Playback

The second task is then analysing the results of the scan. The results can be displayed live on a display screen, or stored and presented all at once or after further scaling and analysis. This playback feature of sample data will be the subject of the remainder of the paper, for as we will see the playback need not be immediate nor on site, but could take place synchronously or asynchronously over the Internet. 

After a molecular dynamics simulation or the playback of a simulation, L-click on Averages in the Molecular Dynamics Options dialog box. 

In Reference 146 three methods for playback of data are presented, which are superior to the usual method based on the contrast in light scattering readout of dichroism, perpendicular readout mode, and readout of birefringence. Some critical comments also are given about global or selective erasure of data. 

Poole, J.H. (1999) Signals and assessment in African elephants evidence from playback experiments. Anim. Behav. 58, 185-193. 

Female lions typically live in prides of two to seven members, around which cluster their dependent offspring and a coalition of immigrant males. The males defend the pride against incursion by other males, whereas the females defend the territory against incursions by other females. Territorial incursions can be simulated by the playback of recorded roars, and these routinely elicit cooperative defense. In response, female lions pair off to approach what must seem to them an unknown and potentially dangerous enemy (see Heinson and Packer, 1995). 

Volatile and nonvolatile memory modules that were capable of storing chromatograms for playback and reintegration... 

Hard disk or tape storage of chromatograms for playback, reintegration, and more importantly data archiving. 

It should be noted that the problem of transient noise pulses can in principle be circumvented by use of suitable playback technology. For example, in the case of gramophone disks the use of a laser-based reader should eliminate any mechanical resonance effects and thus reduce the artifact to a large click which can be restored using the methods of previous sections. Of course, this does not help in the many cases where the original source medium has been discarded after transcription using standard equipment to another medium such as magnetic tape ... 

Model-based separation methods. A full study of the noise pulse mechanism would involve physical modelling of the (possibly non-linear) playback system for both gramophone systems and optical sound track readers. A full description is beyond the scope of this article (see [Roys, 1978] for some more detail), but can be used to shed... 

Summary. Two principal methods for removal of low frequency noise transients are currently available. The model-based separation approach has shown more flexibility and generality, but is computationally rather intensive. It is felt that future work in the area should consider the problem from a realistic physical modelling perspective, which takes into account linear and non-linear characteristics of gramophone and film sound playback systems, in order to detect and correct these artifacts more effectively. Such an approach could involve both experimental work with playback systems and sophisticated non-linear modelling techniques. Statistical approaches related to those outlined in the click removal work (section 4.3.4) may be applicable to this latter task. 

---