Parametric design for custom-fit eyewear frames.

More than half of the people on the planet use eyewear to correct or protect their vision. Eyewear products that fit poorly cause discomfort, dizziness, or blurred vision. One method to improve fit is to create custom-fit eyewear frames on an individual basis. In this paper we propose a new parametric design method to customize the eyewear frames based on individual 3D scanned data of head-and-face measurements. We take the eyeglasses frame as the case study to establish the landmark-product relationship and develop the parametric algorithm in Rhino/Grasshopper software. The results of the case study can generate custom-fitted eyeglass frame models for the two selected subjects, one 33% percentile Asian female and one 90% percentile Caucasian male. The future study will continue validating the eyewear frame fit and optimizing the parametric design method.

Self-categorization as a basis of behavioural mimicry: Experiments in The Hive.

INTRODUCTION: Do we always do what others do, and, if not, when and under what conditions do we do so? In this paper we test the hypothesis that mimicry is moderated by the mere knowledge of whether the source is a member of the same social category as ourselves. METHODS: We investigated group influence on mimicry using three tasks on a software platform which interfaces with mobile computing devices to allow the controlled study of collective behaviour in an everyday environment. RESULTS: Overall, participants (N = 965) were influenced by the movements of confederates (represented as dots on a screen) who belonged to their own category in both purposive and incidental tasks. CONCLUSION: Our results are compatible with collective level explanations of social influence premised on shared social identification. This includes both a heuristic of unintended mimicry (the acts of group members are diagnostic of how one should act), and communication of affiliation (based on a desire to make one's group cohesive). The results are incompatible with traditional 'contagion' accounts which suggest mimicry is automatic and inevitable. The results have practical implications for designing behavioural interventions which can harness the power of copying behaviour, for example in emergency evacuations.

A comparison between Chinese and Caucasian head shapes.

Univariate anthropometric data have long documented a difference in head shape proportion between Chinese and Caucasian populations. This difference has made it impossible to create eyewear, helmets and facemasks that fit both groups well. However, it has been unknown to what extend and precisely how the two populations differ from each other in form. In this study, we applied geometric morphometrics to dense surface data to quantify and characterize the shape differences using a large data set from two recent 3D anthropometric surveys, one in North America and Europe, and one in China. The comparison showed the significant variations between head shapes of the two groups and results demonstrated that Chinese heads were rounder than Caucasian counterparts, with a flatter back and forehead. The quantitative measurements and analyses of these shape differences may be applied in many fields, including anthropometrics, product design, cranial surgery and cranial therapy.