An interactive Java-based educational module in electromagnetics

International Journal of Electrical Engineering Education, Jan 2003 by Chetty, M, Hu, S, Bennett, J

Abstract

This paper explains the design, development and implementation of a web-based educational module for an introductory electromagnetic (EM) course at Monash University. It contains tutorials, interactive simulation and animation. The two most important sections of the module, namely 'electric dipole' and 'experimental field mapping', are described here. Both these sections are interactive and with the help of visual graphical displays and audio files they 'stimulate' the sight and sound senses for understanding. The module can act as an instructional aid and helps not only in understanding the fundamental concepts but also in providing a greater appreciation of the applications of EM theory. The responses from interactive simulation are displayed directly on the client browser. The overall package is developed using Java, HTML, CGI scripts written in Perl and MATLAB.

Keywords electromagnetics; Java; web-based education

Many universities are feeling the need for some form of substitute for a human tutor because a student is often unable to approach a tutor as and when a difficulty is experienced or a need for discussion arises. As a result, many applications have been developed in the field of engineering and science education to meet this objective of educators who see the need to improve the way introductory courses are taught to engineering students.1"5 With the advent of computer technology, a medium for such a substitute is now available in the form of the Internet or world wide web. The web-based material is accessible anywhere, anytime, as often as required, and to a large number of people simultaneously. These advantages of almost unrestricted access alone makes the web a valuable medium even if expert human help were abundant because it would allow students to make 'silly' mistakes, and that too without the embarrassing presence of a tutor.6 Thus, the very impersonal nature of the web is a persuasive reason for using it as a medium for structured instruction even if the amount of feedback offered to the students is very limited in quantity and quality. Further, the web can provide a highly supportive learning environment to distance education.7

Given these obvious advantages of the web, this paper proposes a web-based educational module for electromagnetics (EM), which is one of the cornerstones of electrical engineering practice. The subject is perceived as one of the most difficult courses due to its extensive mathematical content and physical/intuitive concepts. Further, the subject matter relies heavily on vector mathematics with closed-form field solutions only available for highly symmetric, idealised geometries.8 As a result, students have difficulties in understanding and visualising the subject material using conventional teaching methods.

Traditionally, EM has been introduced to students by limiting any illustrations to textbook-type examples that can be easily replicated on the whiteboard. The use of interactive multimedia tools can allow students to have a graphical display of abstract quantities such as fields, potentials etc. and to visualize these; thus making the subject more exciting.8 Another objective in developing a multimedia-based teaching tool is to give students a sense of the 'bigger picture'. To achieve these objectives, both tutorial-type and simulation-type modules across the Internet are found useful. The tutorial-type modules are primarily static and are intended to complement the lectures. Simulation-type modules support interactive visualization with the key parameter variations affecting the performance of a component or system and help to form mental models of the theory, thus improving problem-solving skills. The module presented in this paper is designed to contain both components, i.e. tutorial and simulation.

Efforts to develop both tutorial- and simulation-type modules have been made. An example of one such EM tutorial can be found where the tutorial contains a series of hyperlinks which take the user to different 'static' HTML pages containing explanatory text, figures and equations.9 However, a tutorial with such an abundance of hyperlinks can cause the users to be lost within such a section. Another example of an EM module dealing with simulation is Visual Electromagnetics for Mathcad which is arranged in an electronic book format." However, it has to be used in con junction with the text. Further, it requires Mathcad 8.0 to be installed and can be viewed only locally. Other simulation-type modules for EM are the Graphically Driven Electromagnetics (GDE), and Contact.8'10 Both GDE and Contact have a Graphical User Interface (GUI) to make it user friendly, and are capable of displaying graphical results. However, these interactive modules cannot be easily accessed from the web, nor do they provide both tutorial and simulation component.

This paper deals with the design, development and implementation of a web-based educational module containing not only tutorial and interactive simulation but also animation effects. The two sections of the module, namely, 'electric dipole' and 'experimental field mapping' being presented here can easily be extended to other EM topics. The module has multimedia features which, with the help of visual displays and audio files, 'stimulate' the sight and sound senses for understanding. The responses from interactive simulation are displayed directly on the client browser. The module is developed using Java, HTML, CGI scripts written in Perl and MATLAB.