Web Based Interaction Visualization For Electromagnetics And Antennas

Abstract

This paper reports on three web-based interactive visualization tools developed as an adjunct to instruction in electromagnetics and antennas. The modules (http://www.olemiss.edu/courses/EE/EM/emindex.html) were developed using Macromedia’s interactive authoring tool, Authorware, and can be viewed by any internet connected computer using a Netscape or Internet Explorer browser equipped with the Authorware Web Player *.

1. Background

Many instructors believe that among the reasons that students consider electromagnetics, microwaves, and antennas to be difficult is that humans cannot sense the phenomena being studied without the aid of instruments. In recent years, several visualization tools have been developed using Fortran, Visual Basic, and Java1-4. The author and co-PI Professor Elsherbeni settled on Authorware (AW) as a multimedia development tool during work on two NSF ILI grants to introduce multimedia instruction into electrical engineering laboratories5,6. In 1996, Macromedia introduced “shockwave” technology that compressed and segmented packaged AW files for delivery over the internet via a user’s browser. The modules described here employ this technology to deliver instruction at a time and place convenient to any student who wishes to review or learn this material. The modules described here are intended to augment instruction and have not been created as stand-alone distance learning lessons. While these modules were not developed explicitly during work on the ILI grants, they represent work that has continued since the conclusion of the grant period.

2. The Authoring Environment

Authorware uses a flowline/icon model for programming, and Figure 1 shows a nested flowline construction that includes the structure for a subroutine. “Map” icons allow a hierarchical nesting of functions. Opening the level 1 map icon entitled Subroutines shows a framework with another map. Inside New View is a calculation icon—“Calculation” icons provide a programming environment similar to Basic. Table 1 shows part of the contents of a calculation icon in a subroutine used in conversion of a 3-D wire model to a screen display. “Display” and “Erase” icons present and remove images and text from the screen; while “Wait” icons control timing. When a piece has been debugged in editing mode, it may be “packaged” into an *.exe file which can be executed on an Intel-based computer running Windows, or, alternatively, into a "player" file which may be viewed on either an Intel-based PC or on a Macintosh using the Authorware * Previously called the Shockwave for Authorware plugin