Formal variation in the Kata Kolok lexicon

Sign language lexicons incorporate phonological specifications. Evidence from emerging sign languages suggests that phonological structure emerges gradually in a new language. In this study, we investigate variation in the form of signs across 20 deaf adult signers of Kata Kolok, a sign language that emerged spontaneously in a Balinese village community. Combining methods previously used for sign comparisons, we introduce a new numeric measure of variation. Our nuanced yet comprehensive approach to form variation integrates three levels (iconic motivation, surface realisation, feature differences) and allows for refinement through weighting the variation score by token and signer frequency. We demonstrate that variation in the form of signs appears in different degrees at different levels. Token frequency in a given dataset greatly affects how much variation can surface, suggesting caution in interpreting previous findings. Different sign variants have different scopes of use among the signing population, with some more widely used than others. Both frequency weightings (token and signer) identify dominant sign variants, i.e., sign forms that are produced frequently or by many signers. We argue that variation does not equal the absence of conventionalisation. Indeed, especially in micro-community sign languages, variation may be key to understanding patterns of language emergence.

Stress and strain distributions in the human hand-arm system using finite element analysis

This study presents stress and strain distributions in the human hand-arm system exposed to vibrations using finite element (FE) models. Frequency weightings at shoulder, elbow, wrist and palm based on stress and strain distributions were proposed. The stress/strain-based frequency weightings around the shoulder and elbow are comparable with that reported in the International Organization for Standardization ISO 5349-1, Mechanical vibration and shock– Measurement and evaluation of human exposure to mechanical vibration – part 1: General requirements, 2001. However, stress/strain-based frequency weightings around the palm and wrist are different above 20 Hz from the weighting reported by the International Standard Organization. This study suggests the need for different frequency weightings for the assessment of the potential injury of different components of the hand-arm vibration syndrome.