Self-similar axisymmetric flows with swirl

We consider an infinite vortex line in a fluid which interacts with a boundary surface as a simplified model for tornadoes. We study self-similar solutions for stationary axisymmetric Navier-Stokes equations and investigate the types of motion which are compatible with this structure when viscosity is non-negative. For viscosity equal to zero, we construct a class of explicit stationary solutions. We then consider solutions with slip discontinuity and show that they do not exist in this framework

Moving beyond the monosyllable in models of skilled reading:Mega-study of disyllabic nonword reading

AbstractMost English words are polysyllabic, yet research on reading aloud typically focuses on monosyllables. Forty-one skilled adult readers read aloud 915 disyllabic nonwords that shared important characteristics with English words. Stress, pronunciation, and naming latencies were analyzed and compared to data from three computational accounts of disyllabic reading, including a rule-based algorithm (Rastle & Coltheart, 2000) and connectionist approaches (the CDP++ model of Perry, Ziegler, & Zorzi, 2010, and the print-to-stress network of Ševa, Monaghan, & Arciuli, 2009). Item-based regression analyses revealed orthographic and phonological influences on modal human stress assignment, pronunciation variability, and naming latencies, while human and model data comparisons revealed important strengths and weaknesses of the opposing accounts. Our dataset provides the first normative nonword corpus for British English and the largest database of its kind for any language; hence, it will be critical for assessing generalization performance in future developments of computational models of reading

The locus of serial processing in reading aloud:Orthography-to-phonology computation or speech planning?

Dual-route theories of reading posit that a sublexical reading mechanism that operates serially and from left to right is involved in the orthography-to-phonology computation. These theories attribute the masked onset priming effect (MOPE) and the phonological Stroop effect (PSE) to the serial left-to-right operation of this mechanism. However, both effects may arise during speech planning, in the phonological encoding process, which also occurs serially and from left to right. In the present paper, we sought to determine the locus of serial processing in reading aloud by testing the contrasting predictions that the dual-route and speech planning accounts make in relation to the MOPE and the PSE. The results from three experiments that used the MOPE and the PSE paradigms in English are inconsistent with the idea that these effects arise during speech planning, and consistent with the claim that a sublexical serially operating reading mechanism is involved in the print-to-sound translation. Simulations of the empirical data on the MOPE with the dual route cascaded (DRC) and connectionist dual process (CDP++) models, which are computational implementations of the dual-route theory of reading, provide further support for the dual-route account.24 page(s

Orthographic consistency influences morphological processing in reading aloud: Evidence from a cross‐linguistic study

International audienc

Morphological effects on pronunciation

Converging, albeit inconsistent, empirical evidence suggests that the morphological structure of a word influences its pronunciation. We investigated this issue using Ultrasound Tongue Imaging in the context of an experimental cognitive psychology paradigm. Scottish speakers were trained on apparently homophonous monomorphemic and bimorphemic novel words (e.g. zord, zorred), and tested on speech production tasks. Monomorphemic items were realised acoustically with shorter durations than bimorphemic items; however, this difference was not statistically significant. Progressive coarticulatory effects were also observed in the monomorphemic condition for some speakers. A dynamic analysis of the articulatory data revealed that the observed differences in the pronunciations of the two types of items could be due to factors other than morphological structure. Our results, albeit inconclusive, make a significant contribution to the literature in this research domain insofar as the presence or absence of morphological effects on pronunciation has important implications for extant theories of speech production.https://www.internationalphoneticassociation.org/icphs/icphs2015caslpub3961pub81