The Structure of the Learning Software The software consists of a collection of html-pages which can be divided into the following parts:

Size: px

Start display at page:

Download "The Structure of the Learning Software The software consists of a collection of html-pages which can be divided into the following parts:"

Victoria Williamson
8 years ago
Views:

1 University Teacher Education for Courses "Information Technology" as Part of Teacher Education for Gymnasia Secondary Level with Focus on the Computer based Module "Optical Data Transmission" Denis Bhattacharya, Jürgen Wehling University of Essen Germany The Objective of the Project The project s objective was to develop an interactive learning software for technology teacher education. It is meant as an example of software that can be used in higher level technology classes of gymnasia (grades 11 up to 13). The interactivity of the software is given by the use of HTML in combination with JAVA-Applets. This makes it on the one hand online-capable and on the other hand independent of platforms (operating systems). The simulations which are part of the software represent some crucial effects out of our project's specific topic, optical data transmission. The Structure of the Learning Software The software consists of a collection of html-pages which can be divided into the following parts: 1. Support texts: Fundamentals of the technology of information and communication in general. 2. Central contents: Two topics of optical communication: a) Physical and technological properties of optical fibres in communication technology b) History of optical telegraphy The Contents of the Learning Software Part 1 provides the user with basic information, especially laws and facts regarding theory and technology of information and communication. The programme "Refraktion" is another example for a combination of items from the toolbox mentioned above. It again consists of a numerical component and one that graphically displays the results. This simulation demonstrates Snell's law of refraction at a boundary surface. 35

It is meant as an example of software that can be used in higher level technology classes of gymnasia (grades 11 up to 13).

2 Illustration 1: Screenshot of programme "Refraktion" which is a simulation of the two effects refraction and total reflection of light rays going through a boundary surface (Snell's law).[in the presentation all images of this article will be replaced by real-time programme demonstrations.] Part 2.a), "Properties of optical fibres", informs the user about the following topics: - Bandwidths and transmission rates of optical fibres compared to electric cables - Structures and application problems of optical cables - Characteristics of different types of optical fibres - Physical effects of light travelling through optical fibres, containing the simulation programme "Dispersion" which is described below: 36

a), "Properties of optical fibres", informs the user about the following topics: - Bandwidths and transmission rates of optical fibres compared to electric cables - Structures

3 Illustration 2: Screenshot of programme "Dispersion" which is a simulation of an effect called dispersion of modes.[in the presentation all images of this article will be replaced by real-time programme demonstrations.] The programme "Dispersion" has been assembled using three components out of a so called "toolbox". The latter contains functional units (as shown in the next paragraph) and combines them to a programme according to the user's specific needs. In this programme the components or tools fulfill three tasks: read data, in this case optical parameters, from a graphic interface and compute results according to these data using fixed mathematical functions (first component) - draw lines that represent light rays into a coordinate system of (second component) - display the time-dependent behaviour of a special physical effect, here: the intensity of light passing through an area (third component). The single components can be newly combined, for example by using a different numerical component and displaying its behaviour with the two drawing tools. This simulation demonstrates the dispersion of different modes or rays in a step-index fibre. Changing the parameters allows the user to analyse the change of pulse shape (as an idealized effect). Part 2.b), "History of optical telegraphy", contains information about three telegraphs: - Polybios' torch-telegraph (2 nd century B.C.) This telegraph was operated by people standing behind a wall and putting torches below or above its edge. The number of torches shown first indicates the column, the second the line in a matrix of letters. 37

] The programme "Dispersion" has been assembled using three components out of a so called "toolbox".

4 - Chappe's lever-telegraph or semaphore (1794) The combination of positions of the main lever or régulateur and the two secondary levers or indicateurs pointed at a page and a line in a codebook. Napoleon Bonaparte used lines of optical telegraphs to coordinate his troops from his Paris headquarters. Illustration 3: Lever-telegraph by Claude Chappe - Murray's shutter-telegraph (1795) The British admiralty used this device to co-ordinate ship movements along their coastline. It transmitted combinations of rectangular shutters in vertical or horizontal position, each combination representing either a letter or a complete message. Application of the learning software in school and university education The software has been designed as an example for computer-based learning programmes for technology classes in secondary schools. Teacher training students can test the application of this software in seminars on information technology. Furthermore, the basic structure of learning software and methods to develop it can be generally discussed, analyzing the given example. Also, students can try using the software in class in their practical courses at school. They can hereby enhance their competence of efficient application of computer-assisted teaching methods. As our product is online-capable and published in the world wide web, technology teachers are welcome to use it for their classes. 38

Illustration 3: Lever-telegraph by Claude Chappe - Murray's shutter-telegraph (1795) The British admiralty used this device to co-ordinate ship movements along their coastline.

5 Reference List F. Mitschke, M. Böhm Solitonen in Glasfasern, in: Physikalische Blätter 56 (2000) Nr. 2 Ch. Wrobel Optische Übertragungstechnik in der Praxis, Hüthig 1998 V. Aschoff Geschichte der Nachrichtentechnik, Berlin: Springer 1984 G.J. Holzmann, B. Pehrson Optische Telegraphen und die ersten Informationsnetze, in: Spektrum der Wissenschaft, März 1994 E. Desurvire Signalverstärkung in Lichtleitern, in: Spektrum der Wissenschaft, März 1992 (all texts published in Germany and German language) Our complete software can be found at or (look for "Multimedia-Projekt"). 39

Pehrson Optische Telegraphen und die ersten Informationsnetze, in: Spektrum der Wissenschaft, März 1994 E.

6 40

Welcome in the Master programme

Welcome in the Master programme Prof. Axel Görlitz, HHU Düsseldorf 19.10.2015 Master Programme in Physics Physics Focus (Schwerpunkt) Plasma Physics, Quantum Optics and Quantum Information, Solid State