To understand the factors of shoe sole wear, we examined the relationship among worn shoe sole shapes, usage conditions, and gait parameters in young males. Thirty-five young male subjects participated in this study. Prior to measurements, they were asked to walk at their own pace while wearing new shoes. We measured lower limb angles, joint angles, stride, step width and speed while walking. In addition, we measured regression analyses. Our results showed that the subtalar joint angle during loading response and duration of use strongly influenced the wear of the outer lateral sole section. On the other hand, shuffle distance, ankle joint angle during terminal swing, and knee joint angle during loading response and terminal swing strongly influenced the degree of wear. In addition, step width, ankle and subtalar joint angle during loading response, and terminal swing strongly influenced the angle of wear. These findings suggest that shoe sole wear for young males can be explained in terms of usage conditions and gait parameters. Furthermore, gait must be considered for preventing functional deterioration associated with sole wear and for extending sole durability.

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In order to consider a visual field that can be utilized in visual inspection, this study experimentally evaluates the differences of defect characteristics that affect defect detection by utilizing the peripheral visual field. In the experiment, luminance contrast between inspection object and defect, defect size and defect location are considered as experimental factors. As a result, it is observed that the visual field that can be utilized in visual inspection is different according to defect characteristics, because the conspicuity field differs based on the defect. Moreover, a regression equation for the defect detection rate is calculated based on the experimental results, and a method is proposed to determine a conspicuity field according to the acceptable limit of a defect.

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The purpose of this study is to clarify vibration characteristics of a rider and infants in a bicycle with two child seats. To examine vibrations of the occupants, dummies of infants were designed considering the weight of an infant. An experiment to get over the different lugs using a bicycle with the front dummy, rear dummy and a rider was performed for 4 subjects. From the results, the magnitude of the vibration on the rider and infants was affected strongly by the riding conditions, and the frequency band of the vibration on the rider and infants was affected weakly by the riding conditions. In the experiment, a maximum acceleration in the infant dummy was 7 times of the acceleration of gravity, and the frequency at the maximum amplitude of vibrations was around 7 Hz. Since a human most strongly perceives vibration of around 7 Hz, it is thought that infants are exposed to large vibrations that are easy to perceive. Therefore, it is important to design the bicycle structure considering the reduction of the vibrations for the infants in terms of safety and ride comfort.

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This study compares stopping behaviors between bicycle riding and driving by the same person, and examines bias in self-evaluation of stopping behavior in the case of bicycle riding. Twenty participants drove through the experimental course on roads using a bicycle and a car. There were crossings with a stop sign in the course. We recorded videos and analyzed stopping behavior. Results showed that when participants were riding on a bicycle as opposed to driving a car, the time to pass the crossing was shorter, the number of looking frequencies for crossing the road were smaller, and the total looking time for crossing the road was shorter. All of these differences were statistically significant. We also showed participants the videos after blurring out the drivers. They evaluated their own stopping behavior using the video and their own usual stopping behavior by recall. A comparison of these evaluations showed that there was less bias in self-evaluation of stopping behavior on a bicycle than in a car.

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The comprehension of hierarchical GUI menu operations was investigated in children in the process of developing their cognitive functions. Participants were 120 children aged 3-6 years. They were asked to select a target item presented on a computer screen, according to figures, colors, and patterns on menus constructed of two and three hierarchical structures. Their degree of comprehension was estimated on the basis of the success rate of selection tasks. For 3- to 5-year-old children, the success rate significantly increased with the two-structure menu than with the three-structure menu. Limited processing capacity of their short term memories, difficulty of voice-encoding, and undeveloped verbalization might have influenced their low success rates in the three-structure menu. The 6-year-old children had a success rate near 100%, which suggests that hierarchical menu images can be constructed in 6-year-old children as well as in adults. The points at which the success rate increased rapidly were observed both in the two- and three-structure menus. This suggests the existence of a critical period in the comprehension of hierarchical menus.

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