Scale-free static and dynamical correlations in melts of monodisperse and Flory-distributed homopolymers: A review of recent bond-fluctuation model studies

It has been assumed until very recently that all long-range correlations are screened in three-dimensional melts of linear homopolymers on distances beyond the correlation length $\xi$ characterizing the decay of the density fluctuations. Summarizing simulation results obtained by means of a variant of the bond-fluctuation model with finite monomer excluded volume interactions and topology violating local and global Monte Carlo moves, we show that due to an interplay of the chain connectivity and the incompressibility constraint, both static and dynamical correlations arise on distances $r \gg \xi$. These correlations are scale-free and, surprisingly, do not depend explicitly on the compressibility of the solution. Both monodisperse and (essentially) Flory-distributed equilibrium polymers are considered.Comment: 60 pages, 49 figure

Simulation of vocal fold oscillation behaviour by a self-oscillating glottis model

As a good compromise between simplicity and approximation of real human vocal vold oscillation behaviour the Ishizaka-Flanagan two-mass model [1] is widely used in articulatory speech synthesis. But its poor results in modelling the oscillatory behaviour during glottal abduction/adduction and in modelling leakage flow during normal phonation are drawbacks. The two-mass model can be improved without increasing its complexity, if a non-oscillating and aperture-dependent bypass is added

Audiovisual tools for phonetic and articulatory visu­alitation in computer-aided pronunciation training

Abstract. This paper reviews interactive methods for improving the phonetic competence of subjects in the case of second language learning as well as in the case of speech therapy for subjects suffering from hearing-impairments or articulation disorders. As an example our audiovisual feedback software “Speech-Trainer ” for improving the pronunciation quality of Standard German by visually highlighting acoustics-related and articulation-related sound features will be introduced here. Results from literature on training methods as well as the results concerning our own software indicate that audiovisual tools for phonetic and articulatory visualization are beneficial for computer-aided pronunciation training environments

The organization of a neurocomputational control model for articulatory speech synthesis

The organization of a computational control model of articulatory speech synthesis is outlined in this paper. The model is based on general principles of neurophysiology and cognitive psychology. Thus it is based on such neural control circuits, neural maps and mappings as are hypothesized to exist in the human brain, and the model is based on learning or training mechanisms similar to those occurring during the human process of speech acquisition. The task of the control module is to generate articulatory data for controlling an articulatory-acoustic speech synthesizer. Thus a com plete 'BIONIC' (i.e. BIOlogically motivated and techNICally realized) speech syn the sizer is described, capable of generating linguistic, sensory, and motor neural representations of sounds, syllables, and words, capable of generating articu latory speech movements from neuromuscular activation, and subse quently capable of generating acoustic speech signals by controlling an articu latory-acoustic vocal tract model. The module developed thus far is capable of producing single sounds (vowels and consonants), simple CV- and VC-syllables, and first sample words. In addition, processes of human-human interaction occurring during speech acquisition (mother-child or carer-child interactions) are briefly discussed in this paper