There are many statistical researches about the pilot ejections from high-speed aircrafts in many countries and the contents generally related to the types of emergencies, ejection seats abilities, and/or types and positions of injuries. Although we also have similar studies in Japan, and according to one of these studies, the biggest reason for fatalities is the delay in the decision to eject and it's relation to human factors. Therefore, this research was performed to investigate the influence of ejectees' attributes for their survivability with statistical approach. Data relating to the flight experiences, number of pilots in the aircraft, etc. have been extracted from all accident records, which were accompanied by ejections, experienced in the Japan Air Self-Defense Force and has been analyzed. As a result, it was observed that the pilots who received fatalities have longer total flight hours than those who survived and there was no significant difference in flight hours in the crashed aircrafts, the result suggested that the total flight hours influenced the fatality rate of ejection. It was clarified that the number of pilots in the aircraft didn't influence the success rate of ejection.

View full abstract

The purpose of the present research was to evaluate the security of interactive device for driving support with auditory interface. A lot of devices with auditory interface are used in recent years. We performed experiments with the simplified situation for using auditory interface with simple stimulus and response. We evaluated the effects of auditory task on driving behavior experimentally using dual tasks. We found no influence of auditory input or auditory output when the subject responded to simple somatic response for space. We examined the effect of auditory response to behavior. As the result we found the influence of auditory response accompanied with thinking.

View full abstract

If drivers underestimate the imminent risks of hazardous objects in certain traffic situations, their reaction to the objects would be delayed and risks of collision may increase. This paper found some factors in traffic situations causing drivers to underestimate risk and investigated the influences of the underestimation on their driving behavior in traffic situations with possibilities of a rear-end collision and a cross-path collision. The results of driving simulator experiments demonstrated that although the initial time to collision defined as objective risks was equivalent to 3s in all traffic situations, drivers underestimated the risks in a situations with the possibility of a rear-end collisions caused by factors of initial headway distance, types of lead vehicle, and no existence of oncoming vehicles. In contrast, drivers tended to estimate the risks in the situations with the possibility of a cross-path collision higher than those of rear-end collisions. It was observed that drivers' underestimation of the risk delayed their reaction, and therefore the number of collisions with lead vehicles actually increased. The results suggest that appropriate measures should be taken to prevent drivers from underestimating risks in traffic situations to decrease the number of accidents.

View full abstract

There are some opinions yet to be adjusted concerning linear addition between the kinetic dynamics of catch-up saccades and smooth pursuits.
The present study reports that this linear addition is verified between the velocity of smooth pursuits and the latency of catch-up saccades, and also between the velocity of smooth pursuits and the peak velocity of catch-up saccades. We induced formulas for the linear addition. By using these formulas, we obtained three findings: 1) regardless of the velocity of smooth pursuits, there is one condition for saccades that the duration of catch-up saccades is a constant of approx. 70.6ms; 2) regardless of the saccadic amplitudes, there is one condition that the latency is a constant of approx. 240ms; 3) the peak velocity is no more than 460deg/s.
We can contribute to the clinical neuroscience by these findings for the evaluation indices.

View full abstract

Ergonomic considerations are important for a well-designed bicycle. The aim of our research is to evaluate the influence of seat height on the rider's physical factors, including anthropometry of the human body and joint angles, as well as psychological responses and subjective sensations. A questionnaire utilizing both Borg's scale and the Likert scale were used to determine riders' subjective opinions regarding preferable riding condition. The relationship between preferable riding condition and seat height was then established from the regression curve of the riders' subjective sensations with respect to the seat height. Using the regression curve, one can determine the preferable seat height for a comfortable riding posture. The results of this study can be used to develop a riding simulation model on a computer, which may benefit bicycle designers and manufacturers who are looking to improve the ergonomic design of their products. Research using CAD systems requires standard parameters of bicycle construction to set up a computer-simulated riding model. After creating a data bank of riders' physical factors and psychological responses, one can analyze the parameters of the preferable riding model with computer simulation, including seat height and height of handlebars.

View full abstract

When wheelchair evaluations or environmental assessments are conducted by using subjects without physical impairments, one has to consider lower limb and body trunk movements that are not prominent for persons with upper spinal cord injury. In the present study, we tried to elucidate the EMG activities the movement of upper limbs, lower limbs, body trunk and pressure exerted on the footplate when normal subjects climb up ramps of various angles without strain. The EMG activities of various muscles related to upper limb movements were found to be similar to the data obtained from the persons with lower spinal cord injury. For muscles relating to lower limb movements, the activity of the plantar flexors, gastrocnemius and soleus, increased with the slope of the ramp during two phases: the latter propulsion period and early in the recovery period. During the propulsion period, other tendencies were noted: tension in other muscles, i. e. rectus femoris etc., also increased, the body trunk inclined forward, and the inclination became prominent with increasing the ramp slope. Pressure exerted on the footplate decreased in propulsion period and increased from the late propulsion period to the early recovery period. These results indicate that normal subjects use their lower limbs and body trunk actively to increase propulsion force and stability while driving a wheelchair. It is considered that action of lower limbs and/or body trunk of the subjects without physical impairments has to be restricted in mimicking upper spinal cord injury.

View full abstract

The purpose of this study is to elucidate the efficacy of chewing gum containing ginger, vitamin B₆ and caffeine with the basic taste of sweet peppermint for prevention of motion sickness. Subjects were 12 men and 12 women (age 23.2±SD 2.4 years) who were likely to get motion sickness. Audio-visual stimulus experiment was conducted to induce motion sickness symptoms. Five intensities of stimuli were loaded at the order of weak to heavy. Subject put on a face-mounted display device to gaze at driving simulation images. After 30 minute rest, subject received 8min stimulus at each level and then answered two kinds of questionnaires about the subjective symptoms. Subject took a couple of capsules containing (1) starch, or (2) starch, ginger 250mg, caffeine 50mg, vitamin B₆ 10mg, or (3) test elements at two times of (2), 30min before first stimulus, otherwise chewed at a gum containing (4) peppermint, or (5) peppermint, ginger 27.8mg, caffeine 5.6mg, vitamin B₆ 1.1 mg, or (6) test element of two times of (5), 30min before the first stimulus and changed the gum for another every 10min. As the result, a chewing gum containing ginger 27.8mg, caffeine 5.6mg, vitamin B₆ 1.1mg reduced nausea or vomiting of motion sickness symptoms most effectively.

View full abstract