Anthropometric analysis of 3D ear scans of Koreans and Caucasians for ear product design.

The present study measured 25 dimensions of the ear including the concha and ear canal for ergonomic design of ear products and compared with existing ear measurement studies. Scanning and casting methods were employed to produce 3D ear images for 230 Koreans and 96 Caucasians and measurements of the ear dimensions were obtained by identifying 21 landmarks on individual ear scan image. The Korean ear measurements were found significantly larger (mean difference d¯ = 0.4-3.7 mm) and more varied (ratio of SDs =1.01-1.55) than those of Caucasians in most of ear dimensions. The average ear length and ear breadth of male were significantly longer ( d¯ = 1.3-7.0 mm) and wider ( d¯ = 0.8-3.0 mm) than those of female. Use of gender- and ethnicity-composite ear data is recommended in product design due to the much larger intra-population variations (7.5-22.2 mm) than the corresponding inter-population variations. Practitioner Summary: The 3D ear measurements of Koreans and Caucasians were collected and compared with those of different ethnic populations. The distinct ear features of the populations identified in this study are applicable to ergonomic design of ear products with better fit and comfort. Abbreviations: CCW: cavum concha width; CV: coefficient of variation; EB: ear breadth; EL: ear length; SD: standard deviation; SE: sampling error; 3D: 3 dimensional.

Evaluation of the multivariate accommodation performance of the grid method.

The present study examined the multivariate accommodation performance (MAP) of the grid method, a distributed representative human models (RHM) generation method, in the context of men's pants sizing system design. Using the 1988 US Army male anthropometric data and ± 2.5 cm of fitting tolerance, the grid method selected two key dimensions (waist girth and crotch height) out of 12 anthropometric dimensions and identified 25 RHMs to accommodate 95% of the population. The average MAP of the RHMs decreased dramatically as the number of anthropometric dimensions considered increased (99% for single dimension and 14% for 12 dimensions). A standardized regression model was established which explains the effects of two factors (sum of anthropometric dimension ranges; adjusted R(2) between key dimensions and other anthropometric dimensions) on the MAP of RHMs. This regression model can be used to prioritize anthropometric dimensions for efficient MAP improvement of men's pants design.

Determination of key dimensions for a glove sizing system by analyzing the relationships between hand dimensions.

The present study identified key dimensions for the development of a glove sizing system by analyzing the relationships between hand dimensions and demonstrated the construction process of glove sizing systems based on the selected key dimensions. Three hand dimensions (HL: hand length; HC: hand circumference; HB: hand breadth) were selected as the candidates of glove key dimensions by surveying the literature and industry practices of glove sizing systems. Of the key dimension candidates, HL and HC were selected by examining the results of correlation and multiple regression analyses on the 1988 US Army hand anthropometric data. A cross-tabulation of HL and HC with an interval length of 1.3 cm was constructed for each gender and the corresponding lengths and circumferences of cells covering more than 2% of the population were used to provide glove sizing parameters. It was identified that the glove sizing system for males is different from that for females and has more size categories.