REALSIMPLE Project — work supported by the Wallenberg Global Learning Network .
Center for Computer Research in Music and Acoustics (CCRMA), Stanford University
In Winter quarter, Nelson Lee worked on
CNXML format is used by the Connexions project at Rice University, which is one website where we plan to host our final teaching materials for global accessibility. LATEX is a standard word-processing language for the mathematical/scientific community, and Julius has four relevant on-line books written in this format, parts of which will be ported into the planned teaching materials.
At the beginning of the quarter, Nelson and Julius met for a couple of hours with Cammy Huang-DeVoss at Wallenberg who generously gave us an in-depth look at how she developed animated visualizations and other teaching aids, primarily in Flash. We discussed our overall goals and how they might best be accomplished. We obtained invaluable input and orientation from Cammy. In particular, it was this meeting that convinced us that Flash was the right choice of animation technologies at present.
Since the focus of the planning grant is to prototype an acoustics laboratory assignment on vibrating strings using the proposed technology, Nelson's initial Flash projects were concerned with simulating vibrating strings in various ways. These animations will be utilized in the ``theory background'' section of the string laboratory assignment under development. Much of the theory background section will be adapted from the text for Music 420 (``Signal Processing Models in Musical Acoustics''). Several of the figures in this text would be far clearer if animated, and so two were chosen as initial Flash simulation targets. They are listed in §8.1 above, and serve their intended purpose beautifully.
The flash animations developed this quarter have already been used satisfactorily for in-class demonstrations in Music 420. The ability to animate traveling waves on a string, pause the animation, discuss what is happening, and resume to the next point of discussion, is extremely valuable for teaching purposes.
In addition to these ``theory background'' animations, we plan to construct animations corresponding to specific experiments in the lab assignments under development. In the animations, one can see very clearly what theory predicts, and the student can then check these predictions experimentally, and look for the effects seen in the theoretical simulations. Computer simulations can also be used to check especially difficult measurements in the experimental set up. Even for simple measurements, the theoretical simulation can be used to check the student's recorded observations, alerting the student to recheck when something appears to be out of range. The simulation can check the student's results even when there are free parameters in the experiment such as the precise striking point along the string. In particular, the computer can independently estimate the striking point from the recorded waveform in order to check that it agrees with reported measurements.
Nelson also spent a significant portion of his time investigating how to most efficiently port LATEX to the Connexions CNXML format. Nelson joined the development team for that project and tested its current functionality. He also made a couple of small test modules at Connexions and an example course. (A ``course'' at Connexions is a sequence of ``modules''.) In view of the level of effort already under way in the Connexions project on porting LATEX to CNXML, we decided in early February to postpone work on the LATEX translation front and work more on laboratory animations development. Nelson continued to receive assistance from Cammy Huang-DeVoss in that effort.
We are hoping that by this summer, when we plan to finalize the prototype web site, the LATEX-CNXML translation tools will be in a reasonably usable state, so that we will not need to do a lot of development ourselves. However, based on discussions with Connexions developers, Julius plans to write a Perl script that maximally automates the conversion of LATEX source to sTEX (``semantic TEX'') source, which is the first step in the semi-automatic translation to CNXML, as presently designed.
Finally, in preparation for laboratory development work, we are starting to build a small electronics & acoustics laboratory in Julius's CCRMA office (Knoll 306). Initial purchases planned include an oscilloscope and basic tools for testing and constructing electronic circuits, as well as tools needed for building the acoustics laboratory set-up specified by the KTH team. In addition, a laptop computer was purchased to support Nelson's work on the project.