Sadanova B.M., Oleinikova A.V., Miftahov R.R., Dakibaeva M.K.

Karaganda State Technical University, Kazakhstan

Advantages of object-oriented approach in construction of electronic learning resources models

Nowadays, researching of the creation and development of electronic educational resources has become very frequent. Internet resources play a role not only as means of finding and obtaining a "useful information" but also as the tool for the development of existing forms of education and creating new ones. In this regard, particular attention is paid to the development of concepts and various forms of e-learning. E-learning (e-learning) is based on the use of multimedia technologies and the Internet to enhance learning process by facilitating access to resources and services, as well as sharing and collaboration at the distance.

Educational network systems must have a high level of interoperability (interoperable), which is the possibility of interaction with various other systems [1]. This requirement is very important when creating distributed learning environments in the Intranet / Internet networks. Most educational systems implement this requirement through the open access interfaces to their services or by using a common format for data exchange, namely XML and its associated object model representation of the documents DOM (Document Object Model), carrying out, if necessary, XSL-transformations. This approach allows us to solve the problem of syntactic interoperability. Unfortunately, for interaction between different educational systems in the Intranet / Internet networks in most cases providing only syntactic interoperability is not enough. This is primarily due to the fact that the same information can be syntactically represented in different ways, and as a consequence there may be a natural barrier between the systems.

Thus, the main obstacle in the process of creating web-based distance learning courses is the lack of standardization of network training tools. To solve this problem, it seems appropriate to use Semantic Web technology [2]. Concept of the semantic web (Semantic Web) as a new format for the Web-content was introduced by W3-chairman of the Consortium, Tim Berners-Lee (Tim Berners-Lee) in 2001. Advantages of the new reporting format in the WWW is that it provides the maximum degree of classification of any information, making the joint work of people and cars more efficient. The main difference between Semantic Web from the Web is that each page of a semantic network provides information in two languages: an ordinary, human readable and shown in the browser, and the special, the information which is hidden from human eyes, but can be understood by intelligent software agents, robots . This special language describes the material presented on the page with the tags and attributes that are understandable to machines. Formal semantics of documents in this way can be processed by computers, transferred between different agents, which might be programs and people.

Today, the main volume of structured data sources are the relational database, although it also may be file systems, XML and databases,which extend the scope of its application, and other types of information sources. Regardless of the method of storage, the first issue of integrating heterogeneous data which you will have to deal with during the formation of a repository of information resources - is a variety of models and data schemas, their low level of abstraction, a small level of the adequacy of the semantic domain for high-quality solutions which need to work with data corresponding to a significantly more semantically rich data model. For example, a good solution may be to move to some object-oriented data model, which is in many ways similar to semantic models, where the key unit is a complex structured information object that supports a variety of attributes, that is involved in various associations with other objects [3].

The transition from the relational data model for object-oriented is a necessary step in building an information storage. Object-oriented model allows you to:

• increase the level of abstraction of the domain model;

• it is convenient to highlight the canonical data schemes, representing the intersection of the export schemas of data corresponding to the different subject areas, to build unified object requests for access to distributed data and then aggregating the results of queries in accordance with canonical schemes;

• in the case of RDFS and OWL – you will have a uniform representing format, which provides syntactic and semantic interoperability.

An example of a hierarchy of objects can be a description of electronic educational resources stored on the portal, digital library, etc. In order to allow automated processing, any description shall have a uniform shape. Abstract class "document" (general concept of an information resource) must match the abstract data object that describes the data inherent in any document. Information objects that describe the specific document types (text, test paper, abstract) must obtain the general properties of the document, but also include properties that are unique to a particular type of document.

Methods of working with these information objects are electronic library services: a "smart" search on storage libraries, generation of dynamic catalogs, profiling, etc.

Using the ontology is advised to describe the structure of electronic educational resources. At the formal level ontology is a system consisting of a set of concepts and a set of assertions about these concepts, looking on which one can describe classes, relations, functions and individuals. One of the most famous definitions of ontology was given by Tom Gruber. It says: "Ontology is the exact specification of a conceptualization" [4]. Conceptualization implies the description of a domain that defines a set of objects that exist in the described application domain, and the set of relations between these objects. Ontology consists of a dictionary, that is, a list of logical constants and predicate symbols to refer to a domain and set of logical statements representing the constraints that exist in this subject area and narrowing interpretation dictionary, ontology provides vocabulary for representing knowledge and sharing knowledge on a certain topic as well as many links and features available between entities designated by means of the dictionary.

It was decided to use the ontology editor Protege in order to create and edit ontologies of electronic educational resources. Protégé includes ontology editor which allows designing ontologies by turning the hierarchical structure of abstract or concrete classes and slots. The structure of the ontology is done similar to the hierarchical directory structure. Formed on the basis of ontology, Protégé may generate a form of learning for the introduction of instances of classes and subclasses.

In the developed ontology subclasses and superclasses structure is implemented in the description of language C #, which can then be used as a basis for creating ontologies in other programming languages. Figure 2 shows a possible division into different levels of generalization.

Fig 2. Different levels of taxonomy C #

Content management system (CMS), which creates a convenient WEB-interface to work with educational material is used to build an interface between the machine and user . In order to implement the inference machine was chosen a set of libraries called Jena.It is a clever means of logical inference for context ontologies designed with user interfaces in the areas of knowledge where logical processing of large data sets is required.

Thus, the representation of information, systematic and structured through the ontologies can be used to form the structure of storage of teaching materials as a resource for information and educational environment and the construction of mathematical models and information of the course, as well as to facilitate the retrieval of information resources in distance education learning. It is intended to use modules of the ontology to describe the subjects, establishing links between the basic concepts of the subject area, and also to link each concept with information assets that should be used for exploration of the topic. Further work is to construct a model of informational and educational environment and development of technology for users’ access by the corporate network and the university through the Internet to the data.

References:

1. Scherbak S.S.(2008). Formal models of representation of knowledge for semantic web-services. Eastern-European Journal of Enterprise Technologies,3(33), 68-71.

2. Berners-Lee T., Hendler J., & Lassila O.(2001) The Semantic Web. Scientific American, 284(5), 35-43.

3. Lapshin V.A. (2010) Ontologies in computer systems. Мoscow: Nauchnyi mir.

4. Gruber T.R.(1991) The role of common ontology in achieving sharable, reusable knowledge bases. In J. A. Allen, R.Fikes, & E. Sandewell (Ed.), Principles of Knowledge Representation and Reasoning. Proceedings of the Second International Conference (pp.601-602). Morgan Kaufmann.