Global Congress on Engineering Education
© 1998 UICEE
Cracow, Poland, 6-11 September, 1998
Active virtual laboratory at Internet as an effective tool for learning
Maxim V. Kazitov & Vladislav V. Nelayev
Belorussian State University of Informatics and Radioelectronics
Abstract: At the moment use of Internet virtual libraries and help database in electronic forms already has become norm. Means of the network Internet are used all more often at schools and universities in the educatuonal process. Such approach is sutable almost perfectly for knowledge mastering in humanitarian disciplines, but obviously it is unsufficient for the learning in the field of engineering and physics. However nowadays there is a possibility to convert the Internet as a learning tool from passive means into active through inserting of software elements in Web-pages due to occurrence of the Java language. In these conditions the pupil can receive access not only to an extensive library data, but also to the newest software in the field of computer experiments and their visualization.
Such approach allows to not care of distinctions in information technology components (software and hardware), used by the various developers of the software. The modularity of the Java language facilitates development of the projects by spatially shared teams of developers, as the program can be distributed at the Hyperspice. The updating of the program does not require its complete recompilation - the replacement of its separate modules is necessary only. In the case of large databases it is possible easily to pass from using of applets to CGI applications. Shown specified features allow to consider virtual laboratories at the network Internet as extremely attractive means for collective creation and application of the software developed and used in various areas of a science and engineering including interactive training systems and realization of computer experiments.
The training, being a major sphere of human activity, ensuring formation of intelligent potential of a society, is at the moment in a rather difficult situation. It is connected with a constantly deepening contradiction between traditional methods of training and constantly accelerated rate of knowledge expansion. Volume of knowledge, necessary for the person in a modern society, becomes all more extensive. This volume all is updated faster. But the time, necessary for these knowledge mastering, remains practically constant.
The marked contradiction has fundamental character. Therefore attraction of new information technologies and means are necessary for its solution [1,2]. Already five generations of computer hardware and its updating were replaced on the life extent of one mankind generation. And this process is continuous. One of the most stormly and dinamicly developing areas of information technology is Internet [3,4]. Dynamic development of this global network of knowledge in many respects coincides with dynamics of knowledge development. And just international computer network Internet, not aware of any borders, is the most logical candidate as the universal tool for training and learning. Use of the network Internet allows to the person constantly, on an extent of whole his life, to address to various educational services. The training process at the Internet can take place in remote regime, without a break of the basic activity of the person.
At the moment there is the set of virtual libraries, clubs, help databases and so on at the network Internet. However all of them are characterized by a relative passivity of the interface. Nowadays there is a possibility to convert the Internet as a learning tool from passive means into active through inserting of software elements in Web-pages due to occurrence of the Java language . In these conditions the pupil can receive access not only to an extensive library data, but also to the newest software in the field of computer experiments and their visualization.
We offer for discussion the idea of the Active Virtual Educational Laboratory, use of which with possibilities of the Java language will allow to the person not only to carry out search of the information in the network Internet, but also to carry out the creative educational activity, to adapt existing databases and software for own needs. This virtual educational laboratory at the Internet should be a universal means for training, developed, in particularly, skill of the person to learn. The absence of direct contact with the teacher will help for the pupil to be weakened and to open his creative potential fuller, will learn to his independent work [6,7].
Structure of the active virtual educational laboratory
The active virtual educational laboratory at the network Internet for active process of training should carry out the following functions: to carry out computer experiments and to visualizite their results, to provide access to a necessary database, to supplement and to modify separate making databases of virtual laboratory and to carry out the control of the gained knowledge. Fig. 1 presents the software and hardware structure of the active virtual educational laboratory.
The interface part of the virtual laboratory should function in Hypertext regime.
The offered structure should provide not only an opportunity of dialogue of developers among themselves, but also is called to facilitate the sinhronization of works conducted by various developers.
Technical featuries of the active virtual laboratory for learning
Still absolutely recently the alphanumerical (X) terminals were quite suitable for organization of the user interface with powerful computing systems. Nowadays all more often is required to the users the graphic interface. The X-terminals for this purpose do not approach, as essentially load the network and server. Object-oriented programming language for www Java allows to redistribute loading between server and workplaces. With occurrence of the Java language opportunities are given, firstly, to ensure the creation of the graphic interface; secondly, to unload server and, thirdly, to ensure the centralized management of the system. In spite of the fact that nowadays there is no the uniform, generally accepted standard for the Java language, this temporary lack can be removed by means of establishing the own rules for the Java language using within the limits of the given virtual laboratory.
The allocated computer complexes can be built on the protocol HTTP (Hyper Text Transfer Protocol) basis, which supports the interface with CGI applications  on Web-servers and allows to ensure an access to server computing resources from browsers . The Java language gives an opportunity to create the computing system even more allocated, transferring a part of computing loading, which carries out Web-server, to browser. In result there is a possibility to construct more flexible and productive computing systems.
Thus the Internet-technology complemented by opportunities, which are given by the Java language ideally approaches for a role of the active interface with end-users. Thus main advantage of the Java language is the opportunity to perform once written Java-programs practically at any platform, that allows to keep the funds, invested in computer software and hardware. If not to use the Java language, the client’s software should be rewrite anew, including the software written on the language HTML (HyperText Markup Language) [10,11]. Modularity of the Java language facilitates development of the projects by large various remote groups of the designers, as the program can be distributed in Hyperspace. The updating of the program does not require its complete recompilation - the replacement of its separate modules is necessary only. And in the case of large databases using it is possible easily to proceed pass from use of applets to CGI (common gateway interface) applications.
Java language components usually are established on server of the local computer network. Java-classes are stored at server also, and all loading of the programs written in the language Java, is carried out with use of that server. When the user have own branches with the local computer networks and its communication channels with the center are slow, in each such network separate server is established, on which all Java-programs are replicated from the central server automatically. At such execution the fast and duly updating of the software is guaranteed. In so doing the modernization of system is carried out automatically and is realized imperceptibly for the end user.
However it is necessary to note, that use of the Java language for the more serious purposes, than interface with the user, many experts consider inefficient. One of arguments for the benefit of it is an inefficiency of the mechanism of clearing of memory (garbage collection) used by the Java language. If the C++ language is applied the unused resource is released at once after an exit from the appropriate block of the program. Bat if the Java language is applied it occurs with some delay - while “the dust collector” will think, that the given resource is free. In small systems (for example, in client’s programs) such “dust” almost on anything does not influence. However when the speech goes about server’s Java-programs, simultaneously serving a plenty of the users, volume of the “dust” can achieve such scales, that it will block the work of all system. In the client-server system the client establishes a communication session with server and server allocates for it necessary resources. If the software, installed on server, is written on the C++ language, after a communication break server in an automatic mode causes special means - destructors, which liberate resources reserved for the client resources. In the case of using of the Java language the server’s resources are remained reserved and it is completely unimportant for the user, when they will be exempted. The exemption process of resources is imperceptible for the client and thus of hundred users working with server, can reserve for itself (but it is not necessary to use) rather large volume of memory.
Fig. 2 presents the block diagram of the offered active educational virtual laboratory. Here the group of the designers is a collective developing applets and having access to server, where are stored applets. The members of this collective have an opportunity to update as required, using communication on FTP. The user groups are incorporated in local computer networks with servers, carrying out a role of the network cash. Thus the individual user can be considered as a local network consisting of one server.
The safety of the laboratory database represents a separate technical task, which, basically, is solved, for example, with use of language SHTML (Secure Hyper Text Markup Language) . Other problems connected with the data division between the separate users, different skill level of the users and collisions between them could be solved in principle.
Nowadays the Internet is the most popular means of dialogue between the people. Thus the greatest development have received communication and search means. But that does not allow to realize of all potential opportunities of the Internet. The creation of the active educational virtual laboratory will help to open new opportunities for the Internet. This laboratory gives the possibilities to unify best experts for the developing of the modern software for learning in different fields of knowledge, especially in engineering and physics.
As a software base for the offered active educational virtual laboratory at Internet may be considered the complex of computer training programs for a microelectronics technology curriculum [13-15] developed at Department of Microelectronics of Belorussian State University of Informatics and Radioelectronics .
We hope that the paper will attract the attention of colleagues. We also shall be grateful for improvement remarks and suggestions for collaborations in creation and development of the offerd active educational virtual laboratory at Internet.
Authors acknowledge with thanks the useful discussions and comments of professor W.Kuzmicz of Institute of Microelectronics and Optoelectronics from Warsaw University of Technology in preparing this work.