E-LEARNING FOR SIGNAL PROCESSING TEACHING

E-LEARNING FOR SIGNAL PROCESSING TEACHING Kheira Sahli1, Jérôme Mars1, Jean Luc Mari2, François Glangeaud1 and M. Genton3 ([email protected], [email protected]) 1 Laboratoire des Images et des Signaux, INPG, BP 46, 38402 Saint Martin d’Hères Cedex France, http://www.lis.inpg.fr/ 2 IFP SCHOOL, 228-232 Avenue Napoléon Bonaparte, 92852 Rueil Malmaison Cedex France http://www.ifp.fr/ 3 Institut National Polytechnique de Grenoble http://www.inpg.fr/

KEYWORDS: e-Learning, web based on-line tools, signal processing, interactive simulations

Abstract With the growing development of data processing tools, to teach remotely in a synchronous and asynchronous way is now made it possible. Therefore, we present here an interactive web platform used for petroleum industry. This web based on-line tool offers to geoscientists an opportunity to confirm their expertise or to look further into their knowledge concerning the signal processing techniques and methods. INTRODUCTION The main objective of the bilingual platform (French-English) entitled e-TSLIS is to make more accessible and interactive the signal processing lesson by using the multimedia up to date supports (Internet, Web). The main aspects of this e-formation presented here were conceived within the work of the Research Group SIN (Signals and Image in the Natural environments) of the Signals and Images Laboratory (LIS) of the ENSIEG (“Ecole Nationale Supérieure des Ingénieurs Electriciens de Grenoble”) in collaboration with the ENSPM (“Ecole Nationale Supérieure du Pétrole et des Moteurs”, IFP School). PRESENTATION Through different e-Learning modules, a set of animated lessons illustrate the means and methods of signal processing used in seismic exploration. A series of evolutive and interactive exercises allows the learner to acquire knowledge and at the same time to validate them from a question test. The range of animations is large. Those using data coming from experimental measurements refer to the authors and the organizations which provided them. Content of the e-Formation The currently available courses were elaborated from the CD-ROM of signal processing (F Glangeaud et al. 1999) and from the "Signal processing for geologists and geophysicists" book, which is composed of three volumes (J-L Mari et al. 2000; F Glangeaud et al. 2000; J Mars et al. 2004). Basic techniques of signal processing and their applications in geosciences are provided

in a modern approach. Based on simple lessons (Fourier transform, Convolution product, etc), the on-line course unfolds in a gradual way, increasingly complex processing illustrated with real examples. This course is composed of a chapter entitled "prerequisite of the signal processing", with a specific chapter dedicated to the customer, a glossary and an index (figure 1). The chapters are composed of lessons classified by topics. Each lesson is associated with an animation (figure 3), mathematical formulas which are presented in the form of slides as shown in figure 2.2 and with a multiple choice test (figure 2.1). This one is made to ensure the reader of the good comprehension of the processing suggested in the animation. It also allows understanding the details of its implementation. It allows a validation and gives place to a final grade. The list of the specific formations is currently available: The well seismic.

Figure 1 : e-TSLIS site introduction page

Figure 2.1 : Question test

Figure 2.2 : Formulas

Interactive simulations The e-Learning modules contain currently 28 interactive animations presented with JAVA applets. These applets allow visualizing data. The learner can study the influence of different parameters on the data. The parameters can be modified by playing the cursors; calculations are made in real-time. These dynamic images also allow an immediate visual comparison.

Figure 3 : Animation

Animations can be selected by using a table of contents and the processing is carried out in realtime by a specific version of software MUSTIG (Multidimensional Signal Tools for Interactive and Graphics) transcribed in Java version. The Mustig graph of animation which became an applet can be carried out on the majority of Internet navigators and this independently of the software. Mustig is a signal processing freeware diffused by the Signals and Images Laboratory from INPG (www.lis.inpg.fr). This graphic software makes it possible to program graphs of dependence. The graph which is not available from the web site, is the synoptic of data processing sequence applied to the presented data. The graph shows the architecture of the processing sequence Mustig used to carry out animations. It appears as inter-connected boxes, where each box corresponds to a tool for processing made up of elementary functions. It can be used as model to conceive data processing from the Mustig software. Teaching follow-up of the formation 1. The learner wants easily exchange any type of document (format rtf, doc., pdf, etc...) and communicate constantly. To achieve this goal, e-TSLIS uses the possibilities offered by the electronic mail (e-mail). Then the learner can send files, asks questions to obtain answers within a short time. 2. So that each learner can take advantage of a teaching follow-up by a supervisor, the latter needs to know the results of his trainee during all his formation. With this intention, the platform possesses two convivial spaces: one reserved to tutors and the other to trainees. 3. To offer more flexibility to the teacher in term of course management (change a question test for example), the web site has an interface authorizing some change of the contents of the course in real-time.

TECHNICAL ASPECT Architecture customer/server of the web site e-TSLIS is simple to implement and aims at ensuring a maximum safety with a minimum installation. It allows particularly as much as possible to reduce the download time. On the server side, the database allows the real-time recording of data. On the customer side, two levels of access are defined: general introduction is accessible to all but the courses are reserved to the beforehand recorded users (login and password). The platform e-TSLIS is currently available on website of the Signals and Images Laboratory and Intranet of the IFP School. With each need, its programming language is associated: indeed, the codes are written in languages PHP and SQL for the parts of the site which refer to the database, JAVA for the applet, JavaScript and HTML for the Web pages. The sources of the programs are not available. These choices were realised with an aim of designing a convivial platform, accessible to a large audience, easy to use as well for tutors as for learners.

Figure 4 : Technical installation

PUBLIC CONCERNED This public is very large: 1. Researchers wishing to have at their disposal the fast tools to use: geophysicists seeking to use specific applications to test their new ideas. 2. Geoscientists of oil companies wishing to understand and control the traditional techniques and the last developments of signal processing tools. 3. Students (Master or IFP School), geologists or geophysicists (reservoir, environmental engineers). 4. Bachelor’s degree, undergraduate students for specialised schools.

THE OUTCOME OF EXPERIENCES The e-Formation is currently under evaluation by students of the university and the IFP School. At the beginning, tests were carried out by a team of people, experts or not in signal processing. These tests were realised on different platforms (PC with Windows, Linux, Macintosh, etc.) and with various navigators Web (Internet Explorer, Netscape, etc.). The noted bugs are recorded in real-time by the applicant in a database, thanks to a tool developed and proposed by the Signals and Images Laboratory. The bugs are recorded thanks to forms, and the modifications made to correct them are visible directly by all the testers of the project. The complete evaluation of the platform e-TSLIS is to be considered on long-term, between three and five years. Teachers and students will communicate their remarks and suggestions at during practical work or training courses for example. These outcome of experiences could be made through evaluation sheets and meetings with the users (discussions). However, it is important to note that the on-line course is complementary of signal processing CD-ROMs and does not replace the books which allowed bringing more detailed information (demonstrations of formulas, etc). Resorting to basic works in signal processing remains essential. And the experiment shows that the association of the e-formation with a rather important followup by a tutor (in the form of realization of a project, preparation of a talk ...) makes more effective the acquisition of knowledge.

CONCLUSION The on-line course e-TSLIS proposes a new approach on signal processing teaching through specific applications, belonging to the field of the geosciences. It is diffused via an Internet platform allowing to work remotely, individually or by groups, at its own pace, and is thus adapted to the various types of users, should they be novice or confirmed: the learner builds his knowledge by giving instructions to the computer: he tests, makes errors, solves problems ... (web site interactivity). The e-TSLIS project is in constant evolution: the integration of the "General information in signal processing" course in the platform is the subject of one training course of the Electrical Department of Institut National Polytechnique de Grenoble and IFP School for the year 2004 and the English version of the site will be completely finished in June 2004. In the future, the installation of new functionalities could be considered, such as the automatic creation of a complete course thanks to forms, the installation of a search engine to improve navigation in the site, and the adaptation of the platform to other types of course (image processing, etc).

REFERENCES D. CHAPELLIER, J-L. MARI, G. TACCHINI, F.PERRET, L. BARON, R. MONNET, L. MARESCOT, S. ROCHAT, (2002), Cours on-line de Géophysique, http://www-ig.unil.ch/cours/ F. GLANGEAUD, J.L. MARI, D. BARIBAUD, G. LEJEUNE et J. LIENARD, (1999), Traitement du signal geosciences, cédérom, Paris, Editions Technip (in French / English). F. GLANGEAUD, J-L. MARI et F. COPPENS, (2000), Traitement du signal pour géologues et géophysiciens, Volume 2 : Les techniques de base en traitement du signal, Paris, Editions Technip (in French / English). J-L. MARI, F. GLANGEAUD et F. COPPENS, (2000), Traitement du signal pour géologues et géophysiciens, Volume 1 : La prospection sismique, Paris, Editions Technip (in French / English). J-L. MARI, F. GLANGEAUD et F. COPPENS, (1999), Signal Processing for geologists and geophysicists, Volume 1 : Seismic Acquisition and processing , Paris, Technip Editions. J-L. MARI, F. GLANGEAUD et F. COPPENS, (1999), Signal Processing for geologists and geophysicists, Volume 1 : Signal Processing in geophysic , Paris, Technip Editions. J. MARS, F. GLANGEAUD, J-L. LACOUME et J-L. MARI, (2004), Traitement du signal pour géologues et géophysiciens, Volume 3 : Les techniques avancées en traitement du signal, Paris, Editions Technip (in French). K. SAHLI, J. MARS, J-L. MARI, F. GLANGEAUD, G. LEJEUNE, (2002), CD-ROMs et cours en ligne : de nouveaux outils de formation en traitement du signal, Lyon, TICE2002.