type properties. Properties or attributes are roughly equivalent to slots in protégé. They are also known as roles in description logics and relations in UML and other object oriented notions. Fig. 5 shows a segment of Data properties in Ontology 1 (5a) and Ontology 2 (5b). Individuals, represent objects in the domain that we are interested in. An important difference between ontology and OWL is that OWL does not use the Unique Name Assumption (UNA). OWL allows us to define individuals and to assert properties about them. Individuals can also be used in class descriptions. For example, we could state that the following two URI references actually refer to the same person (Fig. 6) The owl:sameAs statements are often used in defining mappings between ontologies. It is unrealistic to assume everybody will use the same name to refer to individuals.
Inverse Functional Properties e.g. Publish, and Published are inverse functional then it means that the inverse property is functional. For a given individual, there can be at most one individual related to that individual via the property. Properties may have a domain and a range specified. Properties link individuals from the domain to individuals from the range. Fig. 7 and Fig. 8 show OWLviz in Ontology 1 and Ontology 2. The concepts or classes "Publisher", "Author" in ontology 1 (Fig. 7) and "BookPublisher", "Writer" in ontology 2 (Fig. 8) are equivalent, they similarity refer to the same degree as being able to publisher concepts, but we can say that probably class or concept "Publisher" is more common than concept "BookPublisher" or maybe not. Next is an example of the SPARQL query notation in the ontology 1 and Ontology Library 2 ( Fig. 9 and 10). In Notation below Class "Writer" connected with Class "Collcetion" in IRI [14]. HasWritten is an ObjectProperties that used in Ontology 2. Class "Writer", ObjectProperties "Writen" Class "Book". The next step, each class unless Class "Lecturer" will given values as filters. "Writen_By" is ObjectProperties that used in ontology Library 2, i.e. Book: Writen_By ?Lecturer ? Publisher : Publisher_Name ? value1. ? Writer: Name ? value2. FILTER (?value1 = 'McGraw-Hill'). FILTER (?value2 = 'herlina jayadianti').}.   Fig. 11 describes the manual mapping between term in ontology 1 and Ontology 2. Step is validation in RDF validator. We use RDF validator [15], [16] and converter to validate small snippets of RDF/XML (including N-Triples and Turtle). The data will be converted and outputted in the other format. RDF Validator and Converter is a tool for parsing RDF Statements and validating them against an RDF Schema. RDF ontology validation process for CO is shown in Fig. 12. The validation process between Class Author in ontology 1, and Class Writer in Ontology 2. Class Publisher in ontology 1, and Class BookPublisher in Ontology 2. Fig. 13 shows a graph data model between term in ontology 1 and ontology 2 running in RDF Validator. Synonym, ambiguity, and hyponymy problems are a big issue in integration data and we will continue to be our concern on it. A system should not limit the human way of thinking and looking. Humans should be able to do searching process based on their perception and not restricted by syntax.

IV. Conclusion
In the future there will be many systems facing problems of integration knowledge and semantic understanding. The problem of sharing knowledge and semantic can be solved by integrating term and maping process. This study has proved that the problem of terminology differences in digital library domain can be solved by ontology.