This page last updated: 14/02/2007
VSEM is built entirely with mainstream Internet-based technologies, including Java, Adobe Flash, MySQL, PHP, XML, HTML and JavaScript. The advantage of using these is that they make the software easily distributable, and enable it to be run on almost any computer platform.
Different components of the VSEM package use different underlying technologies. However, they are designed to communicate with one another, so that VSEM can become a single, integrated software suite.
Java allows the development of sophisticated programs (applets) which run in a web-browser window. It is used for the SEM simulator in VSEM. High resolution sample images are captured from a real SEM and used as a basic resource for the simulator. The simulator applies appropriate digital image processing algorithms to the images, producing an accurate, real-time response to user operation of the simulated controls.
Adobe Flash is used in the encyclopaedia. It enables the construction of detailed, interactive animations (movies) explaining the scientific theory of the SEM. These complement textual information contained in XML files. A master Flash movie co-ordinates the entire process, ensuring that the encyclopaedia works in a well structured manner.
HTML and JavaScript can be used as a "glue", linking Java applets and Flash movies together with other web-based components - JavaScript functions are embedded in HTML, and interact directly with Java applets, web-page content and Flash movies. One part of VSEM may thus control another (a simple example might be that operating a simulator control could bring up related encyclopaedia information).
The open source Content Management System (CMS), Moodle, is currently being used as the basis for the courseware modules of VSEM. This is a PHP / MySQL driven application. Unlike the other components of VSEM, it runs on a web server remote from the client system. This means it can be used to centrally control the delivery of courses and assessments received by users.
Combined, these elements of VSEM offer the potential for a comprehensive, integrated web-based learning tool.