haracterization of Korean Population Anthropometric Data Using Multivariate Statistics

Abstract

Humans control the interface by using hands and feet. Thus, the men control the machines at their intent and use various tools. Therefore, to design an interface comfortable for men, designing products and systems based on the size information on hands and feet is important. Also, the hands and feet provides various size information as they are composed of numerous numbers of muscles, bones, and joints. Such information is used in various areas including interface design, forensics, and emergency medical science. The purpose of this research is to identify physical properties of hands and feet of South Koreans, and the use the size information to develop a model estimating physical properties like gender, height, and weight. Also, the purpose of the research is to evaluate and estimate the degree of discomforts from using the product by applying the physical properties and measured values to frequently used interface (electronic products, and national defense weaponry system). First, physical properties of hands and feet of South Koreans were understood at Phase I. From the hand size information of 321 adults provided from Size Korea, major factors determining the shape of South Koreans (Width of hand, length of palm, and length of fingers) were identified, and classified the shape into four sections. Compared to other ethnic groups, the research identified that the males and females of South Koreans have wider hand width than other ethnic groups. Moreover, representative hand manikin size accommodating 95% of South Koreans was deducted by using boundary condition method. In case of feet, major factors determining the shape of feet of Koreans were identified by analyzing feet size data of 461 people, and four clusters were identified by using cluster analysis. Also, feet manikin size representing the 95% of the feet size of Koreans was deducted. Second, in phase II, the research has developed a statistical model estimating gender, height, and weight by using body measured value. The research separated males from females by using discriminant analysis on 29 measured variables in the hands. Highest level of accuracy was shown when using the maximum hand circumference, and variables related with width and circumference showed higher estimation accuracy than the length. Feet also estimated the gender by using the size information of 10 parts of feet and discriminant analysis, and navicular circumference showed the highest estimation accuracy (86.2%). When estimating height, height was estimated by using regression analysis using the parts with high relevance with heights among various parts of hand and feet. Both genders showed the highest level of accuracy when using hand length, and for the R2 of the regression equation, males showed 0.678, and females showed 0.534. Among various parts of feet, feet length showed the highest level or accuracy, and for the R2,males showed 0.567 and females showed 0.188 of accuracy. The weight estimation model has developed the model by using regression analysis using the circumference length of 9 parts of the hands, feet and body. The level of accuracy was the highest when using the breast circumference (R2=0.742). Third, in phase III, ergonomic evaluation on the interface of smart phone, F-16 aircraft seat, and K-2 rifle was conducted by using the measured value of hands and feet. Mainly, the level of discomforts on 21 UI points frequently used on 4.3 inch android smartphone was evaluated, and the points capable of easy touching when considering body sizes were identified. For F-16 cockpit, the evaluation was conducted to find out whether the Korean pilots may use the cockpit without discomforts for 6 major piloting postures, and it was expected that the discomforts may arise as 11.6 % of the male pilots and 27.5% of the female pilots could not touch the brake with their feet or had to additionally change postures for their feet to touch the brake when using full brake. On the interface evaluation on the controlling part of the K-2 rifle, it was expected that 39.6% of the males would have collision of finger on the trigger guard when controlling the trigger as they have long finger. In case of 72.1% female soldiers, it was expected that they would feel discomforts as the index finger does not touch the switch on the controlling part of the rifle. It is expected that the result of the current research would help the researchers and engineers when designing interface for South Koreans. The statistical methods and analysis tools may be utilized for evaluating and improving the interface of other products and systems beside smart phones, aircrafts, rifles and others that were evaluated in the current research.